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<settitle spaces=" ">&latex;2e unofficial reference manual (March 2018)</settitle>
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<copying endspaces=" ">
<para>This document is an unofficial reference manual for &latex;, a
document preparation system, version of March 2018.
</para>
<para>This manual was originally translated from <file>LATEX.HLP</file> v1.0a in
the VMS Help Library.  The pre-translation version was written by
George&nbsp;D. Greenwade of Sam Houston State University.  The
&latex;&nbsp;2.09 version was written by Stephen Gilmore.  The
&latex;2e version was adapted from this by Torsten Martinsen.  Karl
Berry made further updates and additions, and gratefully acknowledges
using <cite>Hypertext Help with &latex;</cite>, by Sheldon Green, and
<cite>&latex; Command Summary</cite> (for &latex;&nbsp;2.09) by
L.&nbsp;Botway and C.&nbsp;Biemesderfer (published by the &tex; Users
Group as <cite>&tex;niques</cite> number 10), as reference material (no
text was directly copied).
</para>
<para>Copyright 2007, 2008, 2009, 2010, 2011, 2012, 2013,
2014, 2015, 2016, 2017, 2018 Karl Berry.&linebreak;
Copyright 1988, 1994, 2007 Stephen Gilmore.&linebreak;
Copyright 1994, 1995, 1996 Torsten Martinsen.
</para>
<!-- comment start of License -->
<para>Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.
</para>
<ignore>
Permission is granted to process this file through TeX and print the
results, provided the printed document carries copying permission
notice identical to this one except for the removal of this paragraph
(this paragraph not being relevant to the printed manual).
</ignore>

<para>Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.
</para>
<para>Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions.
<!-- comment end of License -->
</para></copying>

<dircategory spaces=" ">TeX</dircategory>
<direntry endspaces=" ">
<menuentry leadingtext="* "><menutitle separator=": ">LaTeX2e</menutitle><menunode separator=".              ">(latex2e)</menunode><menudescription><pre xml:space="preserve">Unofficial LaTeX reference manual.
</pre></menudescription></menuentry></direntry>

<tex endspaces=" ">
</tex>

<titlepage endspaces=" ">
<title spaces=" ">&latex;2e: An unofficial reference manual</title>
<subtitle spaces=" ">March 2018</subtitle>
<author spaces=" "><url><urefurl>http://puszcza.gnu.org.ua/software/latexrefman/</urefurl></url></author>
<page></page>
<vskip> 0pt plus 1filll</vskip>
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</titlepage>

<shortcontents></shortcontents>
<contents></contents>

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<node name="Top" spaces=" "><nodename>Top</nodename><nodenext automatic="on">About this document</nodenext><nodeup automatic="on">(dir)</nodeup></node>
<top spaces=" "><sectiontitle>&latex;2e: An unofficial reference manual</sectiontitle>

<para>This document is an unofficial reference manual (version of
March 2018) for &latex;2e, a document preparation system.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::         ">About this document</menunode><menudescription><pre xml:space="preserve">Bug reporting, etc.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                    ">Overview</menunode><menudescription><pre xml:space="preserve">What is &latex;?
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		">Document classes</menunode><menudescription><pre xml:space="preserve">Some of the various classes available.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::			">Fonts</menunode><menudescription><pre xml:space="preserve">Italic, bold, typewriter, etc.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::			">Layout</menunode><menudescription><pre xml:space="preserve">Controlling the page layout.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::			">Sectioning</menunode><menudescription><pre xml:space="preserve">How to section properly.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		">Cross references</menunode><menudescription><pre xml:space="preserve">Automatic referencing.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		">Environments</menunode><menudescription><pre xml:space="preserve">Such as enumerate &amp; itemize.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::	        ">Line breaking</menunode><menudescription><pre xml:space="preserve">Influencing line breaks.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::	        ">Page breaking</menunode><menudescription><pre xml:space="preserve">Influencing page breaks.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::			">Footnotes</menunode><menudescription><pre xml:space="preserve">How to produce footnotes.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::			">Definitions</menunode><menudescription><pre xml:space="preserve">Define your own commands, etc.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::			">Counters</menunode><menudescription><pre xml:space="preserve">Internal counters used by &latex;.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::			">Lengths</menunode><menudescription><pre xml:space="preserve">The length commands.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		">Making paragraphs</menunode><menudescription><pre xml:space="preserve">Paragraph commands.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		">Math formulas</menunode><menudescription><pre xml:space="preserve">How to create mathematical formulas.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::			">Modes</menunode><menudescription><pre xml:space="preserve">Paragraph, Math or LR modes.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::			">Page styles</menunode><menudescription><pre xml:space="preserve">Various styles of page layout.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		        ">Spaces</menunode><menudescription><pre xml:space="preserve">Horizontal and vertical space.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                       ">Boxes</menunode><menudescription><pre xml:space="preserve">Making boxes.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                       ">Color</menunode><menudescription><pre xml:space="preserve">Defining and using colors.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                    ">Graphics</menunode><menudescription><pre xml:space="preserve">Importing graphics from outside &latex;.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		">Special insertions</menunode><menudescription><pre xml:space="preserve">Inserting reserved and special characters.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		">Splitting the input</menunode><menudescription><pre xml:space="preserve">Dealing with big files by splitting.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		">Front/back matter</menunode><menudescription><pre xml:space="preserve">Tables of contents, glossaries, indexes.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::			">Letters</menunode><menudescription><pre xml:space="preserve">The <code>letter</code> class.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::	">Terminal input/output</menunode><menudescription><pre xml:space="preserve">User interaction.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                ">Command line</menunode><menudescription><pre xml:space="preserve">System-independent command-line behavior.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::          ">Document templates</menunode><menudescription><pre xml:space="preserve">Starter templates for various document classes.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		">Concept Index</menunode><menudescription><pre xml:space="preserve">General index.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           	">Command Index</menunode><menudescription><pre xml:space="preserve">Alphabetical list of &latex; commands.
</pre></menudescription></menuentry></menu>


</top>
<node name="About-this-document" spaces=" "><nodename>About this document</nodename><nodenext automatic="on">Overview</nodenext><nodeprev automatic="on">Top</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>About this document</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1"><url><urefurl>http://puszcza.gnu.org.ua/software/latexrefman/</urefurl></url> <r>home page</r></indexterm></findex>
<para>This is an unofficial reference manual for the &latex;2e document
preparation system, which is a macro package for the &tex;
typesetting program (<pxref label="Overview"><xrefnodename>Overview</xrefnodename></pxref>).  This document&textrsquo;s home page is
<url><urefurl>http://puszcza.gnu.org.ua/software/latexrefman/</urefurl></url>.  That page has links to the
current output in various formats, sources, mailing list archives and
subscriptions, and other infrastructure.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="1">&latex; vs.&noeos; &latex;2e</indexterm></cindex>
<para>In this document, we will mostly just use &textlsquo;&latex;&textrsquo; rather than
&textlsquo;&latex;2e&textrsquo;, since the previous version of &latex;&nbsp;(2.09) was
frozen decades ago.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="2">unofficial nature of this manual</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="3">&latex; Project team</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="2"><email><emailaddress>latexrefman&arobase;tug.org</emailaddress></email> <r>email address</r></indexterm></findex>
<para>&latex; is currently maintained by a group of volunteers
(<url><urefurl>http://latex-project.org</urefurl></url>).  The official documentation written by
the &latex; project is available from their web site.  This document is
completely unofficial and has not been reviewed by the &latex;
maintainers.  
<cindex index="cp" spaces=" "><indexterm index="cp" number="4">bug reporting</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="5">reporting bugs</indexterm></cindex>
Do not send bug reports or anything else about this document to them.
Instead, please send all comments to <email><emailaddress>latexrefman&arobase;tug.org</emailaddress></email>.
</para>
<para>This document is a reference.  There is a vast array of other sources
of information about &latex;, at all levels.  Here are a few
introductions.
</para>
<table commandarg="url" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="url">http://ctan.org/pkg/latex-doc-ptr</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="3">latex-doc-ptr <r>document</r></indexterm></findex>
<para>Two pages of recommended references to &latex; documentation.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="url">http://ctan.org/pkg/first-latex-doc</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="4">first-latex-doc <r>document</r></indexterm></findex>
<para>Writing your first document, with a bit of both text and math.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="url">http://ctan.org/pkg/usrguide</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="5">usrguide <r>official documentation</r></indexterm></findex>
<para>The guide for document authors that is maintained as part of &latex;.
Many other guides by many other people are also available, independent
of &latex; itself; one such is the next item:
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="url">http://ctan.org/pkg/lshort</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="6">lshort <r>document</r></indexterm></findex>
<para>A short introduction to &latex;, translated to many languages.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="url">http://tug.org/begin.html</itemformat></item>
</tableterm><tableitem><para>Introduction to the &tex; system, including &latex;, with further
references.
</para>
</tableitem></tableentry></table>


</chapter>
<node name="Overview" spaces=" "><nodename>Overview</nodename><nodenext automatic="on">Document classes</nodenext><nodeprev automatic="on">About this document</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Overview of &latex;</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="6">overview of &latex;</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="7">basics of &latex;</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="8">Knuth, Donald E.</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="9">Lamport, Leslie</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="10">&latex; overview</indexterm></cindex>

<para>&latex; is a system for typesetting documents.  It was originally
created by Leslie Lamport and is now maintained by a group of volunteers
(<url><urefurl>http://latex-project.org</urefurl></url>).  It is widely used, particularly for
complex and technical documents, such as those involving mathematics.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="11">macro package, &latex; as</indexterm></cindex>
<para>A &latex; user writes an input file containing text along with
interspersed commands, for instance commands describing how the text
should be formatted.  It is implemented as a set of related commands
that interface with Donald&nbsp;E. Knuth&textrsquo;s &tex; typesetting program
(the technical term is that &latex; is a <dfn>macro package</dfn> for the
&tex; engine).  The user produces the output document by giving that
input file to the &tex; engine.
</para>
<para>The term &latex; is also sometimes used to mean the language in which
the document is marked up, that is, to mean the set of commands
available to a &latex; user.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="12">Lamport &tex;</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="13">pronunciation</indexterm></cindex>
<para>The name &latex; is short for &textldquo;Lamport &tex;&textrdquo;.  It is pronounced
LAH-teck or LAY-teck, or sometimes LAY-tecks.  Inside a document,
produce the logo with <code>\LaTeX</code>.  Where use of the logo is not
sensible, such as in plain text, write it as <samp>LaTeX</samp>.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::  ">Starting and ending</menunode><menudescription><pre xml:space="preserve">The standard beginning and end of a document.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::         ">Output files</menunode><menudescription><pre xml:space="preserve">Files produced.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::          ">&tex; engines</menunode><menudescription><pre xml:space="preserve">Programs that can compile &tex; and  &latex;.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator=":: ">&latex; command syntax</menunode><menudescription><pre xml:space="preserve">General syntax of &latex; commands.
</pre></menudescription></menuentry></menu>


<node name="Starting-and-ending" spaces=" "><nodename>Starting and ending</nodename><nodenext automatic="on">Output files</nodenext><nodeup automatic="on">Overview</nodeup></node>
<section spaces=" "><sectiontitle>Starting and ending</sectiontitle>

<anchor name="Starting-_0026-ending">Starting &amp; ending</anchor><!-- c old name -->
<cindex index="cp" spaces=" "><indexterm index="cp" number="14">starting and ending</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="15">ending and starting</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="16">hello, world</indexterm></cindex>

<para>&latex; files have a simple global structure, with a standard beginning
and ending.  Here is a &textldquo;hello, world&textrdquo; example:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\documentclass&lbrace;article&rbrace;
\begin&lbrace;document&rbrace;
Hello, \LaTeX\ world.
\end&lbrace;document&rbrace;
</pre></example>

<cindex index="cp" spaces=" "><indexterm index="cp" number="17">document class, defined</indexterm></cindex>
<noindent></noindent>
<para>Here, the <samp>article</samp> is the so-called <dfn>document class</dfn>,
implemented in a file <file>article.cls</file>.  Any document class can be
used.  A few document classes are defined by &latex; itself, and vast
array of others are widely available.  <xref label="Document-classes"><xrefnodename>Document classes</xrefnodename></xref>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="18">preamble, defined</indexterm></cindex>
<para>You can include other &latex; commands between the
<code>\documentclass</code> and the <code>\begin&lbrace;document&rbrace;</code> commands.
This area is called the <dfn>preamble</dfn>.
</para>
<para>The <code>\begin&lbrace;document&rbrace; ... \end&lbrace;document&rbrace;</code> is a so-called
<cindex index="cp" spaces=" "><indexterm index="cp" number="19">environment</indexterm></cindex>
<dfn>environment</dfn>; the <samp>document</samp> environment (and no others) is
required in all &latex; documents (<pxref label="document"><xrefnodename>document</xrefnodename></pxref>).  &latex;
provides many environments itself, and many more are defined separately.
<xref label="Environments"><xrefnodename>Environments</xrefnodename></xref>.
</para>
<para>The following sections discuss how to produce PDF or other output from
a &latex; input file.
</para>

</section>
<node name="Output-files" spaces=" "><nodename>Output files</nodename><nodenext automatic="on">&tex; engines</nodenext><nodeprev automatic="on">Starting and ending</nodeprev><nodeup automatic="on">Overview</nodeup></node>
<section spaces=" "><sectiontitle>Output files</sectiontitle>

<para>&latex; produces a main output file and at least two accessory files.
The main output file&textrsquo;s name ends in either <file>.dvi</file> or <file>.pdf</file>.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">.dvi</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="7">.dvi <r>file</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="8">latex <r>command</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="9">xdvi <r>command</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="10">dvips <r>command</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="11">dvipdfmx <r>command</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="12">dvitype <r>command</r></indexterm></findex>
<para>If &latex; is invoked with the system command <command>latex</command> then it
produces a DeVice Independent file, with extension <file>.dvi</file>.  You
can view this file with a command such as <command>xdvi</command>, or convert
it to a PostScript <code>.ps</code> file with <command>dvips</command> or to a
Portable Document Format <code>.pdf</code> file with <command>dvipdfmx</command>.
The contents of the file can be dumped in human-readable form with
<command>dvitype</command>.  A vast array of other DVI utility programs are
available (<url><urefurl>http://mirror.ctan.org/dviware</urefurl></url>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">.pdf</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="13">.pdf <r>file</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="20">pdf&tex;</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="14">pdflatex <r>command</r></indexterm></findex>
<para>If &latex; is invoked via the system command <command>pdflatex</command>,
among other commands (<pxref label="TeX-engines"><xrefnodename>&tex; engines</xrefnodename></pxref>), then the main output is
a Portable Document Format (PDF) file.  Typically this is a
self-contained file, with all fonts and images included.
</para>
</tableitem></tableentry></table>

<para>&latex; also produces at least two additional files.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">.log</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="21">transcript file</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="22">log file</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="15">.log <r>file</r></indexterm></findex>
<para>This transcript file contains summary information such as a list of
loaded packages.  It also includes diagnostic messages and perhaps
additional information for any errors.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">.aux</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="23">auxiliary file</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="16">.aux <r>file</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="24">cross references, resolving</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="25">forward references, resolving</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="26">references, resolving forward</indexterm></cindex>
<para>Auxiliary information is used by &latex; for things such as
cross references.  For example, the first time that &latex; finds a
forward reference&textmdash;a cross reference to something that has not yet
appeared in the source&textmdash;it will appear in the output as a doubled
question mark <code>??</code>.  When the referred-to spot does eventually
appear in the source then &latex; writes its location information to
this <code>.aux</code> file.  On the next invocation, &latex; reads the
location information from this file and uses it to resolve the
reference, replacing the double question mark with the remembered
location.
</para>
</tableitem></tableentry></table>

<findex index="fn" spaces=" "><indexterm index="fn" number="17">.lof <r>file</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="27">list of figures file</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="18">.lot <r>file</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="28">list of tables file</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="19">.toc <r>file</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="29">table of contents file</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="30">contents file</indexterm></cindex>
<para>&latex; may produce yet more files, characterized by the filename
ending.  These include a <code>.lof</code> file that is used to make a list
of figures, a <code>.lot</code> file used to make a list of tables, and a
<code>.toc</code> file used to make a table of contents.  A particular class
may create others; the list is open-ended.
</para>

</section>
<node name="TeX-engines" spaces=" "><nodename>&tex; engines</nodename><nodenext automatic="on">&latex; command syntax</nodenext><nodeprev automatic="on">Output files</nodeprev><nodeup automatic="on">Overview</nodeup></node>
<section spaces=" "><sectiontitle>&tex; engines</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="31">engines, &tex;</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="32">implementations of &tex;</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="33">UTF-8</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="34">Unicode input, native</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="35">TrueType fonts</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="36">OpenType fonts</indexterm></cindex>

<para>&latex; is defined to be a set of commands that are run by a &tex;
implementation (<pxref label="Overview"><xrefnodename>Overview</xrefnodename></pxref>).  This section gives a terse
overview of the main programs.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">latex</itemformat></item>
<itemx spaces=" "><itemformat command="code">pdflatex</itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="37">pdf&tex; engine</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="20">etex <r>command</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="38">e-&tex;</indexterm></cindex>
<para>In &tex; Live (<url><urefurl>http://tug.org/texlive</urefurl></url>), if &latex; is invoked
via either the system command <command>latex</command> or <command>pdflatex</command>,
then the pdf&tex; engine is run (<url><urefurl>http://ctan.org/pkg/pdftex</urefurl></url>).
When invoked as <command>latex</command>, the main output is a <file>.dvi</file>
file; as <command>pdflatex</command>, the main output is a <file>.pdf</file> file.
</para>
<para>pdf&tex; incorporates the e-&tex; extensions to Knuth&textrsquo;s original
program (<url><urefurl>http://ctan.org/pkg/etex</urefurl></url>), including additional
programming features and bi-directional typesetting, and has plenty of
extensions of its own.  e-&tex; is available on its own as the system
command <command>etex</command>, but this is plain &tex; (and produces
<file>.dvi</file>).
</para>
<para>In other &tex; distributions, <command>latex</command> may invoke e-&tex;
rather than pdf&tex;.  In any case, the e-&tex; extensions can be
assumed to be available in &latex;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">lualatex</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="21">lualatex <r>command</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="39">Lua&tex;</indexterm></cindex>
<para>If &latex; is invoked via the system command <command>lualatex</command>, the
Lua&tex; engine is run (<url><urefurl>http://ctan.org/pkg/luatex</urefurl></url>).  This
program allows code written in the scripting language Lua
(<url><urefurl>http://luatex.org</urefurl></url>) to interact with &tex;&textrsquo;s typesetting.
Lua&tex; handles UTF-8 Unicode input natively, can handle OpenType
and TrueType fonts, and produces a <file>.pdf</file> file by default.
There is also <command>dvilualatex</command> to produce a <file>.dvi</file> file,
but this is rarely used.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">xelatex</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="22">xelatex <r>command</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="40">Xe&tex;</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="23">.xdv <r>file</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="24">xdvipdfmx</indexterm></findex>
<para>If &latex; is invoked with the system command <command>xelatex</command>, the
Xe&tex; engine is run (<url><urefurl>http://tug.org/xetex</urefurl></url>).  Like Lua&tex;,
Xe&tex; natively supports UTF-8 Unicode and TrueType and OpenType
fonts, though the implementation is completely different, mainly using
external libraries instead of internal code.  Xe&tex; produces a
<file>.pdf</file> file as output; it does not support DVI output.
</para>
<para>Internally, Xe&tex; creates an <code>.xdv</code> file, a variant of DVI,
and translates that to PDF using the (<code>x</code>)<code>dvipdfmx</code>
program, but this process is automatic.  The <code>.xdv</code> file is only
useful for debugging.
</para>
</tableitem></tableentry></table>

<para>Other variants of &latex; and &tex; exist, e.g., to provide
additional support for Japanese and other languages ([u]p&tex;,
<url><urefurl>http://ctan.org/pkg/ptex</urefurl></url>, <url><urefurl>http://ctan.org/pkg/uptex</urefurl></url>).
</para>

</section>
<node name="LaTeX-command-syntax" spaces=" "><nodename>&latex; command syntax</nodename><nodeprev automatic="on">&tex; engines</nodeprev><nodeup automatic="on">Overview</nodeup></node>
<section spaces=" "><sectiontitle>&latex; command syntax</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="41">command syntax</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="25">\ <r>character starting commands</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="26">[...] <r>for optional arguments</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="27">&lbrace;...&rbrace; <r>for required arguments</r></indexterm></findex>
<para>In the &latex; input file, a command name starts with a backslash
character, <code>\</code>.  The name itself then consists of either
(a)&nbsp;a string of letters or (b)&nbsp;a single non-letter.
</para>
<para>&latex; commands names are case sensitive so that <code>\pagebreak</code>
differs from <code>\Pagebreak</code> (the latter is not a standard command).
Most commands are lowercase, but in any event you must enter all
commands in the same case as they are defined.
</para>
<para>A command may be followed by zero, one, or more arguments. These
arguments may be either required or optional.  Required arguments are
contained in curly braces, <code>&lbrace;...&rbrace;</code>.  Optional arguments are
contained in square brackets, <code>[...]</code>.  Generally, but not
universally, if the command accepts an optional argument, it comes
first, before any required arguments.
</para>
<para>Inside of an optional argument, to use the character close square
bracket&nbsp;(<code>]</code>) hide it inside curly braces, as
in&nbsp;<code>\item[closing bracket &lbrace;]&rbrace;]</code>.  Similarly, if an optional
argument comes last, with no required argument after it, then to make
the first character of the following text be an open square bracket,
hide it inside curly braces.
</para>
<para>&latex; has the convention that some commands have a <code>*</code> form that
is related to the form without a <code>*</code>, such as <code>\chapter</code> and
<code>\chapter*</code>.  The exact difference in behavior varies from command
to command.
</para>
<para>This manual describes all accepted options and <code>*</code>-forms for the
commands it covers (barring unintentional omissions, a.k.a.&noeos; bugs).
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::          ">Environment</menunode><menudescription><pre xml:space="preserve">Area of the source with distinct behavior.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::          ">Declaration</menunode><menudescription><pre xml:space="preserve">Change the value or meaning of a command.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::    ">\makeatletter and \makeatother</menunode><menudescription><pre xml:space="preserve">Change the status of the at-sign character.
</pre></menudescription></menuentry></menu>


<node name="Environment" spaces=" "><nodename>Environment</nodename><nodenext automatic="on">Declaration</nodenext><nodeup automatic="on">&latex; command syntax</nodeup></node>
<subsection spaces=" "><sectiontitle>Environments</sectiontitle>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;<var>environment name</var>&rbrace;
  ...
\end&lbrace;<var>environment name</var>&rbrace;
</pre></example>

<para>An area of &latex; source, inside of which there is a distinct
behavior.  For instance, for poetry in &latex; put the lines between
<code>\begin&lbrace;verse&rbrace;</code> and <code>\end&lbrace;verse&rbrace;</code>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;verse&rbrace;
  There once was a man from Nantucket \\
  ...
\end&lbrace;verse&rbrace;
</pre></example>

<para>See&nbsp;<ref label="Environments"><xrefnodename>Environments</xrefnodename></ref> for a list of environments. 
</para>
<para>The <var>environment name</var> at the beginning must exactly match that at
the end.  This includes the case where <var>environment name</var> ends in a
star&nbsp;(<code>*</code>); both the <code>\begin</code> and <code>\end</code> texts must
include the star.
</para>
<para>Environments may have arguments, including optional arguments.  This
example produces a table.  The first argument is optional (and causes
the table to be aligned on its top row) while the second argument is
required (it specifies the formatting of columns).
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;[t]&lbrace;r|l&rbrace;
  ... rows of table ...
\end&lbrace;tabular&rbrace;
</pre></example> 


</subsection>
<node name="Declaration" spaces=" "><nodename>Declaration</nodename><nodenext automatic="on">\makeatletter and \makeatother</nodenext><nodeprev automatic="on">Environment</nodeprev><nodeup automatic="on">&latex; command syntax</nodeup></node>
<subsection spaces=" "><sectiontitle>Command declarations</sectiontitle>

<para>A command that changes the value, or changes the meaning, of some other
command or parameter.  For instance, the <code>\mainmatter</code> command
changes the setting of page numbers from roman numerals to arabic.
</para>

</subsection>
<node name="_005cmakeatletter-and-_005cmakeatother" spaces=" "><nodename>\makeatletter and \makeatother</nodename><nodeprev automatic="on">Declaration</nodeprev><nodeup automatic="on">&latex; command syntax</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\makeatletter</code> and <code>\makeatother</code></sectiontitle>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\makeatletter
  ... definition of commands with &arobase; in their name ..
\makeatother
</pre></example>

<para>Used to redefine internal &latex; commands.  <code>\makeatletter</code> makes
the at-sign character&nbsp;<code>&arobase;</code> have the category code of a letter,
11.  <code>\makeatother</code> sets the category code of&nbsp;<code>&arobase;</code> to 12,
its original value.
</para>
<para>As each character is read by &tex; for &latex;, it is assigned a
character category code, or 
<cindex index="cp" spaces=" "><indexterm index="cp" number="42">catcode</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="43">character category code</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="44">category code, character</indexterm></cindex>
<dfn>catcode</dfn> for short. For instance, the backslash&nbsp;<code>\</code> is
assigned the catcode 0, for characters that start a command.  These two
commands alter the catcode assigned to <code>&arobase;</code>.
</para>
<para>The alteration is needed because many of &latex;&textrsquo;s commands use
<code>&arobase;</code> in their name, to prevent users from accidentally defining a
command that replaces one of &latex;&textrsquo;s own.  Command names consist of a
category&nbsp;0 character, ordinarily backslash, followed by letters,
category&nbsp;11 characters (except that a command name can also consist
of a category&nbsp;0 character followed by a single non-letter symbol).
So under the default category codes, user-defined commands cannot
contain an <code>&arobase;</code>.  But <code>\makeatletter</code> and <code>\makeatother</code>
allow users to define or redefine commands named with <code>&arobase;</code>.
</para>
<para>Use these two commands inside a <file>.tex</file> file, in the preamble, when
defining or redefining a command with <code>&arobase;</code> in its name.  Don&textrsquo;t use
them inside <file>.sty</file> or <file>.cls</file> files since the
<code>\usepackage</code> and <code>\documentclass</code> commands set the at sign to
have the character code of a letter.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="45"><r>package</r>, <code>macros2e</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="46"><code>macros2e</code> <r>package</r></indexterm></cindex>

<para>For a comprehensive list of macros with an at-sign
in their names see <url><urefurl>http://ctan.org/pkg/macros2e</urefurl></url>. These macros are
mainly intended to package or class authors.
</para>
<para>The example below is typical.  In the user&textrsquo;s class file is a command
<code>\thesis&arobase;universityname</code>.  The user wants to change the
definition.  These three lines should go in the preamble, before the
<code>\begin&lbrace;document&rbrace;</code>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\makeatletter
\renewcommand&lbrace;\thesis&arobase;universityname&rbrace;&lbrace;Saint Michael's College&rbrace;
\makeatother
</pre></example>

<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator=":: ">\&arobase;ifstar</menunode><menudescription><pre xml:space="preserve">Define your own commands with *-variants.
</pre></menudescription></menuentry></menu>


<node name="_005c_0040ifstar" spaces=" "><nodename>\&arobase;ifstar</nodename><nodeup automatic="on">\makeatletter and \makeatother</nodeup></node>
<subsubsection spaces=" "><sectiontitle><code>\&arobase;ifstar</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="28">\&arobase;ifstar</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="47">commands, star-variants</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="48">star-variants, commands</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcommand&lbrace;\mycmd&rbrace;&lbrace;\&arobase;ifstar&lbrace;\mycmd&arobase;star&rbrace;&lbrace;\mycmd&arobase;nostar&rbrace;&rbrace;
\newcommand&lbrace;\mycmd&arobase;nostar&rbrace;[<var>non-starred command number of args</var>]&lbrace;<var>body of non-starred command</var>&rbrace; 
\newcommand&lbrace;\mycmd&arobase;star&rbrace;[<var>starred command number of args</var>]&lbrace;<var>body of starred command</var>&rbrace;
</pre></example>

<para>Many standard &latex; environments or commands have a variant with the
same name but ending with a star character&nbsp;<code>*</code>, an asterisk.
Examples are the <code>table</code> and <code>table*</code> environments and the
<code>\section</code> and <code>\section*</code> commands.
</para>
<para>When defining environments, following this pattern is straightforward
because <code>\newenvironment</code> and <code>\renewenvironment</code> allow the
environment name to contain a star.  For commands the situation is more
complex.  As in the synopsis above, there will be a user-called command,
given above as <code>\mycmd</code>, which peeks ahead to see if it is followed
by a star.  For instance, &latex; does not really have a
<code>\section*</code> command; instead, the <code>\section</code> command peeks
ahead.  This command does not accept arguments but instead expands to
one of two commands that do accept arguments.  In the synopsis these two
are <code>\mycmd&arobase;nostar</code> and <code>\mycmd&arobase;star</code>.  They could take the
same number of arguments or a different number, or no arguments at all.
As always, in a &latex; document a command using at-sign&nbsp;<code>&arobase;</code>
must be enclosed inside a <code>\makeatletter ... \makeatother</code> block
(<pxref label="_005cmakeatletter-and-_005cmakeatother"><xrefnodename>\makeatletter and \makeatother</xrefnodename></pxref>).
</para>
<para>This example of <code>\&arobase;ifstar</code> defines the command <code>\ciel</code> and a
variant <code>\ciel*</code>.  Both have one required argument.  A call to
<code>\ciel&lbrace;night&rbrace;</code> will return &quot;starry night sky&quot; while
<code>\ciel*&lbrace;blue&rbrace;</code> will return &quot;starry not blue sky&quot;.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcommand*&lbrace;\ciel&arobase;unstarred&rbrace;[1]&lbrace;starry #1 sky&rbrace;
\newcommand*&lbrace;\ciel&arobase;starred&rbrace;[1]&lbrace;starry not #1 sky&rbrace;
\newcommand*&lbrace;\ciel&rbrace;&lbrace;\&arobase;ifstar&lbrace;\ciel&arobase;starred&rbrace;&lbrace;\ciel&arobase;unstarred&rbrace;&rbrace;
</pre></example>

<para>In the next example, the starred variant takes a different number of
arguments than does the unstarred one.  With this definition, Agent
007&textrsquo;s <code>``My name is \agentsecret*&lbrace;Bond&rbrace;,
\agentsecret&lbrace;James&rbrace;&lbrace;Bond&rbrace;.''</code> is equivalent to <code>``My name is
\textsc&lbrace;Bond&rbrace;, \textit&lbrace;James&rbrace; textsc&lbrace;Bond&rbrace;.''</code>
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcommand*&lbrace;\agentsecret&arobase;unstarred&rbrace;[2]&lbrace;\textit&lbrace;#1&rbrace; \textsc&lbrace;#2&rbrace;&rbrace;
\newcommand*&lbrace;\agentsecret&arobase;starred&rbrace;[1]&lbrace;\textsc&lbrace;#1&rbrace;&rbrace;
\newcommand*&lbrace;\agentsecret&rbrace;&lbrace;\&arobase;ifstar&lbrace;\agentsecret&arobase;starred&rbrace;&lbrace;\agentsecret&arobase;unstarred&rbrace;&rbrace;
</pre></example>

<para>There are two sometimes more convenient ways to accomplish the work of
<code>\&arobase;ifstar</code>.  The <file>suffix</file> package allows the construct
<code>\newcommand\mycommand&lbrace;<var>unstarred version</var>&rbrace;</code> followed by
<code>\WithSuffix\newcommand\mycommand*&lbrace;<var>starred version</var>&rbrace;</code>.  And
&latex;3 has the <file>xparse</file> package that allows this code.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\NewDocumentCommand\foo&lbrace;s&rbrace;&lbrace;\IfBooleanTF#1
  &lbrace;<var>starred version</var>&rbrace;%
  &lbrace;<var>unstarred version</var>&rbrace;% 
  &rbrace;
</pre></example>


</subsubsection>
</subsection>
</section>
</chapter>
<node name="Document-classes" spaces=" "><nodename>Document classes</nodename><nodenext automatic="on">Fonts</nodenext><nodeprev automatic="on">Overview</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Document classes</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="49">document classes</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="50">classes of documents</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="29">\documentclass</indexterm></findex>

<para>The document&textrsquo;s overall class is defined with this command, which is
normally the first command in a &latex; source file.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\documentclass[<var>options</var>]&lbrace;<var>class</var>&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="30">article <r>class</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="31">report <r>class</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="32">book <r>class</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="33">letter <r>class</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="34">slides <r>class</r></indexterm></findex>
<para>The following document <var>class</var> names are built into &latex;.
(Many other document classes are available as separate packages;
<pxref label="Overview"><xrefnodename>Overview</xrefnodename></pxref>.)
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">article</itemformat></item>
</tableterm><tableitem><para>For a journal article, a presentation, and miscellaneous general use.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">book</itemformat></item>
</tableterm><tableitem><para>Full-length books, including chapters and possibly including front
matter, such as a preface, and back matter, such as an appendix
(<pxref label="Front_002fback-matter"><xrefnodename>Front/back matter</xrefnodename></pxref>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">letter</itemformat></item>
</tableterm><tableitem><para>Mail, optionally including mailing labels 
(<pxref label="Letters"><xrefnodename>Letters</xrefnodename></pxref>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">report</itemformat></item>
</tableterm><tableitem><para>For documents of length between an <code>article</code> and a <code>book</code>,
such as technical reports or theses, which may contain several chapters.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">slides</itemformat></item>
</tableterm><tableitem><para>For slide presentations&textmdash;rarely used today.  In its place the
<code>beamer</code> package is perhaps the most prevalent (<pxref label="beamer-template"><xrefnodename>beamer
template</xrefnodename></pxref>).
</para>
</tableitem></tableentry></table>

<para>Standard <var>options</var> are described in the next section.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::   ">Document class options</menunode><menudescription><pre xml:space="preserve">Global options.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::       ">Additional packages</menunode><menudescription><pre xml:space="preserve">Bring in packages.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::   ">Class and package construction</menunode><menudescription><pre xml:space="preserve">Create new classes and packages.
</pre></menudescription></menuentry></menu>


<node name="Document-class-options" spaces=" "><nodename>Document class options</nodename><nodenext automatic="on">Additional packages</nodenext><nodeup automatic="on">Document classes</nodeup></node>
<section spaces=" "><sectiontitle>Document class options</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="51">document class options</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="52">options, document class</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="53">class options</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="54">global options</indexterm></cindex>

<para>You can specify so-called <dfn>global options</dfn> or <dfn>class options</dfn> to
the <code>\documentclass</code> command by enclosing them in square brackets.
To specify more than one <var>option</var>, separate them with a comma, as in:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\documentclass[<var>option1</var>,<var>option2</var>,...]&lbrace;<var>class</var>&rbrace;
</pre></example>

<para>Here is the list of the standard class options.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="35">10pt <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="36">11pt <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="37">12pt <r>option</r></indexterm></findex>
<para>All of the standard classes except <code>slides</code> accept the following
options for selecting the typeface size (default is <code>10pt</code>):
</para>
<example endspaces=" ">
<pre xml:space="preserve">10pt  11pt  12pt
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="38">a4paper <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="39">a5paper <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="40">b5paper <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="41">executivepaper <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="42">legalpaper <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="43">letterpaper <r>option</r></indexterm></findex>
<para>All of the standard classes accept these options for selecting the paper
size (these show height by width):
</para>
<table commandarg="code" spaces=" " endspaces=" "> 
<tableentry><tableterm><item spaces=" "><itemformat command="code">a4paper </itemformat></item>
</tableterm><tableitem><para>210 by 297<dmn>mm</dmn> (about 8.25 by 11.75&nbsp;inches)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">a5paper </itemformat></item>
</tableterm><tableitem><para>148 by 210<dmn>mm</dmn> (about 5.8 by 8.3&nbsp;inches)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">b5paper</itemformat></item>
</tableterm><tableitem><para>176 by 250<dmn>mm</dmn> (about 6.9 by 9.8&nbsp;inches)
</para> 
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">executivepaper</itemformat></item>
</tableterm><tableitem><para>7.25 by 10.5&nbsp;inches
</para> 
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">legalpaper</itemformat></item>
</tableterm><tableitem><para>8.5 by 14&nbsp;inches
</para> 
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">letterpaper</itemformat></item>
</tableterm><tableitem><para>8.5 by 11&nbsp;inches (the default)
</para></tableitem></tableentry></table>

<findex index="fn" spaces=" "><indexterm index="fn" number="44">\pdfpagewidth</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="45">\pdfpageheight</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="55"><r>package</r>, <code>geometry</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="56"><code>geometry</code> <r>package</r></indexterm></cindex>

<para>When using one of the engines pdf&latex;, Lua&latex;, or Xe&latex;
(<pxref label="TeX-engines"><xrefnodename>&tex; engines</xrefnodename></pxref>), options other than <code>letterpaper</code> set
the print area but you must also set the physical paper size.  One way
to do that is to put <code>\pdfpagewidth=\paperwidth</code> and
<code>\pdfpageheight=\paperheight</code> in your document&textrsquo;s preamble.
<cindex index="cp" spaces=" "><indexterm index="cp" number="57"><r>package</r>, <code>geometry</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="58"><code>geometry</code> <r>package</r></indexterm></cindex>
</para>
<para>The <code>geometry</code> package provides flexible ways of setting the print
area and physical page size.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="46">draft <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="47">final <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="48">fleqn <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="49">landscape <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="50">leqno <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="51">openbib <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="52">titlepage <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="53">notitlepage <r>option</r></indexterm></findex>
<para>Miscellaneous other options:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">draft</itemformat></item>
<itemx spaces=" "><itemformat command="code">final</itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="59">black boxes, omitting</indexterm></cindex>
<para>Mark (<code>draft</code>) or do not mark (<code>final</code>) overfull boxes with a
black box in the margin; default is <code>final</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">fleqn</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="60">flush left equations</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="61">centered equations</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="62">equations, flush left vs.&noeos; centered</indexterm></cindex>
<para>Put displayed formulas flush left; default is centered.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">landscape</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="63">landscape orientation</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="64">portrait orientation</indexterm></cindex>
<para>Selects landscape format; default is portrait.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">leqno</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="65">left-hand equation numbers</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="66">right-hand equation numbers</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="67">equation numbers, left vs.&noeos; right</indexterm></cindex>
<para>Put equation numbers on the left side of equations; default is the right side.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">openbib</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="68">bibliography format, open</indexterm></cindex>
<para>Use &textldquo;open&textrdquo; bibliography format.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">titlepage</itemformat></item>
<itemx spaces=" "><itemformat command="code">notitlepage</itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="69">title page, separate or run-in</indexterm></cindex>
<para>Specifies whether there is a separate page for the title information and
for the abstract also, if there is one.  The default for the
<code>report</code> class is <code>titlepage</code>, for the other classes it is
<code>notitlepage</code>.
</para></tableitem></tableentry></table>

<para>The following options are not available with the <code>slides</code> class.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="54">onecolumn <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="55">twocolumn <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="56">oneside <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="57">twoside <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="58">openright <r>option</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="59">openany <r>option</r></indexterm></findex>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">onecolumn</itemformat></item>
<itemx spaces=" "><itemformat command="code">twocolumn</itemformat></itemx>
</tableterm><tableitem><para>Typeset in one or two columns; default is <code>onecolumn</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">oneside</itemformat></item>
<itemx spaces=" "><itemformat command="code">twoside</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="60">\evensidemargin</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="61">\oddsidemargin</indexterm></findex>
<para>Selects one- or two-sided layout; default is <code>oneside</code>, except
that in the <code>book</code> class the default is <code>twoside</code>.
</para>
<para>For one-sided printing, the text is centered on the page.  For two-sided
printing, the <code>\evensidemargin</code> (<code>\oddsidemargin</code>) parameter
determines the distance on even (odd) numbered pages between the left
side of the page and the text&textrsquo;s left margin, with <code>\oddsidemargin</code>
being 40% of the difference between <code>\paperwidth</code> and
<code>\textwidth</code>, and <code>\evensidemargin</code> is the remainder.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">openright</itemformat></item>
<itemx spaces=" "><itemformat command="code">openany</itemformat></itemx>
</tableterm><tableitem><para>Determines if a chapter should start on a right-hand page; default is
<code>openright</code> for <code>book</code>, and <code>openany</code> for <code>report</code>.
</para></tableitem></tableentry></table>

<findex index="fn" spaces=" "><indexterm index="fn" number="62">clock <r>option to <code>slides</code> class</r></indexterm></findex>
<para>The <code>slides</code> class offers the option <code>clock</code> for printing
the time at the bottom of each note.
</para>

</section>
<node name="Additional-packages" spaces=" "><nodename>Additional packages</nodename><nodenext automatic="on">Class and package construction</nodenext><nodeprev automatic="on">Document class options</nodeprev><nodeup automatic="on">Document classes</nodeup></node>
<section spaces=" "><sectiontitle>Additional packages</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="70">loading additional packages</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="71">packages, loading additional</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="72">additional packages, loading</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="63">\usepackage</indexterm></findex>
<para>Load a package <var>pkg</var>, with the package options given in the comma-separated
list <var>options</var>, as here.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usepackage[<var>options</var>]&lbrace;<var>pkg</var>&rbrace;.
</pre></example>

<para>To specify more than one package you can separate them with a comma,
as in <code>\usepackage&lbrace;<var>pkg1</var>,<var>pkg2</var>,...&rbrace;</code>, or use multiple
<code>\usepackage</code> commands.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="73">global options</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="74">options, global</indexterm></cindex>
<para>Any options given in the <code>\documentclass</code> command that are unknown
to the selected document class are passed on to the packages loaded with
<code>\usepackage</code>.
</para>

</section>
<node name="Class-and-package-construction" spaces=" "><nodename>Class and package construction</nodename><nodeprev automatic="on">Additional packages</nodeprev><nodeup automatic="on">Document classes</nodeup></node>
<section spaces=" "><sectiontitle>Class and package construction</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="75">document class commands</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="76">commands, document class</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="77">new class commands</indexterm></cindex>

<para>You can create new document classes and new packages.  For instance, if
your memos must satisfy some local requirements, such as a
standard header for each page, then you could create a new class
<code>smcmemo.cls</code> and begin your documents with
<code>\documentclass&lbrace;smcmemo&rbrace;</code>.
</para>
<para>What separates a package from a document class is that the commands in a
package are useful across classes while those in a document class are
specific to that class.  Thus, a command to set page headers is for a
package while a command to make the page headers say <code>Memo from the
SMC Math Department</code> is for a class.
<cindex index="cp" spaces=" "><indexterm index="cp" number="78">class and package difference</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="79">difference between class and package</indexterm></cindex>
</para>
<para>Inside of a class or package file you can use the at-sign <code>&arobase;</code> as a
character in command names without having to surround the code
containing that command with <code>\makeatletter</code> and
<code>\makeatother</code>.  <xref label="_005cmakeatletter-and-_005cmakeatother"><xrefnodename>\makeatletter and \makeatother</xrefnodename></xref>. This allow
you to create commands that users will not accidentally redefine.
Another technique is to preface class- or package-specific commands with
some string to prevent your class or package from interfering with
others. For instance, the class <code>smcmemo</code> might have commands
<code>\smc&arobase;tolist</code>, <code>\smc&arobase;fromlist</code>, etc.
</para>

<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::     ">Class and package structure</menunode><menudescription><pre xml:space="preserve">Layout of the file.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::      ">Class and package commands</menunode><menudescription><pre xml:space="preserve">List of commands.
</pre></menudescription></menuentry></menu>


<node name="Class-and-package-structure" spaces=" "><nodename>Class and package structure</nodename><nodenext automatic="on">Class and package commands</nodenext><nodeup automatic="on">Class and package construction</nodeup></node>
<subsection spaces=" "><sectiontitle>Class and package structure</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="80">class and package structure</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="81">class file layout</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="82">package file layout</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="83">options, document class</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="84">options, package</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="85">class options</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="86">package options</indexterm></cindex>

<para>A class file or package file typically has four parts.  
</para><enumerate first="1" endspaces=" ">
<beforefirstitem><para>In the <dfn>identification part</dfn>, the file says that it is a &latex;
package or class and describes itself, using the <code>\NeedsTeXFormat</code>
and <code>\ProvidesClass</code> or <code>\ProvidesPackage</code> commands.
</para></beforefirstitem><listitem>
<para>The <dfn>preliminary declarations part</dfn> declares some commands and
can also load other files. Usually these commands will be those needed
for the code used in the next part.  For example, an <code>smcmemo</code>
class might be called with an option to read in a file with a list of
people for the to-head, as <code>\documentclass[mathto]&lbrace;smcmemo&rbrace;</code>, and
therefore needs to define a command
<code>\newcommand&lbrace;\setto&rbrace;[1]&lbrace;\def\&arobase;tolist&lbrace;#1&rbrace;&rbrace;</code> used in that
file.
</para></listitem><listitem>
<para>In the <dfn>handle options part</dfn> the class or package declares
and processes its options.  Class options allow a user to start their
document as <code>\documentclass[<var>option list</var>]&lbrace;<var>class
name</var>&rbrace;</code>, to modify the behavior of the class.  An example is when you
declare <code>\documentclass[11pt]&lbrace;article&rbrace;</code> to set the default
document font size.  
</para></listitem><listitem>
<para>Finally, in the <dfn>more declarations part</dfn> the class or package usually does
most of its work: declaring new variables, commands and fonts, and
loading other files.
</para></listitem></enumerate>


<para>Here is a starting class file, which should be saved as <file>stub.cls</file>
where &latex; can find it, for example in the same directory as the
<file>.tex</file> file.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\NeedsTeXFormat&lbrace;LaTeX2e&rbrace;
\ProvidesClass&lbrace;stub&rbrace;[2017/07/06 stub to start building classes from]
\DeclareOption*&lbrace;\PassOptionsToClass&lbrace;\CurrentOption&rbrace;&lbrace;article&rbrace;&rbrace;
\ProcessOptions\relax
\LoadClass&lbrace;article&rbrace;
</pre></example>
<cindex index="cp" spaces=" "><indexterm index="cp" number="87">class file example</indexterm></cindex>

<para>It identifies itself, handles the class options via the default of
passing them all to the <code>article</code> class, and then loads the
<code>article</code> class to provide the basis for this class&textrsquo;s code.
</para>
<para>For more, see the official guide for class and package writers, the
Class Guide, at
<url><urefurl>http://www.latex-project.org/help/documentation/clsguide.pdf</urefurl></url> (much
of the descriptions here derive from this document), or the tutorial
<url><urefurl>https://www.tug.org/TUGboat/tb26-3/tb84heff.pdf</urefurl></url>.
</para>
</subsection>
<node name="Class-and-package-commands" spaces=" "><nodename>Class and package commands</nodename><nodeprev automatic="on">Class and package structure</nodeprev><nodeup automatic="on">Class and package construction</nodeup></node>
<subsection spaces=" "><sectiontitle>Class and package commands</sectiontitle>
<cindex index="cp" spaces=" "><indexterm index="cp" number="88">class and package commands</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="89">commands, class and package</indexterm></cindex>

<para>These are the commands designed to help writers of classes or packages.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">\AtBeginDvi&lbrace;specials&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="64">\AtBeginDvi</indexterm></findex>
<para>Save in a box register things that are written to the <file>.dvi</file> file
at the beginning of the shipout of the first page of the document.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\AtEndOfClass&lbrace;<var>code</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\AtEndOfPackage&lbrace;<var>code</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="65">\AtEndOfClass</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="66">\AtEndOfPackage</indexterm></findex>
<para>Hook to insert <var>code</var> to be executed when &latex; finishes
processing the current class or package.  You can use these hooks
multiple times; the <code>code</code> will be executed in the order that you
called it.  See also <ref label="_005cAtBeginDocument"><xrefnodename>\AtBeginDocument</xrefnodename></ref>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\CheckCommand&lbrace;<var>cmd</var>&rbrace;[<var>num</var>][<var>default</var>]&lbrace;<var>definition</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\CheckCommand*&lbrace;<var>cmd</var>&rbrace;[<var>num</var>][<var>default</var>]&lbrace;<var>definition</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="67">\CheckCommand</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="68">\CheckCommand*</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="90">new command, check</indexterm></cindex>
<para>Like <code>\newcommand</code> (<pxref label="_005cnewcommand-_0026-_005crenewcommand"><xrefnodename>\newcommand &amp; \renewcommand</xrefnodename></pxref>) but does
not define <var>cmd</var>; instead it checks that the current definition of
<var>cmd</var> is exactly as given by <var>definition</var> and is or is not 
<cindex index="cp" spaces=" "><indexterm index="cp" number="91">long command</indexterm></cindex>
<dfn>long</dfn> as expected.  A long command is a command that accepts
<code>\par</code> within an argument.  The <var>cmd</var> command is expected to be
long with the unstarred version of <code>\CheckCommand</code>.  Raises an
error when the check fails.  This allows you to check before you start
redefining <code>cmd</code> yourself that no other package has already
redefined this command.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ClassError&lbrace;<var>class name</var>&rbrace;&lbrace;<var>error text</var>&rbrace;&lbrace;<var>help text</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\PackageError&lbrace;<var>package name</var>&rbrace;&lbrace;<var>error text</var>&rbrace;&lbrace;<var>help text</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ClassWarning&lbrace;<var>class name</var>&rbrace;&lbrace;<var>warning text</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\PackageWarning&lbrace;<var>package name</var>&rbrace;&lbrace;<var>warning text</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ClassWarningNoLine&lbrace;<var>class name</var>&rbrace;&lbrace;<var>warning text</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\PackageWarningNoLine&lbrace;<var>package name</var>&rbrace;&lbrace;<var>warning text</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ClassInfo&lbrace;<var>class name</var>&rbrace;&lbrace;<var>info text</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\PackageInfo&lbrace;<var>package name</var>&rbrace;&lbrace;<var>info text</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ClassInfoNoLine&lbrace;<var>class name</var>&rbrace;&lbrace;<var>info text</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\PackageInfoNoLine&lbrace;<var>package name</var>&rbrace;&lbrace;<var>info text</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="69">\ClassError</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="70">\PackageError</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="71">\ClassWarning</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="72">\PackageWarning</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="73">\ClassWarningNoLine</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="74">\PackageWarningNoLine</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="75">\ClassInfo</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="76">\PackageInfo</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="77">\ClassInfoNoLine</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="78">\PackageInfoNoLine</indexterm></findex>
<para>Produce an error message, or warning or informational messages.
</para>
<para>For <code>\ClassError</code> and <code>\PackageError</code> the message is
<var>error text</var>, followed by &tex;&textrsquo;s <code>?</code> error prompt. If the
user then asks for help by typing <code>h</code>, they see the <var>help
text</var>.
</para>
<para>The four warning commands are similar except that they write
<var>warning text</var> on the screen with no error prompt.  The four info
commands write <var>info text</var> only in the transcript file.  The
<code>NoLine</code> versions do not show the number of the line generating the
message, while the other versions do show that number.
</para>
<para>To format the messages, including the <var>help text</var>: use
<code>\protect</code> to stop a command from expanding, get a line break with
<code>\MessageBreak</code>, and get a space with <code>\space</code> when a space
character does not allow it, like after a command.  Note that &latex;
appends a period to the messages.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\CurrentOption</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="79">\CurrentOption</indexterm></findex>
<para>Expands to the name of the currently-being-processed option.  Can only
be used within the <var>code</var> argument of either <code>\DeclareOption</code>
or <code>\DeclareOption*</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\DeclareOption&lbrace;<var>option</var>&rbrace;&lbrace;<var>code</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\DeclareOption*&lbrace;<var>code</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="80">\DeclareOption</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="81">\DeclareOption*</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="92">class options</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="93">package options</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="94">options, class</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="95">options, package</indexterm></cindex>
<para>Make an option available to a user, for invoking in their
<code>\documentclass</code> command.  For example, the <code>smcmemo</code> class
could have an option allowing users to put the institutional logo on the
first page with <code>\documentclass[logo]&lbrace;smcmemo&rbrace;</code>.  The class file
must contain <code>\DeclareOption&lbrace;logo&rbrace;&lbrace;<var>code</var>&rbrace;</code> (and later,
<code>\ProcessOptions</code>).
</para>
<para>If you request an option that has not been declared, by default this
will produce a warning like <code>Unused global option(s): [badoption].</code>
Change this behaviour with the starred version
<code>\DeclareOption*&lbrace;<var>code</var>&rbrace;</code>.  For example, many classes extend
an existing class, using a declaration such as
<code>\LoadClass&lbrace;article&rbrace;</code>, and for passing extra options to the
underlying class use code such as this.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\DeclareOption*&lbrace;%
\PassOptionsToClass&lbrace;\CurrentOption&rbrace;&lbrace;article&rbrace;%
&rbrace;
</pre></example>

<para>Another example is that the class <code>smcmemo</code> may allow users to keep
lists of memo recipients in external files.  Then the user could invoke
<code>\documentclass[math]&lbrace;smcmemo&rbrace;</code> and it will read the file
<code>math.memo</code>.  This code handles the file if it exists and otherwise
passes the option to the <code>article</code> class.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\DeclareOption*&lbrace;\InputIfFileExists&lbrace;\CurrentOption.memo&rbrace;&lbrace;&rbrace;&lbrace;%
    \PassOptionsToClass&lbrace;\CurrentOption&rbrace;&lbrace;article&rbrace;&rbrace;&rbrace;
</pre></example>

</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\DeclareRobustCommand&lbrace;<var>cmd</var>&rbrace;[<var>num</var>][<var>default</var>]&lbrace;<var>definition</var>&rbrace; </itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\DeclareRobustCommand*&lbrace;<var>cmd</var>&rbrace;[<var>num</var>][<var>default</var>]&lbrace;<var>definition</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="82">\DeclareRobustCommand</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="83">\DeclareRobustCommand*</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="96">new command, definition</indexterm></cindex>
<para>Like <code>\newcommand</code> and <code>\newcommand*</code> (<pxref label="_005cnewcommand-_0026-_005crenewcommand"><xrefnodename>\newcommand &amp;
\renewcommand</xrefnodename></pxref>) but these declare a robust command, even if some code
within the <var>definition</var> is fragile.  (For a discussion of robust and
fragile commands <pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>.) Use this command to define new
robust commands or to redefine existing commands and make them
robust. Unlike <code>\newcommand</code> these do not give an error if macro
<var>cmd</var> already exists; instead, a log message is put into the
transcript file if a command is redefined.
</para>
<para>Commands defined this way are a bit less efficient than those defined
using <code>\newcommand</code> so unless the command&textrsquo;s data is fragile and the
command is used within a moving argument, use <code>\newcommand</code>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="97"><r>package</r>, <code>etoolbox</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="98"><code>etoolbox</code> <r>package</r></indexterm></cindex>
 
<para>The <code>etoolbox</code> package offers commands <code>\newrobustcmd</code>,
<code>\newrobustcmd*</code>, <code>\renewrobustcmd</code>, <code>\renewrobustcmd*</code>,
<code>\providerobustcmd</code>, and <code>\providerobustcmd*</code> which are similar
to <code>\newcommand</code>, <code>\newcommand*</code>, <code>\renewcommand</code>,
<code>\renewcommand*</code>, <code>\providecommand</code>, and
<code>\providecommand*</code>, but define a robust <var>cmd</var> with two advantages
as compared to <code>\DeclareRobustCommand</code>:
</para><enumerate first="1" endspaces=" ">
<listitem>
<para>They use the low-level e-&tex; protection mechanism rather than the
higher level &latex; <code>\protect</code> mechanism, so they do not incur
the slight loss of performance mentioned above, and
</para></listitem><listitem>
<para>They make the same distinction between <code>\new&dots;</code>,
<code>\renew&dots;</code>, and <code>\provide&dots;</code>, as the standard
commands, so they do not just make a log message when you redefine
<var>cmd</var> that already exists, in that case you need to use either
<code>\renew&dots;</code> or <code>\provide&dots;</code> or you get an error.
</para></listitem></enumerate>


</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\IfFileExists&lbrace;<var>file name</var>&rbrace;&lbrace;<var>true code</var>&rbrace;&lbrace;<var>false code</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\InputIfFileExists&lbrace;<var>file name</var>&rbrace;&lbrace;<var>true code</var>&rbrace;&lbrace;<var>false code</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="84">\IfFileExists</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="85">\InputIfFileExists</indexterm></findex>
<para>Execute <var>true code</var> if &latex; can find the file <file><var>file
name</var></file> and <var>false code</var> otherwise.  In the second case it inputs the
file immediately after executing <var>true code</var>.  Thus
<code>\IfFileExists&lbrace;img.pdf&rbrace;&lbrace;\includegraphics&lbrace;img.pdf&rbrace;&rbrace;&lbrace;\typeout&lbrace;WARNING:
img.pdf not found&rbrace;&rbrace;</code> will include the graphic <file>img.pdf</file> if it is
found but otherwise just give a warning.
</para>
<para>This command looks for the file in all search paths that &latex; uses,
not only in the current directory.  To look only in the current
directory do something like <code>\IfFileExists&lbrace;./filename&rbrace;&lbrace;<var>true
code</var>&rbrace;&lbrace;<var>false code</var>&rbrace;</code>.  If you ask for a filename without a
<code>.tex</code> extension then &latex; will first look for the file by
appending the <code>.tex</code>; for more on how &latex; handles file
extensions see <ref label="_005cinput"><xrefnodename>\input</xrefnodename></ref>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\LoadClass[<var>options list</var>]&lbrace;<var>class name</var>&rbrace;[<var>release date</var>]</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\LoadClassWithOptions&lbrace;<var>class name</var>&rbrace;[<var>release date</var>]</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="86">\LoadClass</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="87">\LoadClassWithOptions</indexterm></findex>
<para>Load a class, as with <code>\documentclass[<var>options
list</var>]&lbrace;<var>class name</var>&rbrace;[<var>release info</var>]</code>.  An example is
<code>\LoadClass[twoside]&lbrace;article&rbrace;</code>.
</para>
<para>The <var>options list</var>, if present, is a comma-separated list.  The
<var>release date</var> is optional.  If present it must have the form
<var>YYYY/MM/DD</var>.
<!-- c BTW, there are at-macros documented in macros2e.pdf to check the version -->
<!-- c and do some actions conditionnally on version later or not to some -->
<!-- c date. -->
</para>
<para>If you request a <var>release date</var> and the date of
the package installed on your system is earlier, then you get a warning
on the screen and in the log like <code>You have requested, on input
line 4, version `2038/01/19' of document class article, but only version
`2014/09/29 v1.4h Standard LaTeX document class' is available.</code>
</para>
<para>The command version <code>\LoadClassWithOptions</code> uses the list of
options for the current class.  This means it ignores any options passed
to it via <code>\PassOptionsToClass</code>.  This is a convenience command
that lets you build classes on existing ones, such as the standard
<code>article</code> class, without having to track which options were passed.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ExecuteOptions&lbrace;<var>options-list</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="88">\ExecuteOptions</indexterm></findex>
<para>For each option <var>option</var> in the <var>options-list</var>, in order, this command
executes the command <code>\ds&arobase;<var>option</var></code>.  If this command is not
defined then that option is silently ignored.
</para>
<para>It can be used to provide a default option list before
<code>\ProcessOptions</code>.  For example, if in a class file you want the
default to be 11pt fonts then you could specify
<code>\ExecuteOptions&lbrace;11pt&rbrace;\ProcessOptions\relax</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\NeedsTeXFormat&lbrace;<var>format</var>&rbrace;[<var>format date</var>]</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="89">\NeedsTeXFormat</indexterm></findex>
<para>Specifies the format that this class must be run under.  Often issued
as the first line of a class file, and most often used as:
<code>\NeedsTeXFormat&lbrace;LaTeX2e&rbrace;</code>.  When a document using that class is
processed, the format name given here must match the format that is
actually being run (including that the <var>format</var> string is case
sensitive).  If it does not match then execution stops with an error
like <samp>This file needs format `LaTeX2e' but this is `xxx'.</samp>
</para>
<para>To specify a version of the format that you know to have certain
features, include the optional <var>format date</var> on which those features
were implemented.  If present it must be in the form <code>YYYY/MM/DD</code>.
If the format version installed on your system is earlier than
<var>format date</var> then you get a warning like <samp>You have requested
release `2038/01/20' of LaTeX, but only release `2016/02/01' is
available.</samp>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\OptionNotUsed</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="90">\OptionNotUsed</indexterm></findex>
<para>Adds the current option to the list of unused options.  Can only be used
within the <var>code</var> argument of either <code>\DeclareOption</code> or
<code>\DeclareOption*</code>.
</para>
<!-- c I cannot reproduce this behavior as it is documented in clsguide. -->
<!-- c In the absence of a @code{\DeclareOption*} declaration, @LaTeX{} issues -->
<!-- c on the console a warning like @code{LaTeX Warning: Unused global -->
<!-- c option(s): [unusedoption].} with the list of not-used options when it -->
<!-- c reaches @code{\begin@{document@}}. -->

</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\PassOptionsToClass&lbrace;<var>option list</var>&rbrace;&lbrace;<var>class name</var>&rbrace;</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\PassOptionsToPackage&lbrace;<var>option list</var>&rbrace;&lbrace;<var>package name</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="91">\PassOptionsToClass</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="92">\PassOptionsToPackage</indexterm></findex>
<para>Adds the options in the comma-separated list <var>option list</var> to the
options used by any future <code>\RequirePackage</code> or <code>\usepackage</code>
command for package <var>package name</var> or the class <var>class name</var>.
</para>
<para>The reason for these commands is: you may load a package any number of
times with no options but if you want options then you may only supply
them when you first load the package.  Loading a package with options
more than once will get you an error like <code>Option clash for package
foo.</code> (&latex; throws an error even if there is no conflict between the
options.)
</para>
<para>If your own code is bringing in a package twice then you can collapse
that to once, for example replacing the two
<code>\RequirePackage[landscape]&lbrace;geometry&rbrace;\RequirePackage[margins=1in]&lbrace;geometry&rbrace;</code>
with the single
<code>\RequirePackage[landscape,margins=1in]&lbrace;geometry&rbrace;</code>.  But if you
are loading a package that in turn loads another package then you need
to queue up the options you desire for this other package.  For
instance, suppose the package <code>foo</code> loads the package
<code>geometry</code>.  Instead of
<code>\RequirePackage&lbrace;foo&rbrace;\RequirePackage[draft]&lbrace;graphics&rbrace;</code> you must
write <code>\PassOptionsToPackage&lbrace;draft&rbrace;&lbrace;graphics&rbrace;
\RequirePackage&lbrace;foo&rbrace;</code>.  (If <code>foo.sty</code> loads an option in conflict
with what you want then you may have to look into altering its source.)
</para>
<para>These commands are useful for general users as well as class and package
writers.  For instance, suppose a user wants to load the <code>graphicx</code>
package with the option <code>draft</code> and also wants to use a class
<code>foo</code> that loads the <code>graphicx</code> package, but without that
option. The user could start their &latex; file with
<code>\PassOptionsToPackage&lbrace;draft&rbrace;&lbrace;graphicx&rbrace;\documentclass&lbrace;foo&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ProcessOptions</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ProcessOptions*<var>\&arobase;options</var></itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="93">\ProcessOptions</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="94">\ProcessOptions*</indexterm></findex>
<para>Execute the code for each option that the user has invoked.  Include it
in the class file as <code>\ProcessOptions\relax</code> (because of the
existence of the starred command).
</para>
<para>Options come in two types.  <dfn>Local options</dfn> have been specified for this
particular package in the <var>options</var> argument of
<code>\PassOptionsToPackage&lbrace;<var>options</var>&rbrace;</code>,
<code>\usepackage[<var>options</var>]</code>, or
<code>\RequirePackage[<var>options</var>]</code>.  <dfn>Global options</dfn> are those given
by the class user in <code>\documentclass[<var>options</var>]</code> (If an option
is specified both locally and globally then it is local.)
</para>
<para>When <code>\ProcessOptions</code> is called for a package <file>pkg.sty</file>, the
following happens:
</para><enumerate first="1" endspaces=" ">
<listitem>
<para>For each option <var>option</var> so far declared
with <code>\DeclareOption</code>, it looks to see if that option is either a
global or a local option for <code>pkg</code>. If so then it executes the
declared code.  This is done in the order in which these options were
given in <file>pkg.sty</file>.
</para></listitem><listitem>
<para>For each remaining local option, it executes the command
<code>\ds&arobase;</code><var>option</var> if it has been defined somewhere (other than by
a <code>\DeclareOption</code>); otherwise, it executes the default option code
given in <code>\DeclareOption*</code>. If no default option code has been
declared then it gives an error message.  This is done in the order in
which these options were specified.
</para></listitem></enumerate>

<para>When <code>\ProcessOptions</code> is called for a class it works in the same
way except that all options are local, and the default <var>code</var> for
<code>\DeclareOption*</code> is <code>\OptionNotUsed</code> rather than an error.
</para>
<para>The starred version <code>\ProcessOptions*</code> executes the
options in the order specified in the calling commands, rather than in
the order of declaration in the class or package. For a package this
means that the global options are processed first.
</para>

</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ProvidesClass&lbrace;<var>class name</var>&rbrace;[<var>release date</var> <var>brief additional information</var>]</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ProvidesClass&lbrace;<var>class name</var>&rbrace;[<var>release date</var>]</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ProvidesPackage&lbrace;<var>package name</var>&rbrace;[<var>release date</var> <var>brief additional information</var>]</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ProvidesPackage&lbrace;<var>package name</var>&rbrace;[<var>release date</var>]</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="95">\ProvidesClass</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="96">\ProvidesPackage</indexterm></findex>
<para>Identifies the class or package, printing a message to the screen and the log file.
</para>
<para>When a user writes <code>\documentclass&lbrace;smcmemo&rbrace;</code> then &latex; loads
the file <file>smcmemo.cls</file>.  Similarly, a user writing
<code>\usepackage&lbrace;test&rbrace;</code> prompts &latex; to load the file
<code>test.sty</code>.  If the name of the file does not match the declared
class or package name then you get a warning.  Thus, if you invoke
<code>\documentclass&lbrace;smcmemo&rbrace;</code>, and the file <file>smcmemo.cls</file> has
the statement <code>\ProvidesClass&lbrace;xxx&rbrace;</code> then you get a warning like
<code>You have requested document class `smcmemo', but the document
class provides 'xxx'.</code>  This warning does not prevent &latex; from
processing the rest of the class file normally.
</para>
<para>If you include the optional argument, then you must include the date, before
the first space if any, and it must have the form <code>YYYY/MM/DD</code>. The rest
of the optional argument is free-form, although it traditionally identifies
the class, and is written to the screen during compilation and to the
log file.  Thus, if your file <file>smcmemo.cls</file> contains the line
<code>\ProvidesClass&lbrace;smcmemo&rbrace;[2008/06/01 v1.0 SMC memo class]</code> and your
document&textrsquo;s first line is <code>\documentclass&lbrace;smcmemo&rbrace;</code> then you will
see <code>Document Class: smcmemo 2008/06/01 v1.0 SMC memo class</code>.
</para>
<para>The date in the optional argument allows class and package users to ask
to be warned if the version of the class or package installed on their
system is earlier than <var>release date</var>, by using the optional arguments
such as <code>\documentclass&lbrace;smcmemo&rbrace;[2018/10/12]</code> or
<code>\usepackage&lbrace;foo&rbrace;[[2017/07/07]]</code>.  (Note that package users only
rarely include a date, and class users almost never do.)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ProvidesFile&lbrace;<var>file name</var>&rbrace;[<var>additional information</var>]</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="97">\ProvidesFile</indexterm></findex>
<para>Declare a file other than the main class and package files, such as
configuration files or font definition files.  Put this command in that
file and you get in the log a string like <code>File: test.config
2017/10/12 config file for test.cls</code> for <var>file name</var> equal to
<samp>test.config</samp> and <var>additional information</var> equal to
<samp>2017/10/12 config file for test.cls</samp>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\RequirePackage[<var>option list</var>]&lbrace;<var>package name</var>&rbrace;[<var>release date</var>]</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\RequirePackageWithOptions&lbrace;<var>package name</var>&rbrace;[<var>release date</var>]</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="98">\RequirePackage</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="99">\RequirePackageWithOptions</indexterm></findex>
<para>Load a package, like the document author command <code>\usepackage</code>.
<xref label="Additional-packages"><xrefnodename>Additional packages</xrefnodename></xref>. An example is
<code>\RequirePackage[landscape,margin=1in]&lbrace;geometry&rbrace;</code>.  Note that the
&latex; development team strongly recommends use of these commands over
Plain&nbsp;&tex;&textrsquo;s <code>\input</code>; see the Class Guide.
</para>
<para>The <var>option list</var>, if present, is a comma-separated list.  The
<var>release date</var>, if present, must have the form <var>YYYY/MM/DD</var>.  If
the release date of the package as installed on your system is earlier
than <var>release date</var> then you get a warning like <code>You have
requested, on input line 9, version `2017/07/03' of package jhtest, but
only version `2000/01/01' is available</code>.
</para>
<para>The <code>\RequirePackageWithOptions</code> version uses the list of options
for the current class.  This means it ignores any options passed to it
via <code>\PassOptionsToClass</code>.  This is a convenience command to allow
easily building classes on existing ones without having to track which
options were passed.
</para>
<para>The difference between <code>\usepackage</code> and <code>\RequirePackage</code> is
small.  The <code>\usepackage</code> command is intended for the document file
while <code>\RequirePackage</code> is intended for package and class files.
Thus, using <code>\usepackage</code> before the <code>\documentclass</code> command
causes &latex; to give error like <code>\usepackage before
\documentclass</code>, but you can use <code>\RequirePackage</code> there.
</para></tableitem></tableentry></table>


</subsection>
</section>
</chapter>
<node name="Fonts" spaces=" "><nodename>Fonts</nodename><nodenext automatic="on">Layout</nodenext><nodeprev automatic="on">Document classes</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Fonts</sectiontitle>
<anchor name="Typefaces">Typefaces</anchor><!-- c old name -->

<cindex index="cp" spaces=" "><indexterm index="cp" number="99">typefaces</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="100">fonts</indexterm></cindex>

<para>Two important aspects of selecting a <dfn>font</dfn> are specifying a size
and a style.  The &latex; commands for doing this are described here.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::                 ">Font styles</menunode><menudescription><pre xml:space="preserve">Select roman, italics, etc.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                  ">Font sizes</menunode><menudescription><pre xml:space="preserve">Select point size.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::     ">Low-level font commands</menunode><menudescription><pre xml:space="preserve">Select encoding, family, series, shape.
</pre></menudescription></menuentry></menu>


<node name="Font-styles" spaces=" "><nodename>Font styles</nodename><nodenext automatic="on">Font sizes</nodenext><nodeup automatic="on">Fonts</nodeup></node>
<section spaces=" "><sectiontitle>Font styles</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="101">font styles</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="102">type styles</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="103">styles of text</indexterm></cindex>

<para>The following type style commands are supported by &latex;.
</para>
<para>This first group of commands is typically used with an argument, as in
<code>\textit&lbrace;<var>text</var>&rbrace;</code>.  In the table below, the corresponding
command in parenthesis is the &textldquo;declaration form&textrdquo;, which takes no
arguments, as in <code>&lbrace;\itshape <var>text</var>&rbrace;</code>.  The scope of the
declaration form lasts until the next type style command or the end of
the current group.
</para>
<para>These commands, in both the argument form and the declaration form,
are cumulative; e.g., you can say either <code>\sffamily\bfseries</code> or
<code>\bfseries\sffamily</code> to get bold sans serif.
</para>
<para>You can alternatively use an environment form of the declarations; for
instance, <code>\begin&lbrace;ttfamily&rbrace;...\end&lbrace;ttfamily&rbrace;</code>.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="100">\nocorrlist</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="101">\nocorr</indexterm></findex>
<para>These font-switching commands automatically insert italic corrections
if needed.  (<xref label="_005c_002f"><xrefnodename>\/</xrefnodename></xref>, for the details of italic corrections.)
Specifically, they insert the italic correction unless the following
character is in the list <code>\nocorrlist</code>, which by default consists
of a period and a comma.  To suppress the automatic insertion of
italic correction, use <code>\nocorr</code> at the start or end of the
command argument, such as <code>\textit&lbrace;\nocorr text&rbrace;</code> or
<code>\textsc&lbrace;text \nocorr&rbrace;</code>.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">\textrm (\rmfamily)</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="102">\textrm</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="103">\rmfamily</indexterm></findex>
<para>Roman.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\textit (\itshape)</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="104">\textit</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="105">\itshape</indexterm></findex>
<para>Italics.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\textmd (\mdseries)</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="106">\textmd</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="107">\mdseries</indexterm></findex>
<para>Medium weight (default).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\textbf (\bfseries)</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="108">\textbf</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="109">\bfseries</indexterm></findex>
<para>Boldface.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\textup (\upshape)</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="110">\textup</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="111">\upshape</indexterm></findex>
<para>Upright (default).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\textsl (\slshape)</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="112">\textsl</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="113">\slshape</indexterm></findex>
<para>Slanted.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\textsf (\sffamily)</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="114">\textsf</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="115">\sffamily</indexterm></findex>
<para>Sans serif.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\textsc (\scshape)</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="116">\textsc</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="117">\scshape</indexterm></findex>
<para>Small caps.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\texttt (\ttfamily)</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="118">\texttt</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="119">\ttfamily</indexterm></findex>
<para>Typewriter.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\textnormal (\normalfont)</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="120">\textnormal</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="121">\normalfont</indexterm></findex>
<para>Main document font.
</para>
</tableitem></tableentry></table>

<cindex index="cp" spaces=" "><indexterm index="cp" number="104">emphasis</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="122">\emph</indexterm></findex>
<para>Although it also changes fonts, the <code>\emph&lbrace;<var>text</var>&rbrace;</code> command
is semantic, for text to be emphasized, and should not be used as a
substitute for <code>\textit</code>.  For example, <code>\emph&lbrace;<var>start
text</var> \emph&lbrace;<var>middle text</var>&rbrace; <var>end text</var>&rbrace;</code> will result in the
<var>start text</var> and <var>end text</var> in italics, but <var>middle text</var>
will be in roman.
</para>
<para>&latex; also provides the following commands, which unconditionally
switch to the given style, that is, are <emph>not</emph> cumulative.  Also,
they are used differently than the above commands:
<code>&lbrace;\<var>cmd</var>...&rbrace;</code> instead of <code>\<var>cmd</var>&lbrace;...&rbrace;</code>.  These
are two unrelated constructs.
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="123">\bf</indexterm>\bf</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="105">bold font</indexterm></cindex>
<para>Switch to bold face.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="124">\cal</indexterm>\cal</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="106">script letters for math</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="107">calligraphic letters for math</indexterm></cindex>
<para>Switch to calligraphic letters for math.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="125">\it</indexterm>\it</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="108">italic font</indexterm></cindex>
<para>Italics.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="126">\rm</indexterm>\rm</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="109">roman font</indexterm></cindex>
<para>Roman.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="127">\sc</indexterm>\sc</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="110">small caps font</indexterm></cindex>
<para>Small caps.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="128">\sf</indexterm>\sf</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="111">sans serif font</indexterm></cindex>
<para>Sans serif.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="129">\sl</indexterm>\sl</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="112">slanted font</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="113">oblique font</indexterm></cindex>
<para>Slanted (oblique).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="130">\tt</indexterm>\tt</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="114">typewriter font</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="115">monospace font</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="116">fixed-width font</indexterm></cindex>
<para>Typewriter (monospace, fixed-width).
</para>
</tableitem></tableentry></ftable>

<para>The <code>\em</code> command is the unconditional version of <code>\emph</code>.
</para>
<para>(Some people consider the unconditional font-switching commands, such
as <code>\tt</code>, obsolete and that only the cumulative commands
(<code>\texttt</code>) should be used.  Others think that both sets of
commands have their place and sometimes an unconditional font switch
is precisely what you want; for one example,
<pxref label="description"><xrefnodename>description</xrefnodename><xrefprinteddesc><code>description</code></xrefprinteddesc></pxref>.)
</para>
<para>The following commands are for use in math mode.  They are not
cumulative, so <code>\mathbf&lbrace;\mathit&lbrace;<var>symbol</var>&rbrace;&rbrace;</code> does not
create a boldface and italic <var>symbol</var>; instead, it will just be in
italics.  This is because typically math symbols need consistent
typographic treatment, regardless of the surrounding environment.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">\mathrm</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="131">\mathrm</indexterm></findex>
<para>Roman, for use in math mode.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\mathbf</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="132">\mathbf</indexterm></findex>
<para>Boldface, for use in math mode.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\mathsf</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="133">\mathsf</indexterm></findex>
<para>Sans serif, for use in math mode.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\mathtt</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="134">\mathtt</indexterm></findex>
<para>Typewriter, for use in math mode.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\mathit</itemformat></item>
<itemx spaces=" "><itemformat command="code">(\mit)</itemformat></itemx>
</tableterm><tableitem><para>Italics, for use in math mode.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\mathnormal</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="135">\mathnormal</indexterm></findex>
<para>For use in math mode, e.g., inside another type style declaration.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\mathcal</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="136">\mathcal</indexterm></findex>
<para>Calligraphic letters, for use in math mode.
</para>
</tableitem></tableentry></table>

<findex index="fn" spaces=" "><indexterm index="fn" number="137">\mathversion</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="117">math, bold</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="118">bold math</indexterm></cindex>
<para>In addition, the command <code>\mathversion&lbrace;bold&rbrace;</code> can be used for
switching to bold letters and symbols in
formulas. <code>\mathversion&lbrace;normal&rbrace;</code> restores the default.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="138">\oldstylenums</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="119">numerals, old-style</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="120">old-style numerals</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="121">lining numerals</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="122"><r>package</r>, <code>textcomp</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="123"><code>textcomp</code> <r>package</r></indexterm></cindex>

<para>Finally, the command <code>\oldstylenums&lbrace;<var>numerals</var>&rbrace;</code> will typeset
so-called &textldquo;old-style&textrdquo; numerals, which have differing heights and
depths (and sometimes widths) from the standard &textldquo;lining&textrdquo; numerals,
which all have the same height as uppercase letters.  &latex;&textrsquo;s
default fonts support this, and will respect <code>\textbf</code> (but not
other styles; there are no italic old-style numerals in Computer
Modern).  Many other fonts have old-style numerals also; sometimes the
<code>textcomp</code> package must be loaded, and sometimes package options
are provided to make them the default.  FAQ entry:
<url><urefurl>http://www.tex.ac.uk/cgi-bin/texfaq2html?label=osf</urefurl></url>.
</para>

</section>
<node name="Font-sizes" spaces=" "><nodename>Font sizes</nodename><nodenext automatic="on">Low-level font commands</nodenext><nodeprev automatic="on">Font styles</nodeprev><nodeup automatic="on">Fonts</nodeup></node>
<section spaces=" "><sectiontitle>Font sizes</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="124">font sizes</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="125">typeface sizes</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="126">sizes of text</indexterm></cindex>

<para>The following standard type size commands are supported by &latex;.
The table shows the command name and the corresponding actual font
size used (in points) with the <samp>10pt</samp>, <samp>11pt</samp>, and
<samp>12pt</samp> document size options, respectively (<pxref label="Document-class-options"><xrefnodename>Document class
options</xrefnodename></pxref>).
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="139">\tiny</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="140">\scriptsize</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="141">\footnotesize</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="142">\small</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="143">\normalsize</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="144">\large</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="145">\Large</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="146">\LARGE</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="147">\huge</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="148">\Huge</indexterm></findex>

<multitable spaces=" " endspaces=" "><columnprototypes><columnprototype bracketed="on"><code>\normalsize</code> (default)</columnprototype> <columnprototype bracketed="on">24.88</columnprototype> <columnprototype bracketed="on">24.88</columnprototype> <columnprototype bracketed="on">24.88</columnprototype></columnprototypes>
<thead><row><entry command="headitem" spaces=" "><para>Command  </para></entry><entry command="tab" spaces=" "><para><code>10pt</code>  </para></entry><entry command="tab" spaces=" "><para><code>11pt</code>  </para></entry><entry command="tab" spaces=" "><para><code>12pt</code>
</para></entry></row></thead><tbody><row><entry command="item" spaces=" "><para><code>\tiny</code>
</para></entry><entry command="tab" spaces=" "><para>5          </para></entry><entry command="tab" spaces=" "><para>6          </para></entry><entry command="tab" spaces=" "><para>6
</para></entry></row><row><entry command="item" spaces=" "><para><code>\scriptsize</code>
</para></entry><entry command="tab" spaces=" "><para>7          </para></entry><entry command="tab" spaces=" "><para>8          </para></entry><entry command="tab" spaces=" "><para>8
</para></entry></row><row><entry command="item" spaces=" "><para><code>\footnotesize</code>
</para></entry><entry command="tab" spaces=" "><para>8          </para></entry><entry command="tab" spaces=" "><para>9          </para></entry><entry command="tab" spaces=" "><para>10
</para></entry></row><row><entry command="item" spaces=" "><para><code>\small</code>
</para></entry><entry command="tab" spaces=" "><para>9          </para></entry><entry command="tab" spaces=" "><para>10         </para></entry><entry command="tab" spaces=" "><para>10.95
</para></entry></row><row><entry command="item" spaces=" "><para><code>\normalsize</code> (default)
</para></entry><entry command="tab" spaces=" "><para>10         </para></entry><entry command="tab" spaces=" "><para>10.95      </para></entry><entry command="tab" spaces=" "><para>12
</para></entry></row><row><entry command="item" spaces=" "><para><code>\large</code>
</para></entry><entry command="tab" spaces=" "><para>12         </para></entry><entry command="tab" spaces=" "><para>12         </para></entry><entry command="tab" spaces=" "><para>14.4
</para></entry></row><row><entry command="item" spaces=" "><para><code>\Large</code>
</para></entry><entry command="tab" spaces=" "><para>14.4       </para></entry><entry command="tab" spaces=" "><para>14.4       </para></entry><entry command="tab" spaces=" "><para>17.28
</para></entry></row><row><entry command="item" spaces=" "><para><code>\LARGE</code>
</para></entry><entry command="tab" spaces=" "><para>17.28      </para></entry><entry command="tab" spaces=" "><para>17.28      </para></entry><entry command="tab" spaces=" "><para>20.74
</para></entry></row><row><entry command="item" spaces=" "><para><code>\huge</code>
</para></entry><entry command="tab" spaces=" "><para>20.74      </para></entry><entry command="tab" spaces=" "><para>20.74      </para></entry><entry command="tab" spaces=" "><para>24.88
</para></entry></row><row><entry command="item" spaces=" "><para><code>\Huge</code>
</para></entry><entry command="tab" spaces=" "><para>24.88      </para></entry><entry command="tab" spaces=" "><para>24.88      </para></entry><entry command="tab" spaces=" "><para>24.88
</para></entry></row></tbody></multitable>

<para>The commands as listed here are &textldquo;declaration forms&textrdquo;. The scope of
the declaration form lasts until the next type style command or the
end of the current group.  You can also use the environment form of
these commands; for instance, <code>\begin&lbrace;tiny&rbrace;...\end&lbrace;tiny&rbrace;</code>.
</para>

</section>
<node name="Low_002dlevel-font-commands" spaces=" "><nodename>Low-level font commands</nodename><nodeprev automatic="on">Font sizes</nodeprev><nodeup automatic="on">Fonts</nodeup></node>
<section spaces=" "><sectiontitle>Low-level font commands</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="127">low-level font commands</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="128">font commands, low-level</indexterm></cindex>

<para>These commands are primarily intended for writers of macros and
packages.  The commands listed here are only a subset of the available
ones.
<!-- c xx but it should be complete -->
<!-- c xx something about ultimately reading ENCFAM.fd? -->
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">\fontencoding&lbrace;<var>encoding</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="149">\fontencoding</indexterm></findex>
<para>Select the font encoding, the encoding of the output font. There are a
large number of valid encodings.  The most common are <code>OT1</code>,
Knuth&textrsquo;s original encoding for Computer Modern (the default), and
<code>T1</code>, also known as the Cork encoding, which has support for the
accented characters used by the most widespread European languages
(German, French, Italian, Polish and others), which allows &tex; to
hyphenate words containing accented letters. For more, see
<url><urefurl>https://ctan.org/pkg/encguide</urefurl></url>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\fontfamily&lbrace;<var>family</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="150">\fontfamily</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="129">families, of fonts</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="130">font catalogue</indexterm></cindex>
<para>Select the font family.  The web page
<url><urefurl>http://www.tug.dk/FontCatalogue/</urefurl></url> provides one way to browse
through many of the fonts easily used with &latex;.  Here are
examples of some common families:
</para>
<multitable spaces=" " endspaces=" "><columnprototypes><columnprototype bracketed="on">font</columnprototype> <columnprototype bracketed="on">Computer Modern Typewriter XXXX</columnprototype></columnprototypes>
<tbody><row><entry command="item" spaces=" "><para><code>pag</code>
</para></entry><entry command="tab" spaces=" "><para>Avant Garde
</para></entry></row><row><entry command="item" spaces=" "><para><code>fvs</code>
</para></entry><entry command="tab" spaces=" "><para>Bitstream Vera Sans
</para></entry></row><row><entry command="item" spaces=" "><para><code>pbk</code>
</para></entry><entry command="tab" spaces=" "><para>Bookman
</para></entry></row><row><entry command="item" spaces=" "><para><code>bch</code>
</para></entry><entry command="tab" spaces=" "><para>Charter
</para></entry></row><row><entry command="item" spaces=" "><para><code>ccr</code>
</para></entry><entry command="tab" spaces=" "><para>Computer Concrete
</para></entry></row><row><entry command="item" spaces=" "><para><code>cmr</code>
</para></entry><entry command="tab" spaces=" "><para>Computer Modern
</para></entry></row><row><entry command="item" spaces=" "><para><code>cmss</code>
</para></entry><entry command="tab" spaces=" "><para>Computer Modern Sans Serif
</para></entry></row><row><entry command="item" spaces=" "><para><code>cmtt</code>
</para></entry><entry command="tab" spaces=" "><para>Computer Modern Typewriter
</para></entry></row><row><entry command="item" spaces=" "><para><code>pcr</code>
</para></entry><entry command="tab" spaces=" "><para>Courier
</para></entry></row><row><entry command="item" spaces=" "><para><code>phv</code>
</para></entry><entry command="tab" spaces=" "><para>Helvetica
</para></entry></row><row><entry command="item" spaces=" "><para><code>fi4</code>
</para></entry><entry command="tab" spaces=" "><para>Inconsolata
</para></entry></row><row><entry command="item" spaces=" "><para><code>lmr</code>
</para></entry><entry command="tab" spaces=" "><para>Latin Modern
</para></entry></row><row><entry command="item" spaces=" "><para><code>lmss</code>
</para></entry><entry command="tab" spaces=" "><para>Latin Modern Sans
</para></entry></row><row><entry command="item" spaces=" "><para><code>lmtt</code>
</para></entry><entry command="tab" spaces=" "><para>Latin Modern Typewriter
</para></entry></row><row><entry command="item" spaces=" "><para><code>pnc</code>
</para></entry><entry command="tab" spaces=" "><para>New Century Schoolbook
</para></entry></row><row><entry command="item" spaces=" "><para><code>ppl</code>
</para></entry><entry command="tab" spaces=" "><para>Palatino
</para></entry></row><row><entry command="item" spaces=" "><para><code>ptm</code>
</para></entry><entry command="tab" spaces=" "><para>Times
</para></entry></row><row><entry command="item" spaces=" "><para><code>uncl</code>
</para></entry><entry command="tab" spaces=" "><para>Uncial
</para></entry></row><row><entry command="item" spaces=" "><para><code>put</code>
</para></entry><entry command="tab" spaces=" "><para>Utopia
</para></entry></row><row><entry command="item" spaces=" "><para><code>pzc</code>
</para></entry><entry command="tab" spaces=" "><para>Zapf Chancery
</para></entry></row></tbody></multitable>


</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\fontseries&lbrace;<var>series</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="151">\fontseries</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="131">series, of fonts</indexterm></cindex>
<para>Select the font series.  A <dfn>series</dfn> combines a <dfn>weight</dfn> and a
<dfn>width</dfn>.  Typically, a font supports only a few of the possible
combinations.  Some common combined series values include:
</para>
<multitable spaces=" " endspaces=" "><columnprototypes><columnprototype bracketed="on">xx</columnprototype> <columnprototype bracketed="on">Medium (normal)xx</columnprototype></columnprototypes>
<tbody><row><entry command="item" spaces=" "><para><code>m</code>
</para></entry><entry command="tab" spaces=" "><para>Medium (normal)
</para></entry></row><row><entry command="item" spaces=" "><para><code>b</code>
</para></entry><entry command="tab" spaces=" "><para>Bold
</para></entry></row><row><entry command="item" spaces=" "><para><code>c</code>
</para></entry><entry command="tab" spaces=" "><para>Condensed
</para></entry></row><row><entry command="item" spaces=" "><para><code>bc</code>
</para></entry><entry command="tab" spaces=" "><para>Bold condensed
</para></entry></row><row><entry command="item" spaces=" "><para><code>bx</code>
</para></entry><entry command="tab" spaces=" "><para>Bold extended
</para></entry></row></tbody></multitable>

<cindex index="cp" spaces=" "><indexterm index="cp" number="132">weights, of fonts</indexterm></cindex>
<para>The possible values for weight, individually, are:
</para>
<multitable spaces=" " endspaces=" "><columnprototypes><columnprototype bracketed="on">xx</columnprototype> <columnprototype bracketed="on">Medium (normal) xx</columnprototype></columnprototypes>
<tbody><row><entry command="item" spaces=" "><para><code>ul</code>
</para></entry><entry command="tab" spaces=" "><para>Ultra light
</para></entry></row><row><entry command="item" spaces=" "><para><code>el</code>
</para></entry><entry command="tab" spaces=" "><para>Extra light
</para></entry></row><row><entry command="item" spaces=" "><para><code>l</code>
</para></entry><entry command="tab" spaces=" "><para>Light
</para></entry></row><row><entry command="item" spaces=" "><para><code>sl</code>
</para></entry><entry command="tab" spaces=" "><para>Semi light
</para></entry></row><row><entry command="item" spaces=" "><para><code>m</code>
</para></entry><entry command="tab" spaces=" "><para>Medium (normal)
</para></entry></row><row><entry command="item" spaces=" "><para><code>sb</code>
</para></entry><entry command="tab" spaces=" "><para>Semi bold
</para></entry></row><row><entry command="item" spaces=" "><para><code>b</code>
</para></entry><entry command="tab" spaces=" "><para>Bold
</para></entry></row><row><entry command="item" spaces=" "><para><code>eb</code>
</para></entry><entry command="tab" spaces=" "><para>Extra bold
</para></entry></row><row><entry command="item" spaces=" "><para><code>ub</code>
</para></entry><entry command="tab" spaces=" "><para>Ultra bold
</para></entry></row></tbody></multitable>
 
<cindex index="cp" spaces=" "><indexterm index="cp" number="133">widths, of fonts</indexterm></cindex>
<para>The possible values for width, individually, are (the meaning and
relationship of these terms varies with individual typefaces):
</para>

<multitable spaces=" " endspaces=" "><columnprototypes><columnprototype bracketed="on">xx</columnprototype> <columnprototype bracketed="on">Ultra condensed</columnprototype></columnprototypes>
<tbody><row><entry command="item" spaces=" "><para><code>uc</code>
</para></entry><entry command="tab" spaces=" "><para>Ultra condensed
</para></entry></row><row><entry command="item" spaces=" "><para><code>ec</code>
</para></entry><entry command="tab" spaces=" "><para>Extra condensed
</para></entry></row><row><entry command="item" spaces=" "><para><code>c</code>
</para></entry><entry command="tab" spaces=" "><para>Condensed
</para></entry></row><row><entry command="item" spaces=" "><para><code>sc</code>
</para></entry><entry command="tab" spaces=" "><para>Semi condensed
</para></entry></row><row><entry command="item" spaces=" "><para><code>m</code>
</para></entry><entry command="tab" spaces=" "><para>Medium
</para></entry></row><row><entry command="item" spaces=" "><para><code>sx</code>
</para></entry><entry command="tab" spaces=" "><para>Semi expanded
</para></entry></row><row><entry command="item" spaces=" "><para><code>x</code>
</para></entry><entry command="tab" spaces=" "><para>Expanded
</para></entry></row><row><entry command="item" spaces=" "><para><code>ex</code>
</para></entry><entry command="tab" spaces=" "><para>Extra expanded
</para></entry></row><row><entry command="item" spaces=" "><para><code>ux</code>
</para></entry><entry command="tab" spaces=" "><para>Ultra expanded
</para></entry></row></tbody></multitable>


<para>When forming the <var>series</var> string from the weight and width, drop the
<code>m</code> that stands for medium weight or medium width, unless both
weight and width are <code>m</code>, in which case use just one
(<samp><code>m</code></samp>).
</para> 
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\fontshape&lbrace;<var>shape</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="152">\fontshape</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="134">shapes, of fonts</indexterm></cindex>
<para>Select font shape. Valid shapes are:
</para>
<multitable spaces=" " endspaces=" "><columnprototypes><columnprototype bracketed="on">xx</columnprototype> <columnprototype bracketed="on">Slanted (oblique)xx</columnprototype></columnprototypes>
<tbody><row><entry command="item" spaces=" "><para><code>n</code>
</para></entry><entry command="tab" spaces=" "><para>Upright (normal)
</para></entry></row><row><entry command="item" spaces=" "><para><code>it</code>
</para></entry><entry command="tab" spaces=" "><para>Italic
</para></entry></row><row><entry command="item" spaces=" "><para><code>sl</code>
</para></entry><entry command="tab" spaces=" "><para>Slanted (oblique)
</para></entry></row><row><entry command="item" spaces=" "><para><code>sc</code>
</para></entry><entry command="tab" spaces=" "><para>Small caps
</para></entry></row><row><entry command="item" spaces=" "><para><code>ui</code>
</para></entry><entry command="tab" spaces=" "><para>Upright italics
</para></entry></row><row><entry command="item" spaces=" "><para><code>ol</code>
</para></entry><entry command="tab" spaces=" "><para>Outline
</para></entry></row></tbody></multitable>


<para>The two last shapes are not available for most font families, and
small caps are often missing as well.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\fontsize&lbrace;<var>size</var>&rbrace;&lbrace;<var>skip</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="153">\fontsize</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="135">font size</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="154">\baselineskip</indexterm></findex>
<para>Set the font size and the line spacing.  The unit of both parameters
defaults to points (<code>pt</code>).  The line spacing is the nominal
vertical space between lines, baseline to baseline.  It is stored in the
parameter <code>\baselineskip</code>.  The default <code>\baselineskip</code> for
the Computer Modern typeface is 1.2 times the <code>\fontsize</code>.
Changing <code>\baselineskip</code> directly is inadvisable since its value is
reset every time a size change happens; see <code>\baselinestretch</code>, next.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\baselinestretch</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="155">\baselinestretch</indexterm></findex>
<para>&latex; multiplies the line spacing by the value of the
<code>\baselinestretch</code> parameter; the default factor is 1.  A change
takes effect when <code>\selectfont</code> (see below) is called.  You can
make a line skip change happen for the entire document, for instance
doubling it, by doing <code>\renewcommand&lbrace;\baselinestretch&rbrace;&lbrace;2.0&rbrace;</code> in
the preamble.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="136"><r>package</r>, <code>setspace</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="137"><code>setspace</code> <r>package</r></indexterm></cindex>

<cindex index="cp" spaces=" "><indexterm index="cp" number="138">double spacing</indexterm></cindex>
<para>However, the best way to double-space a document is to use the
<file>setspace</file> package.  In addition to offering a number of spacing
options, this package keeps the line spacing single-spaced in places
where that is typically desirable, such as footnotes and figure
captions.  See the package documentation.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\linespread&lbrace;<var>factor</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="156">\linespread</indexterm></findex>
<para>Equivalent to
<code>\renewcommand&lbrace;\baselinestretch&rbrace;&lbrace;<var>factor</var>&rbrace;</code>, and
therefore must be followed by <code>\selectfont</code> to have any effect.
Best specified in the preamble, or use the <code>setspace</code> package, as
just described.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\selectfont</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="157">\selectfont</indexterm></findex>
<para>The effects of the font commands described above do not happen until
<code>\selectfont</code> is called, as in
<code>\fontfamily&lbrace;<var>familyname</var>&rbrace;\selectfont</code>.  It is often useful
to put this in a macro:&linebreak;
<code>\newcommand*&lbrace;\myfont&rbrace;&lbrace;\fontfamily&lbrace;<var>familyname</var>&rbrace;\selectfont&rbrace;</code>&linebreak;
(<pxref label="_005cnewcommand-_0026-_005crenewcommand"><xrefnodename>\newcommand &amp; \renewcommand</xrefnodename></pxref>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\usefont&lbrace;<var>enc</var>&rbrace;&lbrace;<var>family</var>&rbrace;&lbrace;<var>series</var>&rbrace;&lbrace;<var>shape</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="158">\usefont</indexterm></findex>
<para>The same as invoking <code>\fontencoding</code>, <code>\fontfamily</code>,
<code>\fontseries</code> and <code>\fontshape</code> with the given parameters,
followed by <code>\selectfont</code>.  For example:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usefont&lbrace;ot1&rbrace;&lbrace;cmr&rbrace;&lbrace;m&rbrace;&lbrace;n&rbrace;
</pre></example>

</tableitem></tableentry></table>


</section>
</chapter>
<node name="Layout" spaces=" "><nodename>Layout</nodename><nodenext automatic="on">Sectioning</nodenext><nodeprev automatic="on">Fonts</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Layout</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="139">layout commands</indexterm></cindex>

<para>Commands for controlling the general page layout.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::              ">\onecolumn</menunode><menudescription><pre xml:space="preserve">Use one-column layout.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">\twocolumn</menunode><menudescription><pre xml:space="preserve">Use two-column layout.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">\flushbottom</menunode><menudescription><pre xml:space="preserve">Make all text pages the same height.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           ">\raggedbottom</menunode><menudescription><pre xml:space="preserve">Allow text pages of differing height.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::  ">Page layout parameters</menunode><menudescription><pre xml:space="preserve"><code>\headheight</code> <code>\footskip</code>.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                  ">Floats</menunode><menudescription><pre xml:space="preserve">Figures, tables, etc.
</pre></menudescription></menuentry></menu>


<node name="_005conecolumn" spaces=" "><nodename>\onecolumn</nodename><nodenext automatic="on">\twocolumn</nodenext><nodeup automatic="on">Layout</nodeup></node>
<section spaces=" "><sectiontitle><code>\onecolumn</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="159">\onecolumn</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="140">one-column output</indexterm></cindex>

<para>Start a new page and produce single-column output.  If the document is
given the class option <code>onecolumn</code> then this is the default
behavior (<pxref label="Document-class-options"><xrefnodename>Document class options</xrefnodename></pxref>).
</para>
<para>This command is fragile (<pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>).
</para>

</section>
<node name="_005ctwocolumn" spaces=" "><nodename>\twocolumn</nodename><nodenext automatic="on">\flushbottom</nodenext><nodeprev automatic="on">\onecolumn</nodeprev><nodeup automatic="on">Layout</nodeup></node>
<section spaces=" "><sectiontitle><code>\twocolumn</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="160">\twocolumn</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="141">multicolumn text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="142">two-column output</indexterm></cindex>

<para>Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\twocolumn
\twocolumn[<var>prelim one column text</var>]
</pre></example>

<para>Start a new page and produce two-column output. If the document is given
the class option <code>twocolumn</code> then this is the default
(<pxref label="Document-class-options"><xrefnodename>Document class options</xrefnodename></pxref>).
</para>
<para>If the optional <var>prelim one column text</var> argument
is present, it is typeset in one-column mode before the two-column
typesetting starts.
</para>
<para>This command is fragile (<pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>).
</para>
<para>These parameters control typesetting in two-column output:
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="161">\columnsep</indexterm>\columnsep</itemformat></item>
</tableterm><tableitem><para>The distance between columns. The default is 35pt.  Change it with a
command such as <code>\setlength&lbrace;\columnsep&rbrace;&lbrace;40pt&rbrace;</code> You must change
it before the two column environment starts; in the preamble is a good
place.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="162">\columnseprule</indexterm>\columnseprule</itemformat></item>
</tableterm><tableitem><para>The width of the rule between columns. The rule appears halfway between
the two columns.  The default is 0pt, meaning that there is no rule.
Change it with a command such as
<code>\setlength&lbrace;\columnseprule&rbrace;&lbrace;0.4pt&rbrace;</code>, before the two-column
environment starts.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="163">\columnwidth</indexterm>\columnwidth</itemformat></item>
</tableterm><tableitem><para>The width of a single column.  In one-column mode this is equal to
<code>\textwidth</code>.  In two-column mode by default &latex; sets the
width of each of the two columns to be half of <code>\textwidth</code> minus
<code>\columnsep</code>.
</para>
</tableitem></tableentry></ftable>

<para>In a two-column document, the starred environments <code>table*</code> and
<code>figure*</code> are two columns wide, whereas the unstarred environments
<code>table</code> and <code>figure</code> take up only one column (<pxref label="figure"><xrefnodename>figure</xrefnodename></pxref>
and <pxref label="table"><xrefnodename>table</xrefnodename></pxref>). &latex; places starred floats at the top of a page.
The following parameters control float behavior of two-column output.
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="164">\dbltopfraction</indexterm>\dbltopfraction</itemformat></item>
</tableterm><tableitem><para>The maximum fraction at the top of a two-column page that may be
occupied by two-column wide floats.  The default is 0.7, meaning that
the height of a <code>table*</code> or <code>figure*</code> environment must not
exceed <code>0.7\textheight</code> .  If the height of your starred float
environment exceeds this then you can take one of the following actions
to prevent it from floating all the way to the back of the document:
</para>
<itemize commandarg="bullet" spaces=" " endspaces=" "><itemprepend><formattingcommand command="bullet"/></itemprepend>
<listitem><prepend>&bullet;</prepend>
<para>Use the <code>[tp]</code> location specifier to tell LaTeX to try to put
the bulky float on a page by itself, as well as at the top of a page.
</para>
</listitem><listitem><prepend>&bullet;</prepend>
<para>Use the <code>[t!]</code> location specifier to override the effect of
<code>\dbltopfraction</code> for this particular float.
</para>
</listitem><listitem><prepend>&bullet;</prepend>
<para>Increase the value of <code>\dbltopfraction</code> to a suitably large number,
to avoid going to float pages so soon.
</para></listitem></itemize>

<para>You can redefine it, for instance with
<code>\renewcommand&lbrace;\dbltopfraction&rbrace;&lbrace;0.9&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="165">\dblfloatpagefraction</indexterm>\dblfloatpagefraction</itemformat></item>
</tableterm><tableitem><para>For a float page of two-column wide floats, this is the minimum fraction
that must be occupied by floats, limiting the amount of blank space.
&latex;&textrsquo;s default is <code>0.5</code>.  Change it with <code>\renewcommand</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="166">\dblfloatsep</indexterm>\dblfloatsep</itemformat></item>
</tableterm><tableitem><para>On a float page of two-column wide floats, this length is the distance
between floats, at both the top and bottom of the page.  The default is
<code>12pt plus2pt minus2pt</code> for a document set at <code>10pt</code> or
<code>11pt</code>, and <code>14pt plus2pt minus4pt</code> for a document set at
<code>12pt</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="167">\dbltextfloatsep</indexterm>\dbltextfloatsep</itemformat></item>
</tableterm><tableitem><para>This length is the distance between a multi-column float at the top or
bottom of a page and the main text.  The default is <code>20pt plus2pt
minus4pt</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="168">\dbltopnumber</indexterm>\dbltopnumber</itemformat></item>
</tableterm><tableitem><para>On a float page of two-column wide floats, this counter gives the
maximum number of floats allowed at the top of the page.  The &latex;
default is <code>2</code>.
</para>
</tableitem></tableentry></ftable>

<!-- c From egreg at http://tex.stackexchange.com/a/142232/339 -->
<para>This example uses <code>\twocolumn</code>&textrsquo;s optional argument of to create a
title that spans the two-column article:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\documentclass[twocolumn]&lbrace;article&rbrace;
\newcommand&lbrace;\authormark&rbrace;[1]&lbrace;\textsuperscript&lbrace;#1&rbrace;&rbrace;
\begin&lbrace;document&rbrace;
\twocolumn[&lbrace;% inside this optional argument goes one-column text
  \centering
  \LARGE The Title \\[1.5em]
  \large Author One\authormark&lbrace;1&rbrace;,
         Author Two\authormark&lbrace;2&rbrace;,
         Author Three\authormark&lbrace;1&rbrace; \\[1em]
  \normalsize
  \begin&lbrace;tabular&rbrace;&lbrace;p&lbrace;.2\textwidth&rbrace;&arobase;&lbrace;\hspace&lbrace;2em&rbrace;&rbrace;p&lbrace;.2\textwidth&rbrace;&rbrace;
    \authormark&lbrace;1&rbrace;Department one  &amp;\authormark&lbrace;2&rbrace;Department two \\ 
     School one                   &amp;School two 
  \end&lbrace;tabular&rbrace;\\[3em] % space below title part
  &rbrace;]

Two column text here.
</pre></example>


</section>
<node name="_005cflushbottom" spaces=" "><nodename>\flushbottom</nodename><nodenext automatic="on">\raggedbottom</nodenext><nodeprev automatic="on">\twocolumn</nodeprev><nodeup automatic="on">Layout</nodeup></node>
<section spaces=" "><sectiontitle><code>\flushbottom</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="169">\flushbottom</indexterm></findex>

<para>Make all pages in the documents after this declaration have the same
height, by stretching the vertical space where necessary to fill out the
page.  This is most often used when making two-sided documents since the
differences in facing pages can be glaring.
</para>
<para>If &tex; cannot satisfactorily stretch the vertical space in a page
then you get a message like <samp>Underfull \vbox (badness 10000) has
occurred while \output is active</samp>.  If you get that, one option is to
change to <code>\raggedbottom</code> (<pxref label="_005craggedbottom"><xrefnodename>\raggedbottom</xrefnodename></pxref>).  Alternatively,
you can adjust the <code>textheight</code> to make compatible pages, or you
can add some vertical stretch glue between lines or between paragraphs,
as in <code>\setlength&lbrace;\parskip&rbrace;&lbrace;0ex plus0.1ex&rbrace;</code>.  Your last option
is to, in a final editing stage, adjust the height of individual pages
(<pxref label="_005cenlargethispage"><xrefnodename>\enlargethispage</xrefnodename></pxref>).
</para>
<para>The <code>\flushbottom</code> state is the default only if you select the
<code>twoside</code> document class option (<pxref label="Document-class-options"><xrefnodename>Document class options</xrefnodename></pxref>).
</para>

</section>
<node name="_005craggedbottom" spaces=" "><nodename>\raggedbottom</nodename><nodenext automatic="on">Page layout parameters</nodenext><nodeprev automatic="on">\flushbottom</nodeprev><nodeup automatic="on">Layout</nodeup></node>
<section spaces=" "><sectiontitle><code>\raggedbottom</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="170">\raggedbottom</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="143">stretch, omitting vertical</indexterm></cindex>

<para>Make all later pages the natural height of the material on that page; no
rubber vertical lengths will be stretched.  Thus, in a two-sided
document the facing pages may be different heights.  This command can go
at any point in the document body.  See <ref label="_005cflushbottom"><xrefnodename>\flushbottom</xrefnodename></ref>.
</para>
<para>This is the default unless you select the <code>twoside</code> document class
option (<pxref label="Document-class-options"><xrefnodename>Document class options</xrefnodename></pxref>).
</para>

</section>
<node name="Page-layout-parameters" spaces=" "><nodename>Page layout parameters</nodename><nodenext automatic="on">Floats</nodenext><nodeprev automatic="on">\raggedbottom</nodeprev><nodeup automatic="on">Layout</nodeup></node>
<section spaces=" "><sectiontitle>Page layout parameters</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="144">page layout parameters</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="145">parameters, page layout</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="146">layout, page parameters for</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="147">header, parameters for</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="148">footer, parameters for</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="149">running header and footer</indexterm></cindex>

<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="171">\columnsep</indexterm>\columnsep</itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="172">\columnseprule</indexterm>\columnseprule</itemformat></itemx>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="173">\columnwidth</indexterm>\columnwidth</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="174">\columnsep</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="175">\columnseprule</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="176">\columnwidth</indexterm></findex>
<para>The distance between the two columns, the width of a rule between the
columns, and the width of the columns, when the document class option
<code>twocolumn</code> is in effect (<pxref label="Document-class-options"><xrefnodename>Document class options</xrefnodename></pxref>).
<xref label="_005ctwocolumn"><xrefnodename>\twocolumn</xrefnodename></xref>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="177">\headheight</indexterm>\headheight</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="178">\headheight</indexterm></findex>
<para>Height of the box that contains the running head.  The default in the
<code>article</code>, <code>report</code>, and <code>book</code> classes is <samp>12pt</samp>,
at all type sizes.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="179">\headsep</indexterm>\headsep</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="180">\headsep</indexterm></findex>
<para>Vertical distance between the bottom of the header line and the top of
the main text.  The default in the <code>article</code> and <code>report</code>
classes is <samp>25pt</samp>.  In the <code>book</code> class the default is: if the
document is set at 10pt then it is <samp>0.25in</samp>, and at 11pt and 12pt
it is <samp>0.275in</samp>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="181">\footskip</indexterm>\footskip</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="182">\footskip</indexterm></findex>
<para>Distance from the baseline of the last line of text to the baseline of
the page footer.  The default in the <code>article</code> and <code>report</code>
classes is <samp>30pt</samp>.  In the <code>book</code> class the default is: when
the type size is 10pt the default is <samp>0.35in</samp>, while at 11pt it is
<samp>0.38in</samp>, and at 12pt it is <samp>30pt</samp>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="183">\linewidth</indexterm>\linewidth</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="184">\linewidth</indexterm></findex>
<para>Width of the current line, decreased for each nested <code>list</code>
(<pxref label="list"><xrefnodename>list</xrefnodename></pxref>).  That is, the nominal value for <code>\linewidth</code> is to
equal <code>\textwidth</code> but for each nested list the <code>\linewidth</code>
is decreased by the sum of that list&textrsquo;s <code>\leftmargin</code> and
<code>\rightmargin</code> (<pxref label="itemize"><xrefnodename>itemize</xrefnodename></pxref>).
<!-- c The default varies with the font size, paper width, two-column mode, -->
<!-- c etc.  For an @code{article} document set in 10pt, the default is -->
<!-- c @samp{345pt}, while in two-column mode that becomes @samp{229.5pt}. -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="185">\marginparpush</indexterm>\marginparpush</itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="186">\marginsep</indexterm>\marginsep</itemformat></itemx>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="187">\marginparwidth</indexterm>\marginparwidth</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="188">\marginparpush</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="189">\marginsep</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="190">\marginparwidth</indexterm></findex>
<para>The minimum vertical space between two marginal notes, the horizontal
space between the text body and the marginal notes, and the horizontal
width of the notes.
</para>
<para>Normally marginal notes appear on the outside of the page, but the
declaration <code>\reversemarginpar</code> changes that (and
<code>\normalmarginpar</code> changes it back).
</para>
<para>The defaults for <code>\marginparpush</code> in both <code>book</code> and
<code>article</code> classes are: <samp>7pt</samp> if the document is set at 12pt,
and <samp>5pt</samp> if the document is set at 11pt or 10pt.
</para>
<para>For <code>\marginsep</code>, in <code>article</code> class the default is
<samp>10pt</samp> except if the document is set at 10pt and in two-column mode
where the default is <samp>11pt</samp>.
</para>
<para>For <code>\marginsep</code> in <code>book</code> class the default is <samp>10pt</samp> in
two-column mode and <samp>7pt</samp> in one-column mode.  
</para>
<para>For <code>\marginparwidth</code> in both <code>book</code> and <code>article</code>
classes, in two-column mode the default is 60% of <code>\paperwidth
&minus; \textwidth</code>, while in one-column mode it is 50% of that
distance.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="191">\oddsidemargin</indexterm>\oddsidemargin</itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="192">\evensidemargin</indexterm>\evensidemargin</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="193">\oddsidemargin</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="194">\evensidemargin</indexterm></findex>
<para>The <code>\oddsidemargin</code> is the extra distance between the left side of
the page and the text&textrsquo;s left margin, on odd-numbered pages when the
document class option <code>twoside</code> is chosen and on all pages when
<code>oneside</code> is in effect.  When <code>twoside</code> is in effect, on
even-numbered pages the extra distance on the left is
<code>evensidemargin</code>.
</para>
<para>&latex;&textrsquo;s default is that <code>\oddsidemargin</code> is 40% of the
difference between <code>\paperwidth</code> and <code>\textwidth</code>, and
<code>\evensidemargin</code> is the remainder.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="195">\paperheight</indexterm>\paperheight</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="196">\paperheight</indexterm></findex>
<para>The height of the paper, as distinct from the height of the print area.
It is normally set with a document class option, as in
<code>\documentclass[a4paper]&lbrace;article&rbrace;</code> (<pxref label="Document-class-options"><xrefnodename>Document class
options</xrefnodename></pxref>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="197">\paperwidth</indexterm>\paperwidth</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="198">\paperwidth</indexterm></findex>
<para>The width of the paper, as distinct from the width of the print area.
It is normally set with a document class option, as in
<code>\documentclass[a4paper]&lbrace;article&rbrace;</code> (<pxref label="Document-class-options"><xrefnodename>Document class
options</xrefnodename></pxref>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="199">\textheight</indexterm>\textheight</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="200">\textheight</indexterm></findex>
<para>The normal vertical height of the page body.  If the document is set at
a nominal type size of 10pt then for an <code>article</code> or <code>report</code>
the default is <samp>43\baselineskip</samp>, while for a <code>book</code> it is
<samp>41\baselineskip</samp>.  At a type size of 11pt the default is
<samp>38\baselineskip</samp> for all document classes.  At 12pt it is
<samp>36\baselineskip</samp> for all classes.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="201">\textwidth</indexterm>\textwidth</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="202">\textwidth</indexterm></findex>
<para>The full horizontal width of the entire page body.  For an
<code>article</code> or <code>report</code> document, the default is <samp>345pt</samp>
when the chosen type size is 10pt, the default is <samp>360pt</samp> at 11pt,
and it is <samp>390pt</samp> at 12pt.  For a <code>book</code> document, the default
is <samp>4.5in</samp> at a type size of 10pt, and <samp>5in</samp> at 11pt or 12pt.
</para>
<para>In multi-column output, <code>\textwidth</code> remains the width of the
entire page body, while <code>\columnwidth</code> is the width of one column
(<pxref label="_005ctwocolumn"><xrefnodename>\twocolumn</xrefnodename></pxref>).
</para>
<para>In lists (<pxref label="list"><xrefnodename>list</xrefnodename></pxref>), <code>\textwidth</code> remains the width of the
entire page body (and <code>\columnwidth</code> the width of the entire
column), while <code>\linewidth</code> may decrease for nested lists.
</para>
<para>Inside a minipage (<pxref label="minipage"><xrefnodename>minipage</xrefnodename></pxref>) or <code>\parbox</code>
(<pxref label="_005cparbox"><xrefnodename>\parbox</xrefnodename></pxref>), all the width-related parameters are set to the
specified width, and revert to their normal values at the end of the
<code>minipage</code> or <code>\parbox</code>.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="203">\hsize</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="204">\hsize</indexterm></findex>
<para>This entry is included for completeness: <code>\hsize</code> is the &tex;
primitive parameter used when text is broken into lines.  It should not
be used in normal &latex; documents.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="205">\topmargin</indexterm>\topmargin</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="206">topmargin</indexterm></findex>
<para>Space between the top of the &tex; page (one inch from the top of the
paper, by default) and the top of the header.  The value is computed
based on many other parameters: <code>\paperheight &minus; 2in &minus;
\headheight &minus; \headsep &minus; \textheight &minus; \footskip</code>,
and then divided by two.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="207">\topskip</indexterm>\topskip</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="208">\topskip</indexterm></findex>
<para>Minimum distance between the top of the page body and the baseline of
the first line of text.  For the standard classes, the default is the
same as the font size, e.g., <samp>10pt</samp> at a type size of 10pt.
</para>
</tableitem></tableentry></ftable>


</section>
<node name="Floats" spaces=" "><nodename>Floats</nodename><nodeprev automatic="on">Page layout parameters</nodeprev><nodeup automatic="on">Layout</nodeup></node>
<section spaces=" "><sectiontitle>Floats</sectiontitle>

<para>Some typographic elements, such as figures and tables, cannot be broken
across pages.  They must be typeset outside of the normal flow of text,
for instance floating to the top of a later page.
</para>
<para>&latex; can have a number of different classes of floating material.
The default is the two classes, <code>figure</code> (<pxref label="figure"><xrefnodename>figure</xrefnodename></pxref>) and
<code>table</code> (<pxref label="table"><xrefnodename>table</xrefnodename></pxref>), but you can create a new class with the
package <file>float</file>.
</para>
<para>Within any one float class &latex; always respects the order, so that
the first figure in a document source must be typeset before the second
figure.  However, &latex; may mix the classes, so it can happen that
while the first table appears in the source before the first figure, it
appears in the output after it.
</para>
<para>The placement of floats is subject to parameters, given below, that
limit the number of floats that can appear at the top of a page, and
the bottom, etc. If so many floats are queued that the limits prevent
them all from fitting on a page then &latex; places what it can and
defers the rest to the next page.  In this way, floats may end up
being typeset far from their place in the source.  In particular, a
float that is big may migrate to the end of the document. In which
event, because all floats in a class must appear in sequential order,
every following float in that class also appears at the end.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="150">placement of floats</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="151">specifier, float placement</indexterm></cindex>
<para>In addition to changing the parameters, for each float you can tweak
where the float placement algorithm tries to place it by using its
<var>placement</var> argument.  The possible values are a sequence of the
letters below. The default for both <code>figure</code> and <code>table</code>, in
both <code>article</code> and <code>book</code> classes, is <code>tbp</code>.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">t</itemformat></item>
</tableterm><tableitem><para>(Top)&textmdash;at the top of a text page.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">b</itemformat></item>
</tableterm><tableitem><para>(Bottom)&textmdash;at the bottom of a text page.  (However, <code>b</code> is not
allowed for full-width floats (<code>figure*</code>) with double-column
output.  To ameliorate this, use the <file>stfloats</file> or
<file>dblfloatfix</file> package, but see the discussion at caveats in the
FAQ: <url><urefurl>http://www.tex.ac.uk/cgi-bin/texfaq2html?label=2colfloat</urefurl></url>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">h</itemformat></item>
</tableterm><tableitem><para>(Here)&textmdash;at the position in the text where the <code>figure</code> environment
appears.  However, <code>h</code> is not allowed by itself; <code>t</code> is
automatically added.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="152">here, putting floats</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="153"><r>package</r>, <code>float</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="154"><code>float</code> <r>package</r></indexterm></cindex>

<para>To absolutely force a float to appear &textldquo;here&textrdquo;, you can
<code>\usepackage&lbrace;float&rbrace;</code> and use the <code>H</code> specifier which it
defines.  For further discussion, see the FAQ entry at
<url><urefurl>http://www.tex.ac.uk/cgi-bin/texfaq2html?label=figurehere</urefurl></url>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">p</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="155">float page</indexterm></cindex>
<para>(Page of floats)&textmdash;on a separate <dfn>float page</dfn>, which is a page
containing no text, only floats.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">!</itemformat></item>
</tableterm><tableitem><para>Used in addition to one of the above; for this float only, &latex;
ignores the restrictions on both the number of floats that can appear
and the relative amounts of float and non-float text on the page.
The <code>!</code> specifier does <emph>not</emph> mean &textldquo;put the float here&textrdquo;;
see above.
</para>
</tableitem></tableentry></table>

<para>Note: the order in which letters appear in the <var>placement</var> argument
does not change the order in which &latex; tries to place the float;
for instance, <code>btp</code> has the same effect as <code>tbp</code>.  All that
<var>placement</var> does is that if a letter is not present then the
algorithm does not try that location.  Thus, &latex;&textrsquo;s default of
<code>tbp</code> is to try every location except placing the float where it
occurs in the source.
</para>
<para>To prevent &latex; from moving floats to the end of the document or a
chapter you can use a <code>\clearpage</code> command to start a new page and
insert all pending floats. If a pagebreak is undesirable then you can
use the <file>afterpage</file> package and issue
<code>\afterpage&lbrace;\clearpage&rbrace;</code>.  This will wait until the current page
is finished and then flush all outstanding floats.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="156"><r>package</r>, <code>flafter</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="157"><code>flafter</code> <r>package</r></indexterm></cindex>

<para>&latex; can typeset a float before where it appears in the source
(although on the same output page) if there is a <code>t</code> specifier in
the <var>placement</var> parameter.  If this is not desired, and deleting
the <code>t</code> is not acceptable as it keeps the float from being placed
at the top of the next page, then you can prevent it by either using
the <file>flafter</file> package or using the command
<findex index="fn" spaces=" "><indexterm index="fn" number="209">\suppressfloats</indexterm></findex>
<code>\suppressfloats[t]</code>, which causes floats for the top position on
this page to moved to the next page.
</para>
<para>Parameters relating to fractions of pages occupied by float and
non-float text (change them with
<code>\renewcommand&lbrace;<var>parameter</var>&rbrace;&lbrace;<var>decimal between 0 and 1</var>&rbrace;</code>):
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="210">\bottomfraction</indexterm>\bottomfraction</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="211">\bottomfraction</indexterm></findex>
<para>The maximum fraction of the page allowed to be occupied by floats at
the bottom; default <samp>.3</samp>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="212">\floatpagefraction</indexterm>\floatpagefraction</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="213">\floatpagefraction</indexterm></findex>
<para>The minimum fraction of a float page that must be occupied by floats;
default <samp>.5</samp>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="214">\textfraction</indexterm>\textfraction</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="215">\textfraction</indexterm></findex>
<para>Minimum fraction of a page that must be text; if floats take up too
much space to preserve this much text, floats will be moved to a
different page.  The default is <samp>.2</samp>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="216">\topfraction</indexterm>\topfraction</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="217">\topfraction</indexterm></findex>
<para>Maximum fraction at the top of a page that may be occupied before
floats; default <samp>.7</samp>.
</para></tableitem></tableentry></ftable>

<para>Parameters relating to vertical space around floats (change them with
<code>\setlength&lbrace;<var>parameter</var>&rbrace;&lbrace;<var>length expression</var>&rbrace;</code>):
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="218">\floatsep</indexterm>\floatsep</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="219">\floatsep</indexterm></findex>
<para>Space between floats at the top or bottom of a page; default
<samp>12pt plus2pt minus2pt</samp>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="220">\intextsep</indexterm>\intextsep</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="221">\intextsep</indexterm></findex>
<para>Space above and below a float in the middle of the main text; default
<samp>12pt plus2pt minus2pt</samp> for 10 point and 11 point documents,
and <samp>14pt plus4pt minus4pt</samp> for 12 point documents.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="222">\textfloatsep</indexterm>\textfloatsep</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="223">\textfloatsep</indexterm></findex>
<para>Space between the last (first) float at the top (bottom) of a page;
default <samp>20pt plus2pt minus4pt</samp>.
</para></tableitem></tableentry></ftable>

<para>Counters relating to the number of floats on a page (change them with
<code>\setcounter&lbrace;<var>ctrname</var>&rbrace;&lbrace;<var>natural number</var>&rbrace;</code>):
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="224">bottomnumber</indexterm>bottomnumber</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="225">bottomnumber</indexterm></findex>
<para>Maximum number of floats that can appear at the bottom of a text page;
default 1.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="226">dbltopnumber</indexterm>dbltopnumber</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="227">dbltopnumber</indexterm></findex>
<para>Maximum number of full-sized floats that can appear at the top of a
two-column page; default 2.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="228">topnumber</indexterm>topnumber</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="229">topnumber</indexterm></findex>
<para>Maximum number of floats that can appear at the top of a text page;
default 2.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="230">totalnumber</indexterm>totalnumber</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="231">totalnumber</indexterm></findex>
<para>Maximum number of floats that can appear on a text page; default 3.
</para></tableitem></tableentry></ftable>

<para>The principal &tex;&nbsp;FAQ entry relating to floats
<url><urefurl>http://www.tex.ac.uk/cgi-bin/texfaq2html?label=floats</urefurl></url> contains
suggestions for relaxing &latex;&textrsquo;s default parameters to reduce the
problem of floats being pushed to the end.  A full explanation of the
float placement algorithm is in Frank Mittelbach&textrsquo;s article &textldquo;How to
influence the position of float environments like figure and table in
&latex;?&textrdquo;
(<url><urefurl>http://latex-project.org/papers/tb111mitt-float.pdf</urefurl></url>).
</para>

</section>
</chapter>
<node name="Sectioning" spaces=" "><nodename>Sectioning</nodename><nodenext automatic="on">Cross references</nodenext><nodeprev automatic="on">Layout</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Sectioning</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="158">sectioning commands</indexterm></cindex>

<para>Sectioning commands provide the means to structure your text into units:
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="232">\part</indexterm>\part</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="233">\chapter</indexterm>\chapter</itemformat></item>
</tableterm><tableitem><para>(<code>report</code> and <code>book</code> class only)
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="234">\section</indexterm>\section</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="235">\subsection</indexterm>\subsection</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="236">\subsubsection</indexterm>\subsubsection</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="237">\paragraph</indexterm>\paragraph</itemformat></item>
</tableterm></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="238">\subparagraph</indexterm>\subparagraph</itemformat></item>
</tableterm></tableentry></ftable>

<para>All sectioning commands take the same general form, e.g.,
</para>
<example endspaces=" ">
<pre xml:space="preserve">\chapter[<var>toctitle</var>]&lbrace;<var>title</var>&rbrace;
</pre></example>

<para>In addition to providing the heading <var>title</var> in the main text, the
section title can appear in two other places:
</para>
<enumerate first="1" endspaces=" ">
<listitem>
<para>The table of contents.
</para></listitem><listitem>
<para>The running head at the top of the page.
</para></listitem></enumerate>

<para>You may not want the same text in these places as in the main text.
To handle this, the sectioning commands have an optional argument
<var>toctitle</var> that, when given, specifies the text for these other
places.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="159"><code>*</code>-form of sectioning commands</indexterm></cindex>
<para>Also, all sectioning commands have <code>*</code>-forms that print
<var>title</var> as usual, but do not include a number and do not make an
entry in the table of contents.  For instance:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\section*&lbrace;Preamble&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="239">\appendix</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="160">appendix, creating</indexterm></cindex>
<para>The <code>\appendix</code> command changes the way following sectional units
are numbered.  The <code>\appendix</code> command itself generates no text
and does not affect the numbering of parts.  The normal use of this
command is something like
</para>
<example endspaces=" ">
<pre xml:space="preserve">\chapter&lbrace;A Chapter&rbrace;
&dots;
\appendix
\chapter&lbrace;The First Appendix&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="240">secnumdepth <r>counter</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="161">section numbers, printing</indexterm></cindex>
<anchor name="Sectioning_002fsecnumdepth">Sectioning/secnumdepth</anchor>
<para>The <code>secnumdepth</code> counter controls printing of section numbers.
The setting
</para>
<example endspaces=" ">
<pre xml:space="preserve">\setcounter&lbrace;secnumdepth&rbrace;&lbrace;<var>level</var>&rbrace;
</pre></example>

<noindent></noindent>
<para>suppresses heading numbers at any depth <math>&gt; <var>level</var></math>, where
<code>chapter</code> is level zero.  The default <code>secnumdepth</code> is 3 in
&latex;&textrsquo;s <file>article</file> class and 2 in the <file>book</file> and
<file>report</file> classes.  (<xref label="_005csetcounter"><xrefnodename>\setcounter</xrefnodename></xref>.)
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator=":: ">\&arobase;startsection</menunode><menudescription><pre xml:space="preserve">Redefine layout of start of sections, subsections, etc.
</pre></menudescription></menuentry></menu>


<node name="_005c_0040startsection" spaces=" "><nodename>\&arobase;startsection</nodename><nodeup automatic="on">Sectioning</nodeup></node>
<section spaces=" "><sectiontitle><code>\&arobase;startsection</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="241">\&arobase;startsection</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="162">section, redefining</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\&arobase;startsection&lbrace;<var>name</var>&rbrace;&lbrace;<var>level</var>&rbrace;&lbrace;<var>indent</var>&rbrace;&lbrace;<var>beforeskip</var>&rbrace;&lbrace;<var>afterskip</var>&rbrace;&lbrace;<var>style</var>&rbrace;
</pre></example>

<para>Used to help redefine the behavior of commands that start sectioning
divisions such as <code>\section</code> or <code>\subsection</code>.
</para>
<para>Note that the <file>titlesec</file> package makes manipulation of sectioning
easier.  Further, while most requirements for sectioning commands can be
satisfied with <code>\&arobase;startsection</code>, some cannot.  For instance, in
the standard &latex; <code>book</code> and <code>report</code> classes the commands
<code>\chapter</code> and <code>\report</code> are not constructed in this way.  To
make such a command you may want to use the <code>\secdef</code> command.
<!-- c xx define, and make a cross reference to, secdef. -->
</para>
<para>Technically, <code>\&arobase;startsection</code> has the form
</para><example endspaces=" ">
<pre xml:space="preserve">\&arobase;startsection&lbrace;<var>name</var>&rbrace;&lbrace;<var>level</var>&rbrace;&lbrace;<var>indent</var>&rbrace;&lbrace;<var>beforeskip</var>&rbrace;&lbrace;<var>afterskip</var>&rbrace;&lbrace;<var>style</var>&rbrace;*[<var>toctitle</var>]&lbrace;<var>title</var>&rbrace;
</pre></example>
<noindent></noindent> <para>(the star&nbsp;<code>*</code> is optional), so that issuing
</para><example endspaces=" ">
<pre xml:space="preserve">\renewcommand&lbrace;\section&rbrace;&lbrace;\&arobase;startsection&lbrace;<var>name</var>&rbrace;&lbrace;<var>level</var>&rbrace;&lbrace;<var>indent</var>&rbrace;&lbrace;<var>beforeskip</var>&rbrace;&lbrace;<var>afterskip</var>&rbrace;&lbrace;<var>style</var>&rbrace;&rbrace;
</pre></example>
<noindent></noindent> <para>redefines <code>\section</code> to have the form
<code>\section*[<var>toctitle</var>]&lbrace;<var>title</var>&rbrace;</code> (here too, the
star&nbsp;<code>*</code> is optional).  <xref label="Sectioning"><xrefnodename>Sectioning</xrefnodename></xref>.  This implies that
when you write a command like <code>\renewcommand&lbrace;section&rbrace;&lbrace;...&rbrace;</code>,
the <code>\&arobase;startsection&lbrace;...&rbrace;</code> must come last in the definition.  See
the examples below.
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<beforefirstitem>
</beforefirstitem><tableentry><tableterm><item spaces=" "><itemformat command="var">name</itemformat></item>
</tableterm><tableitem><anchor name="_005c_0040startsection_002fname">\&arobase;startsection/name</anchor> <para>Name of the counter used to number the
sectioning header.  This counter must be defined separately.  Most
commonly this is either <code>section</code>, <code>subsection</code>, or
<code>paragraph</code>.  Although in those three cases the counter name is the
same as the sectioning command itself, using the same name is not
required.
</para>
<para>Then <code>\the</code><var>name</var> displays the title number and
<code>\</code><var>name</var><code>mark</code> is for the page headers.  See the third
example below.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">level</itemformat></item>
</tableterm><tableitem><anchor name="_005c_0040startsection_002flevel">\&arobase;startsection/level</anchor> <para>An integer giving the depth of the
sectioning command: 0 for <code>chapter</code> (only applies to the standard
<code>book</code> and <code>report</code> classes), 1 for <code>section</code>, 2 for
<code>subsection</code>, 3 for <code>subsubsection</code>, 4 for <code>paragraph</code>,
and 5 for <code>subparagraph</code>.  In the <code>book</code> and <code>report</code>
classes <code>part</code> has level -1, while in the <code>article</code> class
<code>part</code> has level 0.
</para>
<para>If <var>level</var> is less than or equal to the value of <code>secnumdepth</code>
then the titles for this sectioning command will be numbered.  For
instance, in an <code>article</code>, if <code>secnumdepth</code> is 1 then a
<code>\section&lbrace;Introduction&rbrace;</code> command will produce output like &textldquo;1
Introduction&textrdquo; while <code>\subsection&lbrace;Discussion&rbrace;</code> will produce
output like &textldquo;Discussion&textrdquo;, without the number prefix.
<xref label="Sectioning_002fsecnumdepth"><xrefnodename>Sectioning/secnumdepth</xrefnodename></xref>.
</para>
<para>If <var>level</var> is less than or equal to the value of <var>tocdepth</var> then
the table of contents will have an entry for this sectioning unit.
For instance, in an <code>article</code>, if <var>tocdepth</var> is 1 then the table of
contents will list sections but not subsections.
<!-- c xx add, and cross reference to, tocdepth -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">indent</itemformat></item>
</tableterm><tableitem><anchor name="_005c_0040startsection_002findent">\&arobase;startsection/indent</anchor> <para>A length giving the indentation of all
of the title lines with respect to the left margin.  To have the title
flush with the margin use <code>0pt</code>.  A negative indentation such as
<code>-\parindent</code> will move the title into the left margin.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">beforeskip</itemformat></item>
</tableterm><tableitem><anchor name="_005c_0040startsection_002fbeforeskip">\&arobase;startsection/beforeskip</anchor> <para>The absolute value of this length is
the amount of vertical space that is inserted before this sectioning
unit&textrsquo;s title.  This space will be discarded if the sectioning unit
happens to start at the top of a fresh page.  If this number is negative
then the first paragraph following the header is not indented, if it is
non-negative then the first paragraph is indented.  (Note that the
negative of <code>1pt plus 2pt minus 3pt</code> is <code>-1pt plus -2pt minus
-3pt</code>.)
</para>
<para>For example, if <var>beforeskip</var> is <code>-3.5ex plus -1ex minus -0.2ex</code>
then to start the new sectioning unit, &latex; will add about 3.5 times
the height of a letter x in vertical space, and the first paragraph in
the section will not be indented.  Using a rubber length, with
<code>plus</code> and <code>minus</code>, is good practice here since it gives
&latex; more flexibility in making up the page (<pxref label="Lengths"><xrefnodename>Lengths</xrefnodename></pxref>).
</para>
<para>The full accounting of the vertical space between the baseline of the
line prior to this sectioning unit&textrsquo;s header and the baseline of the
header is that it is the sum of the <code>\parskip</code> of the text font,
the <code>\baselineskip</code> of the title font, and the absolute value of
the <var>beforeskip</var>.  This space is typically rubber so it may stretch
or shrink.  (If the sectioning unit starts on a fresh page so that the
vertical space is discarded then the baseline of the header text will be
where &latex; would put the baseline of the first text line on that
page.)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">afterskip</itemformat></item>
</tableterm><tableitem><anchor name="_005c_0040startsection_002fafterskip">\&arobase;startsection/afterskip</anchor> <para>This is a length.  If <var>afterskip</var>
is non-negative then this is the vertical space inserted after the
sectioning unit&textrsquo;s title header.  If it is negative then the title header
becomes a run-in header, so that it becomes part of the next paragraph.
In this case the absolute value of the length gives the horizontal space
between the end of the title and the beginning of the following
paragraph.  (Note that the negative of <code>1pt plus 2pt minus 3pt</code> is
<code>-1pt plus -2pt minus -3pt</code>.)
</para>
<para>As with <var>beforeskip</var>, using a rubber length, with <code>plus</code> and
<code>minus</code> components, is good practice here since it gives &latex;
more flexibility in putting together the page.
</para>
<para>If <code>afterskip</code> is non-negative then the full accounting of the
vertical space between the baseline of the sectioning unit&textrsquo;s header and
the baseline of the first line of the following paragraph is that it is
the sum of the <code>\parskip</code> of the title font, the
<code>\baselineskip</code> of the text font, and the value of <var>after</var>.
That space is typically rubber so it may stretch or shrink.  (Note that
because the sign of <code>afterskip</code> changes the sectioning unit
header&textrsquo;s from standalone to run-in, you cannot use a negative
<code>afterskip</code> to cancel part of the <code>\parskip</code>.)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">style</itemformat></item>
</tableterm><tableitem><anchor name="_005c_0040startsection_002fstyle">\&arobase;startsection/style</anchor> <para>Controls the styling of the title.  See
the examples below.  Typical commands to use here are <code>\centering</code>,
<code>\raggedright</code>, <code>\normalfont</code>, <code>\hrule</code>, or
<code>\newpage</code>.  The last command in <var>style</var> may be one such as
<code>\MakeUppercase</code> or <code>\fbox</code> that takes one argument. The
section title will be supplied as the argument to this command. For
instance, setting <var>style</var> to <code>\bfseries\MakeUppercase</code> would
produce titles that are bold and upper case.
</para></tableitem></tableentry></table>

<para>These are &latex;&textrsquo;s defaults for the first three sectioning units that
are defined with <code>\&arobase;startsection</code>, for the <file>article</file>,
<file>book</file>, and <file>report</file> classes.
</para>
<multitable spaces=" " endspaces=" "><columnfractions line=" .10 .30 .30 .30"><columnfraction value=".10"></columnfraction><columnfraction value=".30"></columnfraction><columnfraction value=".30"></columnfraction><columnfraction value=".30"></columnfraction></columnfractions>
<thead><row><entry command="headitem" spaces="   "></entry><entry command="tab" spaces=" "><para><code>section</code>  </para></entry><entry command="tab" spaces=" "><para><code>subsection</code>  </para></entry><entry command="tab" spaces=" "><para><code>subsubsection</code>
</para></entry></row></thead><tbody><row><entry command="item" spaces=" "><para><ref label="_005c_0040startsection_002fname"><xrefnodename>\&arobase;startsection/name</xrefnodename><xrefinfoname><var>name</var></xrefinfoname><xrefprinteddesc><var>name</var></xrefprinteddesc></ref>
</para></entry><entry command="tab" spaces=" "><para>section          </para></entry><entry command="tab" spaces=" "><para>subsection          </para></entry><entry command="tab" spaces=" "><para>subsubsection
</para></entry></row><row><entry command="item" spaces="  "><para><ref label="_005c_0040startsection_002flevel"><xrefnodename>\&arobase;startsection/level</xrefnodename><xrefinfoname><var>level</var></xrefinfoname><xrefprinteddesc><var>level</var></xrefprinteddesc></ref>
</para></entry><entry command="tab" spaces=" "><para>1          </para></entry><entry command="tab" spaces=" "><para>2          </para></entry><entry command="tab" spaces=" "><para>3
</para></entry></row><row><entry command="item" spaces=" "><para><ref label="_005c_0040startsection_002findent"><xrefnodename>\&arobase;startsection/indent</xrefnodename><xrefinfoname><var>indent</var></xrefinfoname><xrefprinteddesc><var>indent</var></xrefprinteddesc></ref>
</para></entry><entry command="tab" spaces=" "><para><code>0pt</code>          </para></entry><entry command="tab" spaces=" "><para><code>0pt</code>          </para></entry><entry command="tab" spaces=" "><para><code>0pt</code>
</para></entry></row><row><entry command="item" spaces=" "><para><ref label="_005c_0040startsection_002fbeforeskip"><xrefnodename>\&arobase;startsection/beforeskip</xrefnodename><xrefinfoname><var>beforeskip</var></xrefinfoname><xrefprinteddesc><var>beforeskip</var></xrefprinteddesc></ref>
</para></entry><entry command="tab" spaces=" "><para><code>-3.5ex plus -1ex minus -0.2ex</code>
</para></entry><entry command="tab" spaces=" "><para><code>-3.25ex plus -1ex minus -0.2ex</code>
</para></entry><entry command="tab" spaces=" "><para><code>-3.25ex plus -1ex minus -0.2ex</code>
</para></entry></row><row><entry command="item" spaces=" "><para><ref label="_005c_0040startsection_002fafterskip"><xrefnodename>\&arobase;startsection/afterskip</xrefnodename><xrefinfoname><var>afterskip</var></xrefinfoname><xrefprinteddesc><var>afterskip</var></xrefprinteddesc></ref>
</para></entry><entry command="tab" spaces=" "><para><code>2.3ex plus 0.2ex</code>
</para></entry><entry command="tab" spaces=" "><para><code>1.5ex plus 0.2ex</code>
</para></entry><entry command="tab" spaces=" "><para><code>1.5ex plus 0.2ex</code>
</para></entry></row><row><entry command="item" spaces=" "><para><ref label="_005c_0040startsection_002fstyle"><xrefnodename>\&arobase;startsection/style</xrefnodename><xrefinfoname><var>style</var></xrefinfoname><xrefprinteddesc><var>style</var></xrefprinteddesc></ref>
</para></entry><entry command="tab" spaces=" "><para><code>\normalfont\Large\bfseries</code>
</para></entry><entry command="tab" spaces=" "><para><code>\normalfont\large\bfseries</code>
</para></entry><entry command="tab" spaces=" "><para><code>\normalfont\normalsize\bfseries</code>
</para></entry></row></tbody></multitable>

<para>Here are examples.  They go either in a package or class file or in the
preamble of a &latex; document.  If you put them in the preamble they
must go between a <code>\makeatletter</code> command and a
<code>\makeatother</code>.  (Probably the error message <code>You can't use
`\spacefactor' in vertical mode.</code>  means that you forgot this.)
<xref label="_005cmakeatletter-and-_005cmakeatother"><xrefnodename>\makeatletter and \makeatother</xrefnodename></xref>.
</para>
<para>This will put section titles in large boldface type, centered.  It says
<code>\renewcommand</code> because &latex;&textrsquo;s standard classes have already
defined a <code>\section</code>.  For the same reason it does not define a
<code>section</code> counter, or the commands <code>\thesection</code> and
<code>\l&arobase;section</code>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\renewcommand\section&lbrace;%
  \&arobase;startsection&lbrace;section&rbrace;% <ref label="_005c_0040startsection_002fname"><xrefnodename>\&arobase;startsection/name</xrefnodename><xrefinfoname><var>name</var></xrefinfoname><xrefprinteddesc><var>name</var></xrefprinteddesc></ref>
    &lbrace;1&rbrace;% <ref label="_005c_0040startsection_002flevel"><xrefnodename>\&arobase;startsection/level</xrefnodename><xrefinfoname><var>level</var></xrefinfoname><xrefprinteddesc><var>level</var></xrefprinteddesc></ref>
    &lbrace;0pt&rbrace;% <ref label="_005c_0040startsection_002findent"><xrefnodename>\&arobase;startsection/indent</xrefnodename><xrefinfoname><var>indent</var></xrefinfoname><xrefprinteddesc><var>indent</var></xrefprinteddesc></ref>
    &lbrace;-3.5ex plus -1ex minus -.2ex&rbrace;% <ref label="_005c_0040startsection_002fbeforeskip"><xrefnodename>\&arobase;startsection/beforeskip</xrefnodename><xrefinfoname><var>beforeskip</var></xrefinfoname><xrefprinteddesc><var>beforeskip</var></xrefprinteddesc></ref>
    &lbrace;2.3ex plus.2ex&rbrace;% <ref label="_005c_0040startsection_002fafterskip"><xrefnodename>\&arobase;startsection/afterskip</xrefnodename><xrefinfoname><var>afterskip</var></xrefinfoname><xrefprinteddesc><var>afterskip</var></xrefprinteddesc></ref>
    &lbrace;\centering\normalfont\Large\bfseries&rbrace;% <ref label="_005c_0040startsection_002fstyle"><xrefnodename>\&arobase;startsection/style</xrefnodename><xrefinfoname><var>style</var></xrefinfoname><xrefprinteddesc><var>style</var></xrefprinteddesc></ref>
  &rbrace;
</pre></example>

<para>This will put <code>subsection</code> titles in small caps type, inline with the paragraph.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\renewcommand\subsection&lbrace;%
  \&arobase;startsection&lbrace;subsection&rbrace;%  <ref label="_005c_0040startsection_002fname"><xrefnodename>\&arobase;startsection/name</xrefnodename><xrefinfoname><var>name</var></xrefinfoname><xrefprinteddesc><var>name</var></xrefprinteddesc></ref>
    &lbrace;2&rbrace;% <ref label="_005c_0040startsection_002flevel"><xrefnodename>\&arobase;startsection/level</xrefnodename><xrefinfoname><var>level</var></xrefinfoname><xrefprinteddesc><var>level</var></xrefprinteddesc></ref>
    &lbrace;0em&rbrace;% <ref label="_005c_0040startsection_002findent"><xrefnodename>\&arobase;startsection/indent</xrefnodename><xrefinfoname><var>indent</var></xrefinfoname><xrefprinteddesc><var>indent</var></xrefprinteddesc></ref>
    &lbrace;-1ex plus 0.1ex minus -0.05ex&rbrace;% <ref label="_005c_0040startsection_002fbeforeskip"><xrefnodename>\&arobase;startsection/beforeskip</xrefnodename><xrefinfoname><var>beforeskip</var></xrefinfoname><xrefprinteddesc><var>beforeskip</var></xrefprinteddesc></ref>
    &lbrace;-1em plus 0.2em&rbrace;% <ref label="_005c_0040startsection_002fafterskip"><xrefnodename>\&arobase;startsection/afterskip</xrefnodename><xrefinfoname><var>afterskip</var></xrefinfoname><xrefprinteddesc><var>afterskip</var></xrefprinteddesc></ref>
    &lbrace;\scshape&rbrace;% <ref label="_005c_0040startsection_002fstyle"><xrefnodename>\&arobase;startsection/style</xrefnodename><xrefinfoname><var>style</var></xrefinfoname><xrefprinteddesc><var>style</var></xrefprinteddesc></ref>
  &rbrace;
</pre></example>

<para>The prior examples redefined existing sectional unit title commands.  This defines a new one, illustrating the needed counter and macros to display that counter.
</para>
<!-- c From https://groups.google.com/forum/#!searchin/comp.text.tex/startsection%7Csort:relevance/comp.text.tex/sB-nTS-oL08/ZZeKYdG0llMJ -->
<example endspaces=" ">
<pre xml:space="preserve">\setcounter&lbrace;secnumdepth&rbrace;&lbrace;6&rbrace;% show counters this far down
\newcounter&lbrace;subsubparagraph&rbrace;[subparagraph]% counter for numbering
\renewcommand&lbrace;\thesubsubparagraph&rbrace;%               how to display 
  &lbrace;\thesubparagraph.\&arobase;arabic\c&arobase;subsubparagraph&rbrace;%  numbering
\newcommand&lbrace;\subsubparagraph&rbrace;&lbrace;\&arobase;startsection
                         &lbrace;subsubparagraph&rbrace;%
                         &lbrace;6&rbrace;%
                         &lbrace;0em&rbrace;%
                         &lbrace;\baselineskip&rbrace;%
                         &lbrace;0.5\baselineskip&rbrace;%
                         &lbrace;\normalfont\normalsize&rbrace;&rbrace;
\newcommand*\l&arobase;subsubparagraph&lbrace;\&arobase;dottedtocline&lbrace;6&rbrace;&lbrace;10em&rbrace;&lbrace;5em&rbrace;&rbrace;% for toc
\newcommand&lbrace;\subsubparagraphmark&rbrace;[1]&lbrace;&rbrace;% for page headers
</pre></example>


</section>
</chapter>
<node name="Cross-references" spaces=" "><nodename>Cross references</nodename><nodenext automatic="on">Environments</nodenext><nodeprev automatic="on">Sectioning</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Cross references</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="163">cross references</indexterm></cindex>

<para>One reason for numbering things such as figures and equations is to
refer the reader to them, as in &textldquo;See Figure~3 for more details.&textrdquo;
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="164">label</indexterm></cindex>
<para>Including the figure number in the source is poor practice since if that
number changes as the document evolves then you must remember to update
this reference by hand.  Instead, &latex; has you write a <dfn>label</dfn>
like <code>\label&lbrace;eq:GreensThm&rbrace;</code> and refer to it with <code>See
equation~\ref&lbrace;eq:GreensThm&rbrace;</code>.
</para>
<para>&latex; writes the information from the labels to a file with the same
name as the file containing the <code>\label&lbrace;...&rbrace;</code> but with an
<file>.aux</file> extension.  (The information has the format
<code>\newlabel&lbrace;<var>label</var>&rbrace;&lbrace;&lbrace;<var>currentlabel</var>&rbrace;&lbrace;<var>pagenumber</var>&rbrace;&rbrace;</code>
where <var>currentlabel</var> is the current value of the macro
<code>\&arobase;currentlabel</code> that is usually updated whenever you call
<code>\refstepcounter&lbrace;<var>counter</var>&rbrace;</code>.)
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="165">forward reference</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="166">reference, forward</indexterm></cindex>
<para>The most common side effect of the prior paragraph happens when your
document has a <dfn>forward reference</dfn>, a <code>\ref&lbrace;<var>key</var>&rbrace;</code> that
appears earlier than the associated <code>\label&lbrace;<var>key</var>&rbrace;</code>; see the
example in the <code>\pageref&lbrace;...&rbrace;</code> description.  &latex; gets the
information for references from the <file>.aux</file> file.  If this is the
first time you are compiling the document then you will get a message
<code>LaTeX Warning: Label(s) may have changed. Rerun to get
cross references right.</code> and in the output the reference will appear as
two question marks&nbsp;<samp>??</samp>, in boldface.  Or, if you change some
things so the references change then you get the same warning and the
output contains the old reference information.  The solution in either
case is just to compile the document a second time.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::      ">\label</menunode><menudescription><pre xml:space="preserve">Assign a symbolic name to a piece of text.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::    ">\pageref</menunode><menudescription><pre xml:space="preserve">Refer to a page number.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::        ">\ref</menunode><menudescription><pre xml:space="preserve">Refer to a section, figure or similar.
</pre></menudescription></menuentry></menu>


<node name="_005clabel" spaces=" "><nodename>\label</nodename><nodenext automatic="on">\pageref</nodenext><nodeup automatic="on">Cross references</nodeup></node>
<section spaces=" "><sectiontitle><code>\label</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="242">\label</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\label&lbrace;<var>key</var>&rbrace;
</pre></example>

<para>Assign a reference number to <var>key</var>.  In ordinary text
<code>\label&lbrace;<var>key</var>&rbrace;</code> assigns to <var>key</var> the number of the
current sectional unit. Inside an environment with numbering, such as a
<code>table</code> or <code>theorem</code> environment, <code>\label&lbrace;<var>key</var>&rbrace;</code>
assigns to <var>key</var> the number of that environment.  Retrieve the
assigned number with the <code>\ref&lbrace;<var>key</var>&rbrace;</code> command
(<pxref label="_005cref"><xrefnodename>\ref</xrefnodename></pxref>).
</para>
<para>A key name can consist of any sequence of letters, digits, or common
punctuation characters.  Upper and lowercase letters are
distinguished, as usual.
</para>
<para>A common convention is to use labels consisting of a prefix and a suffix
separated by a colon or period.  This helps to avoid accidentally
creating two labels with the same name, and makes your source more
readable.  Some commonly-used prefixes:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">ch</itemformat></item>
</tableterm><tableitem><para>for chapters
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">sec</itemformat></item>
</tableterm><tableitem><para>for lower-level sectioning commands
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">fig</itemformat></item>
</tableterm><tableitem><para>for figures
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">tab</itemformat></item>
</tableterm><tableitem><para>for tables
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">eq</itemformat></item>
</tableterm><tableitem><para>for equations
</para></tableitem></tableentry></table>

<para>Thus, <code>\label&lbrace;fig:Euler&rbrace;</code> is a label for a figure with a portrait
of the great man.
</para>
<para>In this example below the key <code>sec:test</code> will get the number of the
current section and the key <code>fig:test</code> will get the number of the
figure.  (Incidentally, put labels after captions in figures and
tables.)
</para>
<example endspaces=" ">
<pre xml:space="preserve">\section&lbrace;section name&rbrace;
\label&lbrace;sec:test&rbrace;
This is Section~\ref&lbrace;sec:test&rbrace;.
\begin&lbrace;figure&rbrace;
  ...
  \caption&lbrace;caption text&rbrace;
  \label&lbrace;fig:test&rbrace;
\end&lbrace;figure&rbrace;
See Figure~\ref&lbrace;fig:test&rbrace;.
</pre></example>


</section>
<node name="_005cpageref" spaces=" "><nodename>\pageref</nodename><nodenext automatic="on">\ref</nodenext><nodeprev automatic="on">\label</nodeprev><nodeup automatic="on">Cross references</nodeup></node>
<section spaces=" "><sectiontitle><code>\pageref&lbrace;<var>key</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="243">\pageref</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="167">cross referencing with page number</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="168">page number, cross referencing</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\pageref&lbrace;<var>key</var>&rbrace;
</pre></example>

<para>Produce the page number of the place in the text where the corresponding
<code>\label</code>&lbrace;<var>key</var>&rbrace; command appears.
</para>
<para>In this example the <code>\label&lbrace;eq:main&rbrace;</code> is used both for the
formula number and for the page number.  (Note that the two references
are forward references, so this document would need to be compiled twice
to resolve those.)
</para>
<example endspaces=" ">
<pre xml:space="preserve">The main result is formula~\ref&lbrace;eq:main&rbrace; on page~\pageref&lbrace;eq:main&rbrace;.
  ...
\begin&lbrace;equation&rbrace; \label&lbrace;eq:main&rbrace;
   \mathbf&lbrace;P&rbrace;=\mathbf&lbrace;NP&rbrace;
\end&lbrace;equation&rbrace;
</pre></example>


</section>
<node name="_005cref" spaces=" "><nodename>\ref</nodename><nodeprev automatic="on">\pageref</nodeprev><nodeup automatic="on">Cross references</nodeup></node>
<section spaces=" "><sectiontitle><code>\ref&lbrace;<var>key</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="244">\ref</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="169">cross referencing, symbolic</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="170">section number, cross referencing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="171">equation number, cross referencing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="172">figure number, cross referencing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="173">footnote number, cross referencing</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\ref&lbrace;<var>key</var>&rbrace;
</pre></example>

<para>Produces the number of the sectional unit,
equation, footnote, figure, &dots;, of the corresponding
<code>\label</code> command (<pxref label="_005clabel"><xrefnodename>\label</xrefnodename></pxref>).  It does not produce any text,
such as the word &textlsquo;Section&textrsquo; or &textlsquo;Figure&textrsquo;, just the bare number itself.
</para>
<para>In this example, the <code>\ref&lbrace;popular&rbrace;</code> produces <samp>2</samp>.  Note
that it is a forward reference since it comes before
<code>\label&lbrace;popular&rbrace;</code>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">The most widely-used format is item number~\ref&lbrace;popular&rbrace;.
\begin&lbrace;enumerate&rbrace;
\item Plain \TeX
\item \label&lbrace;popular&rbrace; \LaTeX
\item Con\TeX t
\end&lbrace;enumerate&rbrace;
</pre></example>


</section>
</chapter>
<node name="Environments" spaces=" "><nodename>Environments</nodename><nodenext automatic="on">Line breaking</nodenext><nodeprev automatic="on">Cross references</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Environments</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="174">environments</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="245">\begin</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="246">\end</indexterm></findex>

<para>&latex; provides many environments for delimiting certain behavior.
An environment begins with <code>\begin</code> and ends with <code>\end</code>,
like this:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;<var>environment-name</var>&rbrace;
  ...
\end&lbrace;<var>environment-name</var>&rbrace;
</pre></example>

<para>The <var>environment-name</var> at the beginning must exactly match that at
the end. For instance, the input
<code>\begin&lbrace;table*&rbrace;...\end&lbrace;table&rbrace;</code> will cause an error like:
<samp>! LaTeX Error: \begin&lbrace;table*&rbrace; on input line 5 ended by
\end&lbrace;table&rbrace;.</samp>
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="175">group, and environments</indexterm></cindex>
<para>Environments are executed within a group.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::              ">abstract</menunode><menudescription><pre xml:space="preserve">Produce an abstract.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                 ">array</menunode><menudescription><pre xml:space="preserve">Math arrays.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                ">center</menunode><menudescription><pre xml:space="preserve">Centered lines.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           ">description</menunode><menudescription><pre xml:space="preserve">Labelled lists.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           ">displaymath</menunode><menudescription><pre xml:space="preserve">Formulas that appear on their own line.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">document</menunode><menudescription><pre xml:space="preserve">Enclose the whole document.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::             ">enumerate</menunode><menudescription><pre xml:space="preserve">Numbered lists.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">eqnarray</menunode><menudescription><pre xml:space="preserve">Sequences of aligned equations.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">equation</menunode><menudescription><pre xml:space="preserve">Displayed equation.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                ">figure</menunode><menudescription><pre xml:space="preserve">Floating figures.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::          ">filecontents</menunode><menudescription><pre xml:space="preserve">Writing multiple files from the source.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::             ">flushleft</menunode><menudescription><pre xml:space="preserve">Flushed left lines.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">flushright</menunode><menudescription><pre xml:space="preserve">Flushed right lines.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">itemize</menunode><menudescription><pre xml:space="preserve">Bulleted lists.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                ">letter</menunode><menudescription><pre xml:space="preserve">Letters.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                  ">list</menunode><menudescription><pre xml:space="preserve">Generic list environment.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                  ">math</menunode><menudescription><pre xml:space="preserve">In-line math.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">minipage</menunode><menudescription><pre xml:space="preserve">Miniature page.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">picture</menunode><menudescription><pre xml:space="preserve">Picture with text, arrows, lines and circles.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::   ">quotation and quote</menunode><menudescription><pre xml:space="preserve">Include a quotation.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">tabbing</menunode><menudescription><pre xml:space="preserve">Align text arbitrarily.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                 ">table</menunode><menudescription><pre xml:space="preserve">Floating tables.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">tabular</menunode><menudescription><pre xml:space="preserve">Align text in columns.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::       ">thebibliography</menunode><menudescription><pre xml:space="preserve">Bibliography or reference list.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">theorem</menunode><menudescription><pre xml:space="preserve">Theorems, lemmas, etc.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::             ">titlepage</menunode><menudescription><pre xml:space="preserve">For hand crafted title pages.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">verbatim</menunode><menudescription><pre xml:space="preserve">Simulating typed input.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                 ">verse</menunode><menudescription><pre xml:space="preserve">For poetry and other things.
</pre></menudescription></menuentry></menu>


<node name="abstract" spaces=" "><nodename>abstract</nodename><nodenext automatic="on">array</nodenext><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>abstract</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="247"><r>environment</r>, <code>abstract</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="248"><code>abstract</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="176">abstracts</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;abstract&rbrace;
...
\end&lbrace;abstract&rbrace;
</pre></example>

<para>Produce an abstract, possibly of multiple paragraphs.  This environment
is only defined in the <code>article</code> and <code>report</code> document classes
(<pxref label="Document-classes"><xrefnodename>Document classes</xrefnodename></pxref>).
</para>
<para>Using the example below in the <code>article</code> class produces a displayed
paragraph.  Document class option <code>titlepage</code> causes the abstract
to be on a separate page (<pxref label="Document-class-options"><xrefnodename>Document class options</xrefnodename></pxref>); this is the
default only in the <code>report</code> class.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;abstract&rbrace;
  We compare all known accounts of the proposal made by Porter Alexander 
  to Robert E Lee at the Appomattox Court House that the army continue
  in a guerrilla war, which Lee refused.
\end&lbrace;abstract&rbrace;
</pre></example>

<para>The next example produces a one column abstract in a two column document (for
a more flexible solution, use the package <file>abstract</file>).
</para>
<!-- c Adopted from http://www.tex.ac.uk/FAQ-onecolabs.html -->
<example endspaces=" ">
<pre xml:space="preserve">\documentclass[twocolumn]&lbrace;article&rbrace;
  ...
\begin&lbrace;document&rbrace;
\title&lbrace;Babe Ruth as Cultural Progenitor: a Atavistic Approach&rbrace;
\author&lbrace;Smith \\ Jones \\ Robinson\thanks&lbrace;Railroad tracking grant.&rbrace;&rbrace;
\twocolumn[
  \begin&lbrace;&arobase;twocolumnfalse&rbrace;
     \maketitle
     \begin&lbrace;abstract&rbrace;
       Ruth was not just the Sultan of Swat, he was the entire swat
       team.   
     \end&lbrace;abstract&rbrace;
   \end&lbrace;&arobase;twocolumnfalse&rbrace;
   ]
&lbrace;   % by-hand insert a footnote at page bottom
 \renewcommand&lbrace;\thefootnote&rbrace;&lbrace;\fnsymbol&lbrace;footnote&rbrace;&rbrace;
 \footnotetext[1]&lbrace;Thanks for all the fish.&rbrace;
&rbrace;
</pre></example>


</section>
<node name="array" spaces=" "><nodename>array</nodename><nodenext automatic="on">center</nodenext><nodeprev automatic="on">abstract</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>array</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="249"><r>environment</r>, <code>array</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="250"><code>array</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="177">arrays, math</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;array&rbrace;&lbrace;<var>cols</var>&rbrace;
  <var>column 1 entry</var> &amp;<var>column 2 entry</var> ... &amp;<var>column n entry</var> \\
  ...
\end&lbrace;array&rbrace;
</pre></example>

<para>or
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;array&rbrace;[<var>pos</var>]&lbrace;<var>cols</var>&rbrace;
  <var>column 1 entry</var> &amp;<var>column 2 entry</var> ... &amp;<var>column n entry</var> \\
  ...
\end&lbrace;array&rbrace;
</pre></example>

<para>Produce a mathematical array.  This environment can only be used in math
mode, and normally appears within a displayed mathematics environment
such as <code>equation</code> (<pxref label="equation"><xrefnodename>equation</xrefnodename></pxref>).  Column entries are
separated by an ampersand&nbsp;(<code>&amp;</code>).  Rows are terminated with
double-backslashes (<pxref label="_005c_005c"><xrefnodename>\\</xrefnodename></pxref>).  
</para>
<para>The required argument <var>cols</var> describes the number of columns, their
alignment, and the formatting of the intercolumn regions.  See
<ref label="tabular"><xrefnodename>tabular</xrefnodename></ref> for the complete description of <var>cols</var>, and of the
other common features of the two environments, including the optional
<var>pos</var> argument.
</para>
<para>There are two ways that <code>array</code> diverges from <code>tabular</code>.  The
first is that <code>array</code> entries are typeset in math mode, in
textstyle (except if the <var>cols</var> definition specifies the column with
<code>p&lbrace;...&rbrace;</code>, which causes the entry to be typeset in text mode).
The second is that, instead of <code>tabular</code>&textrsquo;s parameter
<code>\tabcolsep</code>, &latex;&textrsquo;s intercolumn space in an <code>array</code> is governed
by
<findex index="fn" spaces=" "><indexterm index="fn" number="251">\arraycolsep</indexterm></findex>
<code>\arraycolsep</code>, which gives half the width between columns. The
default for this is <samp>5pt</samp>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="178"><r>package</r>, <code>amsmath</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="179"><code>amsmath</code> <r>package</r></indexterm></cindex>

<para>To obtain arrays with braces the standard is to use the <file>amsmath</file>
package.  It comes with environments <code>pmatrix</code> for an array
surrounded by parentheses&nbsp;<code>(...)</code>, <code>bmatrix</code> for an array
surrounded by square brackets&nbsp;<code>[...]</code>, <code>Bmatrix</code> for an
array surrounded by curly braces&nbsp;<code>&lbrace;...&rbrace;</code>, <code>vmatrix</code> for
an array surrounded by vertical bars&nbsp;<code>|...|</code>, and
<code>Vmatrix</code> for an array surrounded by double vertical
bars&nbsp;<code>||...||</code>, along with a number of other array constructs.
</para>
<para>Here is an example of an array:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;equation&rbrace;
  \begin&lbrace;array&rbrace;&lbrace;cr&rbrace;
    \sqrt&lbrace;y&rbrace;  &amp;12.3 \\
    x^2       &amp;3.4       
  \end&lbrace;array&rbrace;
\end&lbrace;equation&rbrace;
</pre></example>

<para>The next example works if <code>\usepackage&lbrace;amsmath&rbrace;</code> is in the
preamble:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;equation&rbrace;
  \begin&lbrace;vmatrix&rbrace;&lbrace;cc&rbrace;
    a  &amp;b \\
    c  &amp;d       
  \end&lbrace;vmatrix&rbrace;=ad-bc
\end&lbrace;equation&rbrace;
</pre></example>


</section>
<node name="center" spaces=" "><nodename>center</nodename><nodenext automatic="on">description</nodenext><nodeprev automatic="on">array</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>center</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="252"><r>environment</r>, <code>center</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="253"><code>center</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="180">centering text, environment for</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;center&rbrace;
  ... text ...
\end&lbrace;center&rbrace;
</pre></example>

<para>Create a new paragraph consisting of a sequence of lines that are
centered within the left and right margins on the current page.  Use
double-backslash to get a line break at a particular spot (<pxref label="_005c_005c"><xrefnodename>\\</xrefnodename></pxref>).
<findex index="fn" spaces=" "><indexterm index="fn" number="254">\\ <r>(for <code>center</code>)</r></indexterm></findex>
If some text environment body is too long to fit on a line, &latex;
will insert line breaks that avoid hyphenation and avoid stretching or
shrinking any interword space.
</para>
<para>This environment inserts space above and below the text body.  See
<ref label="_005ccentering"><xrefnodename>\centering</xrefnodename></ref> to avoid such space, for example inside a <code>figure</code>
environment.
</para>
<para>This example produces three centered lines.  There is extra vertical
space between the last two lines.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;center&rbrace;
  A Thesis Submitted in Partial Fufillment \\
  of the Requirements of \\[0.5ex]
  the School of Environmental Engineering
\end&lbrace;center&rbrace;
</pre></example>

<para>In this example, depending on the page&textrsquo;s line width, &latex; may choose
a line break for the part before the double backslash.  If so, it will
center each of the two lines and if not it will center the single line.
Then &latex; will break at the double backslash, and will center the
ending.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;center&rbrace;
  My father considered that anyone who went to chapel and didn't drink 
  alcohol was not to be tolerated.\\ 
  I grew up in that belief.  --Richard Burton 
\end&lbrace;center&rbrace;
</pre></example>

<para>A double backslash after the final line is optional.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::          ">\centering</menunode><menudescription><pre xml:space="preserve">Declaration form of the <code>center</code> environment.
</pre></menudescription></menuentry></menu>


<node name="_005ccentering" spaces=" "><nodename>\centering</nodename><nodeup automatic="on">center</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\centering</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="255">\centering</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="181">centering text, declaration for</indexterm></cindex>

<para>A declaration that causes material in its scope to be centered.  It is
most often used inside an environment such as <code>figure</code>, or in a
<code>parbox</code>.
</para>
<para>Unlike the <code>center</code> environment, the <code>\centering</code> command does
not add vertical space above and below the text.
</para>
<para>It also does not start a new paragraph; it simply changes how &latex;
formats paragraph units.  If <code>ww &lbrace;\centering xx \\ yy&rbrace; zz</code> is
surrounded by blank lines then &latex; will create a paragraph whose
first line <samp>ww xx</samp> is centered and whose second line, not centered,
contains <samp>yy zz</samp>.  Usually what is desired is for the scope of the
declaration to contain a blank line or the <code>\end</code> command of an
environment such as <code>figure</code> or <code>table</code> that ends the
paragraph unit.  Thus, if <code>&lbrace;\centering xx \\ yy\par&rbrace; zz</code> is
surrounded by blank lines then it makes a new paragraph with two
centered lines <samp>xx</samp> and <samp>yy</samp>, followed by a new paragraph with
<samp>zz</samp> that is formatted as usual.  See also the following example.
</para>
<para>This example&textrsquo;s <code>\centering</code> causes the graphic to be horizontally
centered.  
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;figure&rbrace;
  \centering
  \includegraphics[width=0.6\textwidth]&lbrace;ctan_lion.png&rbrace;
  \caption&lbrace;CTAN Lion&rbrace;  \label&lbrace;fig:CTANLion&rbrace;
\end&lbrace;figure&rbrace;
</pre></example>

<para>The scope of the <code>\centering</code> ends with the <code>\end&lbrace;figure&rbrace;</code>.
</para>

</subsection>
</section>
<node name="description" spaces=" "><nodename>description</nodename><nodenext automatic="on">displaymath</nodenext><nodeprev automatic="on">center</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>description</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="256"><r>environment</r>, <code>description</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="257"><code>description</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="182">labelled lists, creating</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="183">description lists, creating</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;description&rbrace;
\item[<var>label of first item</var>] text of first item
\item[<var>label of second item</var>] text of second item
  ...
\end&lbrace;description&rbrace;
</pre></example>

<para>Environment to make a labeled list of items.  Each item&textrsquo;s <var>label</var> is
typeset in bold, and is flush left so that long labels continue into the
first line of the item text.  There must be at least one item; having
none causes the &latex; error <samp>Something's wrong--perhaps a
missing \item</samp>.
</para>
<para>This example shows the environment used for a sequence of definitions.
The labels <samp>lama</samp> and <samp>llama</samp> come out in boldface with their
left edges aligned on the left margin.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;definition&rbrace;
  \item[lama] A priest.
  \item[llama] A beast.
\end&lbrace;definition&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="258">\item</indexterm></findex>
<para>Start list items with the <code>\item</code> command (<pxref label="_005citem"><xrefnodename>\item</xrefnodename></pxref>).  Use the
optional labels, as in <code>\item[Main point]</code>, because there is
no sensible default.  Following the <code>\item</code> is optional text, which
may contain multiple paragraphs.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="184">bold typewriter, avoiding</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="185">typewriter labels in lists</indexterm></cindex>
<para>Since the labels are in bold style, if the label text calls for a font
change given in argument style (see <ref label="Font-styles"><xrefnodename>Font styles</xrefnodename></ref>) then it will come
out bold.  For instance, if the label text calls for typewriter with
<code>\item[\texttt&lbrace;label text&rbrace;]</code> then it will appear in bold
typewriter, if that is available. The simplest way to get non-bold
typewriter is to use declarative style: <code>\item[&lbrace;\tt label
text&rbrace;]</code>.  Similarly, get the standard roman font with <code>\item[&lbrace;\rm
label text&rbrace;]</code>.
</para>
<para>For other major &latex; labelled list environments, see <ref label="itemize"><xrefnodename>itemize</xrefnodename></ref>
and <ref label="enumerate"><xrefnodename>enumerate</xrefnodename></ref>.  Unlike those environments, nesting
<code>description</code> environments does not change the default label; it is
boldface and flush left at all levels.
</para>
<para>For information about list layout parameters, including the default
values, and for information about customizing list layout, see
<ref label="list"><xrefnodename>list</xrefnodename></ref>.  The package <file>enumitem</file> is useful for customizing
lists.
</para>
<para>This example changes the description labels to small caps.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\renewcommand&lbrace;\descriptionlabel&rbrace;[1]&lbrace;%
  &lbrace;\hspace&lbrace;\labelsep&rbrace;\textsc&lbrace;#1&rbrace;&rbrace;&rbrace;
</pre></example>


</section>
<node name="displaymath" spaces=" "><nodename>displaymath</nodename><nodenext automatic="on">document</nodenext><nodeprev automatic="on">description</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>displaymath</code></sectiontitle>
<!-- c http://tex.stackexchange.com/questions/40492/what-are-the-differences-between-align-equation-and-displaymath -->

<findex index="fn" spaces=" "><indexterm index="fn" number="259"><r>environment</r>, <code>displaymath</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="260"><code>displaymath</code> <r>environment</r></indexterm></findex>
        

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;displaymath&rbrace;
<var>math text</var>
\end&lbrace;displaymath&rbrace;
</pre></example>

<para>Environment to typeset the math text on its own line, in display style
and centered.  To make the text be flush-left use the global option
<code>fleqn</code>; see <ref label="Document-class-options"><xrefnodename>Document class options</xrefnodename></ref>.
</para>
<para>In the <code>displaymath</code> environment no equation number is added to the
math text. One way to get an equation number is to use the
<code>equation</code> environment (<pxref label="equation"><xrefnodename>equation</xrefnodename></pxref>).
</para>
<para>&latex; will not break the <var>math text</var> across lines.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="186"><r>package</r>, <code>amsmath</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="187"><code>amsmath</code> <r>package</r></indexterm></cindex>

<para>Note that the <file>amsmath</file> package has significantly more extensive
displayed equation facilities.  For example, there are a number of
ways in that package for having math text broken across lines.
</para>
<para>The construct <code>\[<var>math text</var>\]</code> is essentially a synonym for
<code>\begin&lbrace;displaymath&rbrace;<var>math text</var>\end&lbrace;displaymath&rbrace;</code> but the
latter is easier to work with in the source file; for instance,
searching for a square bracket may get false positives but the word
<code>displaymath</code> will likely be unique.  (The construct
<code>$$<var>math text</var>$$</code> from Plain&nbsp;&tex; is sometimes
mistakenly used as a synonym for <code>displaymath</code>.  It is not a
synonym, because the <code>displaymath</code> environment checks that it isn&textrsquo;t
started in math mode and that it ends in math mode begun by the matching
environment start, because the <code>displaymath</code> environment has
different vertical spacing, and because the <code>displaymath</code>
environment honors the <code>fleqn</code> option.)
</para>
<para>The output from this example is centered and alone on its line. 
</para><example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;displaymath&rbrace;
  \int_1^2 x^2\,dx=7/3
\end&lbrace;displaymath&rbrace;
</pre></example>
<para>Also, the integral sign is larger than the inline version  
<code>\( \int_1^2 x^2\,dx=7/3 \)</code> produces.
</para>

</section>
<node name="document" spaces=" "><nodename>document</nodename><nodenext automatic="on">enumerate</nodenext><nodeprev automatic="on">displaymath</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>document</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="261"><r>environment</r>, <code>document</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="262"><code>document</code> <r>environment</r></indexterm></findex>
        

<para>The <code>document</code> environment encloses the entire body of a document.
It is required in every &latex; document.  <xref label="Starting-and-ending"><xrefnodename>Starting and ending</xrefnodename></xref>.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::          ">\AtBeginDocument</menunode><menudescription><pre xml:space="preserve">Hook for commands at the start of the document.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">\AtEndDocument</menunode><menudescription><pre xml:space="preserve">Hook for commands at the end of the document.
</pre></menudescription></menuentry></menu>


<node name="_005cAtBeginDocument" spaces=" "><nodename>\AtBeginDocument</nodename><nodenext automatic="on">\AtEndDocument</nodenext><nodeup automatic="on">document</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\AtBeginDocument</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="263">\AtBeginDocument</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="188">beginning of document hook</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\AtBeginDocument&lbrace;<var>code</var>&rbrace;
</pre></example>

<para>Save <var>code</var> and execute it when <code>\begin&lbrace;document&rbrace;</code> is
executed, at the very end of the preamble.  The code is executed after
the font selection tables have been set up, so the normal font for the
document is the current font.  However, the code is executed as part of
the preamble so you cannot do any typesetting with it.
</para>
<para>You can issue this command more than once; the successive code lines
will be executed in the order that you gave them.
</para>

</subsection>
<node name="_005cAtEndDocument" spaces=" "><nodename>\AtEndDocument</nodename><nodeprev automatic="on">\AtBeginDocument</nodeprev><nodeup automatic="on">document</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\AtEndDocument</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="264">\AtEndDocument</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="189">end of document hook</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\AtEndDocument&lbrace;<var>code</var>&rbrace;
</pre></example>

<para>Save <var>code</var> and execute it near the end of the document.
Specifically, it is executed when <code>\end&lbrace;document&rbrace;</code> is executed,
before the final page is finished and before any leftover floating
environments are processed. If you want some of the code to be executed
after these two processes then include a <code>\clearpage</code> at the
appropriate point in <var>code</var>.
</para>
<para>You can issue this command more than once; the successive code lines
will be executed in the order that you gave them.
</para>

</subsection>
</section>
<node name="enumerate" spaces=" "><nodename>enumerate</nodename><nodenext automatic="on">eqnarray</nodenext><nodeprev automatic="on">document</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>enumerate</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="265"><r>environment</r>, <code>enumerate</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="266"><code>enumerate</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="190">lists of items, numbered</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;enumerate&rbrace;
\item[<var>optional label of first item</var>] text of first item
\item[<var>optional label of second item</var>] text of second item
...
\end&lbrace;enumerate&rbrace;
</pre></example>

<para>Environment to produce a numbered list of items.  The format of the
label numbering depends on the nesting level of this environment; see
below. The default top-level numbering is <samp>1.</samp>, <samp>2.</samp>,
etc. Each <code>enumerate</code> list environment must have at least one item;
having none causes the &latex; error <samp>Something's wrong--perhaps a
missing \item</samp>.
</para>
<para>This example gives the first two finishers in the 1908 Olympic marathon.
As a top-level list the labels would come out as <samp>1.</samp> and
<samp>2.</samp>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;enumerate&rbrace;
 \item Johnny Hayes (USA)
 \item Charles Hefferon (RSA) 
\end&lbrace;enumerate&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="267">\item</indexterm></findex>
<para>Start list items with the <code>\item</code> command (<pxref label="_005citem"><xrefnodename>\item</xrefnodename></pxref>).  If you
give <code>\item</code> an optional argument by following it with square
brackets, as in <code>\item[Interstitial label]</code>, then the next item
will continue the interrupted sequence (<pxref label="_005citem"><xrefnodename>\item</xrefnodename></pxref>).  That is, you
will get labels like <samp>1.</samp>, then <samp>Interstitial label</samp>, then
<samp>2.</samp>.  Following the <code>\item</code> is optional text, which may
contain multiple paragraphs.
</para>
<para>Enumerations may be nested within other <code>enumerate</code> environments,
or within any paragraph-making environment such as <code>itemize</code>
(<pxref label="itemize"><xrefnodename>itemize</xrefnodename></pxref>), up to four levels deep.  This gives &latex;&textrsquo;s
default for the format at each nesting level, where 1 is the top level,
the outermost level.
</para>
<enumerate first="1" endspaces=" ">
<listitem spaces=" "><para>arabic number followed by a period: <samp>1.</samp>, <samp>2.</samp>,&nbsp;&dots;
</para></listitem><listitem spaces=" "><para>lower case letter inside parentheses: <samp>(a)</samp>, <samp>(b)</samp>&nbsp;&dots;
</para></listitem><listitem spaces=" "><para>lower case roman numeral followed by a period: <samp>i.</samp>, <samp>ii.</samp>,&nbsp;&dots;
</para></listitem><listitem spaces=" "><para>upper case letter followed by a period: <samp>A.</samp>, <samp>B.</samp>,&nbsp;&dots;
</para></listitem></enumerate>

<findex index="fn" spaces=" "><indexterm index="fn" number="268">\enumi</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="269">\enumii</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="270">\enumiii</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="271">\enumiv</indexterm></findex>
<para>The <code>enumerate</code> environment uses the counters <code>\enumi</code> through
<code>\enumiv</code> (<pxref label="Counters"><xrefnodename>Counters</xrefnodename></pxref>).
</para>
<para>For other major &latex; labeled list environments, see
<ref label="description"><xrefnodename>description</xrefnodename></ref> and <ref label="itemize"><xrefnodename>itemize</xrefnodename></ref>.  For information about list layout
parameters, including the default values, and for information about
customizing list layout, see <ref label="list"><xrefnodename>list</xrefnodename></ref>.  The package <file>enumitem</file> is
useful for customizing lists.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="272">\labelenumi</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="273">\labelenumii</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="274">\labelenumiii</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="275">\labelenumiv</indexterm></findex>
<para>To change the format of the label use <code>\renewcommand</code>
(<pxref label="_005cnewcommand-_0026-_005crenewcommand"><xrefnodename>\newcommand &amp; \renewcommand</xrefnodename></pxref>) on the commands <code>\labelenumi</code>
through <code>\labelenumiv</code>. For instance, this first level list will be
labelled with uppercase letters, in boldface, and without a trailing
period.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="276">\Alph <r>example</r></indexterm></findex>
<example endspaces=" ">
<pre xml:space="preserve">\renewcommand&lbrace;\labelenumi&rbrace;&lbrace;\textbf&lbrace;\Alph&lbrace;enumi&rbrace;&rbrace;&rbrace;
\begin&lbrace;enumerate&rbrace;
  \item Shows as boldface A
  \item Shows as boldface B
\end&lbrace;enumerate&rbrace;
</pre></example>

<para>For a list of counter-labeling commands see <ref label="_005calph-_005cAlph-_005carabic-_005croman-_005cRoman-_005cfnsymbol"><xrefnodename>\alph \Alph \arabic
\roman \Roman \fnsymbol</xrefnodename></ref>.
</para>

</section>
<node name="eqnarray" spaces=" "><nodename>eqnarray</nodename><nodenext automatic="on">equation</nodenext><nodeprev automatic="on">enumerate</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>eqnarray</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="277"><r>environment</r>, <code>eqnarray</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="278"><code>eqnarray</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="191">equations, aligning</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="192">aligning equations</indexterm></cindex>

<cindex index="cp" spaces=" "><indexterm index="cp" number="193">align <r>environment, from <code>amsmath</code></r></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="194">amsmath <r>package, replacing <code>eqnarray</code></r></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="195">Madsen, Lars</indexterm></cindex>
<para>First, a caveat: the <code>eqnarray</code> environment is depreciated.  It has
infelicities that cannot be overcome, including spacing that is
inconsistent with other mathematics elements (see the article &textldquo;Avoid
eqnarray!&textrdquo;&noeos; by Lars Madsen
<url><urefurl>http://tug.org/TUGboat/tb33-1/tb103madsen.pdf</urefurl></url>).  New documents
should include the <file>amsmath</file> package and use the displayed
mathematics environments provided there, such as the <code>align</code>
environment.
</para>
<para>Nevertheless, for completeness and for a reference when working with old
documents, a synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;eqnarray&rbrace; 
  <var>first formula left</var>  &amp;<var>first formula middle</var>  &amp;<var>first formula right</var> \\
  ...
\end&lbrace;eqnarray&rbrace;
</pre></example>

<para>or 
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;eqnarray*&rbrace; 
  <var>first formula left</var>  &amp;<var>first formula middle</var>  &amp;<var>first formula right</var> \\
  ...
\end&lbrace;eqnarray*&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="279">\\ <r>(for <code>eqnarray</code>)</r></indexterm></findex>
<para>Display a sequence of equations or inequalities.  The left and right
sides are typeset in display mode, while the middle is typeset in text
mode.
</para>
<para>It is similar to a three-column <code>array</code> environment, with items
within a row separated by an ampersand&nbsp;(<code>&amp;</code>), and with rows
separated by double backslash&nbsp; <code>\\</code>).
<findex index="fn" spaces=" "><indexterm index="fn" number="280">\\* <r>(for <code>eqnarray</code>)</r></indexterm></findex>
The starred form of line break (<code>\\*</code>) can also be used to separate
equations, and will disallow a page break there (<pxref label="_005c_005c"><xrefnodename>\\</xrefnodename></pxref>).
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="281">\nonumber</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="196">equation numbers, omitting</indexterm></cindex>
<para>The unstarred form <code>eqnarray</code> places an equation number on every
line (using the <code>equation</code> counter), unless that line contains a
<code>\nonumber</code> command.  The starred form <code>eqnarray*</code> omits
equation numbering, while otherwise being the same.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="282">\lefteqn</indexterm></findex>
<para>The command <code>\lefteqn</code> is used for splitting long formulas across
lines. It typesets its argument in display style flush left in a box of
zero width.
</para>
<para>This example shows three lines.  The first two lines make an inequality,
while the third line has not entry on the left side.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;eqnarray*&rbrace;
  \lefteqn&lbrace;x_1+x_2+\cdots+x_n&rbrace;     \\
    &amp;\leq &amp;y_1+y_2+\cdots+y_n      \\
    &amp;=    &amp;z+y_3+\cdots+y_n
\end&lbrace;eqnarray*&rbrace;
</pre></example>


</section>
<node name="equation" spaces=" "><nodename>equation</nodename><nodenext automatic="on">figure</nodenext><nodeprev automatic="on">eqnarray</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>equation</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="283"><r>environment</r>, <code>equation</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="284"><code>equation</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="197">equations, environment for</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="198">formulas, environment for</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;equation&rbrace;
  math text
\end&lbrace;equation&rbrace;
</pre></example>

<para>Make a <code>displaymath</code> environment (<pxref label="displaymath"><xrefnodename>displaymath</xrefnodename></pxref>) with an
equation number in the right margin.
</para>
<para>The equation number is generated using the <code>equation</code> counter.
</para>
<para>You should have no blank lines between <code>\begin&lbrace;equation&rbrace;</code> and
<code>\begin&lbrace;equation&rbrace;</code>, or &latex; will tell you that there is a
missing dollar sign,&nbsp;$<code>$</code>.
</para>
<para>Note that the <file>amsmath</file> package has extensive displayed equation
facilities.  Those facilities are the best approach for such output in
new documents.
</para>

</section>
<node name="figure" spaces=" "><nodename>figure</nodename><nodenext automatic="on">filecontents</nodenext><nodeprev automatic="on">equation</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>figure</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="285"><r>environment</r>, <code>figure</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="286"><code>figure</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="199">inserting figures</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="200">figures, inserting</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;figure&rbrace;[<var>placement</var>]
  figure body
\caption[<var>loftitle</var>]&lbrace;<var>title</var>&rbrace;
\label&lbrace;<var>label&rbrace;</var>
\end&lbrace;figure&rbrace;
</pre></example>

<para>or
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;figure*&rbrace;[<var>placement</var>]
  figure body
\caption[<var>loftitle</var>]&lbrace;<var>title</var>&rbrace;
\label&lbrace;<var>label&rbrace;</var>
\end&lbrace;figure*&rbrace;
</pre></example>

<para>A class of floats (<pxref label="Floats"><xrefnodename>Floats</xrefnodename></pxref>).  Because they cannot be split across
pages, they are not typeset in sequence with the normal text but instead
are &textldquo;floated&textrdquo; to a convenient place, such as the top of a following
page.
</para>
<para>For the possible values of <var>placement</var> and their effect on the 
float placement algorithm, see <ref label="Floats"><xrefnodename>Floats</xrefnodename></ref>.
</para>
<para>The starred form <code>figure*</code> is used when a document is in
double-column mode (<pxref label="_005ctwocolumn"><xrefnodename>\twocolumn</xrefnodename></pxref>).  It produces a figure that
spans both columns, at the top of the page.  To add the possibility of
placing at a page bottom see the discussion of <var>placement</var> <code>b</code>
in <ref label="Floats"><xrefnodename>Floats</xrefnodename></ref>.
</para>
<para>The figure body is typeset in a <code>parbox</code> of width <code>\textwidth</code>
and so it can contain text, commands, etc.
</para>
<para>The label is optional; it is used for cross references (<pxref label="Cross-references"><xrefnodename>Cross
references</xrefnodename></pxref>).
<findex index="fn" spaces=" "><indexterm index="fn" number="287">\caption</indexterm></findex>
The optional <code>\caption</code> command specifies caption text for the
figure.  By default it is numbered.  If <var>loftitle</var> is present, it is
used in the list of figures instead of <var>title</var> (<pxref label="Tables-of-contents"><xrefnodename>Tables of
contents</xrefnodename></pxref>).
</para>
<para>This example makes a figure out of a graphic.  It requires one of the
packages <file>graphics</file> or <file>graphicx</file>.  The graphic, with its
caption, will be placed at the top of a page or, if it is pushed to the
end of the document, on a page of floats.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;figure&rbrace;[t]
  \centering
  \includegraphics[width=0.5\textwidth]&lbrace;CTANlion.png&rbrace;
  \caption&lbrace;The CTAN lion, by Duane Bibby&rbrace;
\end&lbrace;figure&rbrace;
</pre></example>


</section>
<node name="filecontents" spaces=" "><nodename>filecontents</nodename><nodenext automatic="on">flushleft</nodenext><nodeprev automatic="on">figure</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>filecontents</code>: Write an external file</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="288"><r>environment</r>, <code>filecontents</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="289"><code>filecontents</code> <r>environment</r></indexterm></findex>
        
<findex index="fn" spaces=" "><indexterm index="fn" number="290"><r>environment</r>, <code>filecontents*</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="291"><code>filecontents*</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="201">external files, writing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="202">writing external files</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;filecontents&rbrace;&lbrace;<var>filename</var>&rbrace;
  <var>text</var>
\end&lbrace;filecontents&rbrace;
</pre></example>

<para>or
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;filecontents*&rbrace;&lbrace;<var>filename</var>&rbrace;
  <var>text</var>
\end&lbrace;filecontents*&rbrace;
</pre></example>

<para>Create a file named <var>filename</var> and fill it with <var>text</var>.  The
unstarred version of the environment <code>filecontents</code> prefixes the
content of the created file with a header; see the example below.  The
starred version <code>filecontents*</code> does not include the header.
</para>
<para>This environment can be used anywhere in the preamble, although it often
appears before the <code>\documentclass</code> command.  It is typically used
when a source file requires a nonstandard style or class file.  The
environment will write that file to the directory containing the source
and thus make the source file self-contained.  Another use is to include
<code>bib</code> references in the file, again to make it self-contained.
</para>
<para>The environment checks whether a file of that name already exists and if
so, does not do anything.  There is a <file>filecontents</file> package that
redefines the <code>filecontents</code> environment so that instead of doing
nothing in that case, it will overwrite the existing file.
</para>
<para>For example, this document
</para>
<example endspaces=" ">
<pre xml:space="preserve">\documentclass&lbrace;article&rbrace;
\begin&lbrace;filecontents&rbrace;&lbrace;JH.sty&rbrace;
\newcommand&lbrace;\myname&rbrace;&lbrace;Jim Hef&lbrace;&rbrace;feron&rbrace;
\end&lbrace;filecontents&rbrace;
\usepackage&lbrace;JH&rbrace;
\begin&lbrace;document&rbrace;
Article by \myname.
\end&lbrace;document&rbrace;
</pre></example>

<para>produces this file <file>JH.sty</file>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">%% LaTeX2e file `JH.sty'
%% generated by the `filecontents' environment
%% from source `test' on 2015/10/12.
%%
\newcommand&lbrace;\myname&rbrace;&lbrace;Jim Hef&lbrace;&rbrace;feron&rbrace;
</pre></example>


</section>
<node name="flushleft" spaces=" "><nodename>flushleft</nodename><nodenext automatic="on">flushright</nodenext><nodeprev automatic="on">filecontents</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>flushleft</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="292"><r>environment</r>, <code>flushleft</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="293"><code>flushleft</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="203">left-justifying text, environment for</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="204">ragged right text, environment for</indexterm></cindex>

<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;flushleft&rbrace;
<var>line1</var> \\
<var>line2</var> \\
...
\end&lbrace;flushleft&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="294">\\ <r>for <code>flushleft</code></r></indexterm></findex>
<para>The <code>flushleft</code> environment allows you to create a paragraph
consisting of lines that are flush to the left-hand margin and ragged
right. Each line must be terminated with the string <code>\\</code>.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::        ">\raggedright</menunode><menudescription><pre xml:space="preserve">Declaration form of the <code>flushleft</code> environment.
</pre></menudescription></menuentry></menu>


<node name="_005craggedright" spaces=" "><nodename>\raggedright</nodename><nodeup automatic="on">flushleft</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\raggedright</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="295">\raggedright</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="205">ragged right text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="206">left-justifying text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="207">justification, ragged right</indexterm></cindex>

<para>The <code>\raggedright</code> declaration corresponds to the
<code>flushleft</code> environment.  This declaration can be used inside an
environment such as <code>quote</code> or in a <code>parbox</code>.
</para>
<para>Unlike the <code>flushleft</code> environment, the <code>\raggedright</code>
command does not start a new paragraph; it only changes how &latex;
formats paragraph units.  To affect a paragraph unit&textrsquo;s format, the
scope of the declaration must contain the blank line or <code>\end</code>
command that ends the paragraph unit.
</para>

</subsection>
</section>
<node name="flushright" spaces=" "><nodename>flushright</nodename><nodenext automatic="on">itemize</nodenext><nodeprev automatic="on">flushleft</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>flushright</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="296"><r>environment</r>, <code>flushright</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="297"><code>flushright</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="208">ragged left text, environment for</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="209">right-justifying text, environment for</indexterm></cindex>

<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;flushright&rbrace;
<var>line1</var> \\
<var>line2</var> \\
...
\end&lbrace;flushright&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="298">\\ (for <code>flushright</code>)</indexterm></findex>
<para>The <code>flushright</code> environment allows you to create a paragraph
consisting of lines that are flush to the right-hand margin and ragged
left.  Each line must be terminated with the control sequence <code>\\</code>.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::   ">\raggedleft</menunode><menudescription><pre xml:space="preserve">Declaration form of the <code>flushright</code> environment.
</pre></menudescription></menuentry></menu>


<node name="_005craggedleft" spaces=" "><nodename>\raggedleft</nodename><nodeup automatic="on">flushright</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\raggedleft</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="299">\raggedleft</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="210">ragged left text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="211">justification, ragged left</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="212">right-justifying text</indexterm></cindex>

<para>The <code>\raggedleft</code> declaration corresponds to the
<code>flushright</code> environment.  This declaration can be used inside an
environment such as <code>quote</code> or in a <code>parbox</code>.
</para>
<para>Unlike the <code>flushright</code> environment, the <code>\raggedleft</code>
command does not start a new paragraph; it only changes how &latex;
formats paragraph units.  To affect a paragraph unit&textrsquo;s format, the
scope of the declaration must contain the blank line or <code>\end</code>
command that ends the paragraph unit.
</para>

</subsection>
</section>
<node name="itemize" spaces=" "><nodename>itemize</nodename><nodenext automatic="on">letter</nodenext><nodeprev automatic="on">flushright</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>itemize</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="300"><r>environment</r>, <code>itemize</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="301"><code>itemize</code> <r>environment</r></indexterm></findex>
        
<findex index="fn" spaces=" "><indexterm index="fn" number="302">\item</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="213">lists of items</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="214">unordered lists</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="215">bulleted lists</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;itemize&rbrace;
\item[<var>optional label of first item</var>] text of first item
\item[<var>optional label of second item</var>] text of second item
...
\end&lbrace;itemize&rbrace;
</pre></example>

<para>The <code>itemize</code> environment produces an &textldquo;unordered&textrdquo;, &textldquo;bulleted&textrdquo;
list.  The format of the label numbering depends on the nesting level of
this environment; see below.  Each <code>itemize</code> list environment must
have at least one item; having none causes the &latex; error
<samp>Something's wrong--perhaps a missing \item</samp>.
</para>
<para>This example gives a two-item list.  As a top-level list each label
would come out as a bullet, &bullet;.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;itemize&rbrace;
 \item Pencil and watercolor sketch by Cassandra
 \item Rice portrait 
\end&lbrace;itemize&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="303">\item</indexterm></findex>
<para>Start list items with the <code>\item</code> command (<pxref label="_005citem"><xrefnodename>\item</xrefnodename></pxref>).  If you
give <code>\item</code> an optional argument by following it with square
brackets, as in <code>\item[Optional label]</code>, then by default it will
appear in bold and be flush right, so it could extend into the left
margin.  For labels that are flush left see the <ref label="description"><xrefnodename>description</xrefnodename></ref>
environment. Following the <code>\item</code> is optional text, which may
contain multiple paragraphs.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="304">\labelitemi</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="305">\labelitemii</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="306">\labelitemiii</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="307">\labelitemiv</indexterm></findex>
<para>Itemized lists can be nested within one another, up to four levels deep.
They can also be nested within other paragraph-making environments, such
as <code>enumerate</code> (<pxref label="enumerate"><xrefnodename>enumerate</xrefnodename></pxref>).  The <code>itemize</code> environment
uses the commands <code>\labelitemi</code> through <code>\labelitemiv</code> to
produce the default label (this also uses the convention of lower case
roman numerals at the end of the command names that signify the nesting
level).  These are the default marks at each level.
</para>
<enumerate first="1" endspaces=" ">
<listitem spaces=" "><para>&bullet; (bullet, from <code>\textbullet</code>)
</para></listitem><listitem spaces=" "><para><b>-<w>-</w></b> (bold en-dash, from <code>\normalfont\bfseries\textendash</code>)
</para></listitem><listitem spaces=" "><para>* (asterisk, from <code>\textasteriskcentered</code>)
</para></listitem><listitem spaces=" "><para>. (centered dot, rendered here as a period, from <code>\textperiodcentered</code>)
</para></listitem></enumerate>

<para>Change the labels with <code>\renewcommand</code>.  For instance, this makes
the first level use diamonds.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\renewcommand&lbrace;\labelitemi&rbrace;&lbrace;$\diamond$&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="308">\leftmargin</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="309">\leftmargini</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="310">\leftmarginii</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="311">\leftmarginiii</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="312">\leftmarginiv</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="313">\leftmarginv</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="314">\leftmarginvi</indexterm></findex>
<para>The distance between the left margin of the enclosing environment and
the left margin of the <code>itemize</code> list is determined by the
parameters <code>\leftmargini</code> through <code>\leftmarginvi</code>.  (Note the
convention of using lower case roman numerals a the end of the command
name to denote the nesting level.)  The defaults are: <code>2.5em</code> in
level 1 (<code>2em</code> in two-column mode), <code>2.2em</code> in level 2,
<code>1.87em</code> in level 3, and <code>1.7em</code> in level 4, with smaller
values for more deeply nested levels.
</para>
<para>For other major &latex; labeled list environments, see
<ref label="description"><xrefnodename>description</xrefnodename></ref> and <ref label="enumerate"><xrefnodename>enumerate</xrefnodename></ref>.  For information about list
layout parameters, including the default values, and for information
about customizing list layout, see <ref label="list"><xrefnodename>list</xrefnodename></ref>.  The package
<file>enumitem</file> is useful for customizing lists.
</para>
<para>This example greatly reduces the margin space for outermost itemized
lists.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\setlength&lbrace;\leftmargini&rbrace;&lbrace;1.25em&rbrace; % default 2.5em
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="315">\parskip <r>example</r></indexterm></findex>
<para>Especially for lists with short items, it may be desirable to elide
space between items.  Here is an example defining an <code>itemize*</code>
environment with no extra spacing between items, or between paragraphs
within a single item (<code>\parskip</code> is not list-specific,
<pxref label="_005cparskip"><xrefnodename>\parskip</xrefnodename></pxref>):
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newenvironment&lbrace;itemize*&rbrace;%
  &lbrace;\begin&lbrace;itemize&rbrace;%
    \setlength&lbrace;\itemsep&rbrace;&lbrace;0pt&rbrace;%
    \setlength&lbrace;\parsep&rbrace;&lbrace;0pt&rbrace;&rbrace;%
    \setlength&lbrace;\parskip&rbrace;&lbrace;0pt&rbrace;&rbrace;%
  &lbrace;\end&lbrace;itemize&rbrace;&rbrace;
</pre></example>


</section>
<node name="letter" spaces=" "><nodename>letter</nodename><nodenext automatic="on">list</nodenext><nodeprev automatic="on">itemize</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>letter</code> environment: writing letters</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="316"><r>environment</r>, <code>letter</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="317"><code>letter</code> <r>environment</r></indexterm></findex>
        

<para>This environment is used for creating letters.  <xref label="Letters"><xrefnodename>Letters</xrefnodename></xref>.
</para>

</section>
<node name="list" spaces=" "><nodename>list</nodename><nodenext automatic="on">math</nodenext><nodeprev automatic="on">letter</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>list</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="318"><r>environment</r>, <code>list</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="319"><code>list</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="216">lists of items, generic</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;list&rbrace;&lbrace;<var>labeling</var>&rbrace;&lbrace;<var>spacing</var>&rbrace;
\item[<var>optional label of first item</var>] text of first item
\item[<var>optional label of second item</var>] text of second item
...
\end&lbrace;list&rbrace;
</pre></example>

<para>The <code>list</code> environment is a generic environment for constructing
more specialized lists.  It is most often used to create lists via the
<code>description</code>, <code>enumerate</code>, and <code>itemize</code> environments
(<pxref label="description"><xrefnodename>description</xrefnodename></pxref>, <ref label="enumerate"><xrefnodename>enumerate</xrefnodename></ref>, and <ref label="itemize"><xrefnodename>itemize</xrefnodename></ref>).
</para>
<para>Also, many standard &latex; environments that are not visually lists
are constructed using <code>list</code>, including <code>quotation</code>,
<code>quote</code>, <code>center</code>, <code>verbatim</code>, and plenty more
(<pxref label="quotation-and-quote"><xrefnodename>quotation and quote</xrefnodename></pxref>, <pxref label="center"><xrefnodename>center</xrefnodename></pxref>, <pxref label="flushright"><xrefnodename>flushright</xrefnodename></pxref>).
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="217"><r>package</r>, <code>enumitem</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="218"><code>enumitem</code> <r>package</r></indexterm></cindex>

<para>The third-party package <code>enumitem</code> is useful for customizing lists.
Here, we describe the <code>list</code> environment by defining a new custom
environment.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcounter&lbrace;namedlistcounter&rbrace;  % number the items
\newenvironment&lbrace;named&rbrace;
  &lbrace;\begin&lbrace;list&rbrace;
     &lbrace;Item~\Roman&lbrace;namedlistcounter&rbrace;.&rbrace; % labeling argument
     &lbrace;\usecounter&lbrace;namedlistcounter&rbrace;   % spacing argument
      \setlength&lbrace;\leftmargin&rbrace;&lbrace;3.5em&rbrace;&rbrace; % still spacing arg
  &rbrace;
  &lbrace;\end&lbrace;list&rbrace;&rbrace;

\begin&lbrace;named&rbrace;
  \item Shows as ``Item~I.''
  \item[Special label.] Shows as ``Special label.''
  \item Shows as ``Item~II.''
\end&lbrace;named&rbrace;
</pre></example>

<para>The <code>list</code> environment&textrsquo;s mandatory first argument,
<var>labeling</var>, specifies the default labeling of list items.  It can
contain text and &latex; commands, as above where it contains both
<samp>Item</samp> and <samp>\Roman&lbrace;...&rbrace;</samp>.  &latex; forms the label by
putting the <var>labeling</var> argument in a box of width
<code>\labelwidth</code>.  If the label is wider than that, the additional
material extends to the right.  When making an instance of a list you
can override the default labeling by giving <code>\item</code> an optional
argument by including square braces and the text, as in the above
<code>\item[Special label.]</code>; <pxref label="_005citem"><xrefnodename>\item</xrefnodename></pxref>.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="320">\makelabel</indexterm></findex>
<para>The label box is constructed by the command <code>\makelabel</code>.  By
default it positions the contents flush right.  It takes one argument,
the label.  It typesets the contents in LR mode. An example of changing
its definition is that to the above example before the definition of the
<code>named</code> environment add
<code>\newcommand&lbrace;\namedmakelabel&rbrace;[1]&lbrace;\textsc&lbrace;#1&rbrace;&rbrace;</code>, and between
the <code>\setlength</code> command and the parenthesis that closes the
<var>spacing</var> argument also add <code>\let\makelabel\namedmakelabel</code>.
Then the items will be typeset in small caps.  Similarly, changing the
second code line to <code>\let\makelabel\fbox</code> puts the labels inside a
framed box.  Another example is at the bottom of this entry.
</para>
<para>The mandatory second argument <var>spacing</var> can have a list of
commands to redefine the spacing parameters for the list, such as
<code>\setlength&lbrace;\labelwidth&rbrace;&lbrace;2em&rbrace;</code>.  If this argument is empty,
i.e., <code>&lbrace;&rbrace;</code>, then the list will have the default spacing given
below.  To number the items using a counter, put
<code>\usecounter&lbrace;<var>countername</var>&rbrace;</code> in this argument
(<pxref label="_005cusecounter"><xrefnodename>\usecounter</xrefnodename></pxref>).
</para>
<para>Below are the spacing parameters for list formatting.  See also the
figure below.  Each is a length (<pxref label="Lengths"><xrefnodename>Lengths</xrefnodename></pxref>).  The vertical
spaces are normally rubber lengths, with <code>plus</code> and <code>minus</code>
components, to give &tex; flexibility in setting the page.  Change
each with a command such as <code>\setlength&lbrace;itemsep&rbrace;&lbrace;2pt plus1pt
minus1pt&rbrace;</code>.  For some effects these lengths should be zero or
negative.  Default values for derived environments such as
<code>itemize</code> can be changed from the values shown here for the basic
<code>list</code>.
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="321">\itemindent</indexterm>\itemindent</itemformat></item>
</tableterm><tableitem><para>Extra horizontal space indentation, beyond <code>leftmargin</code>, of the
first line each item.  Its default value is <code>0pt</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="322">\itemsep</indexterm>\itemsep</itemformat></item>
</tableterm><tableitem><para>Vertical space between items, beyond the <code>\parsep</code>.  The defaults
for the first three levels in &latex;&textrsquo;s <samp>article</samp>, <samp>book</samp>,
and <samp>report</samp> classes at 10 point size are: <code>4pt plus2pt
minus1pt</code>, <code>\parsep</code> (that is, <code>2pt plus1pt minus1pt</code>), and
<code>\topsep</code> (that is, <code>2pt plus1pt minus1pt</code>).  The defaults at
11 point are: <code>4.5pt plus2pt minus1pt</code>, <code>\parsep</code> (that is,
<code>2pt plus1pt minus1pt</code>), and <code>topsep</code> (that is, <code>2pt
plus1pt minus1pt</code>).  The defaults at 12 point are: <code>5pt plus2.5pt
minus1pt</code>, <code>\parsep</code> (that is, <code>2.5pt plus1pt minus1pt</code>), and
<code>\topsep</code> (that is, <code>2.5pt plus1pt minus1pt</code>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="323">\labelsep</indexterm>\labelsep</itemformat></item>
</tableterm><tableitem><para>Horizontal space between the label and text of an item.
The default for &latex;&textrsquo;s <samp>article</samp>, <samp>book</samp>,
and <samp>report</samp> classes is <code>0.5em</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="324">\labelwidth</indexterm>\labelwidth</itemformat></item>
</tableterm><tableitem><para>Horizontal width.  The box containing the label is nominally this wide.
If <code>\makelabel</code> returns text that is wider than this then the first
line of the item will be indented to make room for this extra material.
If <code>\makelabel</code> returns text of width less than or equal to
<code>\labelwidth</code> then &latex;&textrsquo;s default is that the label is typeset
flush right in a box of this width.
</para>
<para>The left edge of the label box is
<code>\leftmargin</code>+<code>\itemindent</code>-<code>\labelsep</code>-<code>\labelwidth</code>
from the left margin of the enclosing environment.
</para>
<para>The default for &latex;&textrsquo;s <samp>article</samp>, <samp>book</samp>, and
<samp>report</samp> classes at the top level is
<code>\leftmargini</code>-<code>\labelsep</code>, (which is <code>2em</code> in one column
mode and <code>1.5em</code> in two column mode).  At the second level it is
<code>\leftmarginii</code>-<code>\labelsep</code>, and at the third level it is
<code>\leftmarginiii</code>-<code>\labelsep</code>.  These definitions make the
label&textrsquo;s left edge coincide with the left margin of the enclosing
environment.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="325">\leftmargin</indexterm>\leftmargin</itemformat></item>
</tableterm><tableitem><para>Horizontal space between the left margin of the enclosing environment
(or the left margin of the page if this is a top-level list), and the
left margin of this list.  It must be non-negative.
</para>
<para>In the standard &latex; document classes, a top-level list has this set
to the value of <code>\leftmargini</code>, while a list that is nested inside
a top-level list has this margin set to <code>\leftmarginii</code>.  More
deeply nested lists get the values of <code>\leftmarginiii</code> through
<code>\leftmarginvi</code>.  (Nesting greater than level five generates the
error message <samp>Too deeply nested</samp>.)
</para>
<para>The defaults for the first three levels in &latex;&textrsquo;s <samp>article</samp>,
<samp>book</samp>, and <samp>report</samp> classes are: <code>\leftmargini</code> is
<code>2.5em</code> (in two column mode, <code>2em</code>), <code>\leftmarginii</code> is
<code>2.2em</code>, and <code>\leftmarginiii</code> is <code>1.87em</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="326">\listparindent</indexterm>\listparindent</itemformat></item>
</tableterm><tableitem><para>Horizontal space of additional line indentation, beyond
<code>\leftmargin</code>, for second and subsequent paragraphs within a list
item.  A negative value makes this an &textldquo;outdent&textrdquo;.  Its default value
is <code>0pt</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="327">\parsep</indexterm>\parsep</itemformat></item>
</tableterm><tableitem><para>Vertical space between paragraphs within an item.  In the <samp>book</samp>
and <samp>article</samp> classes The defaults for the first three levels in
&latex;&textrsquo;s <samp>article</samp>, <samp>book</samp>, and <samp>report</samp> classes at 10
point size are: <code>4pt plus2pt minus1pt</code>, <code>2pt plus1pt
minus1pt</code>, and <code>0pt</code>.  The defaults at 11 point size are:
<code>4.5pt plus2pt minus1pt</code>, <code>2pt plus1pt minus1pt</code>, and
<code>0pt</code>.  The defaults at 12 point size are: <code>5pt plus2.5pt
minus1pt</code>, <code>2.5pt plus1pt minus1pt</code>, and <code>0pt</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="328">\partopsep</indexterm>\partopsep</itemformat></item>
</tableterm><tableitem><para>Vertical space added, beyond <code>\topsep</code>+<code>\parskip</code>, to the top
and bottom of the entire environment if the list instance is preceded by
a blank line.  (A blank line in the &latex; source before the list
changes spacing at both the top and bottom of the list; whether the line
following the list is blank does not matter.)
</para>
<para>The defaults for the first three levels in &latex;&textrsquo;s <samp>article</samp>,
<samp>book</samp>, and <samp>report</samp> classes at 10 point size are: <code>2pt
plus1 minus1pt</code>, <code>2pt plus1pt minus1pt</code>, and <code>1pt plus0pt
minus1pt</code>.  The defaults at 11 point are: <code>3pt plus1pt minus1pt</code>,
<code>3pt plus1pt minus1pt</code>, and <code>1pt plus0pt minus1pt</code>).  The
defaults at 12 point are: <code>3pt plus2pt minus3pt</code>, <code>3pt plus2pt
minus2pt</code>, and <code>1pt plus0pt minus1pt</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="329">\rightmargin</indexterm>\rightmargin</itemformat></item>
</tableterm><tableitem><para>Horizontal space between the right margin of the list and the right
margin of the enclosing environment.  Its default value is <code>0pt</code>.
It must be non-negative.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="330">\topsep</indexterm>\topsep</itemformat></item>
</tableterm><tableitem><para>Vertical space added to both the top and bottom of the list, in addition
to <code>\parskip</code> (<pxref label="_005cparskip"><xrefnodename>\parskip</xrefnodename></pxref>).  The defaults for the first three
levels in &latex;&textrsquo;s <samp>article</samp>, <samp>book</samp>, and <samp>report</samp>
classes at 10 point size are: <code>8pt plus2pt minus4pt</code>, <code>4pt
plus2pt minus1pt</code>, and <code>2pt plus1pt minus1pt</code>.  The defaults at 11
point are: <code>9pt plus3pt minus5pt</code>, <code>4.5pt plus2pt minus1pt</code>,
and <code>2pt plus1pt minus1pt</code>.  The defaults at 12 point are:
<code>10pt plus4pt minus6pt</code>, <code>5pt plus2.5pt minus1pt</code>, and
<code>2.5pt plus1pt minus1pt</code>.
</para>
</tableitem></tableentry></ftable>

<para>This shows the horizontal and vertical distances.
</para>
<float type="" endspaces=" ">
<image><imagefile>latex2e-figures/list</imagefile><imagewidth>3.21in</imagewidth><imageextension>.png</imageextension></image>
</float>

<para>The lengths shown are listed below.  The key relationship is that the
right edge of the bracket for <var>h1</var> equals the right edge of the
bracket for <var>h4</var>, so that the left edge of the label box is at
<var>h3</var>+<var>h4</var>-(<var>h0</var>+<var>h1</var>).
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="var">v0</itemformat></item>
</tableterm><tableitem><para><math><code>&backslash;topsep</code> + <code>&backslash;parskip</code></math> if
the list environment does not start a new paragraph, and
<code>\topsep</code>+<code>\parskip</code>+<code>\partopsep</code> if it does
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">v1</itemformat></item>
</tableterm><tableitem><para><code>\parsep</code>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">v2</itemformat></item>
</tableterm><tableitem><para><code>\itemsep</code>+<code>\parsep</code>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">v3</itemformat></item>
</tableterm><tableitem><para>Same as <var>v0</var>.  (This space is affected by whether a blank line
appears in the source above the environment; whether a blank line
appears in the source below the environment does not matter.)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">h1</itemformat></item>
</tableterm><tableitem><para><code>\labelsep</code>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">h2</itemformat></item>
</tableterm><tableitem><para><code>\listparindent</code>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">h3</itemformat></item>
</tableterm><tableitem><para><code>\leftmargin</code>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">h4</itemformat></item>
</tableterm><tableitem><para><code>\itemindent</code>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">h5</itemformat></item>
</tableterm><tableitem><para><code>\rightmargin</code>
</para>
</tableitem></tableentry></table>

<para>The list&textrsquo;s left and right margins, shown above as <var>h3</var> and <var>h5</var>,
are with respect to the ones provided by the surrounding environment, or
with respect to the page margins for a top-level list.  The line width
used for typesetting the list items is <code>\linewidth</code> (<pxref label="Page-layout-parameters"><xrefnodename>Page
layout parameters</xrefnodename></pxref>).  For instance, set the list&textrsquo;s left margin to be one
quarter of the distance between the left and right margins of the
enclosing environment with
<code>\setlength&lbrace;\leftmargin&rbrace;&lbrace;0.25\linewidth&rbrace;</code>.
</para>
<para>Page breaking in a list structure is controlled by the three
parameters below. For each, the &latex; default is
<code>-\&arobase;lowpenalty</code>, that is, <code>-51</code>.  Because it is negative,
it somewhat encourages a page break at each spot.  Change it with,
e.g., <code>\&arobase;beginparpenalty=9999</code>; a value of 10000 prohibits a
page break.
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="331">\&arobase;beginparpenalty</indexterm>\&arobase;beginparpenalty</itemformat></item>
</tableterm><tableitem><para>The page breaking penalty for breaking before the list (default <code>-51</code>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="332">\&arobase;itempenalty</indexterm>\&arobase;itempenalty</itemformat></item>
</tableterm><tableitem><para>The page breaking penalty for breaking before a list item (default <code>-51</code>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="333">\&arobase;endparpenalty</indexterm>\&arobase;endparpenalty</itemformat></item>
</tableterm><tableitem><para>The page breaking penalty for breaking after a list (default <code>-51</code>).
</para>
</tableitem></tableentry></ftable>

<para>This example has the labels in red.  They are numbered, and the left
edge of the label lines up with the left edge of the item text.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usepackage&lbrace;color&rbrace;
\newcounter&lbrace;cnt&rbrace;  
\newcommand&lbrace;\makeredlabel&rbrace;[1]&lbrace;\textcolor&lbrace;red&rbrace;&lbrace;#1.&rbrace;&rbrace;
\newenvironment&lbrace;redlabel&rbrace;
  &lbrace;\begin&lbrace;list&rbrace;
    &lbrace;\arabic&lbrace;cnt&rbrace;&rbrace;
    &lbrace;\usecounter&lbrace;cnt&rbrace;
     \setlength&lbrace;\labelwidth&rbrace;&lbrace;0em&rbrace;
     \setlength&lbrace;\labelsep&rbrace;&lbrace;0.5em&rbrace;
     \setlength&lbrace;\leftmargin&rbrace;&lbrace;1.5em&rbrace;
     \setlength&lbrace;\itemindent&rbrace;&lbrace;0.5em&rbrace; % equals \labelwidth+\labelsep
     \let\makelabel=\makeredlabel
    &rbrace;
  &rbrace;
&lbrace;\end&lbrace;list&rbrace; &rbrace;
</pre></example>

<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::          ">\item</menunode><menudescription><pre xml:space="preserve">An entry in a list.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::       ">trivlist</menunode><menudescription><pre xml:space="preserve">A restricted form of <code>list</code>.
</pre></menudescription></menuentry></menu>


<node name="_005citem" spaces=" "><nodename>\item</nodename><nodenext automatic="on">trivlist</nodenext><nodeup automatic="on">list</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\item</code>: An entry in a list</sectiontitle>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\item text of item
</pre></example>

<para>or
</para><example endspaces=" ">
<pre xml:space="preserve">\item[<var>optional-label</var>] text of item
</pre></example>

<para>An entry in a list.  The entries are prefixed by a label, whose default
depends on the list type.
</para>
<para>Because the optional label is surrounded by square brackets
<samp>[...]</samp>, if you have an item whose text starts with <samp>[</samp>, you
have to to hide the bracket inside curly braces, as in: <code>\item
&lbrace;[&rbrace; is an open square bracket</code>; otherwise, &latex; will think it
marks the start of an optional label.
</para>
<para>Similarly, if the item does have the optional label and you need a
close square bracket inside that label, you must hide it in the same
way: <code>\item[Close square bracket, &lbrace;]&rbrace;]</code>.  <xref label="LaTeX-command-syntax"><xrefnodename>&latex;
command syntax</xrefnodename></xref>.
</para>
<para>In this example the enumerate list has two items that use the default
label and one that uses the optional label.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;enumerate&rbrace;
  \item Moe
  \item[sometimes] Shemp
  \item Larry
\end&lbrace;enumerate&rbrace;
</pre></example>

<para>The first item is labelled <samp>1.</samp>, the second item is labelled
<samp>sometimes</samp>, and the third item is labelled <samp>2.</samp>.  Because
of the optional label in the second item, the third item is not
labelled&nbsp;<samp>3.</samp>.
</para>   

</subsection>
<node name="trivlist" spaces=" "><nodename>trivlist</nodename><nodeprev automatic="on">\item</nodeprev><nodeup automatic="on">list</nodeup></node>
<subsection spaces=" "><sectiontitle><code>trivlist</code>: A restricted form of <code>list</code></sectiontitle>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;trivlist&rbrace;
  ...
\end&lbrace;trivlist&rbrace;
</pre></example>

<para>A restricted version of the list environment, in which margins are not
indented and an <code>\item</code> without an optional argument produces no
text.  It is most often used in macros, to define an environment where
the <code>\item</code> command as part of the environment&textrsquo;s definition.  For
instance, the <code>center</code> environment is defined essentially like
this:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newenvironment&lbrace;center&rbrace;
  &lbrace;\begin&lbrace;trivlist&rbrace;\centering\item\relax&rbrace;
  &lbrace;\end&lbrace;trivlist&rbrace;&rbrace;
</pre></example>

<para>Using <code>trivlist</code> in this way allows the macro to inherit some
common code: combining vertical space of two adjacent environments;
detecting whether the text following the environment should be
considered a new paragraph or a continuation of the previous one;
adjusting the left and right margins for possible nested list
environments.
</para>
<para>Specifically, <code>trivlist</code> uses the current values of the list
parameters (<pxref label="list"><xrefnodename>list</xrefnodename></pxref>), except that <code>\parsep</code> is set to the
value of <code>\parskip</code>, and <code>\leftmargin</code>, <code>\labelwidth</code>,
and <code>\itemindent</code> are set to zero.
</para>
<para>This example outputs the items as two paragraphs, except that (by
default) they have no paragraph indent and are vertically separated.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;trivlist&rbrace;
\item The \textit&lbrace;Surprise&rbrace; is not old; no one would call her old.
\item She has a bluff bow, lovely lines.
\end&lbrace;trivlist&rbrace;
</pre></example>


</subsection>
</section>
<node name="math" spaces=" "><nodename>math</nodename><nodenext automatic="on">minipage</nodenext><nodeprev automatic="on">list</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>math</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="334"><r>environment</r>, <code>math</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="335"><code>math</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="219">in-line formulas</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;math&rbrace;
<var>math</var>
\end&lbrace;math&rbrace;
</pre></example>

<para>The <code>math</code> environment inserts given <var>math</var> material within
the running text.  <code>\(...\)</code> and <code>$...$</code> are synonyms.
<xref label="Math-formulas"><xrefnodename>Math formulas</xrefnodename></xref>.
</para>

</section>
<node name="minipage" spaces=" "><nodename>minipage</nodename><nodenext automatic="on">picture</nodenext><nodeprev automatic="on">math</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>minipage</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="336"><r>environment</r>, <code>minipage</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="337"><code>minipage</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="220">minipage, creating a</indexterm></cindex>

<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;minipage&rbrace;[<var>position</var>][<var>height</var>][<var>inner-pos</var>]&lbrace;<var>width</var>&rbrace;
<var>text</var>
\end&lbrace;minipage&rbrace;
</pre></example>

<para>The <code>minipage</code> environment typesets its body <var>text</var> in a
block that will not be broken across pages.  This is similar to the
<code>\parbox</code> command (<pxref label="_005cparbox"><xrefnodename>\parbox</xrefnodename></pxref>), but unlike <code>\parbox</code>,
other paragraph-making environments can be used inside a minipage.
</para>
<!-- c (xxref positions) -->
<para>The arguments are the same as for <code>\parbox</code> (<pxref label="_005cparbox"><xrefnodename>\parbox</xrefnodename></pxref>).
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="221">indentation of paragraphs, in minipage</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="222">paragraph indentation, in minipage</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="338">\parindent</indexterm></findex>
<para>By default, paragraphs are not indented in the <code>minipage</code>
environment.  You can restore indentation with a command such as
<code>\setlength&lbrace;\parindent&rbrace;&lbrace;1pc&rbrace;</code> command.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="223">footnotes in figures</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="224">figures, footnotes in</indexterm></cindex>
<para>Footnotes in a <code>minipage</code> environment are handled in a way that is
particularly useful for putting footnotes in figures or tables.  A
<code>\footnote</code> or <code>\footnotetext</code> command puts the footnote at
the bottom of the minipage instead of at the bottom of the page, and it
uses the <code>\mpfootnote</code> counter instead of the ordinary
<code>footnote</code> counter (<pxref label="Counters"><xrefnodename>Counters</xrefnodename></pxref>).
</para>
<para>However, don&textrsquo;t put one minipage inside another if you are using
footnotes; they may wind up at the bottom of the wrong minipage.
</para>

</section>
<node name="picture" spaces=" "><nodename>picture</nodename><nodenext automatic="on">quotation and quote</nodenext><nodeprev automatic="on">minipage</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>picture</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="339"><r>environment</r>, <code>picture</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="340"><code>picture</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="225">creating pictures</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="226">pictures, creating</indexterm></cindex>

<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;picture&rbrace;(<var>width</var>,<var>height</var>)(<var>xoffset</var>,<var>yoffset</var>)
&dots; <var>picture commands</var> &dots;
\end&lbrace;picture&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="341">\unitlength</indexterm></findex>
<para>The <code>picture</code> environment allows you to create just about any
kind of picture you want containing text, lines, arrows and circles.
You tell &latex; where to put things in the picture by specifying
their coordinates.  A coordinate is a number that may have a decimal
point and a minus sign&textmdash;a number like <code>5</code>, <code>0.3</code> or
<code>-3.1416</code>.  A coordinate specifies a length in multiples of the
unit length <code>\unitlength</code>, so if <code>\unitlength</code> has been set
to <code>1cm</code>, then the coordinate 2.54 specifies a length of 2.54
centimeters.
</para>
<para>You should only change the value of <code>\unitlength</code>, using the
<code>\setlength</code> command, outside of a <code>picture</code> environment.
The default value is <code>1pt</code>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="227"><r>package</r>, <code>picture</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="228"><code>picture</code> <r>package</r></indexterm></cindex>

<para>The <code>picture</code> package redefine the <code>picture</code> environment so
that everywhere a number is used in a <var>picture commands</var> to specify
a coordinate, one can use alternatively a length. Be aware however that
this will prevent scaling those lengths by changing <code>\unitlength</code>.
</para>

<cindex index="cp" spaces=" "><indexterm index="cp" number="229">position, in picture</indexterm></cindex>
<para>A <dfn>position</dfn> is a pair of coordinates, such as <code>(2.4,-5)</code>, specifying
the point with x-coordinate <code>2.4</code> and y-coordinate <code>-5</code>.
Coordinates are specified in the usual way with respect to an origin,
which is normally at the lower-left corner of the picture.  Note that
when a position appears as an argument, it is not enclosed in braces;
the parentheses serve to delimit the argument.
</para>
<para>The <code>picture</code> environment has one mandatory argument which is a
position (<var>width</var>,<var>height</var>), which specifies the size of the
picture.  The environment produces a rectangular box with these
<var>width</var> and <var>height</var>.
</para>
<para>The <code>picture</code> environment also has an optional position argument
(<var>xoffset</var>,<var>yoffset</var>), following the size argument, that can
change the origin.  (Unlike ordinary optional arguments, this argument
is not contained in square brackets.) The optional argument gives the
coordinates of the point at the lower-left corner of the picture
(thereby determining the origin).  For example, if <code>\unitlength</code>
has been set to <code>1mm</code>, the command
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;picture&rbrace;(100,200)(10,20)
</pre></example>

<noindent></noindent> <para>produces a picture of width 100 millimeters and height 200
millimeters, whose lower-left corner is the point (10,20) and whose
upper-right corner is therefore the point (110,220).  When you first
draw a picture, you typically omit the optional argument, leaving the
origin at the lower-left corner.  If you then want to modify your
picture by shifting everything, you can just add the appropriate
optional argument.
</para>
<para>The environment&textrsquo;s mandatory argument determines the nominal size of the
picture.  This need bear no relation to how large the picture really is;
&latex; will happily allow you to put things outside the picture, or even
off the page.  The picture&textrsquo;s nominal size is used by &latex; in determining
how much room to leave for it.
</para>
<para>Everything that appears in a picture is drawn by the <code>\put</code>
command. The command
</para>
<example endspaces=" ">
<pre xml:space="preserve">\put (11.3,-.3)&lbrace;...&rbrace;
</pre></example>

<noindent></noindent> <para>puts the object specified by <code>...</code> in the
picture, with its reference point at coordinates <math>(11.3,-.3)</math>.
The reference points for various objects will be described below.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="342">lR box</indexterm></findex>
<para>The <code>\put</code> command creates an <dfn>LR box</dfn>.  You can put anything
that can go in an <code>\mbox</code> (<pxref label="_005cmbox"><xrefnodename>\mbox</xrefnodename></pxref>) in the text argument of
the <code>\put</code> command.  When you do this, the reference point will
be the lower left corner of the box.
</para>
<para>The <code>picture</code> commands are described in the following sections.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::             ">\circle</menunode><menudescription><pre xml:space="preserve">Draw a circle.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::  ">\makebox (picture)</menunode><menudescription><pre xml:space="preserve">Draw a box of the specified size.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator=":: ">\framebox (picture)</menunode><menudescription><pre xml:space="preserve">Draw a box with a frame around it.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">\dashbox</menunode><menudescription><pre xml:space="preserve">Draw a dashed box.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">\frame</menunode><menudescription><pre xml:space="preserve">Draw a frame around an object.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">\line</menunode><menudescription><pre xml:space="preserve">Draw a straight line.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::      ">\linethickness</menunode><menudescription><pre xml:space="preserve">Set the line thickness.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::         ">\thicklines</menunode><menudescription><pre xml:space="preserve">A heavier line thickness.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::          ">\thinlines</menunode><menudescription><pre xml:space="preserve">The default line thickness.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           ">\multiput</menunode><menudescription><pre xml:space="preserve">Draw multiple instances of an object.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">\oval</menunode><menudescription><pre xml:space="preserve">Draw an ellipse.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                ">\put</menunode><menudescription><pre xml:space="preserve">Place an object at a specified place.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::         ">\shortstack</menunode><menudescription><pre xml:space="preserve">Make a pile of objects.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::             ">\vector</menunode><menudescription><pre xml:space="preserve">Draw a line with an arrow.
</pre></menudescription></menuentry></menu>


<node name="_005ccircle" spaces=" "><nodename>\circle</nodename><nodenext automatic="on">\makebox (picture)</nodenext><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\circle</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="343">\circle</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\circle[*]&lbrace;<var>diameter</var>&rbrace;
</pre></example>

<para>The <code>\circle</code> command produces a circle with a diameter as close
to the specified one as possible.  The <code>*</code>-form of the command
draws a solid circle.
</para>
<para>Circles up to 40<dmn>pt</dmn> can be drawn.
</para>

</subsection>
<node name="_005cmakebox-_0028picture_0029" spaces=" "><nodename>\makebox (picture)</nodename><nodenext automatic="on">\framebox (picture)</nodenext><nodeprev automatic="on">\circle</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\makebox</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="344">\makebox <r>(for <code>picture</code>)</r></indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\makebox(<var>width</var>,<var>height</var>)[<var>position</var>]&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>The <code>\makebox</code> command for the picture environment is similar to
the normal <code>\makebox</code> command except that you must specify a
<var>width</var> and <var>height</var> in multiples of <code>\unitlength</code>.
</para>
<para>The optional argument, <code>[<var>position</var>]</code>, specifies the quadrant that
your <var>text</var> appears in.  You may select up to two of the following:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">t</itemformat></item>
</tableterm><tableitem><para>Moves the item to the top of the rectangle.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">b</itemformat></item>
</tableterm><tableitem><para>Moves the item to the bottom.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">l</itemformat></item>
</tableterm><tableitem><para>Moves the item to the left.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">r</itemformat></item>
</tableterm><tableitem><para>Moves the item to the right.
</para>
</tableitem></tableentry></table>

<para><xref label="_005cmakebox"><xrefnodename>\makebox</xrefnodename></xref>.
</para>

</subsection>
<node name="_005cframebox-_0028picture_0029" spaces=" "><nodename>\framebox (picture)</nodename><nodenext automatic="on">\dashbox</nodenext><nodeprev automatic="on">\makebox (picture)</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\framebox</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="345">\framebox</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\framebox(<var>width</var>,<var>height</var>)[<var>pos</var>]&lbrace;...&rbrace;
</pre></example>

<para>The <code>\framebox</code> command is like <code>\makebox</code> (see previous
section), except that it puts a frame around the outside of the box
that it creates.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="346">\fboxrule</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="347">\fboxsep</indexterm></findex>
<para>The <code>\framebox</code> command produces a rule of thickness
<code>\fboxrule</code>, and leaves a space <code>\fboxsep</code> between the rule
and the contents of the box.
</para>

</subsection>
<node name="_005cdashbox" spaces=" "><nodename>\dashbox</nodename><nodenext automatic="on">\frame</nodenext><nodeprev automatic="on">\framebox (picture)</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\dashbox</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="348">\dashbox</indexterm></findex>

<para>Draws a box with a dashed line.  Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\dashbox&lbrace;<var>dlen</var>&rbrace;(<var>rwidth</var>,<var>rheight</var>)[<var>pos</var>]&lbrace;<var>text</var>&rbrace;
</pre></example>

<para><code>\dashbox</code> creates a dashed rectangle around <var>text</var> in a
<code>picture</code> environment.  Dashes are <var>dlen</var> units long, and the
rectangle has overall width <var>rwidth</var> and height <var>rheight</var>.
The <var>text</var> is positioned at optional <var>pos</var>.  <!-- c xxref positions. -->
</para>
<para>A dashed box looks best when the <var>rwidth</var> and <var>rheight</var> are
multiples of the <var>dlen</var>.
</para>

</subsection>
<node name="_005cframe" spaces=" "><nodename>\frame</nodename><nodenext automatic="on">\line</nodenext><nodeprev automatic="on">\dashbox</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\frame</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="349">\frame</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\frame&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>The <code>\frame</code> command puts a rectangular frame around <var>text</var>.
The reference point is the bottom left corner of the frame.  No extra
space is put between the frame and the object.
</para>

</subsection>
<node name="_005cline" spaces=" "><nodename>\line</nodename><nodenext automatic="on">\linethickness</nodenext><nodeprev automatic="on">\frame</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\line</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="350">\line</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\line(<var>xslope</var>,<var>yslope</var>)&lbrace;<var>length</var>&rbrace;
</pre></example>

<para>The <code>\line</code> command draws a line with the given <var>length</var> and
slope <var>xslope</var>/<var>yslope</var>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="230"><code>pict2e</code> package</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="231">graphics packages</indexterm></cindex>
<para>Standard &latex; can only draw lines with <math><var>slope</var> = x/y</math>,
where <math>x</math> and <math>y</math> have integer values from &minus;6
through&nbsp;6.  For lines of any slope, and plenty of other shapes,
see <code>pict2e</code> and many other packages on CTAN.
</para>

</subsection>
<node name="_005clinethickness" spaces=" "><nodename>\linethickness</nodename><nodenext automatic="on">\thicklines</nodenext><nodeprev automatic="on">\line</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\linethickness</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="351">\linethickness</indexterm></findex>

<para>The <code>\linethickness&lbrace;<var>dim</var>&rbrace;</code> command declares the thickness
of horizontal and vertical lines in a picture environment to be
<var>dim</var>, which must be a positive length.
</para>
<para><code>\linethickness</code> does not affect the thickness of slanted lines,
circles, or the quarter circles drawn by <code>\oval</code>.
</para>

</subsection>
<node name="_005cthicklines" spaces=" "><nodename>\thicklines</nodename><nodenext automatic="on">\thinlines</nodenext><nodeprev automatic="on">\linethickness</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\thicklines</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="352">\thicklines</indexterm></findex>

<para>The <code>\thicklines</code> command is an alternate line thickness for
horizontal and vertical lines in a picture environment;
cf.&nbsp;<ref label="_005clinethickness"><xrefnodename>\linethickness</xrefnodename></ref> and <ref label="_005cthinlines"><xrefnodename>\thinlines</xrefnodename></ref>.
</para>

</subsection>
<node name="_005cthinlines" spaces=" "><nodename>\thinlines</nodename><nodenext automatic="on">\multiput</nodenext><nodeprev automatic="on">\thicklines</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\thinlines</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="353">\thinlines</indexterm></findex>

<para>The <code>\thinlines</code> command is the default line thickness for
horizontal and vertical lines in a picture environment;
cf.&nbsp;<ref label="_005clinethickness"><xrefnodename>\linethickness</xrefnodename></ref> and <ref label="_005cthicklines"><xrefnodename>\thicklines</xrefnodename></ref>.
</para>

</subsection>
<node name="_005cmultiput" spaces=" "><nodename>\multiput</nodename><nodenext automatic="on">\oval</nodenext><nodeprev automatic="on">\thinlines</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\multiput</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="354">\multiput</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\multiput(<var>x</var>,<var>y</var>)(<var>delta_x</var>,<var>delta_y</var>)&lbrace;<var>n</var>&rbrace;&lbrace;<var>obj</var>&rbrace;
</pre></example>

<para>The <code>\multiput</code> command copies the object <var>obj</var> in a regular
pattern across a picture.  <var>obj</var> is first placed at position
<math>(x,y)</math>, then at <math>(x+\delta x,y+\delta y)</math>, and so on,
<var>n</var> times.
</para>

</subsection>
<node name="_005coval" spaces=" "><nodename>\oval</nodename><nodenext automatic="on">\put</nodenext><nodeprev automatic="on">\multiput</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\oval</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="355">\oval</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\oval(<var>width</var>,<var>height</var>)[<var>portion</var>]
</pre></example>

<para>The <code>\oval</code> command produces a rectangle with rounded corners.  The
optional argument <var>portion</var> allows you to produce only half of the
oval via the following:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">t</itemformat></item>
</tableterm><tableitem><para>selects the top half;
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">b</itemformat></item>
</tableterm><tableitem><para>selects the bottom half;
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">r</itemformat></item>
</tableterm><tableitem><para>selects the right half;
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">l</itemformat></item>
</tableterm><tableitem><para>selects the left half.
</para></tableitem></tableentry></table>

<para>It is also possible to produce only one quarter of the oval by setting
<var>portion</var> to <code>tr</code>, <code>br</code>, <code>bl</code>, or <code>tl</code>.
</para>
<para>The &textldquo;corners&textrdquo; of the oval are made with quarter circles with a
maximum radius of 20<dmn>pt</dmn>, so large &textldquo;ovals&textrdquo; will look more like
boxes with rounded corners.
</para>

</subsection>
<node name="_005cput" spaces=" "><nodename>\put</nodename><nodenext automatic="on">\shortstack</nodenext><nodeprev automatic="on">\oval</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\put</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="356">\put</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\put(<var>xcoord</var>,<var>ycoord</var>)&lbrace; ... &rbrace;
</pre></example>

<para>The <code>\put</code> command places the material specified by the
(mandatory) argument in braces at the given coordinate,
(<var>xcoord</var>,<var>ycoord</var>).
</para>

</subsection>
<node name="_005cshortstack" spaces=" "><nodename>\shortstack</nodename><nodenext automatic="on">\vector</nodenext><nodeprev automatic="on">\put</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\shortstack</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="357">\shortstack</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\shortstack[<var>position</var>]&lbrace;...\\...\\...&rbrace;
</pre></example>

<para>The <code>\shortstack</code> command produces a stack of objects.  The valid
positions are:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">r</itemformat></item>
</tableterm><tableitem><para>Move the objects to the right of the stack.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">l</itemformat></item>
</tableterm><tableitem><para>Move the objects to the left of the stack
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">c</itemformat></item>
</tableterm><tableitem><para>Move the objects to the centre of the stack (default)
</para></tableitem></tableentry></table>

<findex index="fn" spaces=" "><indexterm index="fn" number="358">\\ <r>(for <code>\shortstack</code> objects)</r></indexterm></findex>
<para>Objects are separated with <code>\\</code>.
</para>

</subsection>
<node name="_005cvector" spaces=" "><nodename>\vector</nodename><nodeprev automatic="on">\shortstack</nodeprev><nodeup automatic="on">picture</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\vector</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="359">\vector</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\vector(<var>xslope</var>,<var>yslope</var>)&lbrace;<var>length</var>&rbrace;
</pre></example>

<para>The <code>\vector</code> command draws a line with an arrow of the specified
length and slope.  The <math><var>xslope</var></math> and <math><var>yslope</var></math>
values must lie between &minus;4 and +4, inclusive.
</para>

</subsection>
</section>
<node name="quotation-and-quote" spaces=" "><nodename>quotation and quote</nodename><nodenext automatic="on">tabbing</nodenext><nodeprev automatic="on">picture</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>quotation</code> and <code>quote</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="360"><r>environment</r>, <code>quotation</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="361"><code>quotation</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="232">quoted text with paragraph indentation, displaying</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="233">displaying quoted text with paragraph indentation</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="234">paragraph indentations in quoted text</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="362"><r>environment</r>, <code>quote</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="363"><code>quote</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="235">quoted text without paragraph indentation, displaying</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="236">displaying quoted text without paragraph indentation</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="237">paragraph indentations in quoted text, omitting</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;quotation&rbrace;
<var>text</var>
\end&lbrace;quotation&rbrace;
</pre></example>

<para>or 
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;quote&rbrace;
<var>text</var>
\end&lbrace;quote&rbrace;
</pre></example>

<para>Include a quotation. 
</para>
<para>In both environments, margins are indented on both sides by
<code>\leftmargin</code> and the text is justified at both.  As with the main
text, leaving a blank line produces a new paragraph.
</para>
<para>To compare the two: in the <code>quotation</code> environment, paragraphs are
indented by 1.5<dmn>em</dmn> and the space between paragraphs is small,
<code>0pt plus 1pt</code>.  In the <code>quote</code> environment, paragraphs are
not indented and there is vertical space between paragraphs (it is the
rubber length <code>\parsep</code>).  Thus, the <code>quotation</code> environment
may be more suitable for documents where new paragraphs are marked by an
indent rather than by a vertical separation.  In addition, <code>quote</code>
may be more suitable for a short quotation or a sequence of short
quotations.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;quotation&rbrace;
\it Four score and seven years ago
  ... shall not perish from the earth.
\hspace&lbrace;1em plus 1fill&rbrace;---Abraham Lincoln
\end&lbrace;quotation&rbrace;
</pre></example>


</section>
<node name="tabbing" spaces=" "><nodename>tabbing</nodename><nodenext automatic="on">table</nodenext><nodeprev automatic="on">quotation and quote</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>tabbing</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="364"><r>environment</r>, <code>tabbing</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="365"><code>tabbing</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="238">tab stops, using</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="239">lining text up using tab stops</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="240">alignment via tabbing</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabbing&rbrace;
<var>row1col1</var> \= <var>row1col2</var> ...  \\
<var>row2col1</var> \&gt; <var>row2col2</var> ...  \\
...
\end&lbrace;tabbing&rbrace;
</pre></example>

<para>The <code>tabbing</code> environment aligns text in columns.  It works by
setting tab stops and tabbing to them much as was done on a typewriter.
It is best suited for cases where the width of each column is constant
and known in advance.
</para>
<para>This example has a first line where the tab stops are set to explicit
widths, ended by a <code>\kill</code> command (which is described below):
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabbing&rbrace;
\hspace&lbrace;0.75in&rbrace;     \= \hspace&lbrace;0.40in&rbrace;  \= \hspace&lbrace;0.40in&rbrace;    \kill
Ship                \&gt; Guns             \&gt; Year    \\ 
\textit&lbrace;Sophie&rbrace;     \&gt; 14               \&gt; 1800    \\
\textit&lbrace;Polychrest&rbrace; \&gt; 24               \&gt; 1803    \\
\textit&lbrace;Lively&rbrace;     \&gt; 38               \&gt; 1804    \\
\textit&lbrace;Surprise&rbrace;   \&gt; 28               \&gt; 1805    \\
\end&lbrace;tabbing&rbrace;
</pre></example>

<para>Both the <code>tabbing</code> environment and the more widely-used
<code>tabular</code> environment put text in columns.  The most important
distinction is that in <code>tabular</code> the width of columns is
determined automatically by &latex;, while in <code>tabbing</code> the user
sets the tab stops.  Another distinction is that <code>tabular</code>
generates a box, but <code>tabbing</code> can be broken across pages.
Finally, while <code>tabular</code> can be used in any mode, <code>tabbing</code>
can be used only in paragraph mode and it starts a new paragraph.
</para>
<para>A <code>tabbing</code> environment always starts a new paragraph, without
indentation. Moreover, as shown in the example above, there is no need
to use the starred form of the <code>\hspace</code> command at the beginning
of a tabbed row.  The right margin of the <code>tabbing</code> environment is
the end of line, so that the width of the environment is
<code>\linewidth</code>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="241">row, <r>tabbing</r></indexterm></cindex>
<para>The <code>tabbing</code> environment contains a sequence of <dfn>tabbed
rows</dfn>.  The first tabbed row begins immediately after
<code>\begin&lbrace;tabbing&rbrace;</code> and each row ends with <code>\\</code> or
<code>\kill</code>. The last row may omit the <code>\\</code> and end with just
<code>\end&lbrace;tabbing&rbrace;</code>.
</para>
<para>At any point the <code>tabbing</code> environment has a current tab stop
pattern, a sequence of <math><var>n</var> &gt; 0</math> tab stops, numbered 0, 1,
etc.  These create <var>n</var> corresponding columns.  Tab stop&nbsp;0 is
always the left margin, defined by the enclosing environment.  Tab
stop number&nbsp;<var>i</var> is set if it is assigned a horizontal
position on the page.  Tab stop number&nbsp;<var>i</var> can only be set if
all the stops 0, &dots;, <math>i-1</math> have already been set; normally
later stops are to the right of earlier ones.
</para>
<para>By default any text typeset in a <code>tabbing</code> environment is typeset
ragged right and left-aligned on the current tab stop. Typesetting is
done in LR mode (<pxref label="Modes"><xrefnodename>Modes</xrefnodename></pxref>).
</para>
<para>The following commands can be used inside a <code>tabbing</code> environment.
They are all fragile (<pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>).
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="366">\\ <r>(tabbing)</r></indexterm>\\ <r>(tabbing)</r></itemformat></item>
</tableterm><tableitem><para>End a tabbed line and typeset it.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="367">\= <r>(tabbing)</r></indexterm>\= <r>(tabbing)</r></itemformat></item>
</tableterm><tableitem><para>Sets a tab stop at the current position.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="368">\&gt; <r>(tabbing)</r></indexterm>\&gt; <r>(tabbing)</r></itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="369">\&gt;</indexterm></findex>
<para>Advances to the next tab stop.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="370">\&lt;</indexterm>\&lt;</itemformat></item>
</tableterm><tableitem><para>Put following text to the left of the local margin (without changing
the margin).  Can only be used at the start of the line.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="371">\+</indexterm>\+</itemformat></item>
</tableterm><tableitem><para>Moves the left margin of the next and all the
following commands one tab stop to the right, beginning tabbed line if
necessary.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="372">\-</indexterm>\-</itemformat></item>
</tableterm><tableitem><para>Moves the left margin of the next and all the
following commands one tab stop to the left, beginning tabbed line if
necessary.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="373">\' <r>(tabbing)</r></indexterm>\' <r>(tabbing)</r></itemformat></item>
</tableterm><tableitem><para>Moves everything that you have typed so far in the current column, i.e.,
everything from the most recent <code>\&gt;</code>, <code>\&lt;</code>, <code>\'</code>,
<code>\\</code>, or <code>\kill</code> command, to the previous column and aligned
to the right, flush against the current column&textrsquo;s tab stop.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="374">\` <r>(tabbing)</r></indexterm>\` <r>(tabbing)</r></itemformat></item>
</tableterm><tableitem><para>Allows you to put text flush right against any tab stop, including tab
stop&nbsp;0.  However, it can&textrsquo;t move text to the right of the last
column because there&textrsquo;s no tab stop there.  The <code>\`</code> command moves
all the text that follows it, up to the <code>\\</code> or
<code>\end&lbrace;tabbing&rbrace;</code> command that ends the line, to the right margin
of the <code>tabbing</code> environment.  There must be no <code>\&gt;</code> or
<code>\'</code> command between the <code>\`</code> and the <code>\\</code> or
<code>\end&lbrace;tabbing&rbrace;</code> command that ends the line.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="375">\a <r>(tabbing)</r></indexterm>\a <r>(tabbing)</r></itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="376">\a' <r>(acute accent in tabbing)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="377">\a` <r>(grave accent in tabbing)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="378">\a= <r>(macron accent in tabbing)</r></indexterm></findex>
<para>In a <code>tabbing</code> environment, the commands <code>\=</code>, <code>\'</code> and
<code>\`</code> do not produce accents as usual (<pxref label="Accents"><xrefnodename>Accents</xrefnodename></pxref>).  Instead,
use the commands <code>\a=</code>, <code>\a'</code> and <code>\a`</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="379">\kill</indexterm>\kill</itemformat></item>
</tableterm><tableitem><para>Sets tab stops without producing text.  Works just like <code>\\</code> except
that it throws away the current line instead of producing output for it.
Any <code>\=</code>, <code>\+</code> or <code>\-</code> commands in that line remain in
effect.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="380">\poptabs</indexterm>\poptabs</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="381">\poptabs</indexterm></findex>
<para>Restores the tab stop positions saved by the last <code>\pushtabs</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="382">\pushtabs</indexterm>\pushtabs</itemformat></item>
</tableterm><tableitem><para>Saves all current tab stop positions. Useful for temporarily changing
tab stop positions in the middle of a <code>tabbing</code> environment.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="383">\tabbingsep</indexterm>\tabbingsep</itemformat></item>
</tableterm><tableitem><para>Distance of the text moved by <code>\'</code> to left of current tab stop.
</para>
</tableitem></tableentry></ftable>

<para>This example typesets a Pascal function:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabbing&rbrace;
function \= fact(n : integer) : integer;\\
         \&gt; begin \= \+ \\
               \&gt; if \= n &gt; 1 then \+ \\
                        fact := n * fact(n-1) \- \\
                  else \+ \\
                        fact := 1; \-\- \\
            end;\\
\end&lbrace;tabbing&rbrace;
</pre></example>

<para>The output looks like this:
</para><example endspaces=" ">
<pre xml:space="preserve">function fact(n : integer) : integer;
         begin
               if n &gt; 1 then
                  fact := n * fact(n-1);
               else
                  fact := 1;
         end;
</pre></example>

<cindex index="cp" spaces=" "><indexterm index="cp" number="242"><r>package</r>, <code>algorithm2e</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="243"><code>algorithm2e</code> <r>package</r></indexterm></cindex>
 <cindex index="cp" spaces=" "><indexterm index="cp" number="244"><r>package</r>, <code>listings</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="245"><code>listings</code> <r>package</r></indexterm></cindex>
 <cindex index="cp" spaces=" "><indexterm index="cp" number="246"><r>package</r>, <code>minted</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="247"><code>minted</code> <r>package</r></indexterm></cindex>

<cindex index="cp" spaces=" "><indexterm index="cp" number="248"><r>package</r>, <code>fancyvrb</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="249"><code>fancyvrb</code> <r>package</r></indexterm></cindex>


<para>(The above example is just for illustration of the environment.  To
actually typeset computer code in typewriter like this, a verbatim
environment (<pxref label="verbatim"><xrefnodename>verbatim</xrefnodename></pxref>) would normally suffice.  For
pretty-printed code, there are quite a few packages, including
<code>algorithm2e</code>, <code>fancyvrb</code>, <code>listings</code>, and
<code>minted</code>.)
</para>
        
</section>
<node name="table" spaces=" "><nodename>table</nodename><nodenext automatic="on">tabular</nodenext><nodeprev automatic="on">tabbing</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>table</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="384"><r>environment</r>, <code>table</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="385"><code>table</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="250">tables, creating</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="251">creating tables</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;table&rbrace;[<var>placement</var>]
  table body
\caption[<var>loftitle</var>]&lbrace;<var>title</var>&rbrace;
\label&lbrace;<var>label&rbrace;</var>
\end&lbrace;table&rbrace;
</pre></example>

<para>A class of floats (<pxref label="Floats"><xrefnodename>Floats</xrefnodename></pxref>).  Because they cannot be split across
pages, they are not typeset in sequence with the normal text but instead
are &textldquo;floated&textrdquo; to a convenient place, such as the top of a following
page.
</para>
<para>For the possible values of <var>placement</var> and their effect on the 
float placement algorithm, see <ref label="Floats"><xrefnodename>Floats</xrefnodename></ref>.
</para>
<para>The table body is typeset in a <code>parbox</code> of width <code>\textwidth</code>
and so it can contain text, commands, etc.
</para>
<para>The label is optional; it is used for cross references (<pxref label="Cross-references"><xrefnodename>Cross
references</xrefnodename></pxref>).  
<findex index="fn" spaces=" "><indexterm index="fn" number="386">\caption</indexterm></findex>
The optional <code>\caption</code> command specifies caption text for the
table.  By default it is numbered.  If <var>lottitle</var> is present, it is
used in the list of tables instead of <var>title</var> (<pxref label="Tables-of-contents"><xrefnodename>Tables of
contents</xrefnodename></pxref>).
</para>
<para>In this example the table and caption will float to the bottom of a page,
unless it is pushed to a float page at the end.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;table&rbrace;[b]
  \centering
  \begin&lbrace;tabular&rbrace;&lbrace;r|p&lbrace;2in&rbrace;&rbrace; \hline
    One &amp;The loneliest number \\
    Two &amp;Can be as sad as one.
         It's the loneliest number since the number one.
  \end&lbrace;tabular&rbrace;
  \caption&lbrace;Cardinal virtues&rbrace;
  \label&lbrace;tab:CardinalVirtues&rbrace;
\end&lbrace;table&rbrace;
</pre></example> 


</section>
<node name="tabular" spaces=" "><nodename>tabular</nodename><nodenext automatic="on">thebibliography</nodenext><nodeprev automatic="on">table</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>tabular</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="387"><r>environment</r>, <code>tabular</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="388"><code>tabular</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="252">lines in tables</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="253">lining text up in tables</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;[<var>pos</var>]&lbrace;<var>cols</var>&rbrace;
column 1 entry &amp;column 2 entry ... &amp;column n entry \\
  ...
\end&lbrace;tabular&rbrace;
</pre></example>

<noindent></noindent>
<para>or
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular*&rbrace;&lbrace;<var>width</var>&rbrace;[<var>pos</var>]&lbrace;<var>cols</var>&rbrace;
column 1 entry &amp;column 2 entry ... &amp;column n entry \\
  ...
\end&lbrace;tabular*&rbrace;
</pre></example>

<para>These environments produce a table, a box consisting of a sequence of
horizontal rows.  Each row consists of items that are aligned vertically
in columns.  This illustrates many of the features.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;&lbrace;l|l&rbrace;
  \textit&lbrace;Player name&rbrace;  &amp;\textit&lbrace;Career home runs&rbrace;  \\ 
  \hline
  Hank Aaron  &amp;755 \\
  Babe Ruth   &amp;714
\end&lbrace;tabular&rbrace;
</pre></example>

<para>The vertical format of two left-aligned columns, with a vertical bar
between them, is specified in <code>tabular</code>&textrsquo;s argument <code>&lbrace;l|l&rbrace;</code>.
<findex index="fn" spaces=" "><indexterm index="fn" number="389">&amp;</indexterm></findex>
Columns are separated with an ampersand <code>&amp;</code>.  A horizontal rule
between two rows is created with <code>\hline</code>.
<findex index="fn" spaces=" "><indexterm index="fn" number="390">\\ <r>for <code>tabular</code></r></indexterm></findex>
The end of each row is marked with a double backslash&nbsp;<code>\\</code>.
This <code>\\</code> is optional after the last row unless an <code>\hline</code>
command follows, to put a rule below the table.
</para>
<para>The required and optional arguments to <code>tabular</code> consist of:
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="var">width</itemformat></item>
</tableterm><tableitem><para>Required for <code>tabular*</code>, not allowed for <code>tabular</code>. Specifies
the width of the <code>tabular*</code> environment.  The space between columns
should be rubber, as with <code>&arobase;&lbrace;\extracolsep&lbrace;\fill&rbrace;&rbrace;</code>, to allow
the table to stretch or shrink to make the specified width, or else you
are likely to get the <code>Underfull \hbox (badness 10000) in alignment
...</code> warning.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">pos</itemformat></item>
</tableterm><tableitem><para>Optional.  Specifies the table&textrsquo;s vertical position.  The default is to
align the table so its vertical center matches the baseline of the
surrounding text.  There are two other possible alignments: <code>t</code>
aligns the table so its top row matches the baseline of the surrounding
text, and <code>b</code> aligns on the bottom row.
</para>
<para>This only has an effect if there is other text.  In the common case of a
<code>tabular</code> alone in a <code>center</code> environment this option makes
no difference.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">cols</itemformat></item>
</tableterm><tableitem><para>Required.  Specifies the formatting of columns.  It consists of a
sequence of the following specifiers, corresponding to the types of
column and intercolumn material.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">l</itemformat></item>
</tableterm><tableitem><para>A column of left-aligned items.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">r</itemformat></item>
</tableterm><tableitem><para>A column of right-aligned items.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">c</itemformat></item>
</tableterm><tableitem><para>A column of centered items.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">|</itemformat></item>
</tableterm><tableitem><para>A vertical line the full height and depth of the environment.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">&arobase;&lbrace;<var>text or space</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>This inserts <var>text or space</var> at this location in every row.  The
<var>text or space</var> material is typeset in LR mode.  This text is
fragile (<pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>).
</para>
<para>This specifier is optional: with no &arobase;-expression, &latex;&textrsquo;s
<code>book</code>, <code>article</code>, and <code>report</code> classes will put on
either side of each column a space of length <code>\tabcolsep</code>, which
by default is <samp>6pt</samp>.  That is, by default adjacent columns are
separated by 12pt (so <code>\tabcolsep</code> is misleadingly-named since it
is not the separation between tabular columns).  By implication, a
space of 6pt also comes before the first column and after the final
column, unless you put a <code>&arobase;&lbrace;...&rbrace;</code> or <code>|</code> there.
</para>
<para>If you override the default and use an &arobase;-expression then you must
insert any desired space yourself, as in <code>&arobase;&lbrace;\hspace&lbrace;1em&rbrace;&rbrace;</code>.
</para>
<para>An empty expression <code>&arobase;&lbrace;&rbrace;</code> will eliminate the space, including
the space at the start or end, as in the example below where the tabular
lines need to lie on the left margin.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;flushleft&rbrace;
  \begin&lbrace;tabular&rbrace;&lbrace;&arobase;&lbrace;&rbrace;l&rbrace;
    ...
  \end&lbrace;tabular&rbrace;
\end&lbrace;flushleft&rbrace;
</pre></example>

<para>This example shows text, a decimal point, between the columns, arranged
so the numbers in the table are aligned on that decimal point.
</para>
<example endspaces=" "> 
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;&lbrace;r&arobase;&lbrace;$.$&rbrace;l&rbrace;
  $3$ &amp;$14$  \\
  $9$ &amp;$80665$
\end&lbrace;tabular&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="391">\extracolsep</indexterm></findex>
<para>An <code>\extracolsep&lbrace;<var>wd</var>&rbrace;</code> command in an &arobase;-expression causes an
extra space of width <var>wd</var> to appear to the left of all subsequent
columns, until countermanded by another <code>\extracolsep</code> command.
Unlike ordinary intercolumn space, this extra space is not suppressed by
an &arobase;-expression.  An <code>\extracolsep</code> command can be used only in an
&arobase;-expression in the <code>cols</code> argument.  Below, &latex; inserts the
right amount of intercolumn space to make the entire table 4 inches
wide.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;center&rbrace;
  \begin&lbrace;tabular*&rbrace;&lbrace;4in&rbrace;&lbrace;l&arobase;&lbrace;\ \ldots\extracolsep&lbrace;\fill&rbrace;&rbrace;l&rbrace;
    Seven times down, eight times up 
    &amp;such is life!
  \end&lbrace;tabular*&rbrace;
\end&lbrace;center&rbrace;
</pre></example>

<para>To insert commands that are automatically executed before a given
column, load the <code>array</code> package and use the <code>&gt;&lbrace;...&rbrace;</code>
specifier.
<!-- c xx should fully explain array, tabularx, and all other base packages... -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">p&lbrace;<var>wd</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Each item in the column is typeset in a parbox of width <var>wd</var>.
</para>
<para>Note that a line break double backslash <code>\\</code> may not appear in the
item, except inside an environment like <code>minipage</code>, <code>array</code>,
or <code>tabular</code>, or inside an explicit <code>\parbox</code>, or in the scope
of a <code>\centering</code>, <code>\raggedright</code>, or <code>\raggedleft</code>
declaration (when used in a <code>p</code>-column element these declarations
must appear inside braces, as with <code>&lbrace;\centering .. \\
..&rbrace;</code>). Otherwise &latex; will misinterpret the double backslash as
ending the row.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">*&lbrace;<var>num</var>&rbrace;&lbrace;<var>cols</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Equivalent to <var>num</var> copies of <var>cols</var>, where <var>num</var> is a
positive integer and <var>cols</var> is a list of specifiers.  Thus
<code>\begin&lbrace;tabular&rbrace;&lbrace;|*&lbrace;3&rbrace;&lbrace;l|r&rbrace;|&rbrace;</code> is equivalent to
<code>\begin&lbrace;tabular&rbrace;&lbrace;|l|rl|rl|r|&rbrace;</code>.  Note that <var>cols</var> may
contain another <code>*</code>-expression.
</para> 
</tableitem></tableentry></table>
</tableitem></tableentry></table>

<para>Parameters that control formatting:
<!-- c xx defaults, own node (xref from array)? -->
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="392">\arrayrulewidth</indexterm>\arrayrulewidth</itemformat></item>
</tableterm><tableitem><para>A length that is the thickness of the rule created by <code>|</code>,
<code>\hline</code>, and <code>\vline</code> in the <code>tabular</code> and <code>array</code>
environments.  The default is <samp>.4pt</samp>. Change it as in
<code>\setlength&lbrace;\arrayrulewidth&rbrace;&lbrace;0.8pt&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="393">\arraystretch</indexterm>\arraystretch</itemformat></item>
</tableterm><tableitem><para>A factor by which the spacing between rows in the <code>tabular</code> and
<code>array</code> environments is multiplied.  The default is <samp>1</samp>, for
no scaling.  Change it as <code>\renewcommand&lbrace;\arraystretch&rbrace;&lbrace;1.2&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="394">\doublerulesep</indexterm>\doublerulesep</itemformat></item>
</tableterm><tableitem><para>A length that is the distance between the vertical rules produced by the
<code>||</code> specifier.  The default is <samp>2pt</samp>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="395">\tabcolsep</indexterm>\tabcolsep</itemformat></item>
</tableterm><tableitem><para>A length that is half of the space between columns. The default is
<samp>6pt</samp>.  Change it with <code>\setlength</code>.
</para>
</tableitem></tableentry></ftable>

<para>The following commands can be used inside the body of a <code>tabular</code>
environment, the first two inside an entry and the second two between
lines:
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::        ">\multicolumn</menunode><menudescription><pre xml:space="preserve">Make an item spanning several columns.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">\vline</menunode><menudescription><pre xml:space="preserve">Draw a vertical line.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">\cline</menunode><menudescription><pre xml:space="preserve">Draw a horizontal line spanning some columns.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">\hline</menunode><menudescription><pre xml:space="preserve">Draw a horizontal line spanning all columns.
</pre></menudescription></menuentry></menu>


<node name="_005cmulticolumn" spaces=" "><nodename>\multicolumn</nodename><nodenext automatic="on">\vline</nodenext><nodeup automatic="on">tabular</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\multicolumn</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="396">\multicolumn</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\multicolumn&lbrace;<var>numcols</var>&rbrace;&lbrace;<var>cols</var>&rbrace;&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>Make an <code>array</code> or <code>tabular</code> entry that spans several columns.
The first argument <var>numcols</var> gives the number of columns to span.
The second argument <var>cols</var> specifies the formatting of the entry,
with <code>c</code> for centered, <code>l</code> for flush left, or <code>r</code> for
flush right.  The third argument <var>text</var> gives the contents of that
entry.
</para>
<para>In this example, in the first row, the second and third columns are
spanned by the single heading <samp>Name</samp>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;&lbrace;lccl&rbrace; 
  \textit&lbrace;ID&rbrace;       &amp;\multicolumn&lbrace;2&rbrace;&lbrace;c&rbrace;&lbrace;\textit&lbrace;Name&rbrace;&rbrace; &amp;\textit&lbrace;Age&rbrace; \\ \hline % row one 
  978-0-393-03701-2 &amp;O'Brian &amp;Patrick                  &amp;55           \\        % row two 
    ...
\end&lbrace;tabular&rbrace;
</pre></example>

<para>What counts as a column is:&nbsp;the column format specifier for the
<code>array</code> or <code>tabular</code> environment is broken into parts, where
each part (except the first) begins with <code>l</code>, <code>c</code>, <code>r</code>,
or&nbsp;<code>p</code>.  So from <code>\begin&lbrace;tabular&rbrace;&lbrace;|r|ccp&lbrace;1.5in&rbrace;|&rbrace;</code>
the parts are <code>|r|</code>, <code>c</code>, <code>c</code>,
and&nbsp;<code>p&lbrace;1.5in&rbrace;|</code>.
</para>
<para>The <var>cols</var> argument overrides the <code>array</code> or <code>tabular</code>
environment&textrsquo;s intercolumn area default adjoining this multicolumn
entry. To affect that area, this argument can contain vertical bars
<code>|</code> indicating the placement of vertical rules, and <code>&arobase;&lbrace;...&rbrace;</code>
expressions.  Thus if <var>cols</var> is <samp>|c|</samp> then this multicolumn
entry will be centered and a vertical rule will come in the intercolumn
area before it and after it.  This table details the exact behavior.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;&lbrace;|cc|c|c|&rbrace;
  \multicolumn&lbrace;1&rbrace;&lbrace;r&rbrace;&lbrace;w&rbrace;       % entry one
    &amp;\multicolumn&lbrace;1&rbrace;&lbrace;|r|&rbrace;&lbrace;x&rbrace;  % entry two 
    &amp;\multicolumn&lbrace;1&rbrace;&lbrace;|r&rbrace;&lbrace;y&rbrace;   % entry three
    &amp;z                        % entry four
\end&lbrace;tabular&rbrace;
</pre></example>

<para>Before the first entry the output will not have a vertical rule because
the <code>\multicolumn</code> has the <var>cols</var> specifier <samp>r</samp> with no
initial vertical bar.  Between entry one and entry two there will be a
vertical rule; although the first <var>cols</var> does not have an ending
vertical bar, the second <var>cols</var> does have a starting one.  Between
entry two and entry three there is a single vertical rule; despite that
the <var>cols</var> in both of the surrounding <code>multicolumn</code>&textrsquo;s call for
a vertical rule, you only get one rule.  Between entry three and entry
four there is no vertical rule; the default calls for one but the
<var>cols</var> in the entry three <code>\multicolumn</code> leaves it out, and
that takes precedence.  Finally, following entry four there is a
vertical rule because of the default.
</para>
<para>The number of spanned columns <var>numcols</var> can be 1.  Besides giving
the ability to change the horizontal alignment, this also is useful to
override for one row the <code>tabular</code> definition&textrsquo;s default intercolumn
area specification, including the placement of vertical rules.
</para>
<para>In the example below, in the <code>tabular</code> definition the first column
is specified to default to left justified but in the first row the entry
is centered with <code>\multicolumn&lbrace;1&rbrace;&lbrace;c&rbrace;&lbrace;\textsc&lbrace;Period&rbrace;&rbrace;</code>.
Also in the first row, the second and third columns are spanned by a
single entry with <code>\multicolumn&lbrace;2&rbrace;&lbrace;c&rbrace;&lbrace;\textsc&lbrace;Span&rbrace;&rbrace;</code>,
overriding the specification to center those two columns on the page
range en-dash.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;&lbrace;l|r&arobase;&lbrace;--&rbrace;l&rbrace; 
  \multicolumn&lbrace;1&rbrace;&lbrace;c&rbrace;&lbrace;\textsc&lbrace;Period&rbrace;&rbrace;  
    &amp;multicolumn&lbrace;2&rbrace;&lbrace;c&rbrace;&lbrace;\textsc&lbrace;Span&rbrace;&rbrace; \\ \hline
  Baroque          &amp;1600           &amp;1760         \\
  Classical        &amp;1730           &amp;1820         \\
  Romantic         &amp;1780           &amp;1910         \\
  Impressionistic  &amp;1875           &amp;1925
\end&lbrace;tabular&rbrace;
</pre></example>

<para>Note that although the <code>tabular</code> specification by default puts a
vertical rule between the first and second columns, because there is no
vertical bar in the <var>cols</var> of either of the first row&textrsquo;s
<code>\multicolumn</code> commands, no rule appears in the first row.
</para>

</subsection>
<node name="_005cvline" spaces=" "><nodename>\vline</nodename><nodenext automatic="on">\cline</nodenext><nodeprev automatic="on">\multicolumn</nodeprev><nodeup automatic="on">tabular</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\vline</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="397">\vline</indexterm></findex>
<para>Draw a vertical line in a <code>tabular</code> or <code>array</code> environment
extending the full height and depth of an entry&textrsquo;s row.  Can also be
used in an &arobase;-expression, although its synonym vertical
bar&nbsp;<code>|</code> is more common.  This command is rarely used in the
body of a table; typically a table&textrsquo;s vertical lines are specified in
<code>tabular</code>&textrsquo;s <var>cols</var> argument and overridden as needed with
<code>\multicolumn</code>.
</para>
<para>This example illustrates some pitfalls.  In the first line&textrsquo;s second
entry the <code>\hfill</code> moves the <code>\vline</code> to the left edge of the
cell.  But that is different than putting it halfway between the two
columns, so in that row between the first and second columns there are
two vertical rules, with the one from the <code>&lbrace;c|cc&rbrace;</code> specifier
coming before the one produced by the <code>\vline\hfill</code>.  In contrast,
the first line&textrsquo;s third entry shows the usual way to put a vertical bar
between two columns.  In the second line, the <code>ghi</code> is the widest
entry in its column so in the <code>\vline\hfill</code> the <code>\hfill</code> has
no effect and the vertical line in that entry appears immediately next
to the <code>g</code>, with no whitespace.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;&lbrace;c|cc&rbrace;
  x   &amp;\vline\hfill y   &amp;\multicolumn&lbrace;1&rbrace;&lbrace;|r&rbrace;&lbrace;z&rbrace; \\  
  abc &amp;def &amp;\vline\hfill ghi 
\end&lbrace;tabular&rbrace;
</pre></example>


</subsection>
<node name="_005ccline" spaces=" "><nodename>\cline</nodename><nodenext automatic="on">\hline</nodenext><nodeprev automatic="on">\vline</nodeprev><nodeup automatic="on">tabular</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\cline</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="398">\cline</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\cline&lbrace;<var>i</var>-<var>j</var>&rbrace;
</pre></example>

<para>Draw a horizontal rule in an <code>array</code> or <code>tabular</code> environment
beginning in column <var>i</var> and ending in column <var>j</var>. The
dash&nbsp;<code>-</code> must appear in the mandatory argument. To span a
single column use the number twice.
</para>
<para>This example puts two horizontal lines between the first and second
rows, one line in the first column only, and the other spanning the
third and fourth columns.  The two lines are side-by-side, at the same
height.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;&lbrace;llrr&rbrace; 
  a &amp;b &amp;c &amp;d \\ \cline&lbrace;1-1&rbrace; \cline&lbrace;3-4&rbrace; 
  e &amp;f &amp;g &amp;h 
\end&lbrace;tabular&rbrace;
</pre></example>


</subsection>
<node name="_005chline" spaces=" "><nodename>\hline</nodename><nodeprev automatic="on">\cline</nodeprev><nodeup automatic="on">tabular</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\hline</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="399">\hline</indexterm></findex>

<para>Draws a horizontal line the width of the enclosing <code>tabular</code> or
<code>array</code> environment.  It&textrsquo;s most commonly used to draw a line at the
top, bottom, and between the rows of a table.
</para>
<para>In this example the top of the table has two horizontal rules, one above
the other, that span both columns.  The bottom of the table has a single
rule spanning both columns.  Because of the <code>\hline</code>, the
<code>tabular</code> second row&textrsquo;s line ending double backslash&nbsp;<code>\\</code>
is required.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;&lbrace;ll&rbrace; \hline\hline
  Baseball   &amp;Red Sox  \\
  Basketball &amp;Celtics  \\ \hline
\end&lbrace;tabular&rbrace;
</pre></example>


</subsection>
</section>
<node name="thebibliography" spaces=" "><nodename>thebibliography</nodename><nodenext automatic="on">theorem</nodenext><nodeprev automatic="on">tabular</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>thebibliography</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="400"><r>environment</r>, <code>thebibliography</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="401"><code>thebibliography</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="254">bibliography, creating (manually)</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;thebibliography&rbrace;&lbrace;<var>widest-label</var>&rbrace;
\bibitem[<var>label</var>]&lbrace;<var>cite_key&rbrace;</var>
...
\end&lbrace;thebibliography&rbrace;
</pre></example>

<para>The <code>thebibliography</code> environment produces a bibliography or
reference list.
</para>
<para>In the <code>article</code> class, this reference list is labelled
<samp>References</samp> and the label is stored in macro <code>\refname</code>; in
the <code>report</code> class, it is labelled <samp>Bibliography</samp> and the
label is stored in macro <code>\bibname</code>.
</para>
<para>You can change the label by redefining the command <code>\refname</code> or
<code>\bibname</code>, whichever is applicable depending on the class:
</para>
<itemize commandarg="bullet" endspaces=" ">
<listitem><prepend>&bullet;</prepend>
<findex index="fn" spaces=" "><indexterm index="fn" number="402">\bibname</indexterm></findex>
<para>For standard classes whose top level sectioning is <code>\chapter</code>
(such as <file>book</file> and <file>report</file>), the label is in the macro
<code>\bibname</code>;
</para>
</listitem><listitem><prepend>&bullet;</prepend>
<findex index="fn" spaces=" "><indexterm index="fn" number="403">\refname</indexterm></findex>
<para>For standard classes whose the top level sectioning is <code>\section</code>
(such as <file>article</file>), the label is in macro <code>\refname</code>.
</para></listitem></itemize>

<cindex index="cp" spaces=" "><indexterm index="cp" number="255"><r>package</r>, <code>babel</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="256"><code>babel</code> <r>package</r></indexterm></cindex>

<para>Typically it is neither necessary nor desirable to directly redefine
<code>\refname</code> or <code>\bibname</code>; language support packages like
<file>babel</file> do this.
</para>
<para>The mandatory <var>widest-label</var> argument is text that, when typeset,
is as wide as the widest item label produced by the <code>\bibitem</code>
commands.  It is typically given as <code>9</code> for bibliographies with
less than 10 references, <code>99</code> for ones with less than 100, etc.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::            ">\bibitem</menunode><menudescription><pre xml:space="preserve">Specify a bibliography item.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">\cite</menunode><menudescription><pre xml:space="preserve">Refer to a bibliography item.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::             ">\nocite</menunode><menudescription><pre xml:space="preserve">Include an item in the bibliography.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::        ">Using BibTeX</menunode><menudescription><pre xml:space="preserve">Automatic generation of bibliographies.
</pre></menudescription></menuentry></menu>


<node name="_005cbibitem" spaces=" "><nodename>\bibitem</nodename><nodenext automatic="on">\cite</nodenext><nodeup automatic="on">thebibliography</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\bibitem</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="404">\bibitem</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\bibitem[<var>label</var>]&lbrace;<var>cite_key</var>&rbrace;
</pre></example>

<para>The <code>\bibitem</code> command generates an entry labelled by <var>label</var>.
If the <var>label</var> argument is missing, a number is automatically
generated using the <code>enumi</code> counter.  The <var>cite_key</var> is a
<cindex index="cp" spaces=" "><indexterm index="cp" number="257">citation key</indexterm></cindex>
<dfn>citation key</dfn> consisting in any sequence of
letters, numbers, and punctuation symbols not containing a comma.
</para>
<para>This command writes an entry to the <file>.aux</file> file containing the
item&textrsquo;s <var>cite_key</var> and <var>label</var>.  When the <file>.aux</file> file is
read by the <code>\begin&lbrace;document&rbrace;</code> command, the item&textrsquo;s <var>label</var> is
associated with <code>cite_key</code>, causing references to <var>cite_key</var>
with a <code>\cite</code> command (<pxref label="_005ccite"><xrefnodename>\cite</xrefnodename></pxref>) to produce the associated
<var>label</var>.
</para>

</subsection>
<node name="_005ccite" spaces=" "><nodename>\cite</nodename><nodenext automatic="on">\nocite</nodenext><nodeprev automatic="on">\bibitem</nodeprev><nodeup automatic="on">thebibliography</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\cite</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="405">\cite</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\cite[<var>subcite</var>]&lbrace;<var>keys</var>&rbrace;
</pre></example>

<para>The <var>keys</var> argument is a list of one or more citation keys
(<pxref label="_005cbibitem"><xrefnodename>\bibitem</xrefnodename></pxref>), separated by commas.  This command generates an
in-text citation to the references associated with <var>keys</var> by entries
in the <file>.aux</file> file.
</para>
<para>The text of the optional <var>subcite</var> argument appears after the
citation.  For example, <code>\cite[p.~314]&lbrace;knuth&rbrace;</code> might produce
<samp>[Knuth, p.&nbsp;314]</samp>.
</para>

</subsection>
<node name="_005cnocite" spaces=" "><nodename>\nocite</nodename><nodenext automatic="on">Using BibTeX</nodenext><nodeprev automatic="on">\cite</nodeprev><nodeup automatic="on">thebibliography</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\nocite</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="406">\nocite</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve"><code>\nocite&lbrace;<var>keys</var>&rbrace;</code>
</pre></example>

<para>The <code>\nocite</code> command produces no text, but writes <var>keys</var>,
which is a list of one or more citation keys, to the <file>.aux</file> file.
</para>

</subsection>
<node name="Using-BibTeX" spaces=" "><nodename>Using BibTeX</nodename><nodeprev automatic="on">\nocite</nodeprev><nodeup automatic="on">thebibliography</nodeup></node>
<subsection spaces=" "><sectiontitle>Using Bib&tex;</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="258">using Bib&tex;</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="259">bib&tex;, using</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="260">bibliography, creating (automatically)</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="407">\bibliographystyle</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="408">\bibliography</indexterm></findex>

<para>If you use the Bib&tex; program by Oren Patashnik (highly
recommended if you need a bibliography of more than a couple of
titles) to maintain your bibliography, you don&textrsquo;t use the
<code>thebibliography</code> environment (<pxref label="thebibliography"><xrefnodename>thebibliography</xrefnodename></pxref>). Instead,
you include the lines
</para>
<example endspaces=" ">
<pre xml:space="preserve">\bibliographystyle&lbrace;<var>bibstyle</var>&rbrace;
\bibliography&lbrace;<var>bibfile1</var>,<var>bibfile2</var>&rbrace;
</pre></example>

<para>The <code>\bibliographystyle</code> command does not produce any output of
its own.  Rather, it defines the style in which the bibliography will
be produced: <var>bibstyle</var> refers to a file
<var>bibstyle</var><file>.bst</file>, which defines how your citations will look.
The standard <var>bibstyle</var> names distributed with Bib&tex; are:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">alpha</itemformat></item>
</tableterm><tableitem><para>Sorted alphabetically. Labels are formed from name of author and year of
publication.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">plain</itemformat></item>
</tableterm><tableitem><para>Sorted alphabetically. Labels are numeric.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">unsrt</itemformat></item>
</tableterm><tableitem><para>Like <code>plain</code>, but entries are in order of citation.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">abbrv</itemformat></item>
</tableterm><tableitem><para>Like <code>plain</code>, but more compact labels.
</para></tableitem></tableentry></table>

<para>In addition, numerous other Bib&tex; style files exist tailored to
the demands of various publications.  See
<url><urefurl>http://mirror.ctan.org/biblio/bibtex/contrib</urefurl></url>.
</para>
<para>The <code>\bibliography</code> command is what actually produces the
bibliography.  The argument to <code>\bibliography</code> refers to files
named <file><var>bibfile1</var>.bib</file>, <file><var>bibfile2</var>.bib</file>, &dots;,
which should contain your database in
Bib&tex; format.  Only the entries referred to via <code>\cite</code> and
<code>\nocite</code> will be listed in the bibliography.
</para>

</subsection>
</section>
<node name="theorem" spaces=" "><nodename>theorem</nodename><nodenext automatic="on">titlepage</nodenext><nodeprev automatic="on">thebibliography</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>theorem</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="409"><r>environment</r>, <code>theorem</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="410"><code>theorem</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="261">theorems, typesetting</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;theorem&rbrace;
<var>theorem-text</var>
\end&lbrace;theorem&rbrace;
</pre></example>

<para>The <code>theorem</code> environment produces &textldquo;Theorem <var>n</var>&textrdquo; in
boldface followed by <var>theorem-text</var>, where the numbering
possibilities for <var>n</var> are described under <code>\newtheorem</code>
(<pxref label="_005cnewtheorem"><xrefnodename>\newtheorem</xrefnodename></pxref>).
</para>

</section>
<node name="titlepage" spaces=" "><nodename>titlepage</nodename><nodenext automatic="on">verbatim</nodenext><nodeprev automatic="on">theorem</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>titlepage</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="411"><r>environment</r>, <code>titlepage</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="412"><code>titlepage</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="262">making a title page</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="263">title pages, creating</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;titlepage&rbrace;
  ... text and spacing ...
\end&lbrace;titlepage&rbrace;
</pre></example>

<para>Create a title page, a page with no printed page number or heading.  The
following page will be numbered page one.
</para>
<para>To instead produce a standard title page without a <code>titlepage</code>
environment you can use <code>\maketitle</code> (<pxref label="_005cmaketitle"><xrefnodename>\maketitle</xrefnodename></pxref>).
</para>
<para>Notice in this example that all formatting, including vertical spacing,
is left to the author.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;titlepage&rbrace;
\vspace*&lbrace;\stretch&lbrace;1&rbrace;&rbrace;
\begin&lbrace;center&rbrace;
  &lbrace;\huge\bfseries Thesis \\[1ex] 
                  title&rbrace;                  \\[6.5ex]
  &lbrace;\large\bfseries Author name&rbrace;           \\
  \vspace&lbrace;4ex&rbrace;
  Thesis  submitted to                    \\[5pt]
  \textit&lbrace;University name&rbrace;                \\[2cm]
  in partial fulfilment for the award of the degree of \\[2cm]
  \textsc&lbrace;\Large Doctor of Philosophy&rbrace;    \\[2ex]
  \textsc&lbrace;\large Mathematics&rbrace;             \\[12ex]
  \vfill
  Department of Mathematics               \\
  Address                                 \\
  \vfill
  \today
\end&lbrace;center&rbrace;
\vspace&lbrace;\stretch&lbrace;2&rbrace;&rbrace;
\end&lbrace;titlepage&rbrace;
</pre></example>


</section>
<node name="verbatim" spaces=" "><nodename>verbatim</nodename><nodenext automatic="on">verse</nodenext><nodeprev automatic="on">titlepage</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>verbatim</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="413"><r>environment</r>, <code>verbatim</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="414"><code>verbatim</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="264">verbatim text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="265">simulating typed text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="266">typed text, simulating</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="267">code, typesetting</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="268">computer programs, typesetting</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;verbatim&rbrace;
<var>literal-text</var>
\end&lbrace;verbatim&rbrace;
</pre></example>

<para>The <code>verbatim</code> environment is a paragraph-making environment in
which &latex; produces exactly what you type in; for instance the
<code>\</code> character produces a printed <samp>\</samp>.  It turns &latex;
into a typewriter with carriage returns and blanks having the same
effect that they would on a typewriter.
</para>
<para>The <code>verbatim</code> environment uses a monospaced typewriter-like font
(<code>\tt</code>).
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::       ">\verb</menunode><menudescription><pre xml:space="preserve">The macro form of the <code>verbatim</code> environment.
</pre></menudescription></menuentry></menu>

<node name="_005cverb" spaces=" "><nodename>\verb</nodename><nodeup automatic="on">verbatim</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\verb</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="415">\verb</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="269">verbatim text, inline</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\verb<var>char</var><var>literal-text</var><var>char</var>
\verb*<var>char</var><var>literal-text</var><var>char</var>
</pre></example>

<para>The <code>\verb</code> command typesets <var>literal-text</var> as it is input,
including special characters and spaces, using the typewriter
(<code>\tt</code>) font.  No spaces are allowed between <code>\verb</code> or
<code>\verb*</code> and the delimiter <var>char</var>, which begins and ends the
verbatim text.  The delimiter must not appear in <var>literal-text</var>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="270">visible space</indexterm></cindex>
<para>The <code>*</code>-form differs only in that spaces are printed with a
&textldquo;visible space&textrdquo; character.
<tex endspaces=" ">
</tex>
</para>

</subsection>
</section>
<node name="verse" spaces=" "><nodename>verse</nodename><nodeprev automatic="on">verbatim</nodeprev><nodeup automatic="on">Environments</nodeup></node>
<section spaces=" "><sectiontitle><code>verse</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="416"><r>environment</r>, <code>verse</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="417"><code>verse</code> <r>environment</r></indexterm></findex>
        
<cindex index="cp" spaces=" "><indexterm index="cp" number="271">poetry, an environment for</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;verse&rbrace;
<var>line1</var> \\
<var>line2</var> \\
...
\end&lbrace;verse&rbrace;
</pre></example>

<para>The <code>verse</code> environment is designed for poetry, though you may find
other uses for it.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="418">\\ <r>for <code>verse</code></r></indexterm></findex>
<para>The margins are indented on the left and the right, paragraphs are not
indented, and the text is not justified.  Separate the lines of each
stanza with <code>\\</code>, and use one or more blank lines to separate the
stanzas.
</para>

</section>
</chapter>
<node name="Line-breaking" spaces=" "><nodename>Line breaking</nodename><nodenext automatic="on">Page breaking</nodenext><nodeprev automatic="on">Environments</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Line breaking</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="272">line breaking</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="273">breaking lines</indexterm></cindex>

<para>The first thing &latex; does when processing ordinary text is to
translate your input file into a sequence of glyphs and spaces.  To
produce a printed document, this sequence must be broken into lines
(and these lines must be broken into pages).
</para>
<para>&latex; usually does the line (and page) breaking in the text body for
you but in some environments you manually force line breaks.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::                         ">\\</menunode><menudescription><pre xml:space="preserve">Start a new line.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::       ">\obeycr &amp; \restorecr</menunode><menudescription><pre xml:space="preserve">Make each input line start a new output line.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                   ">\newline</menunode><menudescription><pre xml:space="preserve">Break the line
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           ">\- (hyphenation)</menunode><menudescription><pre xml:space="preserve">Insert explicit hyphenation.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::             ">\discretionary</menunode><menudescription><pre xml:space="preserve">Insert explicit hyphenation with control of hyphen character.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                     ">\fussy</menunode><menudescription><pre xml:space="preserve">Be fussy about line breaking.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                    ">\sloppy</menunode><menudescription><pre xml:space="preserve">Be sloppy about line breaking.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">\hyphenation</menunode><menudescription><pre xml:space="preserve">Tell &latex; how to hyphenate a word.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::  ">\linebreak &amp; \nolinebreak</menunode><menudescription><pre xml:space="preserve">Forcing &amp; avoiding line breaks.
</pre></menudescription></menuentry></menu>


<node name="_005c_005c" spaces=" "><nodename>\\</nodename><nodenext automatic="on">\obeycr &amp; \restorecr</nodenext><nodeup automatic="on">Line breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\\</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="419">\\ <r>force line break</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="274">new line, starting</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="275">line break, forcing</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\\[<var>morespace</var>]
</pre></example>

<para>or 
</para>
<example endspaces=" ">
<pre xml:space="preserve">\\*[<var>morespace</var>]
</pre></example>

<para>Start a new line.  The optional argument <var>morespace</var> specifies extra
vertical space to be insert before the next line.  This can be a
negative length.  The text before the break is set at its normal length,
that is, it is not stretched to fill out the line width.
</para>
<para>Explicit line breaks in the text body are unusual in &latex;.  In
particular, to start a new paragraph instead leave a blank line.  This
command is mostly used outside of the main flow of text such as in
a <code>tabular</code> or <code>array</code> environment.
</para>
<para>Under ordinary circumstances (e.g., outside of a <code>p&lbrace;...&rbrace;</code> column
in a <code>tabular</code> environment) the <code>\newline</code> command is a synonym for
<code>\\</code> (<pxref label="_005cnewline"><xrefnodename>\newline</xrefnodename></pxref>).
</para>
<para>In addition to starting a new line, the starred form <code>\\*</code> tells
&latex; not to start a new page between the two lines, by issuing a
<code>\nobreak</code>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\title&lbrace;My story: \\[0.25in]
       a tale of woe&rbrace;
</pre></example>


</section>
<node name="_005cobeycr-_0026-_005crestorecr" spaces=" "><nodename>\obeycr &amp; \restorecr</nodename><nodenext automatic="on">\newline</nodenext><nodeprev automatic="on">\\</nodeprev><nodeup automatic="on">Line breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\obeycr</code> &amp; <code>\restorecr</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="420">\obeycr</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="421">\restorecr</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="276">new line, output as input</indexterm></cindex>

<para>The <code>\obeycr</code> command makes a return in the input file
(<samp>^^M</samp>, internally) the same as <code>\\</code> (followed by
<code>\relax</code>).  So each new line in the input will also be a new line
in the output.
</para>
<para><code>\restorecr</code> restores normal line-breaking behavior.
</para>

</section>
<node name="_005cnewline" spaces=" "><nodename>\newline</nodename><nodenext automatic="on">\- (hyphenation)</nodenext><nodeprev automatic="on">\obeycr &amp; \restorecr</nodeprev><nodeup automatic="on">Line breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\newline</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="422">\newline</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="277">new line, starting (paragraph mode)</indexterm></cindex>

<para>In ordinary text this is equivalent to double-backslash (<pxref label="_005c_005c"><xrefnodename>\\</xrefnodename></pxref>); it
breaks a line, with no stretching of the text before it.
</para>
<para>Inside a <code>tabular</code> or <code>array</code> environment, in a column with a
specifier producing a paragraph box, like typically <code>p&lbrace;...&rbrace;</code>,
<code>\newline</code> will insert a line break inside of the column, that is,
it does not break the entire row.  To break the entire row use <code>\\</code>
or its equivalent <code>\tabularnewline</code>.
</para>
<para>This will print <samp>Name:</samp> and <samp>Address:</samp> as two lines in a
single cell of the table.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;&lbrace;p&lbrace;1in&rbrace;&lbrace;\hspace&lbrace;2in&rbrace;&rbrace;p&lbrace;1in&rbrace;&rbrace;
  Name: \newline Address: &amp;Date: \\ \hline
\end&lbrace;tabular&rbrace;
</pre></example>

<para>The <samp>Date:</samp> will be baseline-aligned with <samp>Name:</samp>.
</para>

</section>
<node name="_005c_002d-_0028hyphenation_0029" spaces=" "><nodename>\- (hyphenation)</nodename><nodenext automatic="on">\discretionary</nodenext><nodeprev automatic="on">\newline</nodeprev><nodeup automatic="on">Line breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\-</code> (discretionary hyphen)</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="423">\- <r>(hyphenation)</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="278">hyphenation, forcing</indexterm></cindex>

<para>The <code>\-</code> command tells &latex; that it may hyphenate the word at
that point.  &latex; is pretty good at hyphenating, and usually finds
most of the correct hyphenation points, while almost never using an
incorrect one.  The <code>\-</code> command is used for the exceptional
cases.
</para>
<para>When you insert <code>\-</code> commands in a word, the word will only be
hyphenated at those points and not at any of the hyphenation points
that &latex; might otherwise have chosen.
</para>
</section>
<node name="_005cdiscretionary" spaces=" "><nodename>\discretionary</nodename><nodenext automatic="on">\fussy</nodenext><nodeprev automatic="on">\- (hyphenation)</nodeprev><nodeup automatic="on">Line breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\discretionary</code> (generalized hyphenation point)</sectiontitle>
<cindex index="cp" spaces=" "><indexterm index="cp" number="279">hyphenation, discretionary</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="280">discretionary hyphenation</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\discretionary&lbrace;<var>pre-break-text</var>&rbrace;&lbrace;<var>post-break-text</var>&rbrace;&lbrace;<var>no-break-text</var>&rbrace;
</pre></example>

<!-- c xxx TODO, complete this node, see LaTeX-fr -->

</section>
<node name="_005cfussy" spaces=" "><nodename>\fussy</nodename><nodenext automatic="on">\sloppy</nodenext><nodeprev automatic="on">\discretionary</nodeprev><nodeup automatic="on">Line breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\fussy</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="424">\fussy</indexterm></findex>

<para>The declaration <code>\fussy</code> (which is the default) makes &tex;
picky about line breaking.  This usually avoids too much space between
words, at the cost of an occasional overfull box.
</para>
<para>This command cancels the effect of a previous <code>\sloppy</code> command
(<pxref label="_005csloppy"><xrefnodename>\sloppy</xrefnodename></pxref>).
</para>

</section>
<node name="_005csloppy" spaces=" "><nodename>\sloppy</nodename><nodenext automatic="on">\hyphenation</nodenext><nodeprev automatic="on">\fussy</nodeprev><nodeup automatic="on">Line breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\sloppy</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="425">\sloppy</indexterm></findex>

<para>The declaration <code>\sloppy</code> makes &tex; less fussy about line
breaking. This will avoid overfull boxes, at the cost of loose
interword spacing.
</para>
<para>Lasts until a <code>\fussy</code> command is issued (<pxref label="_005cfussy"><xrefnodename>\fussy</xrefnodename></pxref>).
</para>

</section>
<node name="_005chyphenation" spaces=" "><nodename>\hyphenation</nodename><nodenext automatic="on">\linebreak &amp; \nolinebreak</nodenext><nodeprev automatic="on">\sloppy</nodeprev><nodeup automatic="on">Line breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\hyphenation</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="426">\hyphenation</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="281">hyphenation, defining</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\hyphenation&lbrace;<var>word-one</var> <var>word-two</var>&rbrace;
</pre></example>

<para>The <code>\hyphenation</code> command declares allowed hyphenation points
with a <code>-</code> character in the given words.  The words are separated
by spaces.  &tex; will only hyphenate if the word matches exactly, no
inflections are tried.  Multiple <code>\hyphenation</code> commands
accumulate.  Some examples (the default &tex; hyphenation patterns
misses the hyphenations in these words):
</para>
<example endspaces=" ">
<pre xml:space="preserve">\hyphenation&lbrace;ap-pen-dix col-umns data-base data-bases&rbrace;
</pre></example>


</section>
<node name="_005clinebreak-_0026-_005cnolinebreak" spaces=" "><nodename>\linebreak &amp; \nolinebreak</nodename><nodeprev automatic="on">\hyphenation</nodeprev><nodeup automatic="on">Line breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\linebreak</code> &amp; <code>\nolinebreak</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="427">\linebreak</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="428">\nolinebreak</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="282">line breaks, forcing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="283">line breaks, preventing</indexterm></cindex>

<para>Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\linebreak[<var>priority</var>]
\nolinebreak[<var>priority</var>]
</pre></example>

<para>By default, the <code>\linebreak</code> (<code>\nolinebreak</code>) command forces
(prevents) a line break at the current position.  For
<code>\linebreak</code>, the spaces in the line are stretched out so that it
extends to the right margin as usual.
</para>
<para>With the optional argument <var>priority</var>, you can convert the command
from a demand to a request.  The <var>priority</var> must be a number from
0 to&nbsp;4.  The higher the number, the more insistent the request.
</para>

</section>
</chapter>
<node name="Page-breaking" spaces=" "><nodename>Page breaking</nodename><nodenext automatic="on">Footnotes</nodenext><nodeprev automatic="on">Line breaking</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Page breaking</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="284">page breaking</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="285">breaking pages</indexterm></cindex>

<para>&latex; starts new pages asynchronously, when enough material has
accumulated to fill up a page.  Usually this happens automatically,
but sometimes you may want to influence the breaks.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::           ">\cleardoublepage</menunode><menudescription><pre xml:space="preserve">Start a new right-hand page.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                 ">\clearpage</menunode><menudescription><pre xml:space="preserve">Start a new page.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                   ">\newpage</menunode><menudescription><pre xml:space="preserve">Start a new page.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           ">\enlargethispage</menunode><menudescription><pre xml:space="preserve">Enlarge the current page a bit.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::  ">\pagebreak &amp; \nopagebreak</menunode><menudescription><pre xml:space="preserve">Forcing &amp; avoiding page breaks.
</pre></menudescription></menuentry></menu>


<node name="_005ccleardoublepage" spaces=" "><nodename>\cleardoublepage</nodename><nodenext automatic="on">\clearpage</nodenext><nodeup automatic="on">Page breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\cleardoublepage</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="429">\cleardoublepage</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="286">starting on a right-hand page</indexterm></cindex>

<para>The <code>\cleardoublepage</code> command ends the current page and causes all
the pending floating figures and tables that have so far appeared in the
input to be printed.  In a two-sided printing style, it also makes the
next page a right-hand (odd-numbered) page, producing a blank page if
necessary.
</para>

</section>
<node name="_005cclearpage" spaces=" "><nodename>\clearpage</nodename><nodenext automatic="on">\newpage</nodenext><nodeprev automatic="on">\cleardoublepage</nodeprev><nodeup automatic="on">Page breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\clearpage</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="430">\clearpage</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="287">flushing floats and starting a page</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="288">starting a new page and clearing floats</indexterm></cindex>

<para>The <code>\clearpage</code> command ends the current page and causes all the
pending floating figures and tables that have so far appeared in the
input to be printed.
</para>

</section>
<node name="_005cnewpage" spaces=" "><nodename>\newpage</nodename><nodenext automatic="on">\enlargethispage</nodenext><nodeprev automatic="on">\clearpage</nodeprev><nodeup automatic="on">Page breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\newpage</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="431">\newpage</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="289">new page, starting</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="290">starting a new page</indexterm></cindex>

<para>The <code>\newpage</code> command ends the current page, but does not clear
floats (<pxref label="_005cclearpage"><xrefnodename>\clearpage</xrefnodename></pxref>).
</para>

</section>
<node name="_005cenlargethispage" spaces=" "><nodename>\enlargethispage</nodename><nodenext automatic="on">\pagebreak &amp; \nopagebreak</nodenext><nodeprev automatic="on">\newpage</nodeprev><nodeup automatic="on">Page breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\enlargethispage</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="432">\enlargethispage</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="291">enlarge current page</indexterm></cindex>

<para><code>\enlargethispage&lbrace;size&rbrace;</code>
</para>
<para><code>\enlargethispage*&lbrace;size&rbrace;</code>
</para>
<para>Enlarge the <code>\textheight</code> for the current page by the specified
amount; e.g., <code>\enlargethispage&lbrace;\baselineskip&rbrace;</code> will allow one
additional line.
</para>
<para>The starred form tries to squeeze the material together on the page as
much as possible. This is normally used together with an explicit
<code>\pagebreak</code>.
</para>

</section>
<node name="_005cpagebreak-_0026-_005cnopagebreak" spaces=" "><nodename>\pagebreak &amp; \nopagebreak</nodename><nodeprev automatic="on">\enlargethispage</nodeprev><nodeup automatic="on">Page breaking</nodeup></node>
<section spaces=" "><sectiontitle><code>\pagebreak</code> &amp; <code>\nopagebreak</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="433">\pagebreak</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="434">\nopagebreak</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="292">page break, forcing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="293">page break, preventing</indexterm></cindex>

<para>Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\pagebreak[<var>priority</var>]
\nopagebreak[<var>priority</var>]
</pre></example>

<para>By default, the <code>\pagebreak</code> (<code>\nopagebreak</code>) command forces
(prevents) a page break at the current position.  With
<code>\pagebreak</code>, the vertical space on the page is stretched out
where possible so that it extends to the normal bottom margin.
</para>
<para>With the optional argument <var>priority</var>, you can convert the
<code>\pagebreak</code> command from a demand to a request.  The number must
be a number from 0 to&nbsp;4.  The higher the number, the more
insistent the request is.
</para>

</section>
</chapter>
<node name="Footnotes" spaces=" "><nodename>Footnotes</nodename><nodenext automatic="on">Definitions</nodenext><nodeprev automatic="on">Page breaking</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Footnotes</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="294">footnotes, creating</indexterm></cindex>

<para>Place a numbered footnote at the bottom of the current page, as here.
</para>
<example endspaces=" ">
<pre xml:space="preserve">No<accent type="uml">e</accent>l Coward quipped that having to read a footnote is like having
to go downstairs to answer the door, while in the midst of making
love.\footnote&lbrace;I wouldn't know, I don't read footnotes.&rbrace;
</pre></example>

<para>You can place multiple footnotes on a page. If the text becomes too long
it will flow to the next page.
</para>
<para>You can also produce footnotes by combining the <code>\footnotemark</code> and
the <code>\footnotetext</code> commands, which is useful in special
circumstances.
</para>
<para>To make bibliographic references come out as footnotes you need to
include a bibliographic style with that behavior.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::                ">\footnote</menunode><menudescription><pre xml:space="preserve">Insert a footnote.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">\footnotemark</menunode><menudescription><pre xml:space="preserve">Insert footnote mark only.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">\footnotetext</menunode><menudescription><pre xml:space="preserve">Insert footnote text only.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::     ">Footnotes in a table</menunode><menudescription><pre xml:space="preserve">Table footnotes.  
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::     ">Footnotes in section headings</menunode><menudescription><pre xml:space="preserve">Chapter or section titles.  
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::   ">Footnotes of footnotes</menunode><menudescription><pre xml:space="preserve">Multiple classes of footnotes.  
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::   ">Multiple reference to footnotes</menunode><menudescription><pre xml:space="preserve">Referring to a footnote more than once.  
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::      ">Footnote parameters</menunode><menudescription><pre xml:space="preserve">Parameters for footnote formatting.
</pre></menudescription></menuentry></menu>


<node name="_005cfootnote" spaces=" "><nodename>\footnote</nodename><nodenext automatic="on">\footnotemark</nodenext><nodeup automatic="on">Footnotes</nodeup></node>
<section spaces=" "><sectiontitle><code>\footnote</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="435">\footnote</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\footnote[<var>number</var>]&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>Place a numbered footnote <var>text</var> at the bottom of the current page.
</para>
<example endspaces=" ">
<pre xml:space="preserve">There are over a thousand footnotes in Gibbon's 
\textit&lbrace;Decline and Fall of the Roman Empire&rbrace;.\footnote&lbrace;After
reading an early version with endnotes David Hume complained, 
``One is also plagued with his Notes, according to the present Method 
of printing the Book'' and suggested that they ``only to be printed 
at the Margin or the Bottom of the Page.''&rbrace;
</pre></example>

<para>The optional argument <var>number</var> allows you to specify the footnote
number.  If you use this option then the footnote number counter is not
incremented, and if you do not use it then the counter is incremented.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="295">footnotes, symbols instead of numbers</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="436">\fnsymbol<r>, and footnotes</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="437">\&arobase;fnsymbol</indexterm></findex>
<para>Change how &latex; shows the footnote counter with something like
<code>\renewcommand&lbrace;\thefootnote&rbrace;&lbrace;\fnsymbol&lbrace;footnote&rbrace;&rbrace;</code>, which
uses a sequence of symbols (<pxref label="_005calph-_005cAlph-_005carabic-_005croman-_005cRoman-_005cfnsymbol"><xrefnodename>\alph \Alph \arabic \roman \Roman
\fnsymbol</xrefnodename></pxref>).  To make this change global put that in the preamble.  If
you make the change local then you may want to reset the counter with
<code>\setcounter&lbrace;footnote&rbrace;&lbrace;0&rbrace;</code>.  By default &latex; uses arabic
numbers.
</para>
<para>&latex;&textrsquo;s default puts many restrictions on where you can use a
<code>\footnote</code>; for instance, you cannot use it in an argument to a
sectioning command such as <code>\chapter</code> (it can only be used in outer
paragraph mode).  There are some workarounds; see following sections.
<!-- c xx mention packages that fix this -->
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="296">Footnotes, in a minipage</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="297">mpfootnote counter</indexterm></cindex>
<para>In a <code>minipage</code> environment the <code>\footnote</code>
command uses the <code>mpfootnote</code> counter instead of the
<code>footnote</code> counter, so they are numbered independently.  They are
shown at the bottom of the environment, not at the bottom of the page.
And by default they are shown alphabetically. <xref label="minipage"><xrefnodename>minipage</xrefnodename></xref>.
</para>

</section>
<node name="_005cfootnotemark" spaces=" "><nodename>\footnotemark</nodename><nodenext automatic="on">\footnotetext</nodenext><nodeprev automatic="on">\footnote</nodeprev><nodeup automatic="on">Footnotes</nodeup></node>
<section spaces=" "><sectiontitle><code>\footnotemark</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="438">\footnotemark</indexterm></findex>

<para>Synopsis, one of:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\footnotemark
\footnotemark[<var>number</var>]
</pre></example>

<para>Put the current footnote number in the
text. (See&nbsp;<ref label="_005cfootnotetext"><xrefnodename>\footnotetext</xrefnodename></ref> for giving the text of the footnote
separately.)  The version with the optional argument <var>number</var> uses
that number to determine the mark printed. This command can be used in
inner paragraph mode.
</para>
<para>This example gives the same institutional affiliation to both the first
and third authors (<code>\thanks</code> is a version of <code>footnote</code>).
</para>
<example endspaces=" ">
<pre xml:space="preserve">\title&lbrace;A Treatise on the Binomial Theorem&rbrace;
\author&lbrace;J Moriarty\thanks&lbrace;University of Leeds&rbrace; 
  \and A C Doyle\thanks&lbrace;Durham University&rbrace; 
  \and S Holmes\footnotemark[1]&rbrace;
\begin&lbrace;document&rbrace;
\maketitle
</pre></example> 

<para>If you use <code>\footnotemark</code> without the optional argument then it
increments the footnote counter but if you use the optional <var>number</var>
then it does not. This produces several consecutive footnote markers
referring to the same footnote.
</para>
<example endspaces=" ">
<pre xml:space="preserve">The first theorem\footnote&lbrace;Due to Gauss.&rbrace; 
and the second theorem\footnotemark[\value&lbrace;footnote&rbrace;] 
and the third theorem.\footnotemark[\value&lbrace;footnote&rbrace;]
</pre></example>


</section>
<node name="_005cfootnotetext" spaces=" "><nodename>\footnotetext</nodename><nodenext automatic="on">Footnotes in a table</nodenext><nodeprev automatic="on">\footnotemark</nodeprev><nodeup automatic="on">Footnotes</nodeup></node>
<section spaces=" "><sectiontitle><code>\footnotetext</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="439">\footnotetext</indexterm></findex>

<para>Synopsis, one of:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\footnotetext&lbrace;<var>text</var>&rbrace;
\footnotetext[<var>number</var>]&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>Place <var>text</var> at the bottom of the page as a footnote.  This command
can come anywhere after the <code>\footnotemark</code> command.  The optional
argument <var>number</var> changes the displayed footnote number.  The
<code>\footnotetext</code> command must appear in outer paragraph mode.
</para>

</section>
<node name="Footnotes-in-a-table" spaces=" "><nodename>Footnotes in a table</nodename><nodenext automatic="on">Footnotes in section headings</nodenext><nodeprev automatic="on">\footnotetext</nodeprev><nodeup automatic="on">Footnotes</nodeup></node>
<section spaces=" "><sectiontitle>Footnotes in a table</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="298">Footnotes, in a table</indexterm></cindex>

<para>Inside a <code>table</code> environment the <code>\footnote</code> command does not
work.  For instance, if the code below appears on its own then the
footnote simply disappears; there is a footnote mark in the table cell
but nothing is set at the bottom of the page.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;center&rbrace;
     \begin&lbrace;tabular&rbrace;&lbrace;l|l&rbrace;
     \textsc&lbrace;Ship&rbrace;  &amp;\textsc&lbrace;Book&rbrace; \\ \hline 
     \textit&lbrace;HMS Sophie&rbrace;     &amp;Master and Commander  \\ 
     \textit&lbrace;HMS Polychrest&rbrace; &amp;Post Captain  \\  
     \textit&lbrace;HMS Lively&rbrace;     &amp;Post Captain \\
     \textit&lbrace;HMS Surprise&rbrace;   &amp;A number of books\footnote&lbrace;Starting with
                                HMS Surprise.&rbrace;
     \end&lbrace;tabular&rbrace;
\end&lbrace;center&rbrace;
</pre></example>

<para>The solution is to surround the <code>tabular</code> environment with a
<code>minipage</code> environment, as here (<pxref label="minipage"><xrefnodename>minipage</xrefnodename></pxref>).
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;center&rbrace;
  \begin&lbrace;minipage&rbrace;&lbrace;.5\textwidth&rbrace;
    ... tabular material ...
  \end&lbrace;minipage&rbrace;
\end&lbrace;center&rbrace;
</pre></example>

<para>The same technique will work inside a floating <code>table</code> environment
(<pxref label="table"><xrefnodename>table</xrefnodename></pxref>).  To get the footnote at the bottom of the page use the
<file>tablefootnote</file> package, as illustrated in this example.  If you
put <code>\usepackage&lbrace;tablefootnote&rbrace;</code> in the preamble and use the code
shown then the footnote appears at the bottom and is numbered in
sequence with other footnotes.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;table&rbrace;
  \centering
     \begin&lbrace;tabular&rbrace;&lbrace;l|l&rbrace;
     \textsc&lbrace;Date&rbrace;  &amp;\textsc&lbrace;Campaign&rbrace; \\ \hline 
     1862           &amp;Fort Donelson \\ 
     1863           &amp;Vicksburg     \\  
     1865           &amp;Army of Northern Virginia\footnote&lbrace;Ending the war.&rbrace;
     \end&lbrace;tabular&rbrace;
    \caption&lbrace;Forces captured by US Grant&rbrace;
\end&lbrace;table&rbrace;
</pre></example>


</section>
<node name="Footnotes-in-section-headings" spaces=" "><nodename>Footnotes in section headings</nodename><nodenext automatic="on">Footnotes of footnotes</nodenext><nodeprev automatic="on">Footnotes in a table</nodeprev><nodeup automatic="on">Footnotes</nodeup></node>
<section spaces=" "><sectiontitle>Footnotes in section headings</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="299">footnotes, in section headings</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="300">table of contents, avoiding footnotes</indexterm></cindex>
<para>Putting a footnote in a section heading, as in:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\section&lbrace;Full sets\protect\footnote&lbrace;This material due to ...&rbrace;&rbrace;
</pre></example>

<cindex index="cp" spaces=" "><indexterm index="cp" number="301"><r>package</r>, <code>footmisc</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="302"><code>footmisc</code> <r>package</r></indexterm></cindex>

<cindex index="cp" spaces=" "><indexterm index="cp" number="303"><code>stable</code> option to <code>footmisc</code> package</indexterm></cindex>
<noindent></noindent>
<para>causes the footnote to appear at the bottom of the page where the
section starts, as usual, but also at the bottom of the table of
contents, where it is not likely to be desired.  To have it not appear
on the table of contents use the package <file>footmisc</file> with the
<code>stable</code> option.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usepackage[stable]&lbrace;footmisc&rbrace;
...
\begin&lbrace;document&rbrace;
...
\section&lbrace;Full sets\footnote&lbrace;This material due to ...&rbrace;&rbrace;
</pre></example>

<para>Note that the <code>\protect</code> is gone; including it would cause the
footnote to reappear on the table of contents.
</para>

</section>
<node name="Footnotes-of-footnotes" spaces=" "><nodename>Footnotes of footnotes</nodename><nodenext automatic="on">Multiple reference to footnotes</nodenext><nodeprev automatic="on">Footnotes in section headings</nodeprev><nodeup automatic="on">Footnotes</nodeup></node>
<section spaces=" "><sectiontitle>Footnotes of footnotes</sectiontitle>

<para>Particularly in the humanities, authors can have multiple classes of
footnotes, including having footnotes of footnotes.  The package
<file>bigfoot</file> extends &latex;&textrsquo;s default footnote mechanism in many
ways, including allow these two, as in this example.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usepackage&lbrace;bigfoot&rbrace;
\DeclareNewFootnote&lbrace;Default&rbrace;
\DeclareNewFootnote&lbrace;from&rbrace;[alph]   % create class \footnotefrom&lbrace;&rbrace;
 ...
\begin&lbrace;document&rbrace;
...
The third theorem is a partial converse of the 
second.\footnotefrom&lbrace;First noted in Wilson.\footnote&lbrace;Second edition only.&rbrace;&rbrace;
...
</pre></example>


</section>
<node name="Multiple-reference-to-footnotes" spaces=" "><nodename>Multiple reference to footnotes</nodename><nodenext automatic="on">Footnote parameters</nodenext><nodeprev automatic="on">Footnotes of footnotes</nodeprev><nodeup automatic="on">Footnotes</nodeup></node>
<section spaces=" "><sectiontitle>Multiple references to footnotes</sectiontitle>

<para>You can refer to a single footnote more than once.  This example
uses the package <file>cleverref</file>.
</para>
<!-- c from SE user Jake http://tex.stackexchange.com/a/10116/339 -->
<example endspaces=" ">
<pre xml:space="preserve">\usepackage&lbrace;cleveref&rbrace;[2012/02/15]   % this version of package or later 
\crefformat&lbrace;footnote&rbrace;&lbrace;#2\footnotemark[#1]#3&rbrace;
...
\begin&lbrace;document&rbrace;
...
The theorem is from Evers.\footnote&lbrace;\label&lbrace;fn:TE&rbrace;Tinker and Evers, 1994.&rbrace;
The corollary is from Chance.\footnote&lbrace;Evers and Chance, 1990.&rbrace;
But the key lemma is from Tinker.\cref&lbrace;fn:TE&rbrace;
...
</pre></example>

<para>This solution will work with the package <file>hyperref</file>.
See&nbsp;<ref label="_005cfootnotemark"><xrefnodename>\footnotemark</xrefnodename></ref> for a simpler solution in the common case
of multiple authors with the same affiliation.
</para>

</section>
<node name="Footnote-parameters" spaces=" "><nodename>Footnote parameters</nodename><nodeprev automatic="on">Multiple reference to footnotes</nodeprev><nodeup automatic="on">Footnotes</nodeup></node>
<section spaces=" "><sectiontitle>Footnote parameters</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="304">footnote parameters</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="305">parameters, for footnotes</indexterm></cindex>

<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="440">\footnoterule</indexterm>\footnoterule</itemformat></item>
</tableterm><tableitem><para>Produces the rule separating the main text on a page from the page&textrsquo;s
footnotes.  Default dimensions: <code>0.4pt</code> thick (or wide), and
<code>0.4\columnwidth</code> long in the standard document classes (except
<code>slides</code>, where it does not appear).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="441">\footnotesep</indexterm>\footnotesep</itemformat></item>
</tableterm><tableitem><para>The height of the strut placed at the beginning of the footnote.  By
default, this is set to the normal strut for <code>\footnotesize</code>
fonts (<pxref label="Font-sizes"><xrefnodename>Font sizes</xrefnodename></pxref>), therefore there is no extra space between
footnotes.  This is <samp>6.65pt</samp> for <samp>10pt</samp>, <samp>7.7pt</samp> for
<samp>11pt</samp>, and <samp>8.4pt</samp> for <samp>12pt</samp>.
</para>
</tableitem></tableentry></ftable>


</section>
</chapter>
<node name="Definitions" spaces=" "><nodename>Definitions</nodename><nodenext automatic="on">Counters</nodenext><nodeprev automatic="on">Footnotes</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Definitions</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="306">definitions</indexterm></cindex>

<para>&latex; has support for making new commands of many different kinds.
</para>
<!-- c xx everything in this chapter needs examples. -->
<!-- c xx Add DeclareRobustCommand (see clsguide.pdf) -->

<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::           ">\newcommand &amp; \renewcommand</menunode><menudescription><pre xml:space="preserve">(Re)define a new command.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                       ">\providecommand</menunode><menudescription><pre xml:space="preserve">Define a new command, if name not used.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                           ">\newcounter</menunode><menudescription><pre xml:space="preserve">Define a new counter.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                            ">\newlength</menunode><menudescription><pre xml:space="preserve">Define a new length.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                           ">\newsavebox</menunode><menudescription><pre xml:space="preserve">Define a new box.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::   ">\newenvironment &amp; \renewenvironment</menunode><menudescription><pre xml:space="preserve">Define a new environment.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                           ">\newtheorem</menunode><menudescription><pre xml:space="preserve">Define a new theorem-like environment.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                              ">\newfont</menunode><menudescription><pre xml:space="preserve">Define a new font name.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                              ">\protect</menunode><menudescription><pre xml:space="preserve">Using tricky commands.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator=":: ">\ignorespaces &amp; \ignorespacesafterend</menunode><menudescription><pre xml:space="preserve">Discard extra spaces.
</pre></menudescription></menuentry></menu>


<node name="_005cnewcommand-_0026-_005crenewcommand" spaces=" "><nodename>\newcommand &amp; \renewcommand</nodename><nodenext automatic="on">\providecommand</nodenext><nodeup automatic="on">Definitions</nodeup></node>
<section spaces=" "><sectiontitle><code>\newcommand</code> &amp; <code>\renewcommand</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="442">\newcommand</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="307">commands, defining new ones</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="308">commands, redefining</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="309">defining a new command</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="310">new commands, defining</indexterm></cindex>

<para><code>\newcommand</code> and <code>\renewcommand</code> define and redefine a
command, respectively.  Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">  \newcommand&lbrace;\<var>cmd</var>&rbrace;[<var>nargs</var>][<var>optargdefault</var>]&lbrace;<var>defn</var>&rbrace;
  \newcommand*&lbrace;\<var>cmd</var>&rbrace;[<var>nargs</var>][<var>optargdefault</var>]&lbrace;<var>defn</var>&rbrace;
\renewcommand&lbrace;\<var>cmd</var>&rbrace;[<var>nargs</var>][<var>optargdefault</var>]&lbrace;<var>defn</var>&rbrace;
\renewcommand*&lbrace;\<var>cmd</var>&rbrace;[<var>nargs</var>][<var>optargdefault</var>]&lbrace;<var>defn</var>&rbrace;
</pre></example>

<cindex index="cp" spaces=" "><indexterm index="cp" number="311">starred form, defining new commands</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="312">*-form, defining new commands</indexterm></cindex>
<para>The starred form of these two commands requires that the arguments not
contain multiple paragraphs of text (not <code>\long</code>, in plain &tex;
terms).
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="var">cmd</itemformat></item>
</tableterm><tableitem><para>Required; <code>\<var>cmd</var></code> is the command name.  For <code>\newcommand</code>, it
must not be already defined and must not begin with <code>\end</code>.  For
<code>\renewcommand</code>, it must already be defined.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">nargs</itemformat></item>
</tableterm><tableitem><para>Optional; an integer from 0 to 9, specifying the number of arguments
that the command can take, including any optional argument.  If this
argument is not present, the default is for the command to have no
arguments.  When redefining a command, the new version can have a
different number of arguments than the old version.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">optargdefault</itemformat></item>
</tableterm><tableitem><para>Optional; if this argument is present then the first argument of defined
command <code>\<var>cmd</var></code> is optional, with default value <var>optargdefault</var>
(which may be the empty string).  If this argument is not present then
<code>\<var>cmd</var></code> does not take an optional argument.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="313">positional parameter</indexterm></cindex>
<para>That is, if <code>\<var>cmd</var></code> is used with square brackets following,
as in <code>\<var>cmd</var>[<var>myval</var>]</code>, then within <var>defn</var> the first
<dfn>positional parameter</dfn> <code>#1</code> expands <var>myval</var>.  On the
other hand, if <code>\<var>cmd</var></code> is called without square brackets
following, then within <var>defn</var> the positional parameter <code>#1</code>
expands to the default <var>optargdefault</var>.  In either case, any
required arguments will be referred to starting with <code>#2</code>.
</para>
<para>Omitting <code>[<var>myval</var>]</code> in a call is different from having the
square brackets with no contents, as in <code>[]</code>.  The former results
in <code>#1</code> expanding to <var>optargdefault</var>; the latter results in
<code>#1</code> expanding to the empty string.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">defn</itemformat></item>
</tableterm><tableitem><para>The text to be substituted for every occurrence of <code>\<var>cmd</var></code>; the
positional parameter <code>#<var>n</var></code> in <var>defn</var> is replaced by
the text of the <var>n</var>th argument.
</para>
</tableitem></tableentry></table>

<para>&tex; ignores spaces in the source following an alphabetic control
sequence, as in <samp>\cmd </samp>.  If you actually want a space there, one
solution is to type <code>&lbrace;&rbrace;</code> after the command (<samp>\cmd&lbrace;&rbrace; </samp>;
another solution is to use an explicit control space (<samp>\cmd\ </samp>).
</para>
<para>A simple example of defining a new command:
<code>\newcommand&lbrace;\RS&rbrace;&lbrace;Robin Smith&rbrace;</code> results in
<code>\RS</code> being replaced by the longer text.
</para>
<para>Redefining an existing command is similar:
<code>\renewcommand&lbrace;\qedsymbol&rbrace;&lbrace;&lbrace;\small QED&rbrace;&rbrace;</code>.
</para>
<para>Here&textrsquo;s a command definition with one required argument:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcommand&lbrace;\defref&rbrace;[1]&lbrace;Definition~\ref&lbrace;#1&rbrace;&rbrace;
</pre></example>

<noindent></noindent> <para>Then, <code>\defref&lbrace;def:basis&rbrace;</code> expands to
<code>Definition~\ref&lbrace;def:basis&rbrace;</code>, which will ultimately expand to
something like <samp>Definition~3.14</samp>.
</para>
<para>An example with two required arguments:
<code>\newcommand&lbrace;\nbym&rbrace;[2]&lbrace;$#1 \times #2$&rbrace;</code> is invoked as
<code>\nbym&lbrace;2&rbrace;&lbrace;k&rbrace;</code>.
</para>
<para>An example with an optional argument:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcommand&lbrace;\salutation&rbrace;[1][Sir or Madam]&lbrace;Dear #1:&rbrace;
</pre></example>

<noindent></noindent> <para>Then, <code>\salutation</code> gives <samp>Dear Sir or Madam:</samp> while
<code>\salutation[John]</code> gives <samp>Dear John:</samp>.  And
<code>\salutation[]</code> gives <samp>Dear :</samp>.
</para>
<para>The braces around <var>defn</var> do not define a group, that is, they do
not delimit the scope of the result of expanding <var>defn</var>.  So
<code>\newcommand&lbrace;\shipname&rbrace;[1]&lbrace;\it #1&rbrace;</code> is problematic; in this
sentence,
</para>
<example endspaces=" ">
<pre xml:space="preserve">The \shipname&lbrace;Monitor&rbrace; met the \shipname&lbrace;Merrimac&rbrace;.
</pre></example>

<noindent></noindent> <para>the words <samp>met the</samp> would incorrectly be in italics.  Another
pair of braces in the definition is needed, like this:
<code>\newcommand&lbrace;\shipname&rbrace;[1]&lbrace;&lbrace;\it #1&rbrace;&rbrace;</code>.  Those braces are
part of the definition and thus do define a group.
</para>

</section>
<node name="_005cprovidecommand" spaces=" "><nodename trailingspaces=" ">\providecommand</nodename><nodenext automatic="on">\newcounter</nodenext><nodeprev automatic="on">\newcommand &amp; \renewcommand</nodeprev><nodeup automatic="on">Definitions</nodeup></node>
<section spaces=" "><sectiontitle><code>\providecommand</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="443">\providecommand</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="314">commands, defining new ones</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="315">defining a new command</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="316">new commands, defining</indexterm></cindex>

<para>Defines a command, as long as no command of this name already exists.
Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\providecommand&lbrace;<var>cmd</var>&rbrace;[<var>nargs</var>][<var>optargdefault</var>]&lbrace;<var>defn</var>&rbrace;
\providecommand*&lbrace;<var>cmd</var>&rbrace;[<var>nargs</var>][<var>optargdefault</var>]&lbrace;<var>defn</var>&rbrace;
</pre></example>

<para>If no command of this name already exists then this has the same effect
as <code>\newcommand</code> (<pxref label="_005cnewcommand-_0026-_005crenewcommand"><xrefnodename>\newcommand &amp; \renewcommand</xrefnodename></pxref>).  If a
command of this name already exists then this definition does nothing.
This is particularly useful in a style file, or other file that may be
loaded more than once.
</para>

</section>
<node name="_005cnewcounter" spaces=" "><nodename>\newcounter</nodename><nodenext automatic="on">\newlength</nodenext><nodeprev automatic="on">\providecommand</nodeprev><nodeup automatic="on">Definitions</nodeup></node>
<section spaces=" "><sectiontitle><code>\newcounter</code>: Allocating a counter</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="444">\newcounter</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="317">counters, defining new</indexterm></cindex>

<para>Synopsis, one of:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcounter&lbrace;<var>countername</var>&rbrace;
\newcounter&lbrace;<var>countername</var>&rbrace;[<var>supercounter</var>]
</pre></example>

<para>Globally defines a new counter named <var>countername</var> and initialize
the new counter to zero.
</para>
<para>The name <var>countername</var> must consists of letters only, and does not
begin with a backslash.  This name must not already be in use by another
counter.
</para>
<para>When you use the optional argument <code>[<var>supercounter</var>]</code> then
<var>countername</var> will be numbered within, or subsidiary to, the
existing counter <var>supercounter</var>.  For example, ordinarily
<code>subsection</code> is numbered within <code>section</code> so that any time
<var>supercounter</var> is incremented with <code>\stepcounter</code>
(<pxref label="_005cstepcounter"><xrefnodename>\stepcounter</xrefnodename></pxref>) or <code>\refstepcounter</code>
(<pxref label="_005crefstepcounter"><xrefnodename>\refstepcounter</xrefnodename></pxref>) then <var>countername</var> is reset to zero.
</para>
<para><xref label="Counters"><xrefnodename>Counters</xrefnodename></xref>, for more information about counters.
</para>

</section>
<node name="_005cnewlength" spaces=" "><nodename>\newlength</nodename><nodenext automatic="on">\newsavebox</nodenext><nodeprev automatic="on">\newcounter</nodeprev><nodeup automatic="on">Definitions</nodeup></node>
<section spaces=" "><sectiontitle><code>\newlength</code>: Allocating a length</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="445">\newlength</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="318">lengths, allocating new</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="319">rubber lengths, defining new</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="320">skip register, plain &tex;</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="321">glue register, plain &tex;</indexterm></cindex>

<para>Allocate a new <dfn>length</dfn> register.  Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newlength&lbrace;\<var>arg</var>&rbrace;
</pre></example>

<para>This command takes one required argument, which must begin with a
backslash (<samp>\</samp>).  It creates a new length register named
<code>\<var>arg</var></code>, which is a place to hold (rubber) lengths such as
<code>1in plus.2in minus.1in</code> (what plain &tex; calls a <code>skip</code>
register).  The register gets an initial value of zero.  The control
sequence <code>\<var>arg</var></code> must not already be defined.
</para>
<para><xref label="Lengths"><xrefnodename>Lengths</xrefnodename></xref>, for more about lengths.
</para>

</section>
<node name="_005cnewsavebox" spaces=" "><nodename>\newsavebox</nodename><nodenext automatic="on">\newenvironment &amp; \renewenvironment</nodenext><nodeprev automatic="on">\newlength</nodeprev><nodeup automatic="on">Definitions</nodeup></node>
<section spaces=" "><sectiontitle><code>\newsavebox</code>: Allocating a box</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="446">\newsavebox</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="322">box, allocating new</indexterm></cindex>

<para>Allocate a &textldquo;bin&textrdquo; for holding a box.  Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newsavebox&lbrace;\<var>cmd</var>&rbrace;
</pre></example>

<para>Defines <code>\<var>cmd</var></code> to refer to a new bin for storing boxes.
Such a box is for holding typeset material, to use multiple times
(<pxref label="Boxes"><xrefnodename>Boxes</xrefnodename></pxref>) or to measure or manipulate.  The name
<code>\<var>cmd</var></code> must start with a backslash (<samp>\</samp>), and must not
be already defined.
</para>
<para>The allocation of a box is global.  This command is fragile
(<pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>).
</para>

</section>
<node name="_005cnewenvironment-_0026-_005crenewenvironment" spaces=" "><nodename>\newenvironment &amp; \renewenvironment</nodename><nodenext automatic="on">\newtheorem</nodenext><nodeprev automatic="on">\newsavebox</nodeprev><nodeup automatic="on">Definitions</nodeup></node>
<section spaces=" "><sectiontitle><code>\newenvironment</code> &amp; <code>\renewenvironment</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="447">\newenvironment</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="448">\renewenvironment</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="323">environments, defining</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="324">defining new environments</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="325">redefining environments</indexterm></cindex>

<para>These commands define or redefine an environment <var>env</var>, that is,
<code>\begin&lbrace;<var>env</var>&rbrace; <var>body</var> \end&lbrace;<var>env</var>&rbrace;</code>.  Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">   \newenvironment&lbrace;<var>env</var>&rbrace;[<var>nargs</var>][<var>optargdefault</var>]&lbrace;<var>begdefn</var>&rbrace;&lbrace;<var>enddefn</var>&rbrace;
  \newenvironment*&lbrace;<var>env</var>&rbrace;[<var>nargs</var>][<var>optargdefault</var>]&lbrace;<var>begdefn</var>&rbrace;&lbrace;<var>enddefn</var>&rbrace;
 \renewenvironment&lbrace;<var>env</var>&rbrace;[<var>nargs</var>][<var>optargdefault</var>]&lbrace;<var>begdefn</var>&rbrace;&lbrace;<var>enddefn</var>&rbrace;
\renewenvironment*&lbrace;<var>env</var>&rbrace;[<var>nargs</var>][<var>optargdefault</var>]&lbrace;<var>begdefn</var>&rbrace;&lbrace;<var>enddefn</var>&rbrace;
</pre></example>

<cindex index="cp" spaces=" "><indexterm index="cp" number="326"><code>*</code>-form of environment commands</indexterm></cindex>
<para>The starred form of these commands requires that the arguments not
contain multiple paragraphs of text.  The body of these environments can
still contain multiple paragraphs.
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="var">env</itemformat></item>
</tableterm><tableitem><para>Required; the environment name.  It consists only of letters or the
<code>*</code> character, and thus does not begin with backslash
(<code>\</code>).  It must not begin with the string <code>end</code>.  For
<code>\newenvironment</code>, the name <var>env</var> must not be the name of an
already existing environment, and also the command <code>\<var>env</var></code>
must be undefined.  For <code>\renewenvironment</code>, <var>env</var> must be the
name of an existing environment.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">nargs</itemformat></item>
</tableterm><tableitem><para>Optional; an integer from 0 to 9 denoting the number of arguments of
that the environment will take.  When the environment is used these
arguments appear after the <code>\begin</code>, as in
<code>\begin&lbrace;<var>env</var>&rbrace;&lbrace;<var>arg1</var>&rbrace;&dots;&lbrace;<var>argn</var>&rbrace;</code>.  If this
argument is not present then the default is for the environment to have
no arguments.  When redefining an environment, the new version can have
a different number of arguments than the old version.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">optargdefault</itemformat></item>
</tableterm><tableitem><para>Optional; if this argument is present then the first argument of the
defined environment is optional, with default value <var>optargdefault</var>
(which may be the empty string).  If this argument is not present then
the environment does not take an optional argument.
</para>
<para>That is, when <code>[<var>optargdefault</var>]</code> is present in the
environment definition, if <code>\begin&lbrace;<var>env</var>&rbrace;</code> is used with
square brackets following, as in
<code>\begin&lbrace;<var>env</var>&rbrace;[<var>myval</var>]</code>, then, within <var>begdefn</var>,
the positional parameter <code>#1</code> expands to <var>myval</var>.  If
<code>\begin&lbrace;<var>env</var>&rbrace;</code> is called without square brackets
following, then, within within <var>begdefn</var>, the positional parameter
<code>#1</code> expands to the default <var>optargdefault</var>.  In either case,
any required arguments will be referred to starting with <code>#2</code>.
</para>
<para>Omitting <code>[<var>myval</var>]</code> in the call is different from having the
square brackets with no contents, as in <code>[]</code>.  The former results
in <code>#1</code> expanding to <var>optargdefault</var>; the latter results in
<code>#1</code> expanding to the empty string.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">begdefn</itemformat></item>
</tableterm><tableitem><para>Required; the text expanded at every occurrence of
<code>\begin&lbrace;<var>env</var>&rbrace;</code>.  Within <var>begdef</var>, the <var>n</var>th
positional parameter (i.e., <code>#<var>n</var></code>) is replaced by the text
of the <var>n</var>th argument.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">enddefn</itemformat></item>
</tableterm><tableitem><para>Required; the text expanded at every occurrence of
<code>\end&lbrace;<var>env</var>&rbrace;</code>.  This may not contain any positional
parameters, so <code>#<var>n</var></code> cannot be used here (but see the final
example below).
</para>
</tableitem></tableentry></table>

<para>All environments, that is to say the <var>begdefn</var> code, the environment
body and the <var>enddefn</var> code, are processed within a group.  Thus, in
the first example below, the effect of the <code>\small</code> is limited to
the quote and does not extend to material following the environment.
</para>
<para>This example gives an environment like &latex;&textrsquo;s <code>quotation</code>
except that it will be set in smaller type:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newenvironment&lbrace;smallquote&rbrace;&lbrace;%
  \small\begin&lbrace;quotation&rbrace;
&rbrace;&lbrace;%
  \end&lbrace;quotation&rbrace;
&rbrace;
</pre></example>

<para>This one shows the use of arguments; it gives a quotation environment
that cites the author:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newenvironment&lbrace;citequote&rbrace;[1][Shakespeare]&lbrace;%
  \begin&lbrace;quotation&rbrace;
  \noindent\textit&lbrace;#1&rbrace;: 
&rbrace;&lbrace;%
  \end&lbrace;quotation&rbrace;
&rbrace;
</pre></example>

<noindent></noindent> <para>The author&textrsquo;s name is optional, and defaults to <samp>Shakespeare</samp>.
In the document, use the environment like this:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;citequote&rbrace;[Lincoln]
  ...
\end&lbrace;citequote&rbrace;
</pre></example>

<para>The final example shows how to save the value of an argument to use in 
<var>enddefn</var>, in this case in a box (<pxref label="_005csbox"><xrefnodename>\sbox</xrefnodename></pxref>):
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newsavebox&lbrace;\quoteauthor&rbrace;
\newenvironment&lbrace;citequote&rbrace;[1][Shakespeare]&lbrace;%
  \sbox\quoteauthor&lbrace;#1&rbrace;%
  \begin&lbrace;quotation&rbrace; 
&rbrace;&lbrace;%
  \hspace&lbrace;1em plus 1fill&rbrace;---\usebox&lbrace;\quoteauthor&rbrace;
  \end&lbrace;quotation&rbrace;
&rbrace;
</pre></example>


</section>
<node name="_005cnewtheorem" spaces=" "><nodename>\newtheorem</nodename><nodenext automatic="on">\newfont</nodenext><nodeprev automatic="on">\newenvironment &amp; \renewenvironment</nodeprev><nodeup automatic="on">Definitions</nodeup></node>
<section spaces=" "><sectiontitle><code>\newtheorem</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="449">\newtheorem</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="327">theorems, defining</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="328">defining new theorems</indexterm></cindex>

<cindex index="cp" spaces=" "><indexterm index="cp" number="329">theorem-like environment</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="330">environment, theorem-like</indexterm></cindex>
<para>Define a new theorem-like environment.  Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newtheorem&lbrace;<var>name</var>&rbrace;&lbrace;<var>title</var>&rbrace;
\newtheorem&lbrace;<var>name</var>&rbrace;&lbrace;<var>title</var>&rbrace;[<var>numbered_within</var>]
\newtheorem&lbrace;<var>name</var>&rbrace;[<var>numbered_like</var>]&lbrace;<var>title</var>&rbrace;
</pre></example>

<para>Using the first form, <code>\newtheorem&lbrace;<var>name</var>&rbrace;&lbrace;<var>title</var>&rbrace;</code>
creates an environment that will be labelled with <var>title</var>.  See the
first example below.
</para>
<para>The second form
<code>\newtheorem&lbrace;<var>name</var>&rbrace;&lbrace;<var>title</var>&rbrace;[<var>numbered_within</var>]</code>
creates an environment whose counter is subordinate to the existing
counter <var>numbered_within</var> (its counter will be reset when
<var>numbered_within</var> is reset).
</para>

<para>The third form
<code>\newtheorem&lbrace;<var>name</var>&rbrace;[<var>numbered_like</var>]&lbrace;<var>title</var>&rbrace;</code>,
with optional argument between the two required arguments, will create
an environment whose counter will share the previously defined counter
<var>numbered_like</var>.
</para>
<para>You can specify one of <var>numbered_within</var> and <var>numbered_like</var>,
or neither, but not both.
</para>
<para>This command creates a counter named <var>name</var>.  In addition, unless
the optional argument <var>numbered_like</var> is used, inside of the
theorem-like environment the current <code>\ref</code> value will be that of
<code>\the<var>numbered_within</var></code> (<pxref label="_005cref"><xrefnodename>\ref</xrefnodename></pxref>).
</para>
<para>This declaration is global.  It is fragile (<pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>).
</para>
<para>Arguments:
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="var">name</itemformat></item>
</tableterm><tableitem><para>The name of the environment.  It must not begin with a backslash
(<samp>\</samp>).  It must not be the name of an existing environment; indeed,
the command name <code>\<var>name</var></code> must not already be defined as anything.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">title</itemformat></item>
</tableterm><tableitem><para>The text printed at the beginning of the environment, before the
number. For example, <samp>Theorem</samp>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">numbered_within</itemformat></item>
</tableterm><tableitem><para>Optional; the name of an already defined counter, usually a sectional
unit such as <code>chapter</code> or <code>section</code>.  When the
<var>numbered_within</var> counter is reset then the <var>name</var> environment&textrsquo;s
counter will also be reset.
</para>
<para>If this optional argument is not used then the command
<code>\the<var>name</var></code> is set to <code>\arabic&lbrace;<var>name</var>&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">numbered_like</itemformat></item>
</tableterm><tableitem><para>Optional; the name of an already defined theorem-like environment. The
new environment will be numbered in sequence with <var>numbered_like</var>.
</para>
</tableitem></tableentry></table>

<para>Without any optional arguments the environments are numbered
sequentially.  The example below has a declaration in the preamble that
results in <samp>Definition&nbsp;1</samp> and <samp>Definition&nbsp;2</samp> in the
output.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newtheorem&lbrace;defn&rbrace;&lbrace;Definition&rbrace;
\begin&lbrace;document&rbrace;
\section&lbrace;...&rbrace;
\begin&lbrace;defn&rbrace;
  First def 
\end&lbrace;defn&rbrace;

\section&lbrace;...&rbrace;
\begin&lbrace;defn&rbrace;
  Second def
\end&lbrace;defn&rbrace;
</pre></example>

<para>Because the next example specifies the optional argument
<var>numbered_within</var> to <code>\newtheorem</code> as <code>section</code>, the
example, with the same document body, gives <samp>Definition&nbsp;1.1</samp>
and <samp>Definition&nbsp;2.1</samp>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newtheorem&lbrace;defn&rbrace;&lbrace;Definition&rbrace;[section]
\begin&lbrace;document&rbrace;
\section&lbrace;...&rbrace;
\begin&lbrace;defn&rbrace;
  First def 
\end&lbrace;defn&rbrace;

\section&lbrace;...&rbrace;
\begin&lbrace;defn&rbrace;
  Second def
\end&lbrace;defn&rbrace;
</pre></example>

<para>In the next example there are two declarations in the preamble, the
second of which calls for the new <code>thm</code> environment to use the same
counter as <code>defn</code>.  It gives <samp>Definition&nbsp;1.1</samp>, followed
by <samp>Theorem&nbsp;2.1</samp> and <samp>Definition&nbsp;2.2</samp>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newtheorem&lbrace;defn&rbrace;&lbrace;Definition&rbrace;[section]
\newtheorem&lbrace;thm&rbrace;[defn]&lbrace;Theorem&rbrace;
\begin&lbrace;document&rbrace;
\section&lbrace;...&rbrace;
\begin&lbrace;defn&rbrace;
  First def 
\end&lbrace;defn&rbrace;

\section&lbrace;...&rbrace;
\begin&lbrace;thm&rbrace;
  First thm
\end&lbrace;thm&rbrace;

\begin&lbrace;defn&rbrace;
  Second def
\end&lbrace;defn&rbrace;
</pre></example>


</section>
<node name="_005cnewfont" spaces=" "><nodename>\newfont</nodename><nodenext automatic="on">\protect</nodenext><nodeprev automatic="on">\newtheorem</nodeprev><nodeup automatic="on">Definitions</nodeup></node>
<section spaces=" "><sectiontitle><code>\newfont</code>: Define a new font (obsolete)</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="450">\newfont</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="331">fonts, new commands for</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="332">defining new fonts</indexterm></cindex>

<para><code>\newfont</code>, now obsolete, defines a command that will switch fonts.
Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newfont&lbrace;\<var>cmd</var>&rbrace;&lbrace;<var>font description</var>&rbrace;
</pre></example>

<para>This defines a control sequence <code>\<var>cmd</var></code> that will change the
current font.  &latex; will look on your system for a file named
<file><var>fontname</var>.tfm</file>.  The control sequence must must not already
be defined.  It must begin with a backslash (<samp>\</samp>).
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="451">.fd <r>file</r></indexterm></findex>
<para>This command is obsolete.  It is a low-level command for setting up an
individual font.  Today fonts are almost always defined in families
(which allows you to, for example, associate a boldface with a roman)
through the so-called &textldquo;New Font Selection Scheme&textrdquo;, either by using
<file>.fd</file> files or through the use of an engine that can access
system fonts such as Xe&latex; (<pxref label="TeX-engines"><xrefnodename>&tex; engines</xrefnodename></pxref>).
<!-- c xx explain nfss somewhere -->
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="333">at clause, in font definitions</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="334">design size, in font definitions</indexterm></cindex>
<para>But since it is part of &latex;, here is an explanation: the
<var>font description</var> consists of a <var>fontname</var> and an optional
<dfn>at clause</dfn>; this can have the form either <code>at <var>dimen</var></code>
or <code>scaled <var>factor</var></code>, where a <var>factor</var> of <samp>1000</samp>
means no scaling.  For &latex;&textrsquo;s purposes, all this does is scale all
the character and other font dimensions relative to the font&textrsquo;s design
size, which is a value defined in the <file>.tfm</file> file.
</para>
<para>This example defines two equivalent fonts and typesets a few
characters in each:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newfont&lbrace;\testfontat&rbrace;&lbrace;cmb10 at 11pt&rbrace;
\newfont&lbrace;\testfontscaled&rbrace;&lbrace;cmb10 scaled 1100&rbrace;
\testfontat abc
\testfontscaled abc
</pre></example>


</section>
<node name="_005cprotect" spaces=" "><nodename>\protect</nodename><nodenext automatic="on">\ignorespaces &amp; \ignorespacesafterend</nodenext><nodeprev automatic="on">\newfont</nodeprev><nodeup automatic="on">Definitions</nodeup></node>
<section spaces=" "><sectiontitle><code>\protect</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="452">\protect</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="335">fragile commands</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="336">robust commands</indexterm></cindex>

<para>All &latex; commands are either <dfn>fragile</dfn> or <dfn>robust</dfn>.  A
fragile command can break when it is used in the argument to certain
other commands.  Commands that contain data that &latex; writes to an
auxiliary file and re-reads later are fragile.  This includes material
that goes into a table of contents, list of figures, list of tables,
etc.  Fragile commands also include line breaks, any command that has an
optional argument, and many more. To prevent such commands from
breaking, one solution is to preceded them with the command
<code>\protect</code>.
</para>
<para>For example, when &latex; runs the <code>\section&lbrace;<var>section
name</var>&rbrace;</code> command it writes the <var>section name</var> text to the
<file>.aux</file> auxiliary file, moving it there for use elsewhere in the
document such as in the table of contents.  Any argument that is
internally expanded by &latex; without typesetting it directly is
referred to as a 
<cindex index="cp" spaces=" "><indexterm index="cp" number="337">moving arguments</indexterm></cindex>
<dfn>moving argument</dfn>.  A command is fragile if it can
expand during this process into invalid &tex; code.  Some examples of
moving arguments are those that appear in the <code>\caption&lbrace;...&rbrace;</code>
command (<pxref label="figure"><xrefnodename>figure</xrefnodename></pxref>), in the <code>\thanks&lbrace;...&rbrace;</code> command
(<pxref label="_005cmaketitle"><xrefnodename>\maketitle</xrefnodename></pxref>), and in &arobase;-expressions in the <code>tabular</code> and
<code>array</code> environments (<pxref label="tabular"><xrefnodename>tabular</xrefnodename></pxref>).
</para>
<para>If you get strange errors from commands used in moving arguments, try
preceding it with <code>\protect</code>.  Every fragile commands must be
protected with their own <code>\protect</code>.  
</para>
<para>Although usually a <code>\protect</code> command doesn&textrsquo;t hurt, length
commands are robust and should not be preceded by a <code>\protect</code>
command. Nor can a <code>\protect</code> command be used in the argument to
<code>\addtocounter</code> or <code>\setcounter</code> command.
</para>
<para>In this example the <code>\caption</code> command gives a mysterious error
about an extra curly brace.  Fix the problem by preceding each
<code>\raisebox</code> command with <code>\protect</code>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;figure&rbrace;
  ...
  \caption&lbrace;Company headquarters of A\raisebox&lbrace;1pt&rbrace;&lbrace;B&rbrace;\raisebox&lbrace;-1pt&rbrace;&lbrace;C&rbrace;&rbrace;
\end&lbrace;figure&rbrace;
</pre></example>

<para>In the next example the <code>\tableofcontents</code> command gives an error
because the <code>\(..\)</code> in the section title expands to illegal &tex;
in the <file>.toc</file> file.  You can solve this by changing <code>\(..\)</code>
to <code>\protect\(..\protect\)</code>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;document&rbrace;
\tableofcontents
...
\section&lbrace;Einstein's \( e=mc^2 \)&rbrace;
...
</pre></example>


</section>
<node name="_005cignorespaces-_0026-_005cignorespacesafterend" spaces=" "><nodename>\ignorespaces &amp; \ignorespacesafterend</nodename><nodeprev automatic="on">\protect</nodeprev><nodeup automatic="on">Definitions</nodeup></node>
<section spaces=" "><sectiontitle><code>\ignorespaces &amp; \ignorespacesafterend</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="453">\ignorespaces</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="454">\ignorespacesafterend</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="338">spaces, ignore around commands</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="339">commands, ignore spaces</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\ignorespaces
</pre></example>

<para>or
</para>
<example endspaces=" ">
<pre xml:space="preserve">\ignorespacesafterend
</pre></example>

<para>Both commands cause &latex; to ignore spaces after the end of the
command up until the first non-space character.  The first is a command
from Plain &tex;, and the second is &latex;-specific.
</para>
<para>The <code>ignorespaces</code> is often used when defining commands via
<code>\newcommand</code>, or <code>\newenvironment</code>, or <code>\def</code>.  The
example below illustrates.  It allows a user to show the points values
for quiz questions in the margin but it is inconvenient because, as
shown in the <code>enumerate</code> list, users must not put any space between
the command and the question text.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcommand&lbrace;\points&rbrace;[1]&lbrace;\makebox[0pt]&lbrace;\makebox[10em][l]&lbrace;#1~pts&rbrace;&rbrace;
\begin&lbrace;enumerate&rbrace; 
  \item\points&lbrace;10&rbrace;no extra space output here
  \item\points&lbrace;15&rbrace; extra space output between the number and the word `extra'
\end&lbrace;enumerate&rbrace; 
</pre></example>

<para>The solution is to change to
<code>\newcommand&lbrace;\points&rbrace;[1]&lbrace;\makebox[0pt]&lbrace;\makebox[10em][l]&lbrace;#1~pts&rbrace;&rbrace;\ignorespaces&rbrace;</code>.
</para>
<para>A second example shows spaces being removed from the front of text.  The
commands below allow a user to uniformly attach a title to names.  But,
as given, if a title accidentally starts with a space then
<code>\fullname</code> will reproduce that.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\makeatletter
\newcommand&lbrace;\honorific&rbrace;[1]&lbrace;\def\&arobase;honorific&lbrace;#1&rbrace;&rbrace; % remember title
\newcommand&lbrace;\fullname&rbrace;[1]&lbrace;\&arobase;honorific~#1&rbrace;       % recall title; put before name
\makeatother
\begin&lbrace;tabular&rbrace;&lbrace;|l|&rbrace;
\honorific&lbrace;Mr/Ms&rbrace;  \fullname&lbrace;Jones&rbrace; \\  % no extra space here
\honorific&lbrace; Mr/Ms&rbrace; \fullname&lbrace;Jones&rbrace;     % extra space before title
\end&lbrace;tabular&rbrace;
</pre></example>

<para>To fix this, change to
<code>\newcommand&lbrace;\fullname&rbrace;[1]&lbrace;\ignorespaces\&arobase;honorific~#1&rbrace;</code>.
</para>
<para>The <code>\ignorespaces</code> is also often used in a <code>\newenvironment</code>
at the end of the <var>begin</var> clause, that is, as part of the second
argument, as in <code>\begin&lbrace;newenvironment&rbrace;&lbrace;<var>env
name</var>&rbrace;&lbrace;... \ignorespaces&rbrace;&lbrace;...&rbrace;</code>.
</para>
<para>To strip spaces off the end of an environment use
<code>\ignorespacesafterend</code>.  An example is that this will show a much
larger vertical space between the first and second environments than
between the second and third.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newenvironment&lbrace;eq&rbrace;&lbrace;\begin&lbrace;equation&rbrace;&rbrace;&lbrace;\end&lbrace;equation&rbrace;&rbrace;
\begin&lbrace;eq&rbrace;
e=mc^2
\end&lbrace;eq&rbrace;
\begin&lbrace;equation&rbrace;
F=ma
\end&lbrace;equation&rbrace;
\begin&lbrace;equation&rbrace;
E=IR
\end&lbrace;equation&rbrace;
</pre></example>

<para>Putting a comment character&nbsp;<code>%</code> immediately after the
<code>\end&lbrace;eq&rbrace;</code> will make the vertical space disappear, but that is
inconvenient.  The solution is to change to
<code>\newenvironment&lbrace;eq&rbrace;&lbrace;\begin&lbrace;equation&rbrace;&rbrace;&lbrace;\end&lbrace;equation&rbrace;\ignorespacesafterend&rbrace;</code>.
</para>

</section>
</chapter>
<node name="Counters" spaces=" "><nodename>Counters</nodename><nodenext automatic="on">Lengths</nodenext><nodeprev automatic="on">Definitions</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Counters</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="340">counters, a list of</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="341">variables, a list of</indexterm></cindex>

<para>Everything &latex; numbers for you has a counter associated with
it. The name of the counter is often the same as the name of the
environment or command associated with the number, except that the
counter&textrsquo;s name has no backslash&nbsp;<code>\</code>.  Thus, associated with
the <code>\chapter</code> command is the <code>chapter</code> counter that keeps
track of the chapter number.  
</para>
<para>Below is a list of the counters used in &latex;&textrsquo;s standard document
classes to control numbering.
</para>
<example endspaces=" ">
<pre xml:space="preserve">part            paragraph       figure          enumi
chapter         subparagraph    table           enumii
section         page            footnote        enumiii
subsection      equation        mpfootnote      enumiv
subsubsection
</pre></example>

<para>The <code>mpfootnote</code> counter is used by the <code>\footnote</code> command
inside of a minipage (<pxref label="minipage"><xrefnodename>minipage</xrefnodename></pxref>).  The counters <code>enumi</code>
through <code>enumiv</code> are used in the <code>enumerate</code> environment, for
up to four levels of nesting (<pxref label="enumerate"><xrefnodename>enumerate</xrefnodename></pxref>).
</para>
<para>New counters are created with <code>\newcounter</code>.  <xref label="_005cnewcounter"><xrefnodename>\newcounter</xrefnodename></xref>.
</para>

<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator=":: ">\alph \Alph \arabic \roman \Roman \fnsymbol</menunode><menudescription><pre xml:space="preserve">Print value of a counter.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::       ">\usecounter</menunode><menudescription><pre xml:space="preserve">Use a specified counter in a list environment.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">\value</menunode><menudescription><pre xml:space="preserve">Use the value of a counter in an expression.  
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::       ">\setcounter</menunode><menudescription><pre xml:space="preserve">Set the value of a counter.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::     ">\addtocounter</menunode><menudescription><pre xml:space="preserve">Add a quantity to a counter.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::   ">\refstepcounter</menunode><menudescription><pre xml:space="preserve">Add to a counter.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::      ">\stepcounter</menunode><menudescription><pre xml:space="preserve">Add to a counter, resetting subsidiary counters.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator=":: ">\day \month \year</menunode><menudescription><pre xml:space="preserve">Numeric date values.
</pre></menudescription></menuentry></menu>


<node name="_005calph-_005cAlph-_005carabic-_005croman-_005cRoman-_005cfnsymbol" spaces=" "><nodename>\alph \Alph \arabic \roman \Roman \fnsymbol</nodename><nodenext automatic="on">\usecounter</nodenext><nodeup automatic="on">Counters</nodeup></node>
<section spaces=" "><sectiontitle><code>\alph \Alph \arabic \roman \Roman \fnsymbol</code>: Printing counters</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="342">counters, printing</indexterm></cindex>

<para>Print the value of a counter, in a specified style.  For instance, if
the counter <var>counter</var> has the value 1 then a
<code>\alph&lbrace;<var>counter</var>&rbrace;</code> in your source will result in a lower case
letter&nbsp;a appearing in the output.
</para>
<para>All of these commands take a single counter as an argument, for
instance, <code>\alph&lbrace;enumi&rbrace;</code>.  Note that the counter name does not
start with a backslash.
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="455">\alph&lbrace;<var>counter</var>&rbrace;</indexterm>\alph&lbrace;<var>counter</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Print the value of <var>counter</var> in lowercase letters: &textlsquo;a&textrsquo;, &textlsquo;b&textrsquo;, &enddots;
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="456">\Alph&lbrace;<var>counter</var>&rbrace;</indexterm>\Alph&lbrace;<var>counter</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Print in uppercase letters: &textlsquo;A&textrsquo;, &textlsquo;B&textrsquo;, &enddots;
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="457">\arabic&lbrace;<var>counter</var>&rbrace;</indexterm>\arabic&lbrace;<var>counter</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Print in Arabic numbers: &textlsquo;1&textrsquo;, &textlsquo;2&textrsquo;, &enddots;
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="458">\roman&lbrace;<var>counter</var>&rbrace;</indexterm>\roman&lbrace;<var>counter</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Print in lowercase roman numerals: &textlsquo;i&textrsquo;, &textlsquo;ii&textrsquo;, &enddots;
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="459">\Roman&lbrace;<var>counter</var>&rbrace;</indexterm>\Roman&lbrace;<var>counter</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Print in uppercase roman numerals: &textlsquo;I&textrsquo;, &textlsquo;II&textrsquo;, &enddots;
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="460">\fnsymbol&lbrace;<var>counter</var>&rbrace;</indexterm>\fnsymbol&lbrace;<var>counter</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Prints the value of <var>counter</var> in a specific sequence of nine
symbols (conventionally used for labeling footnotes).  The value of
<var>counter</var> must be between&nbsp;1 and&nbsp;9, inclusive.
</para>
<para>Here are the symbols:
</para>
<multitable spaces="  " endspaces=" "><columnfractions line=" .33 .33 .33"><columnfraction value=".33"></columnfraction><columnfraction value=".33"></columnfraction><columnfraction value=".33"></columnfraction></columnfractions>
<thead><row><entry command="headitem" spaces=" "><para>Name</para></entry><entry command="tab" spaces=" "><para>Command</para></entry><entry command="tab"><para>Equivalent Unicode symbol and/or numeric code point<!-- c
 -->
</para></entry></row></thead><tbody><row><entry command="item">
<para>asterisk</para></entry><entry command="tab"><para><code>\ast</code></para></entry><entry command="tab"><para>*<!-- c
 -->
</para></entry></row><row><entry command="item">
<para>dagger</para></entry><entry command="tab"><para><code>\dagger</code></para></entry><entry command="tab"><para><U>2020</U>
</para></entry></row><row><entry command="item">
<para>ddagger</para></entry><entry command="tab"><para><code>\ddagger</code></para></entry><entry command="tab"><para><U>2021</U>
</para></entry></row><row><entry command="item">
<para>section-sign</para></entry><entry command="tab"><para><code>\S</code></para></entry><entry command="tab"><para><U>00A7</U>
</para></entry></row><row><entry command="item">
<para>paragraph-sign</para></entry><entry command="tab"><para><code>\P</code></para></entry><entry command="tab"><para><U>00B6</U>
</para></entry></row><row><entry command="item">
<para>double-vert</para></entry><entry command="tab"><para><code>\parallel</code></para></entry><entry command="tab"><para><U>2016</U>
</para></entry></row><row><entry command="item">
<para>double-asterisk</para></entry><entry command="tab"><para><code>\ast\ast</code></para></entry><entry command="tab"><para>**<!-- c
 -->
</para></entry></row><row><entry command="item">
<para>double-dagger</para></entry><entry command="tab"><para><code>\dagger\dagger</code></para></entry><entry command="tab"><para><U>2020</U><U>2020</U>
</para></entry></row><row><entry command="item">
<para>double-ddagger</para></entry><entry command="tab"><para><code>\ddagger\ddagger</code></para></entry><entry command="tab"><para><U>2021</U><U>2021</U>
</para></entry></row></tbody></multitable>

</tableitem></tableentry></ftable>


</section>
<node name="_005cusecounter" spaces=" "><nodename>\usecounter</nodename><nodenext automatic="on">\value</nodenext><nodeprev automatic="on">\alph \Alph \arabic \roman \Roman \fnsymbol</nodeprev><nodeup automatic="on">Counters</nodeup></node>
<section spaces=" "><sectiontitle><code>\usecounter&lbrace;<var>counter</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="461">\usecounter</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="343">list items, specifying counter</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="344">numbered items, specifying counter</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usecounter&lbrace;<var>counter</var>&rbrace;
</pre></example>

<para>In the <code>list</code> environment, when used in the second argument, this
command sets up <var>counter</var> to number the list items.  It initializes
<var>counter</var> to zero, and arranges that when <code>\item</code> is called
without its optional argument then <var>counter</var> is incremented by
<code>\refstepcounter</code>, making its value be the current <code>ref</code>
value.  This command is fragile (<pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>).
</para>
<para>Put in the preamble, this makes a new list environment enumerated with
<var>testcounter</var>:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcounter&lbrace;testcounter&rbrace;
\newenvironment&lbrace;test&rbrace;&lbrace;%
  \begin&lbrace;list&rbrace;&lbrace;&rbrace;&lbrace;%
    \usecounter&lbrace;testcounter&rbrace;
  &rbrace;
&rbrace;&lbrace;%
  \end&lbrace;list&rbrace;
&rbrace;
</pre></example>


</section>
<node name="_005cvalue" spaces=" "><nodename>\value</nodename><nodenext automatic="on">\setcounter</nodenext><nodeprev automatic="on">\usecounter</nodeprev><nodeup automatic="on">Counters</nodeup></node>
<section spaces=" "><sectiontitle><code>\value&lbrace;<var>counter</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="462">\value</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="345">counters, getting value of</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\value&lbrace;<var>counter</var>&rbrace;
</pre></example>

<para>This command expands to the value of <var>counter</var>.  It is often used
in <code>\setcounter</code> or <code>\addtocounter</code>, but <code>\value</code> can
be used anywhere that &latex; expects a number.  It must not be
preceded by <code>\protect</code> (<pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>).
</para>
<para>The <code>\value</code> command is not used for typesetting the value of the
counter.  <xref label="_005calph-_005cAlph-_005carabic-_005croman-_005cRoman-_005cfnsymbol"><xrefnodename>\alph \Alph \arabic \roman \Roman \fnsymbol</xrefnodename></xref>.
</para>
<para>This example outputs <samp>Test counter is&nbsp;6. Other counter
is&nbsp;5.</samp>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcounter&lbrace;test&rbrace; \setcounter&lbrace;test&rbrace;&lbrace;5&rbrace;
\newcounter&lbrace;other&rbrace; \setcounter&lbrace;other&rbrace;&lbrace;\value&lbrace;test&rbrace;&rbrace;
\addtocounter&lbrace;test&rbrace;&lbrace;1&rbrace;

Test counter is \arabic&lbrace;test&rbrace;.
Other counter is \arabic&lbrace;other&rbrace;.
</pre></example>

<para>This example inserts <code>\hspace&lbrace;4\parindent&rbrace;</code>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\setcounter&lbrace;myctr&rbrace;&lbrace;3&rbrace; \addtocounter&lbrace;myctr&rbrace;&lbrace;1&rbrace;
\hspace&lbrace;\value&lbrace;myctr&rbrace;\parindent&rbrace;
</pre></example>


</section>
<node name="_005csetcounter" spaces=" "><nodename>\setcounter</nodename><nodenext automatic="on">\addtocounter</nodenext><nodeprev automatic="on">\value</nodeprev><nodeup automatic="on">Counters</nodeup></node>
<section spaces=" "><sectiontitle><code>\setcounter&lbrace;<var>counter</var>&rbrace;&lbrace;<var>value</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="463">\setcounter</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="346">counters, setting</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="347">setting counters</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\setcounter&lbrace;<var>counter</var>&rbrace;&lbrace;<var>value</var>&rbrace;
</pre></example>

<para>The <code>\setcounter</code> command globally sets the value of <var>counter</var>
to the <var>value</var> argument.  Note that the counter name does not start
with a backslash.
</para>
<para>In this example the section value appears as <samp>V</samp>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\setcounter&lbrace;section&rbrace;&lbrace;5&rbrace;
Here it is in Roman: \Roman&lbrace;section&rbrace;.
</pre></example>


</section>
<node name="_005caddtocounter" spaces=" "><nodename>\addtocounter</nodename><nodenext automatic="on">\refstepcounter</nodenext><nodeprev automatic="on">\setcounter</nodeprev><nodeup automatic="on">Counters</nodeup></node>
<section spaces=" "><sectiontitle><code>\addtocounter&lbrace;<var>counter</var>&rbrace;&lbrace;<var>value</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="464">\addtocounter</indexterm></findex>

<para>The <code>\addtocounter</code> command globally increments <var>counter</var> by
the amount specified by the <var>value</var> argument, which may be negative.
</para>
<para>In this example the section value appears as <samp>VII</samp>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\setcounter&lbrace;section&rbrace;&lbrace;5&rbrace;
\addtocounter&lbrace;section&rbrace;&lbrace;2&rbrace;
Here it is in Roman: \Roman&lbrace;section&rbrace;.
</pre></example>


</section>
<node name="_005crefstepcounter" spaces=" "><nodename>\refstepcounter</nodename><nodenext automatic="on">\stepcounter</nodenext><nodeprev automatic="on">\addtocounter</nodeprev><nodeup automatic="on">Counters</nodeup></node>
<section spaces=" "><sectiontitle><code>\refstepcounter&lbrace;<var>counter</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="465">\refstepcounter</indexterm></findex>

<para>The <code>\refstepcounter</code> command works in the same way as
<code>\stepcounter</code> (<pxref label="_005cstepcounter"><xrefnodename>\stepcounter</xrefnodename></pxref>): it globally increments the
value of <var>counter</var> by one and resets the value of any counter
numbered within it.  (For the definition of &textldquo;counters numbered
within&textrdquo;, <pxref label="_005cnewcounter"><xrefnodename>\newcounter</xrefnodename></pxref>.)
</para>
<para>In addition, this command also defines the current <code>\ref</code> value
to be the result of <code>\thecounter</code>.
</para>
<para>While the counter value is set globally, the <code>\ref</code> value is set
locally, i.e., inside the current group.
</para>

</section>
<node name="_005cstepcounter" spaces=" "><nodename>\stepcounter</nodename><nodenext automatic="on">\day \month \year</nodenext><nodeprev automatic="on">\refstepcounter</nodeprev><nodeup automatic="on">Counters</nodeup></node>
<section spaces=" "><sectiontitle><code>\stepcounter&lbrace;<var>counter</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="466">\stepcounter</indexterm></findex>

<para>The <code>\stepcounter</code> command globally adds one to <var>counter</var> and
resets all counters numbered within it.  (For the definition of
&textldquo;counters numbered within&textrdquo;, <pxref label="_005cnewcounter"><xrefnodename>\newcounter</xrefnodename></pxref>.)
</para>

</section>
<node name="_005cday-_005cmonth-_005cyear" spaces=" "><nodename>\day \month \year</nodename><nodeprev automatic="on">\stepcounter</nodeprev><nodeup automatic="on">Counters</nodeup></node>
<section spaces=" "><sectiontitle><code>\day \month \year</code>: Predefined counters</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="467">\day</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="468">\month</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="469">\year</indexterm></findex>

<para>&latex; defines counters for the day of the month (<code>\day</code>,
1&textndash;31), month of the year (<code>\month</code>, 1&textndash;12), and year
(<code>\year</code>, Common Era).  When &tex; starts up, they are
set to the current values on the system where &tex; is running.  They
are not updated as the job progresses.
</para>
<para>The related command <code>\today</code> produces a string representing the
current day (<pxref label="_005ctoday"><xrefnodename>\today</xrefnodename></pxref>).
</para>

</section>
</chapter>
<node name="Lengths" spaces=" "><nodename>Lengths</nodename><nodenext automatic="on">Making paragraphs</nodenext><nodeprev automatic="on">Counters</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Lengths</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="348">lengths, defining and using</indexterm></cindex>

<para>A <dfn>length</dfn> is a measure of distance.  Many &latex; commands take a
length as an argument.
</para>
<para>Lengths come in two types.  A <dfn>rigid length</dfn> (what Plain &tex;
calls a <dfn>dimen</dfn>) such as <code>10pt</code> cannot contain a <code>plus</code> or
<code>minus</code> component.  A <dfn>rubber length</dfn> (what Plain &tex; calls
a <dfn>skip</dfn>) can contain those, as with <code>1cm plus0.05cm
minus0.01cm</code>.  These give the ability to stretch or shrink; the length
in the prior sentence could appear in the output as long as 1.05&nbsp;cm
or as short as 0.99&nbsp;cm, depending on what &tex;&textrsquo;s typesetting
algorithm finds optimum.
</para>
<para>The <code>plus</code> or <code>minus</code> component of a rubber length can contain
a <dfn>fill</dfn> component, as in <code>1in plus2fill</code>.  This gives the
length infinite stretchability or shrinkability, so that the length in
the prior sentence can be set by &tex; to any distance greater than or
equal to 1&nbsp;inch.  &tex; actually provides three infinite glue
components <code>fil</code>, <code>fill</code>, and <code>filll</code>, such that the
later ones overcome the earlier ones, but only the middle value is
ordinarily used.  <xref label="_005chfill"><xrefnodename>\hfill</xrefnodename></xref>, <xref label="_005cvfill"><xrefnodename>\vfill</xrefnodename></xref>.
</para>
<para>Multiplying an entire rubber length by a number turns it into a rigid
length, so that after <code>\setlength&lbrace;\ylength&rbrace;&lbrace;1in plus 0.2in&rbrace;</code>
and <code>\setlength&lbrace;\zlength&rbrace;&lbrace;3\ylength&rbrace;</code> then the value of
<code>\zlength</code> is <code>3in</code>.
</para>

<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::     ">Units of length</menunode><menudescription><pre xml:space="preserve">The units that &latex; knows.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::          ">\setlength</menunode><menudescription><pre xml:space="preserve">Set the value of a length.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::        ">\addtolength</menunode><menudescription><pre xml:space="preserve">Add a quantity to a length.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::         ">\settodepth</menunode><menudescription><pre xml:space="preserve">Set a length to the depth of something.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::        ">\settoheight</menunode><menudescription><pre xml:space="preserve">Set a length to the height of something.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::         ">\settowidth</menunode><menudescription><pre xml:space="preserve">Set a length to the width of something.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::  ">Predefined lengths</menunode><menudescription><pre xml:space="preserve">Lengths that are, like, predefined.
</pre></menudescription></menuentry></menu>


<node name="Units-of-length" spaces=" "><nodename>Units of length</nodename><nodenext automatic="on">\setlength</nodenext><nodeup automatic="on">Lengths</nodeup></node>
<section spaces=" "><sectiontitle>Units of length</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="349">units, of length</indexterm></cindex>

<para>&tex; and &latex; know about these units both inside and outside of
math mode.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">pt </itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="470">pt</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="350">Point</indexterm></cindex>
<para>Point 1/72.27 inch.  The conversion to metric units, to two decimal
places, is 1<dmn>point</dmn> = 2.85<dmn>mm</dmn> = 28.45<dmn>cm</dmn>. 
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">pc</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="351">pica</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="471">pc</indexterm></findex>
<para>Pica, 12 pt
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">in </itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="472">in</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="473">inch</indexterm></findex>
<para>Inch,  72.27 pt
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces="  "><itemformat command="code">bp </itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="474">bp</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="352">Big point</indexterm></cindex>
<para>Big point, 1/72 inch.  This length is the definition of a point in
PostScript and many desktop publishing systems.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">cm </itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="353">Centimeter</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="475">cm</indexterm></findex>
<para>Centimeter
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">mm </itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="354">Millimeter</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="476">mm</indexterm></findex>
<para>Millimeter
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">dd </itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="355">Didot point</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="477">dd</indexterm></findex>
<para>Didot point, 1.07 pt
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">cc </itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="356">Cicero</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="478">cc</indexterm></findex>
<para>Cicero, 12 dd
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">sp </itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="357">Scaled point</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="479">sp</indexterm></findex>
<para>Scaled point, 1/65536 pt
</para>
</tableitem></tableentry></table> 

<cindex index="cp" spaces=" "><indexterm index="cp" number="358">ex</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="359">x-height</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="480">ex</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="360">m-width</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="361">em</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="481">em</indexterm></findex>
<para>Two other lengths that are often used are values set by the designer of
the font.  The x-height of the current font <dfn>ex</dfn>, traditionally the
height of the lower case letter x, is often used for vertical
lengths. Similarly <dfn>em</dfn>, traditionally the width of the capital
letter M, is often used for horizontal lengths (there is also
<code>\enspace</code>, which is <code>0.5em</code>).  Use of these can help make a
definition work better across font changes.  For example, a definition
of the vertical space between list items given as
<code>\setlength&lbrace;\itemsep&rbrace;&lbrace;1ex plus 0.05ex minus 0.01ex&rbrace;</code> is more
likely to still be reasonable if the font is changed than a definition
given in points.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="362">mu, math unit</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="482">mu</indexterm></findex>
<para>In math mode, many definitions are expressed in terms of the math unit
<dfn>mu</dfn> given by 1 em = 18 mu, where the em is taken from the current
math symbols family.  <xref label="Spacing-in-math-mode"><xrefnodename>Spacing in math mode</xrefnodename></xref>.
</para>

</section>
<node name="_005csetlength" spaces=" "><nodename>\setlength</nodename><nodenext automatic="on">\addtolength</nodenext><nodeprev automatic="on">Units of length</nodeprev><nodeup automatic="on">Lengths</nodeup></node>
<section spaces=" "><sectiontitle><code>\setlength</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="483">\setlength</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="363">lengths, setting</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\setlength&lbrace;<var>\len</var>&rbrace;&lbrace;<var>amount</var>&rbrace;
</pre></example>

<para>The <code>\setlength</code> sets the value of <dfn>length command</dfn>
<cindex index="cp" spaces=" "><indexterm index="cp" number="364">length command</indexterm></cindex>
<code>\<var>len</var></code> to the <var>value</var> argument which can be expressed in any
units that &latex; understands, i.e., inches (<code>in</code>), millimeters
(<code>mm</code>), points (<code>pt</code>), big points (<code>bp</code>), etc.
</para>

</section>
<node name="_005caddtolength" spaces=" "><nodename>\addtolength</nodename><nodenext automatic="on">\settodepth</nodenext><nodeprev automatic="on">\setlength</nodeprev><nodeup automatic="on">Lengths</nodeup></node>
<section spaces=" "><sectiontitle><code>\addtolength</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="484">\addtolength</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="365">lengths, adding to</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\addtolength&lbrace;<var>\len</var>&rbrace;&lbrace;<var>amount</var>&rbrace;
</pre></example>


<para>The <code>\addtolength</code> command increments a length command <code>\<var>len</var></code>
by the amount specified in the <var>amount</var> argument, which may be
negative.
</para>

</section>
<node name="_005csettodepth" spaces=" "><nodename>\settodepth</nodename><nodenext automatic="on">\settoheight</nodenext><nodeprev automatic="on">\addtolength</nodeprev><nodeup automatic="on">Lengths</nodeup></node>
<section spaces=" "><sectiontitle><code>\settodepth</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="485">\settodepth</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\settodepth&lbrace;\<var>len</var>&rbrace;&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>The <code>\settodepth</code> command sets the value of a length command
<code>\<var>len</var></code> equal to the depth of the <var>text</var> argument.
</para>

</section>
<node name="_005csettoheight" spaces=" "><nodename>\settoheight</nodename><nodenext automatic="on">\settowidth</nodenext><nodeprev automatic="on">\settodepth</nodeprev><nodeup automatic="on">Lengths</nodeup></node>
<section spaces=" "><sectiontitle><code>\settoheight</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="486">\settoheight</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\settoheight&lbrace;\<var>len</var>&rbrace;&lbrace;text&rbrace;
</pre></example>

<para>The <code>\settoheight</code> command sets the value of a length command <code>\<var>len</var></code>
equal to the height of the <code>text</code> argument.
</para>


</section>
<node name="_005csettowidth" spaces=" "><nodename>\settowidth</nodename><nodenext automatic="on">Predefined lengths</nodenext><nodeprev automatic="on">\settoheight</nodeprev><nodeup automatic="on">Lengths</nodeup></node>
<section spaces=" "><sectiontitle><code>\settowidth&lbrace;\<var>len</var>&rbrace;&lbrace;<var>text</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="487">\settowidth</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\settowidth&lbrace;\<var>len</var>&rbrace;&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>The <code>\settowidth</code> command sets the value of the command <var>\len</var>
to the width of the <var>text</var> argument.
</para>

</section>
<node name="Predefined-lengths" spaces=" "><nodename>Predefined lengths</nodename><nodeprev automatic="on">\settowidth</nodeprev><nodeup automatic="on">Lengths</nodeup></node>
<section spaces=" "><sectiontitle>Predefined lengths</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="366">lengths, predefined</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="367">predefined lengths</indexterm></cindex>

<para><code>\width</code>
<findex index="fn" spaces=" "><indexterm index="fn" number="488">\width</indexterm></findex>
</para>
<para><code>\height</code>
<findex index="fn" spaces=" "><indexterm index="fn" number="489">\height</indexterm></findex>
</para>
<para><code>\depth</code>
<findex index="fn" spaces=" "><indexterm index="fn" number="490">\depth</indexterm></findex>
</para>
<para><code>\totalheight</code>
<findex index="fn" spaces=" "><indexterm index="fn" number="491">\totalheight</indexterm></findex>
</para>
<para>These length parameters can be used in the arguments of the box-making
commands (<pxref label="Boxes"><xrefnodename>Boxes</xrefnodename></pxref>).  They specify the natural width, etc., of
the text in the box. <code>\totalheight</code> equals <math><code>&backslashchar;height</code> +
<code>&backslashchar;depth</code></math>. To make a box with the text stretched to double the
natural size, e.g., say
</para>
<example endspaces=" ">
<pre xml:space="preserve">\makebox[2\width]&lbrace;Get a stretcher&rbrace;
</pre></example>


</section>
</chapter>
<node name="Making-paragraphs" spaces=" "><nodename>Making paragraphs</nodename><nodenext automatic="on">Math formulas</nodenext><nodeprev automatic="on">Lengths</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Making paragraphs</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="368">making paragraphs</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="369">paragraphs</indexterm></cindex>

<para>A paragraph is ended by one or more completely blank lines&textmdash;lines not
containing even a <code>%</code>.  A blank line should not appear where a new
paragraph cannot be started, such as in math mode or in the argument of
a sectioning command.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::        ">\indent</menunode><menudescription><pre xml:space="preserve">Indent this paragraph.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::      ">\noindent</menunode><menudescription><pre xml:space="preserve">Do not indent this paragraph.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::       ">\parskip</menunode><menudescription><pre xml:space="preserve">Space added before paragraphs.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator=":: ">Marginal notes</menunode><menudescription><pre xml:space="preserve">Putting remarks in the margin.
</pre></menudescription></menuentry></menu>


<node name="_005cindent" spaces=" "><nodename>\indent</nodename><nodenext automatic="on">\noindent</nodenext><nodeup automatic="on">Making paragraphs</nodeup></node>
<section spaces=" "><sectiontitle><code>\indent</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="492">\indent</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="493">\parindent</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="370">indent, forcing</indexterm></cindex>

<para><code>\indent</code> produces a horizontal space whose width equals to the
<code>\parindent</code> length, the normal paragraph indentation.  It is used
to add paragraph indentation where it would otherwise be suppressed.
</para>
<para>The default value for <code>\parindent</code> is <code>1em</code> in two-column
mode, otherwise <code>15pt</code> for <code>10pt</code> documents, <code>17pt</code> for
<code>11pt</code>, and <code>1.5em</code> for <code>12pt</code>.
</para>

</section>
<node name="_005cnoindent" spaces=" "><nodename>\noindent</nodename><nodenext automatic="on">\parskip</nodenext><nodeprev automatic="on">\indent</nodeprev><nodeup automatic="on">Making paragraphs</nodeup></node>
<section spaces=" "><sectiontitle><code>\noindent</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="494">\noindent</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="371">indent, suppressing</indexterm></cindex>

<para>When used at the beginning of the paragraph, this command suppresses any
paragraph indentation, as in this example.
</para>
<example endspaces=" ">
<pre xml:space="preserve">... end of the prior paragraph.

\noindent This paragraph is not indented.
</pre></example>

<para>It has no effect when used in the middle of a paragraph.
</para>
<para>To eliminate paragraph indentation in an entire document, put
<code>\setlength&lbrace;\parindent&rbrace;&lbrace;0pt&rbrace;</code> in the preamble.
</para>

</section>
<node name="_005cparskip" spaces=" "><nodename>\parskip</nodename><nodenext automatic="on">Marginal notes</nodenext><nodeprev automatic="on">\noindent</nodeprev><nodeup automatic="on">Making paragraphs</nodeup></node>
<section spaces=" "><sectiontitle><code>\parskip</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="495">\parskip</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="372">vertical space before paragraphs</indexterm></cindex>

<para><code>\parskip</code> is a rubber length defining extra vertical space added
before each paragraph.  The default is <code>0pt plus1pt</code>.
</para>

</section>
<node name="Marginal-notes" spaces=" "><nodename>Marginal notes</nodename><nodeprev automatic="on">\parskip</nodeprev><nodeup automatic="on">Making paragraphs</nodeup></node>
<section spaces=" "><sectiontitle>Marginal notes</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="373">marginal notes</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="374">notes in the margin</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="375">remarks in the margin</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="496">\marginpar</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\marginpar[<var>left</var>]&lbrace;<var>right</var>&rbrace;
</pre></example>

<para>The <code>\marginpar</code> command creates a note in the margin.  The first
line of the note will have the same baseline as the line in the text
where the <code>\marginpar</code> occurs.
</para>
<para>When you only specify the mandatory argument <var>right</var>, the text
will be placed
</para>
<itemize commandarg="bullet" spaces=" " endspaces=" "><itemprepend><formattingcommand command="bullet"/></itemprepend>
<listitem><prepend>&bullet;</prepend>
<para>in the right margin for one-sided layout (option <code>oneside</code>, see <ref label="Document-class-options"><xrefnodename>Document class options</xrefnodename></ref>);
</para></listitem><listitem><prepend>&bullet;</prepend>
<para>in the outside margin for two-sided layout (option <code>twoside</code>, see <ref label="Document-class-options"><xrefnodename>Document class options</xrefnodename></ref>);
</para></listitem><listitem><prepend>&bullet;</prepend>
<para>in the nearest margin for two-column layout (option <code>twocolumn</code>, see <ref label="Document-class-options"><xrefnodename>Document class options</xrefnodename></ref>).
</para></listitem></itemize>

<findex index="fn" spaces=" "><indexterm index="fn" number="497">\reversemarginpar</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="498">\normalmarginpar</indexterm></findex>
<para>The command <code>\reversemarginpar</code> places subsequent marginal notes
in the opposite (inside) margin.  <code>\normalmarginpar</code> places them
in the default position.
</para>
<para>When you specify both arguments, <var>left</var> is used for the left
margin, and <var>right</var> is used for the right margin.
</para>
<para>The first word will normally not be hyphenated; you can enable
hyphenation there by beginning the node with <code>\hspace&lbrace;0pt&rbrace;</code>.
</para>
<para>These parameters affect the formatting of the note:
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="499">\marginparpush</indexterm>\marginparpush</itemformat></item>
</tableterm><tableitem><para>Minimum vertical space between notes; default <samp>7pt</samp> for
<samp>12pt</samp> documents, <samp>5pt</samp> else.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="500">\marginparsep</indexterm>\marginparsep</itemformat></item>
</tableterm><tableitem><para>Horizontal space between the main text and the note; default
<samp>11pt</samp> for <samp>10pt</samp> documents, <samp>10pt</samp> else.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="501">\marginparwidth</indexterm>\marginparwidth</itemformat></item>
</tableterm><tableitem><para>Width of the note itself; default for a one-sided <samp>10pt</samp> document
is <samp>90pt</samp>, <samp>83pt</samp> for <samp>11pt</samp>, and <samp>68pt</samp> for
<samp>12pt</samp>; <samp>17pt</samp> more in each case for a two-sided document.
In two column mode, the default is <samp>48pt</samp>.
</para>
</tableitem></tableentry></ftable>

<para>The standard &latex; routine for marginal notes does not prevent
notes from falling off the bottom of the page.
<!-- c  @TeX{} FAQ entry on this topic (xx when there): -->
<!-- c @url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=marginparside}. -->
<!-- c (+marginfix) -->
</para>

</section>
</chapter>
<node name="Math-formulas" spaces=" "><nodename>Math formulas</nodename><nodenext automatic="on">Modes</nodenext><nodeprev automatic="on">Making paragraphs</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Math formulas</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="376">math formulas</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="377">formulas, math</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="378">math mode, entering</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="502"><r>environment</r>, <code>math</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="503"><code>math</code> <r>environment</r></indexterm></findex>
        
<findex index="fn" spaces=" "><indexterm index="fn" number="504"><r>environment</r>, <code>displaymath</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="505"><code>displaymath</code> <r>environment</r></indexterm></findex>
        
<findex index="fn" spaces=" "><indexterm index="fn" number="506"><r>environment</r>, <code>equation</code></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="507"><code>equation</code> <r>environment</r></indexterm></findex>
        

<para>There are three environments that put &latex; in math mode:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">math</itemformat></item>
</tableterm><tableitem><para>For formulas that appear right in the text.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">displaymath</itemformat></item>
</tableterm><tableitem><para>For formulas that appear on their own line.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">equation</itemformat></item>
</tableterm><tableitem><para>The same as the displaymath environment except that it adds an equation
number in the right margin.
</para></tableitem></tableentry></table>

<findex index="fn" spaces=" "><indexterm index="fn" number="508">\(</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="509">\)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="510">\[</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="511">\]</indexterm></findex>
<para>The <code>math</code> environment can be used in both paragraph and LR mode,
but the <code>displaymath</code> and <code>equation</code> environments can be used
only in paragraph mode.  The <code>math</code> and <code>displaymath</code>
environments are used so often that they have the following short forms:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\(...\)   <r>instead of</r>   \begin&lbrace;math&rbrace;...\end&lbrace;math&rbrace;
\[...\]   <r>instead of</r>   \begin&lbrace;displaymath&rbrace;...\end&lbrace;displaymath&rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="512">$</indexterm></findex>
<para>In fact, the <code>math</code> environment is so common that it has an even
shorter form:
</para>
<example endspaces=" ">
<pre xml:space="preserve">$ ... $   <r>instead of</r>   \(...\)
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="513">\boldmath</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="514">\unboldmath</indexterm></findex>
<para>The <code>\boldmath</code> command changes math letters and symbols to be in
a bold font.  It is used <emph>outside</emph> of math mode.  Conversely, the
<code>\unboldmath</code> command changes math glyphs to be in a normal font;
it too is used <emph>outside</emph> of math mode.
</para>
<!-- c xx own section? Math fonts? -->
<findex index="fn" spaces=" "><indexterm index="fn" number="515">\displaystyle</indexterm></findex>
<para>The <code>\displaystyle</code> declaration forces the size and style of the
formula to be that of <code>displaymath</code>, e.g., with limits above and
below summations.  For example:
</para>
<example endspaces=" ">
<pre xml:space="preserve">$\displaystyle \sum_&lbrace;n=0&rbrace;^\infty x_n $
</pre></example>

<!-- c xx see also \cal, \mathcal -->

<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::   ">Subscripts &amp; superscripts</menunode><menudescription><pre xml:space="preserve">Also known as exponent or index.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                ">Math symbols</menunode><menudescription><pre xml:space="preserve">Various mathematical squiggles.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">Math functions</menunode><menudescription><pre xml:space="preserve">Math function names like sin and exp.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                ">Math accents</menunode><menudescription><pre xml:space="preserve">Accents in math.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::        ">Spacing in math mode</menunode><menudescription><pre xml:space="preserve">Thick, medium, thin and negative spaces.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::             ">Math miscellany</menunode><menudescription><pre xml:space="preserve">Stuff that doesn&textrsquo;t fit anywhere else.
</pre></menudescription></menuentry></menu>


<node name="Subscripts-_0026-superscripts" spaces=" "><nodename>Subscripts &amp; superscripts</nodename><nodenext automatic="on">Math symbols</nodenext><nodeup automatic="on">Math formulas</nodeup></node>
<section spaces=" "><sectiontitle>Subscripts &amp; superscripts</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="379">superscript</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="380">subscript</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="381">exponent</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="516">_</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="517">^</indexterm></findex>

<para>In math mode, use the caret character&nbsp;<code>^</code> to make the
<var>exp</var> appear as a superscript: <code>^&lbrace;<var>exp</var>&rbrace;</code>.
Similarly, in math mode, underscore&nbsp;<code>_&lbrace;<var>exp</var>&rbrace;</code> makes a
subscript out of <var>exp</var>.
</para>
<para>In this example the <code>0</code> and <code>1</code> appear as subscripts while the
<code>2</code> is a superscript.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\( (x_0+x_1)^2 \)
</pre></example> 

<para>To have more than one character in <var>exp</var> use curly braces as in
<code>e^&lbrace;-2x&rbrace;</code>.
</para>
<para>&latex; handles superscripts on superscripts, and all of that stuff, in
the natural way, so expressions such as <code>e^&lbrace;x^2&rbrace;</code> and
<code>x_&lbrace;a_0&rbrace;</code> will look right.  It also does the right thing when
something has both a subscript and a superscript.  In this example the
<code>0</code> appears at the bottom of the integral sign while the <code>10</code>
appears at the top.
</para> 
<example endspaces=" ">
<pre xml:space="preserve">\int_0^&lbrace;10&rbrace; x^2 \,dx
</pre></example>

<para>You can put a superscript or subscript before a symbol with a construct
such as <code>&lbrace;&rbrace;_t K^2</code> in math mode (the initial <code>&lbrace;&rbrace;</code> prevents
the prefixed subscript from being attached to any prior symbols in the
expression).
</para>
<para>Outside of math mode, a construct like <code>A
test$_\textnormal&lbrace;subscript&rbrace;$</code> will produce a subscript typeset in
text mode, not math mode.  Note that there are packages specialized for
writing Chemical formulas such as <file>mhchem</file>.
<!-- c xx display mode -->
</para>

</section>
<node name="Math-symbols" spaces=" "><nodename>Math symbols</nodename><nodenext automatic="on">Math functions</nodenext><nodeprev automatic="on">Subscripts &amp; superscripts</nodeprev><nodeup automatic="on">Math formulas</nodeup></node>
<section spaces=" "><sectiontitle>Math symbols</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="382">math symbols</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="383">symbols, math</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="384">greek letters</indexterm></cindex>

<para>&latex; provides almost any mathematical symbol you&textrsquo;re likely to need.
For example, if you include <code>$\pi$</code> in your source, you will get
the pi symbol <U>03C0</U>.
</para> 
<para>Below is a list of commonly-available symbols.  It is by no means an
exhaustive list.  Each symbol here is described with a short phrase, and
its symbol class (which determines the spacing around it) is given in
parenthesis.  Unless said otherwise, the commands for these symbols can
be used only in math mode.
</para>
<para>To redefine a command so that it can be used whatever the current mode,
see <ref label="_005censuremath"><xrefnodename>\ensuremath</xrefnodename></ref>.
</para>

<!-- c xx Add Negation: @code{} for negations of relevant symbols -->
<!-- c Useful: http://www.w3.org/TR/WD-math-970515/section6.html -->

<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="518">\|</indexterm>\|</itemformat></item>
</tableterm><tableitem><para><U>2225</U> Parallel (relation). Synonym:&nbsp;<code>\parallel</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="519">\aleph</indexterm>\aleph</itemformat></item>
</tableterm><tableitem><para><U>2135</U> Aleph, transfinite cardinal (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="520">\alpha</indexterm>\alpha</itemformat></item>
</tableterm><tableitem><para><U>03B1</U> Lower case Greek letter alpha (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="521">\amalg</indexterm>\amalg</itemformat></item>
</tableterm><tableitem><para><U>2A3F</U> Disjoint union (binary)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="522">\angle</indexterm>\angle</itemformat></item>
</tableterm><tableitem><para><U>2220</U> Geometric angle (ordinary). Similar: less-than
sign&nbsp;<code>&lt;</code> and angle bracket&nbsp;<code>\langle</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="523">\approx</indexterm>\approx</itemformat></item>
</tableterm><tableitem><para><U>2248</U> Almost equal to (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="524">\ast</indexterm>\ast</itemformat></item>
</tableterm><tableitem><para><U>2217</U> Asterisk operator, convolution, six-pointed
(binary). Synonym:&nbsp;<code>*</code>, which is often a superscript or
subscript, as in the Kleene star. Similar:&nbsp;<code>\star</code>, which is
five-pointed, and is sometimes used as a general binary operation, and
sometimes reserved for cross-correlation.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="525">\asymp</indexterm>\asymp</itemformat></item>
</tableterm><tableitem><para><U>224D</U> Asymptotically equivalent (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="526">\backslash</indexterm>\backslash</itemformat></item>
</tableterm><tableitem><para>\ Backslash (ordinary).  Similar: set minus&nbsp;<code>\setminus</code>, and
<code>\textbackslash</code> for backslash outside of math mode.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="527">\beta</indexterm>\beta</itemformat></item>
</tableterm><tableitem><para><U>03B2</U> Lower case Greek letter beta (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="528">\bigcap</indexterm>\bigcap</itemformat></item>
</tableterm><tableitem><para><U>22C2</U> Variable-sized, or n-ary, intersection (operator). Similar:
binary intersection&nbsp;<code>\cap</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="529">\bigcirc</indexterm>\bigcirc</itemformat></item>
</tableterm><tableitem><para><U>26AA</U> Circle, larger (binary).  Similar: function
composition&nbsp;<code>\circ</code>.
<!-- c bb Best unicode symbol for this? -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="530">\bigcup</indexterm>\bigcup</itemformat></item>
</tableterm><tableitem><para><U>22C3</U> Variable-sized, or n-ary, union (operator). Similar: binary
union&nbsp;<code>\cup</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="531">\bigodot</indexterm>\bigodot</itemformat></item>
</tableterm><tableitem><para><U>2A00</U> Variable-sized, or n-ary, circled dot operator (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="532">\bigoplus</indexterm>\bigoplus</itemformat></item>
</tableterm><tableitem><para><U>2A01</U> Variable-sized, or n-ary, circled plus operator (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="533">\bigotimes</indexterm>\bigotimes</itemformat></item>
</tableterm><tableitem><para><U>2A02</U> Variable-sized, or n-ary, circled times operator (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="534">\bigtriangledown</indexterm>\bigtriangledown</itemformat></item>
</tableterm><tableitem><para><U>25BD</U> Variable-sized, or n-ary, open triangle pointing down
(operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="535">\bigtriangleup</indexterm>\bigtriangleup</itemformat></item>
</tableterm><tableitem><para><U>25B3</U> Variable-sized, or n-ary, open triangle pointing up (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="536">\bigsqcup</indexterm>\bigsqcup</itemformat></item>
</tableterm><tableitem><para><U>2A06</U> Variable-sized, or n-ary, square union (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="537">\biguplus</indexterm>\biguplus</itemformat></item>
</tableterm><tableitem><para><U>2A04</U> Variable-sized, or n-ary, union operator with a plus
(operator).  (Note that the name has only one p.)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="538">\bigvee</indexterm>\bigvee</itemformat></item>
</tableterm><tableitem><para><U>22C1</U> Variable-sized, or n-ary, logical-and (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="539">\bigwedge</indexterm>\bigwedge</itemformat></item>
</tableterm><tableitem><para><U>22C0</U> Variable-sized, or n-ary, logical-or (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="540">\bot</indexterm>\bot</itemformat></item>
</tableterm><tableitem><para><U>22A5</U> Up tack, bottom, least element of a partially ordered
set, or a contradiction (ordinary).  See also&nbsp;<code>\top</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="541">\bowtie</indexterm>\bowtie</itemformat></item>
</tableterm><tableitem><para><U>22C8</U> Natural join of two relations (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="542">\Box</indexterm>\Box</itemformat></item>
</tableterm><tableitem><para><U>25A1</U> Modal operator for necessity; square open box
(ordinary).  Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.
<!-- c bb Best Unicode equivalent? -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="543">\bullet</indexterm>\bullet</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="385">bullet symbol</indexterm></cindex>
<para><U>2022</U> Bullet (binary).  Similar: multiplication
dot&nbsp;<code>\cdot</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="544">\cap</indexterm>\cap</itemformat></item>
</tableterm><tableitem><para><U>2229</U> Intersection of two sets (binary).  Similar: variable-sized
operator&nbsp;<code>\bigcap</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="545">\cdot</indexterm>\cdot</itemformat></item>
</tableterm><tableitem><para><U>22C5</U> Multiplication (binary).  Similar: Bullet
dot&nbsp;<code>\bullet</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="546">\chi</indexterm>\chi</itemformat></item>
</tableterm><tableitem><para><U>03C7</U> Lower case Greek chi (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="547">\circ</indexterm>\circ</itemformat></item>
</tableterm><tableitem><para><U>2218</U> Function composition, ring operator (binary).  Similar:
variable-sized operator&nbsp;<code>\bigcirc</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="548">\clubsuit</indexterm>\clubsuit</itemformat></item>
</tableterm><tableitem><para><U>2663</U> Club card suit (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="549">\complement</indexterm>\complement</itemformat></item>
</tableterm><tableitem><para><U>2201</U> Set complement, used as a superscript as in
<code>$S^\complement$</code> (ordinary).  Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package. Also
used: <code>$S^&lbrace;\mathsf&lbrace;c&rbrace;&rbrace;$</code> or&nbsp;<code>$\bar&lbrace;S&rbrace;$</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="550">\cong</indexterm>\cong</itemformat></item>
</tableterm><tableitem><para><U>2245</U> Congruent (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="551">\coprod</indexterm>\coprod</itemformat></item>
</tableterm><tableitem><para><U>2210</U> Coproduct (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="552">\cup</indexterm>\cup</itemformat></item>
</tableterm><tableitem><para><U>222A</U> Union of two sets (binary).  Similar: variable-sized
operator&nbsp;<code>\bigcup</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="553">\dagger</indexterm>\dagger</itemformat></item>
</tableterm><tableitem><para><U>2020</U> Dagger relation (binary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="554">\dashv</indexterm>\dashv</itemformat></item>
</tableterm><tableitem><para><U>22A3</U> Dash with vertical, reversed turnstile (relation).  Similar:
turnstile&nbsp;<code>\vdash</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="555">\ddagger</indexterm>\ddagger</itemformat></item>
</tableterm><tableitem><para><U>2021</U> Double dagger relation (binary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="556">\Delta</indexterm>\Delta</itemformat></item>
</tableterm><tableitem><para><U>0394</U> Greek upper case delta, used for increment (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="557">\delta</indexterm>\delta</itemformat></item>
</tableterm><tableitem><para><U>03B4</U> Greek lower case delta (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="558">\Diamond</indexterm>\Diamond</itemformat></item>
</tableterm><tableitem><para><U>25C7</U> Large diamond operator (ordinary).  Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.
<!-- c bb Best Unicode equivalent? -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="559">\diamond</indexterm>\diamond</itemformat></item>
</tableterm><tableitem><para><U>22C4</U> Diamond operator, or diamond bullet (binary).  Similar: large
diamond&nbsp;<code>\Diamond</code>, circle bullet&nbsp;<code>\bullet</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="560">\diamondsuit</indexterm>\diamondsuit</itemformat></item>
</tableterm><tableitem><para><U>2662</U> Diamond card suit (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="561">\div</indexterm>\div</itemformat></item>
</tableterm><tableitem><para><U>00F7</U> Division sign (binary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="562">\doteq</indexterm>\doteq</itemformat></item>
</tableterm><tableitem><para><U>2250</U> Approaches the limit (relation).  Similar: geometrically equal
to&nbsp;<code>\Doteq</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="563">\downarrow</indexterm>\downarrow</itemformat></item>
</tableterm><tableitem><para><U>2193</U> Down arrow, converges (relation).  Similar: double line down
arrow&nbsp;<code>\Downarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="564">\Downarrow</indexterm>\Downarrow</itemformat></item>
</tableterm><tableitem><para><U>21D3</U> Double line down arrow (relation).  Similar: single line down
arrow&nbsp;<code>\downarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="565">\ell</indexterm>\ell</itemformat></item>
</tableterm><tableitem><para><U>2113</U> Lowercase cursive letter l (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="566">\emptyset</indexterm>\emptyset</itemformat></item>
</tableterm><tableitem><para><U>2205</U> Empty set symbol (ordinary).  The variant form is
<code>\varnothing</code>.
<!-- c bb Why Unicode has \revemptyset but no \emptyset? -->
</para>	
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="567">\epsilon</indexterm>\epsilon</itemformat></item>
</tableterm><tableitem><para><U>03F5</U> Lower case lunate epsilon (ordinary). Similar to
Greek text letter. More widely used in mathematics is the script small
letter epsilon <code>\varepsilon</code>&nbsp;<U>03B5</U>. Related:
the set membership relation <code>\in</code>&nbsp;<U>2208</U>.
<!-- c src: David Carlisle http://tex.stackexchange.com/a/98018/339 and -->
<!-- c Unicode referenced there asserts varepsilon is much more widely used. -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="568">\equiv</indexterm>\equiv</itemformat></item>
</tableterm><tableitem><para><U>2261</U> Equivalence (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="569">\eta</indexterm>\eta</itemformat></item>
</tableterm><tableitem><para><U>03B7</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="570">\exists</indexterm>\exists</itemformat></item>
</tableterm><tableitem><para><U>2203</U> Existential quantifier (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="571">\flat</indexterm>\flat</itemformat></item>
</tableterm><tableitem><para><U>266D</U> Musical flat (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="572">\forall</indexterm>\forall</itemformat></item>
</tableterm><tableitem><para><U>2200</U> Universal quantifier (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="573">\frown</indexterm>\frown</itemformat></item>
</tableterm><tableitem><para><U>2322</U> Downward curving arc (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="574">\Gamma</indexterm>\Gamma</itemformat></item>
</tableterm><tableitem><para><U>0393</U> Upper case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="575">\gamma</indexterm>\gamma</itemformat></item>
</tableterm><tableitem><para><U>03B3</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="576">\ge</indexterm>\ge</itemformat></item>
</tableterm><tableitem><para><U>2265</U> Greater than or equal to (relation).  This is a synonym
for&nbsp;<code>\geq</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="577">\geq</indexterm>\geq</itemformat></item>
</tableterm><tableitem><para><U>2265</U> Greater than or equal to (relation).  This is a synonym
for&nbsp;<code>\ge</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="578">\gets</indexterm>\gets</itemformat></item>
</tableterm><tableitem><para><U>2190</U> Is assigned the value (relation).
Synonym:&nbsp;<code>\leftarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="579">\gg</indexterm>\gg</itemformat></item>
</tableterm><tableitem><para><U>226B</U> Much greater than (relation).  Similar: much less
than&nbsp;<code>\ll</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="580">\hbar</indexterm>\hbar</itemformat></item>
</tableterm><tableitem><para><U>210F</U> Planck constant over two pi (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="581">\heartsuit</indexterm>\heartsuit</itemformat></item>
</tableterm><tableitem><para><U>2661</U> Heart card suit (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="582">\hookleftarrow</indexterm>\hookleftarrow</itemformat></item>
</tableterm><tableitem><para><U>21A9</U> Hooked left arrow (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="583">\hookrightarrow</indexterm>\hookrightarrow</itemformat></item>
</tableterm><tableitem><para><U>21AA</U> Hooked right arrow (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="584">\iff</indexterm>\iff</itemformat></item>
</tableterm><tableitem><para><U>27F7</U> If and only if (relation).  It is <code>\Longleftrightarrow</code>
with a <code>\thickmuskip</code> on either side.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="585">\Im</indexterm>\Im</itemformat></item>
</tableterm><tableitem><para><U>2111</U> Imaginary part (ordinary).  See: real part&nbsp;<code>\Re</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="586">\in</indexterm>\in</itemformat></item>
</tableterm><tableitem><para><U>2208</U> Set element (relation).  See also: lower case lunate
epsilon&nbsp;<code>\epsilon</code><U>03F5</U> and small letter script
epsilon&nbsp;<code>\varepsilon</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="587">\infty</indexterm>\infty</itemformat></item>
</tableterm><tableitem><para><U>221E</U> Infinity (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="588">\int</indexterm>\int</itemformat></item>
</tableterm><tableitem><para><U>222B</U> Integral (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="589">\iota</indexterm>\iota</itemformat></item>
</tableterm><tableitem><para><U>03B9</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="590">\Join</indexterm>\Join</itemformat></item>
</tableterm><tableitem><para><U>2A1D</U> Condensed bowtie symbol (relation).  Not available in Plain
&tex;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="591">\kappa</indexterm>\kappa</itemformat></item>
</tableterm><tableitem><para><U>03BA</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="592">\Lambda</indexterm>\Lambda</itemformat></item>
</tableterm><tableitem><para><U>039B</U> Upper case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="593">\lambda</indexterm>\lambda</itemformat></item>
</tableterm><tableitem><para><U>03BB</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="594">\land</indexterm>\land</itemformat></item>
</tableterm><tableitem><para><U>2227</U> Logical and (binary).  This is a synonym for <code>\wedge</code>.
See also logical or&nbsp;<code>\lor</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="595">\langle</indexterm>\langle</itemformat></item>
</tableterm><tableitem><para><U>27E8</U> Left angle, or sequence, bracket (opening).  Similar:
less-than&nbsp;<code>&lt;</code>. Matches&nbsp;<code>\rangle</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="596">\lbrace</indexterm>\lbrace</itemformat></item>
</tableterm><tableitem><para><U>007B</U> Left curly brace
(opening). Synonym:&nbsp;<code>\&lbrace;</code>. Matches&nbsp;<code>\rbrace</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="597">\lbrack</indexterm>\lbrack</itemformat></item>
</tableterm><tableitem><para><U>005B</U> Left square bracket (opening).
Synonym:&nbsp;<code>[</code>. Matches&nbsp;<code>\rbrack</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="598">\lceil</indexterm>\lceil</itemformat></item>
</tableterm><tableitem><para><U>2308</U> Left ceiling bracket, like a square bracket but with the bottom
shaved off (opening). Matches&nbsp;<code>\rceil</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="599">\le</indexterm>\le</itemformat></item>
</tableterm><tableitem><para><U>2264</U> Less than or equal to (relation).  This is a synonym
for&nbsp;<code>\leq</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="600">\leadsto</indexterm>\leadsto</itemformat></item>
</tableterm><tableitem><para><U>21DD</U> Squiggly right arrow (relation).  Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.
To get this symbol outside of math mode you can put
<code>\newcommand*&lbrace;\Leadsto&rbrace;&lbrace;\ensuremath&lbrace;\leadsto&rbrace;&rbrace;</code> in the
preamble and then use <code>\Leadsto</code> instead.
<!-- c bb Best Unicode equivalent? -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="601">\Leftarrow</indexterm>\Leftarrow</itemformat></item>
</tableterm><tableitem><para><U>21D0</U> Is implied by, double-line left arrow (relation).  Similar:
single-line left arrow&nbsp;<code>\leftarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="602">\leftarrow</indexterm>\leftarrow</itemformat></item>
</tableterm><tableitem><para><U>2190</U> Single-line left arrow (relation).
Synonym:&nbsp;<code>\gets</code>. Similar: double-line left
arrow&nbsp;<code>\Leftarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="603">\leftharpoondown</indexterm>\leftharpoondown</itemformat></item>
</tableterm><tableitem><para><U>21BD</U> Single-line left harpoon, barb under bar (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="604">\leftharpoonup</indexterm>\leftharpoonup</itemformat></item>
</tableterm><tableitem><para><U>21BC</U> Single-line left harpoon, barb over bar (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="605">\Leftrightarrow</indexterm>\Leftrightarrow</itemformat></item>
</tableterm><tableitem><para><U>21D4</U> Bi-implication; double-line double-headed arrow (relation).
Similar: single-line double headed arrow&nbsp;<code>\leftrightarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="606">\leftrightarrow</indexterm>\leftrightarrow</itemformat></item>
</tableterm><tableitem><para><U>2194</U> Single-line double-headed arrow (relation).  Similar:
double-line double headed arrow&nbsp;<code>\Leftrightarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="607">\leq</indexterm>\leq</itemformat></item>
</tableterm><tableitem><para><U>2264</U> Less than or equal to (relation).  This is a synonym
for&nbsp;<code>\le</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="608">\lfloor</indexterm>\lfloor</itemformat></item>
</tableterm><tableitem><para><U>230A</U> Left floor bracket (opening). Matches:&nbsp;<code>\floor</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="609">\lhd</indexterm>\lhd</itemformat></item>
</tableterm><tableitem><para><U>25C1</U> Arrowhead, that is, triangle, pointing left (binary).
Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package. For the normal subgroup symbol you should load
<file>amssymb</file> and use&nbsp;<code>\vartriangleleft</code> (which is a relation
and so gives better spacing).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="610">\ll</indexterm>\ll</itemformat></item>
</tableterm><tableitem><para><U>226A</U> Much less than (relation).  Similar: much greater
than&nbsp;<code>\gg</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="611">\lnot</indexterm>\lnot</itemformat></item>
</tableterm><tableitem><para><U>00AC</U> Logical negation (ordinary). Synonym:&nbsp;<code>\neg</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="612">\longleftarrow</indexterm>\longleftarrow</itemformat></item>
</tableterm><tableitem><para><U>27F5</U> Long single-line left arrow (relation).  Similar: long
double-line left arrow&nbsp;<code>\Longleftarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="613">\longleftrightarrow</indexterm>\longleftrightarrow</itemformat></item>
</tableterm><tableitem><para><U>27F7</U> Long single-line double-headed arrow (relation).  Similar: long
double-line double-headed arrow&nbsp;<code>\Longleftrightarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="614">\longmapsto</indexterm>\longmapsto</itemformat></item>
</tableterm><tableitem><para><U>27FC</U> Long single-line left arrow starting with vertical bar
(relation).  Similar: shorter version&nbsp;<code>\mapsto</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="615">\longrightarrow</indexterm>\longrightarrow</itemformat></item>
</tableterm><tableitem><para><U>27F6</U> Long single-line right arrow (relation).  Similar: long
double-line right arrow&nbsp;<code>\Longrightarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="616">\lor</indexterm>\lor</itemformat></item>
</tableterm><tableitem><para><U>2228</U> Logical or (binary).  Synonym: wedge&nbsp;<code>\wedge</code>. 
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="617">\mapsto</indexterm>\mapsto</itemformat></item>
</tableterm><tableitem><para><U>21A6</U> Single-line left arrow starting with vertical bar (relation).
Similar: longer version&nbsp;<code>\longmapsto</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="618">\mho</indexterm>\mho</itemformat></item>
</tableterm><tableitem><para><U>2127</U> Conductance, half-circle rotated capital omega (ordinary).
Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="619">\mid</indexterm>\mid</itemformat></item>
</tableterm><tableitem><para><U>2223</U> Single-line vertical bar (relation).  A typical use of
<code>\mid</code> is for a set <code>\&lbrace;\, x \mid x\geq 5 \,\&rbrace;</code>.
</para>
<para>Similar: <code>\vert</code> and&nbsp;<code>|</code> produce the same single-line
vertical bar symbol but without any spacing (they fall in class
ordinary) and you should not use them as relations but instead only as
ordinals, i.e., footnote symbols.  For absolute value, see the entry
for&nbsp;<code>\vert</code> and for norm see the entry for&nbsp;<code>\Vert</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="620">\models</indexterm>\models</itemformat></item>
</tableterm><tableitem><para><U>22A8</U> Entails, or satisfies; double turnstile, short double dash
(relation).  Similar: long double dash&nbsp;<code>\vDash</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="621">\mp</indexterm>\mp</itemformat></item>
</tableterm><tableitem><para><U>2213</U> Minus or plus (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="622">\mu</indexterm>\mu</itemformat></item>
</tableterm><tableitem><para><U>03BC</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="623">\nabla</indexterm>\nabla</itemformat></item>
</tableterm><tableitem><para><U>2207</U> Hamilton&textrsquo;s del, or differential, operator (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="624">\natural</indexterm>\natural</itemformat></item>
</tableterm><tableitem><para><U>266E</U> Musical natural notation (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="625">\ne</indexterm>\ne</itemformat></item>
</tableterm><tableitem><para><U>2260</U> Not equal (relation). Synonym:&nbsp;<code>\neq</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="626">\nearrow</indexterm>\nearrow</itemformat></item>
</tableterm><tableitem><para><U>2197</U> North-east arrow (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="627">\neg</indexterm>\neg</itemformat></item>
</tableterm><tableitem><para><U>00AC</U> Logical negation (ordinary).
Synonym:&nbsp;<code>\lnot</code>. Sometimes instead used for
negation:&nbsp;<code>\sim</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="628">\neq</indexterm>\neq</itemformat></item>
</tableterm><tableitem><para><U>2260</U> Not equal (relation). Synonym:&nbsp;<code>\ne</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="629">\ni</indexterm>\ni</itemformat></item>
</tableterm><tableitem><para><U>220B</U> Reflected membership epsilon; has the member
(relation). Synonym:&nbsp;<code>\owns</code>. Similar: is a member
of&nbsp;<code>\in</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="630">\not</indexterm>\not</itemformat></item>
</tableterm><tableitem><para><U>0020</U><U>00A0</U><U>0338</U> Long solidus, or slash, used to overstrike a
following operator (relation).
<!-- c Need blank space for it to overstrike -->
</para>
<para>Many negated operators that don&textrsquo;t require <code>\not</code> are available,
particularly with the <file>amssymb</file> package. For example, <code>\notin</code>
is probably typographically preferable to <code>\not\in</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="631">\notin</indexterm>\notin</itemformat></item>
</tableterm><tableitem><para><U>2209</U> Not an element of (relation).  Similar: not subset
of&nbsp;<code>\nsubseteq</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="632">\nu</indexterm>\nu</itemformat></item>
</tableterm><tableitem><para><U>03BD</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="633">\nwarrow</indexterm>\nwarrow</itemformat></item>
</tableterm><tableitem><para><U>2196</U> North-west arrow (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="634">\odot</indexterm>\odot</itemformat></item>
</tableterm><tableitem><para><U>2299</U> Dot inside a circle (binary).  Similar: variable-sized
operator&nbsp;<code>\bigodot</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="635">\oint</indexterm>\oint</itemformat></item>
</tableterm><tableitem><para><U>222E</U> Contour integral, integral with circle in the middle (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="636">\Omega</indexterm>\Omega</itemformat></item>
</tableterm><tableitem><para><U>03A9</U> Upper case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="637">\omega</indexterm>\omega</itemformat></item>
</tableterm><tableitem><para><U>03C9</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="638">\ominus</indexterm>\ominus</itemformat></item>
</tableterm><tableitem><para><U>2296</U> Minus sign, or dash, inside a circle (binary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="639">\oplus</indexterm>\oplus</itemformat></item>
</tableterm><tableitem><para><U>2295</U> Plus sign inside a circle (binary).  Similar: variable-sized
operator&nbsp;<code>\bigoplus</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="640">\oslash</indexterm>\oslash</itemformat></item>
</tableterm><tableitem><para><U>2298</U> Solidus, or slash, inside a circle (binary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="641">\otimes</indexterm>\otimes</itemformat></item>
</tableterm><tableitem><para><U>2297</U> Times sign, or cross, inside a circle (binary).  Similar:
variable-sized operator&nbsp;<code>\bigotimes</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="642">\owns</indexterm>\owns</itemformat></item>
</tableterm><tableitem><para><U>220B</U> Reflected membership epsilon; has the member
(relation). Synonym:&nbsp;<code>\ni</code>. Similar: is a member
of&nbsp;<code>\in</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="643">\parallel</indexterm>\parallel</itemformat></item>
</tableterm><tableitem><para><U>2225</U> Parallel (relation). Synonym:&nbsp;<code>\|</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="644">\partial</indexterm>\partial</itemformat></item>
</tableterm><tableitem><para><U>2202</U> Partial differential (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="645">\perp</indexterm>\perp</itemformat></item>
</tableterm><tableitem><para><U>27C2</U> Perpendicular (relation).  Similar:&nbsp;<code>\bot</code> uses the
same glyph but the spacing is different because it is in the class
ordinary.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="646">\phi</indexterm>\phi</itemformat></item>
</tableterm><tableitem><para><U>03D5</U> Lower case Greek letter (ordinary).  The variant form is
<code>\varphi</code>&nbsp;<U>03C6</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="647">\Pi</indexterm>\Pi</itemformat></item>
</tableterm><tableitem><para><U>03A0</U> Upper case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="648">\pi</indexterm>\pi</itemformat></item>
</tableterm><tableitem><para><U>03C0</U> Lower case Greek letter (ordinary).  The variant form is
<code>\varpi</code>&nbsp;<U>03D6</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="649">\pm</indexterm>\pm</itemformat></item>
</tableterm><tableitem><para><U>00B1</U> Plus or minus (binary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="650">\prec</indexterm>\prec</itemformat></item>
</tableterm><tableitem><para><U>227A</U> Precedes (relation). Similar: less than&nbsp;<code>&lt;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="651">\preceq</indexterm>\preceq</itemformat></item>
</tableterm><tableitem><para><U>2AAF</U> Precedes or equals (relation). Similar: less than or
equals&nbsp;<code>\leq</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="652">\prime</indexterm>\prime</itemformat></item>
</tableterm><tableitem><para><U>2032</U> Prime, or minute in a time expression (ordinary).
Typically used as a superscript: <code>$f^\prime$</code>; <code>$f^\prime$</code>
and <code>$f'$</code> produce the same result.  An advantage of the second
is that <code>$f'''$</code> produces the desired symbol, that is, the same
result as <code>$f^&lbrace;\prime\prime\prime&rbrace;$</code>, but uses rather less
typing.  You can only use <code>\prime</code> in math mode.  Using the right
single quote&nbsp;<code>'</code> in text mode produces a different character
(apostrophe).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="653">\prod</indexterm>\prod</itemformat></item>
</tableterm><tableitem><para><U>220F</U> Product (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="654">\propto</indexterm>\propto</itemformat></item>
</tableterm><tableitem><para><U>221D</U> Is proportional to (relation)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="655">\Psi</indexterm>\Psi</itemformat></item>
</tableterm><tableitem><para><U>03A8</U> Upper case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="656">\psi</indexterm>\psi</itemformat></item>
</tableterm><tableitem><para><U>03C8</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="657">\rangle</indexterm>\rangle</itemformat></item>
</tableterm><tableitem><para><U>27E9</U> Right angle, or sequence, bracket (closing). Similar: greater
than&nbsp;<code>&gt;</code>.  Matches:<code>\langle</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="658">\rbrace</indexterm>\rbrace</itemformat></item>
</tableterm><tableitem><para><U>007D</U> Right curly brace
(closing). Synonym:&nbsp;<code>\&rbrace;</code>. Matches&nbsp;<code>\lbrace</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="659">\rbrack</indexterm>\rbrack</itemformat></item>
</tableterm><tableitem><para><U>005D</U> Right square bracket
(closing). Synonym:&nbsp;<code>]</code>. Matches&nbsp;<code>\lbrack</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="660">\rceil</indexterm>\rceil</itemformat></item>
</tableterm><tableitem><para><U>2309</U> Right ceiling bracket (closing). Matches&nbsp;<code>\lceil</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="661">\Re</indexterm>\Re</itemformat></item>
</tableterm><tableitem><para><U>211C</U> Real part, real numbers, cursive capital R (ordinary). Related:
double-line, or blackboard bold, R&nbsp;<code>\mathbb&lbrace;R&rbrace;</code>; to access
this, load the <file>amsfonts</file> package.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="662">\restriction</indexterm>\restriction</itemformat></item>
</tableterm><tableitem><para><U>21BE</U> Restriction of a function
(relation). Synonym:&nbsp;<code>\upharpoonright</code>.  Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="663">\revemptyset</indexterm>\revemptyset</itemformat></item>
</tableterm><tableitem><para><U>29B0</U> Reversed empty set symbol (ordinary).  Related:
<code>\varnothing</code>. Not available in plain &tex;. In &latex; you need to load the <file>stix</file> package.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="664">\rfloor</indexterm>\rfloor</itemformat></item>
</tableterm><tableitem><para><U>230B</U> Right floor bracket, a right square bracket with the top cut
off (closing). Matches&nbsp;<code>\lfloor</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="665">\rhd</indexterm>\rhd</itemformat></item>
</tableterm><tableitem><para><U>25C1</U> Arrowhead, that is, triangle, pointing right (binary).
Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package. For the normal subgroup symbol you should instead
load <file>amssymb</file> and use&nbsp;<code>\vartriangleright</code> (which
is a relation and so gives better spacing).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="666">\rho</indexterm>\rho</itemformat></item>
</tableterm><tableitem><para><U>03C1</U> Lower case Greek letter (ordinary).  The variant form is
<code>\varrho</code>&nbsp;<U>03F1</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="667">\Rightarrow</indexterm>\Rightarrow</itemformat></item>
</tableterm><tableitem><para><U>21D2</U> Implies, right-pointing double line arrow (relation). Similar:
right single-line arrow&nbsp;<code>\rightarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="668">\rightarrow</indexterm>\rightarrow</itemformat></item>
</tableterm><tableitem><para><U>2192</U> Right-pointing single line arrow (relation). Synonym:&nbsp;<code>\to</code>. Similar: right double line arrow&nbsp;<code>\Rightarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="669">\rightharpoondown</indexterm>\rightharpoondown</itemformat></item>
</tableterm><tableitem><para><U>21C1</U> Right-pointing harpoon with barb below the line (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="670">\rightharpoonup</indexterm>\rightharpoonup</itemformat></item>
</tableterm><tableitem><para><U>21C0</U> Right-pointing harpoon with barb above the line (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="671">\rightleftharpoons</indexterm>\rightleftharpoons</itemformat></item>
</tableterm><tableitem><para><U>21CC</U> Right harpoon up above left harpoon down (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="672">\searrow</indexterm>\searrow</itemformat></item>
</tableterm><tableitem><para><U>2198</U> Arrow pointing southeast (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="673">\setminus</indexterm>\setminus</itemformat></item>
</tableterm><tableitem><para><U>29F5</U> Set difference, reverse solidus or slash, like \
(binary). Similar: backslash&nbsp;<code>\backslash</code> and also
<code>\textbackslash</code> outside of math mode.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="674">\sharp</indexterm>\sharp</itemformat></item>
</tableterm><tableitem><para><U>266F</U> Musical sharp (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="675">\Sigma</indexterm>\Sigma</itemformat></item>
</tableterm><tableitem><para><U>03A3</U> Upper case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="676">\sigma</indexterm>\sigma</itemformat></item>
</tableterm><tableitem><para><U>03C3</U> Lower case Greek letter (ordinary). The variant form is
<code>\varsigma</code>&nbsp;<U>03C2</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="677">\sim</indexterm>\sim</itemformat></item>
</tableterm><tableitem><para><U>223C</U> Similar, in a relation (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="678">\simeq</indexterm>\simeq</itemformat></item>
</tableterm><tableitem><para><U>2243</U> Similar or equal to, in a relation (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="679">\smallint</indexterm>\smallint</itemformat></item>
</tableterm><tableitem><para><U>222B</U> Integral sign that does not change to a larger size in a
display (operator).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="680">\smile</indexterm>\smile</itemformat></item>
</tableterm><tableitem><para><U>2323</U> Upward curving arc, smile (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="681">\spadesuit</indexterm>\spadesuit</itemformat></item>
</tableterm><tableitem><para><U>2660</U> Spade card suit (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="682">\sqcap</indexterm>\sqcap</itemformat></item>
</tableterm><tableitem><para><U>2293</U> Square intersection symbol (binary). Similar:
intersection&nbsp;<code>cap</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="683">\sqcup</indexterm>\sqcup</itemformat></item>
</tableterm><tableitem><para><U>2294</U> Square union symbol (binary). Similar:
union&nbsp;<code>cup</code>. Related: variable-sized
operator&nbsp;<code>\bigsqcup</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="684">\sqsubset</indexterm>\sqsubset</itemformat></item>
</tableterm><tableitem><para><U>228F</U> Square subset symbol (relation). Similar:
subset&nbsp;<code>\subset</code>. Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="685">\sqsubseteq</indexterm>\sqsubseteq</itemformat></item>
</tableterm><tableitem><para><U>2291</U> Square subset or equal symbol (binary). Similar: subset or
equal to&nbsp;<code>\subseteq</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="686">\sqsupset</indexterm>\sqsupset</itemformat></item>
</tableterm><tableitem><para><U>2290</U> Square superset symbol (relation). Similar:
superset&nbsp;<code>\supset</code>. Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="687">\sqsupseteq</indexterm>\sqsupseteq</itemformat></item>
</tableterm><tableitem><para><U>2292</U> Square superset or equal symbol (binary). Similar: superset or
equal&nbsp;<code>\supseteq</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="688">\star</indexterm>\star</itemformat></item>
</tableterm><tableitem><para><U>22C6</U> Five-pointed star, sometimes used as a general binary operation
but sometimes reserved for cross-correlation (binary). Similar: the
synonyms asterisk&nbsp;<code>*</code> and <code>\ast</code>, which are six-pointed,
and more often appear as a superscript or subscript, as with the Kleene
star.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="689">\subset</indexterm>\subset</itemformat></item>
</tableterm><tableitem><para><U>2282</U> Subset (occasionally, is implied by) (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="690">\subseteq</indexterm>\subseteq</itemformat></item>
</tableterm><tableitem><para><U>2286</U> Subset or equal to (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="691">\succ</indexterm>\succ</itemformat></item>
</tableterm><tableitem><para><U>227B</U> Comes after, succeeds (relation). Similar: is less
than&nbsp;<code>&gt;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="692">\succeq</indexterm>\succeq</itemformat></item>
</tableterm><tableitem><para><U>2AB0</U> Succeeds or is equal to (relation). Similar: less
than or equal to&nbsp;<code>\leq</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="693">\sum</indexterm>\sum</itemformat></item>
</tableterm><tableitem><para><U>2211</U> Summation (operator). Similar: Greek capital
sigma&nbsp;<code>\Sigma</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="694">\supset</indexterm>\supset</itemformat></item>
</tableterm><tableitem><para><U>2283</U> Superset (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="695">\supseteq</indexterm>\supseteq</itemformat></item>
</tableterm><tableitem><para><U>2287</U> Superset or equal to (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="696">\surd</indexterm>\surd</itemformat></item>
</tableterm><tableitem><para><U>221A</U> Radical symbol (ordinary).  The &latex; command
<code>\sqrt&lbrace;...&rbrace;</code> typesets the square root of the argument, with a bar
that extends to cover the argument.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="697">\swarrow</indexterm>\swarrow</itemformat></item>
</tableterm><tableitem><para><U>2199</U> Southwest-pointing  arrow (relation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="698">\tau</indexterm>\tau</itemformat></item>
</tableterm><tableitem><para><U>03C4</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="699">\theta</indexterm>\theta</itemformat></item>
</tableterm><tableitem><para><U>03B8</U> Lower case Greek letter (ordinary). The variant form is
<code>\vartheta</code>&nbsp;<U>03D1</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="700">\times</indexterm>\times</itemformat></item>
</tableterm><tableitem><para><U>00D7</U> Primary school multiplication sign (binary). See
also&nbsp;<code>\cdot</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="701">\to</indexterm>\to</itemformat></item>
</tableterm><tableitem><para><U>2192</U> Right-pointing single line arrow (relation).
Synonym:&nbsp;<code>\rightarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="702">\top</indexterm>\top</itemformat></item>
</tableterm><tableitem><para><U>22A4</U> Top, greatest element of a partially ordered set
(ordinary). See also&nbsp;<code>\bot</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="703">\triangle</indexterm>\triangle</itemformat></item>
</tableterm><tableitem><para><U>25B3</U> Triangle (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="704">\triangleleft</indexterm>\triangleleft</itemformat></item>
</tableterm><tableitem><para><U>25C1</U> Not-filled triangle pointing left
(binary). Similar:&nbsp;<code>\lhd</code>. For the normal subgroup symbol you
should load <file>amssymb</file> and use&nbsp;<code>\vartriangleleft</code> (which
is a relation and so gives better spacing).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="705">\triangleright</indexterm>\triangleright</itemformat></item>
</tableterm><tableitem><para><U>25B7</U> Not-filled triangle pointing right
(binary). For the normal subgroup symbol you should instead load
<file>amssymb</file> and use&nbsp;<code>\vartriangleright</code> (which is a
relation and so gives better spacing).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="706">\unlhd</indexterm>\unlhd</itemformat></item>
</tableterm><tableitem><para><U>22B4</U> Left-pointing not-filled underlined arrowhead, that
is, triangle, with a line under (binary). Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.  For
the normal subgroup symbol load <file>amssymb</file> and
use&nbsp;<code>\vartrianglelefteq</code> (which is a relation and so gives
better spacing).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="707">\unrhd</indexterm>\unrhd</itemformat></item>
</tableterm><tableitem><para><U>22B5</U> Right-pointing not-filled underlined arrowhead, that
is, triangle, with a line under (binary). Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.  For
the normal subgroup symbol load <file>amssymb</file> and
use&nbsp;<code>\vartrianglerighteq</code> (which is a relation and so gives
better spacing).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="708">\Uparrow</indexterm>\Uparrow</itemformat></item>
</tableterm><tableitem><para><U>21D1</U> Double-line upward-pointing arrow
(relation). Similar: single-line up-pointing
arrow&nbsp;<code>\uparrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="709">\uparrow</indexterm>\uparrow</itemformat></item>
</tableterm><tableitem><para><U>2191</U> Single-line upward-pointing arrow, diverges
(relation). Similar: double-line up-pointing
arrow&nbsp;<code>\Uparrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="710">\Updownarrow</indexterm>\Updownarrow</itemformat></item>
</tableterm><tableitem><para><U>21D5</U> Double-line upward-and-downward-pointing arrow
(relation). Similar: single-line upward-and-downward-pointing
arrow&nbsp;<code>\updownarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="711">\updownarrow</indexterm>\updownarrow</itemformat></item>
</tableterm><tableitem><para><U>2195</U> Single-line upward-and-downward-pointing arrow (relation). Similar:
double-line upward-and-downward-pointing arrow&nbsp;<code>\Updownarrow</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="712">\upharpoonright</indexterm>\upharpoonright</itemformat></item>
</tableterm><tableitem><para><U>21BE</U> Up harpoon, with barb on right side
(relation). Synonym:&nbsp;<code>&backslashchar;restriction</code>.  Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="713">\uplus</indexterm>\uplus</itemformat></item>
</tableterm><tableitem><para><U>228E</U> Multiset union, a union symbol with a plus symbol in
the middle (binary). Similar: union&nbsp;<code>\cup</code>. Related:
variable-sized operator&nbsp;<code>\biguplus</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="714">\Upsilon</indexterm>\Upsilon</itemformat></item>
</tableterm><tableitem><para><U>03A5</U> Upper case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="715">\upsilon</indexterm>\upsilon</itemformat></item>
</tableterm><tableitem><para><U>03C5</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="716">\varepsilon</indexterm>\varepsilon</itemformat></item>
</tableterm><tableitem><para><U>03B5</U> Small letter script epsilon (ordinary).  This is
more widely used in mathematics than the non-variant lunate epsilon form
<code>\epsilon</code>&nbsp;<U>03F5</U>. Related: set
membership&nbsp;<code>\in</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="717">\vanothing</indexterm>\vanothing</itemformat></item>
</tableterm><tableitem><para><U>2205</U> Empty set symbol. Similar:
<code>\emptyset</code>. Related: <code>\revemptyset</code>. Not available in plain &tex;. In &latex; you need to load the <file>amssymb</file> package.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="718">\varphi</indexterm>\varphi</itemformat></item>
</tableterm><tableitem><para><U>03C6</U> Variant on the lower case Greek letter (ordinary).
The non-variant form is <code>\phi</code>&nbsp;<U>03D5</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="719">\varpi</indexterm>\varpi</itemformat></item>
</tableterm><tableitem><para><U>03D6</U> Variant on the lower case Greek letter (ordinary).
The non-variant form is <code>\pi</code>&nbsp;<U>03C0</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="720">\varrho</indexterm>\varrho</itemformat></item>
</tableterm><tableitem><para><U>03F1</U> Variant on the lower case Greek letter (ordinary).
The non-variant form is <code>\rho</code>&nbsp;<U>03C1</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="721">\varsigma</indexterm>\varsigma</itemformat></item>
</tableterm><tableitem><para><U>03C2</U> Variant on the lower case Greek letter
(ordinary).  The non-variant form is
<code>\sigma</code>&nbsp;<U>03C3</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="722">\vartheta</indexterm>\vartheta</itemformat></item>
</tableterm><tableitem><para><U>03D1</U> Variant on the lower case Greek letter
(ordinary).  The non-variant form is
<code>\theta</code>&nbsp;<U>03B8</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="723">\vdash</indexterm>\vdash</itemformat></item>
</tableterm><tableitem><para><U>22A2</U> Provable; turnstile, vertical and a dash
(relation). Similar: turnstile rotated a
half-circle&nbsp;<code>\dashv</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="724">\vee</indexterm>\vee</itemformat></item>
</tableterm><tableitem><para><U>2228</U> Logical or; a downwards v shape (binary). Related:
logical and&nbsp;<code>\wedge</code>. Similar: variable-sized
operator&nbsp;<code>\bigvee</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="725">\Vert</indexterm>\Vert</itemformat></item>
</tableterm><tableitem><para><U>2016</U> Vertical double bar (ordinary). Similar: vertical single
bar&nbsp;<code>\vert</code>.
</para>
<para>For a norm symbol, you can use the <file>mathtools</file> package and add
<code>\DeclarePairedDelimiter\norm&lbrace;\lVert&rbrace;&lbrace;\rVert&rbrace;</code> to your
preamble. This gives you three command variants for double-line
vertical bars that are correctly horizontally spaced: if in the
document body you write the starred version <code>$\norm*&lbrace;M^\perp&rbrace;$</code>
then the height of the vertical bars will match the height of the
argument, whereas with <code>\norm&lbrace;M^\perp&rbrace;</code> the bars do not grow
with the height of the argument but instead are the default height,
and <code>\norm[<var>size command</var>]&lbrace;M^\perp&rbrace;</code> also gives bars that
do not grow but are set to the size given in the <var>size command</var>,
e.g., <code>\Bigg</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="726">\vert</indexterm>\vert</itemformat></item>
</tableterm><tableitem><para><U>007C</U> Single line vertical bar (ordinary). Similar: double-line
vertical bar&nbsp;<code>\Vert</code>. For such that, as in the definition of a 
set, use&nbsp;<code>\mid</code> because it is a relation.  
</para>
<para>For absolute value you can use the <file>mathtools</file> package and add
<code>\DeclarePairedDelimiter\abs&lbrace;\lvert&rbrace;&lbrace;\rvert&rbrace;</code> to your
preamble. This gives you three command variants for single-line vertical
bars that are correctly horizontally spaced: if in the document body you
write the starred version <code>$\abs*&lbrace;\frac&lbrace;22&rbrace;&lbrace;7&rbrace;&rbrace;$</code> then the
height of the vertical bars will match the height of the argument,
whereas with <code>\abs&lbrace;\frac&lbrace;22&rbrace;&lbrace;7&rbrace;&rbrace;</code> the bars do not grow with
the height of the argument but instead are the default height, and
<code>\abs[<var>size command</var>]&lbrace;\frac&lbrace;22&rbrace;&lbrace;7&rbrace;&rbrace;</code> also gives bars
that do not grow but are set to the size given in the <var>size
command</var>, e.g., <code>\Bigg</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="727">\wedge</indexterm>\wedge</itemformat></item>
</tableterm><tableitem><para><U>2227</U> Logical and (binary).  Synonym:&nbsp;<code>\land</code>.  See also
logical or <code>\vee</code>. Similar: variable-sized
operator&nbsp;<code>\bigwedge</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="728">\wp</indexterm>\wp</itemformat></item>
</tableterm><tableitem><para><U>2118</U> Weierstrass p (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="729">\wr</indexterm>\wr</itemformat></item>
</tableterm><tableitem><para><U>2240</U> Wreath product (binary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="730">\Xi</indexterm>\Xi</itemformat></item>
</tableterm><tableitem><para><U>039E</U> Upper case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="731">\xi</indexterm>\xi</itemformat></item>
</tableterm><tableitem><para><U>03BE</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="732">\zeta</indexterm>\zeta</itemformat></item>
</tableterm><tableitem><para><U>03B6</U> Lower case Greek letter (ordinary).
</para>
</tableitem></tableentry></ftable>


</section>
<node name="Math-functions" spaces=" "><nodename>Math functions</nodename><nodenext automatic="on">Math accents</nodenext><nodeprev automatic="on">Math symbols</nodeprev><nodeup automatic="on">Math formulas</nodeup></node>
<section spaces=" "><sectiontitle>Math functions</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="386">math functions</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="387">functions, math</indexterm></cindex>

<para>These commands produce roman function names in math mode with proper
spacing.
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="733">\arccos</indexterm>\arccos</itemformat></item>
</tableterm><tableitem><para><math>\arccos</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="734">\arcsin</indexterm>\arcsin</itemformat></item>
</tableterm><tableitem><para><math>\arcsin</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="735">\arctan</indexterm>\arctan</itemformat></item>
</tableterm><tableitem><para><math>\arctan</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="736">\arg</indexterm>\arg</itemformat></item>
</tableterm><tableitem><para><math>\arg</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="737">\bmod</indexterm>\bmod</itemformat></item>
</tableterm><tableitem><para>Binary modulo operator (<math>x \bmod y</math>)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="738">\cos</indexterm>\cos</itemformat></item>
</tableterm><tableitem><para><math>\cos</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="739">\cosh</indexterm>\cosh</itemformat></item>
</tableterm><tableitem><para><math>\cosh</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="740">\cot</indexterm>\cot</itemformat></item>
</tableterm><tableitem><para><math>\cot</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="741">\coth</indexterm>\coth</itemformat></item>
</tableterm><tableitem><para><math>\coth</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="742">\csc</indexterm>\csc</itemformat></item>
</tableterm><tableitem><para><math>\csc</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="743">\deg</indexterm>\deg</itemformat></item>
</tableterm><tableitem><para><math>\deg</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="744">\det</indexterm>\det</itemformat></item>
</tableterm><tableitem><para><math>\det</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="745">\dim</indexterm>\dim</itemformat></item>
</tableterm><tableitem><para><math>\dim</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="746">\exp</indexterm>\exp</itemformat></item>
</tableterm><tableitem><para><math>\exp</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="747">\gcd</indexterm>\gcd</itemformat></item>
</tableterm><tableitem><para><math>\gcd</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="748">\hom</indexterm>\hom</itemformat></item>
</tableterm><tableitem><para><math>\hom</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="749">\inf</indexterm>\inf</itemformat></item>
</tableterm><tableitem><para><math>\inf</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="750">\ker</indexterm>\ker</itemformat></item>
</tableterm><tableitem><para><math>\ker</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="751">\lg</indexterm>\lg</itemformat></item>
</tableterm><tableitem><para><math>\lg</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="752">\lim</indexterm>\lim</itemformat></item>
</tableterm><tableitem><para><math>\lim</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="753">\liminf</indexterm>\liminf</itemformat></item>
</tableterm><tableitem><para><math>\liminf</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="754">\limsup</indexterm>\limsup</itemformat></item>
</tableterm><tableitem><para><math>\limsup</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="755">\ln</indexterm>\ln</itemformat></item>
</tableterm><tableitem><para><math>\ln</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="756">\log</indexterm>\log</itemformat></item>
</tableterm><tableitem><para><math>\log</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="757">\max</indexterm>\max</itemformat></item>
</tableterm><tableitem><para><math>\max</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="758">\min</indexterm>\min</itemformat></item>
</tableterm><tableitem><para><math>\min</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="759">\pmod</indexterm>\pmod</itemformat></item>
</tableterm><tableitem><para>parenthesized modulus, as in (<math>\pmod 2^n - 1</math>)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="760">\Pr</indexterm>\Pr</itemformat></item>
</tableterm><tableitem><para><math>\Pr</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="761">\sec</indexterm>\sec</itemformat></item>
</tableterm><tableitem><para><math>\sec</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="762">\sin</indexterm>\sin</itemformat></item>
</tableterm><tableitem><para><math>\sin</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="763">\sinh</indexterm>\sinh</itemformat></item>
</tableterm><tableitem><para><math>\sinh</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="764">\sup</indexterm>\sup</itemformat></item>
</tableterm><tableitem><para><math>\sup</math>
<!-- c don't try to use \sup with dvi/pdf output since that turned into a -->
<!-- c Texinfo command and it's not worth hassling with different versions -->
<!-- c when it's just three roman letters anyway. -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="765">\tan</indexterm>\tan</itemformat></item>
</tableterm><tableitem><para><math>\tan</math>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="766">\tanh</indexterm>\tanh</itemformat></item>
</tableterm><tableitem><para><math>\tanh</math>
</para>
</tableitem></tableentry></ftable>


</section>
<node name="Math-accents" spaces=" "><nodename>Math accents</nodename><nodenext automatic="on">Spacing in math mode</nodenext><nodeprev automatic="on">Math functions</nodeprev><nodeup automatic="on">Math formulas</nodeup></node>
<section spaces=" "><sectiontitle>Math accents</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="388">math accents</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="389">accents, mathematical</indexterm></cindex>

<para>&latex; provides a variety of commands for producing accented letters
in math.  These are different from accents in normal text
(<pxref label="Accents"><xrefnodename>Accents</xrefnodename></pxref>).
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="767">\acute</indexterm>\acute</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="390">acute accent, math</indexterm></cindex>
<para>Math acute accent: <math>\acute{x}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="768">\bar</indexterm>\bar</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="391">bar-over accent, math</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="392">macron accent, math</indexterm></cindex>
<para>Math bar-over accent: <math>\bar{x}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="769">\breve</indexterm>\breve</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="393">breve accent, math</indexterm></cindex>
<para>Math breve accent: <math>\breve{x}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="770">\check</indexterm>\check</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="394">check accent, math</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="395">h<accent type="acute" bracketed="off">a</accent><accent type="caron">c</accent>ek accent, math</indexterm></cindex>
<para>Math h<accent type="acute" bracketed="off">a</accent><accent type="caron">c</accent>ek (check) accent: <math>\check{x}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="771">\ddot</indexterm>\ddot</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="396">double dot accent, math</indexterm></cindex>
<para>Math dieresis accent: <math>\ddot{x}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="772">\dot</indexterm>\dot</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="397">overdot accent, math</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="398">dot over accent, math</indexterm></cindex>
<para>Math dot accent: <math>\dot{x}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="773">\grave</indexterm>\grave</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="399">grave accent, math</indexterm></cindex>
<para>Math grave accent: <math>\grave{x}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="774">\hat</indexterm>\hat</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="400">hat accent, math</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="401">circumflex accent, math</indexterm></cindex>
<para>Math hat (circumflex) accent: <math>\hat{x}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="775">\imath</indexterm>\imath</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="402">dotless i, math</indexterm></cindex>
<para>Math dotless i.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="776">\jmath</indexterm>\jmath</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="403">dotless j, math</indexterm></cindex>
<para>Math dotless j.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="777">\mathring</indexterm>\mathring</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="404">ring accent, math</indexterm></cindex>
<para>Math ring accent: <accent type="ring">x</accent>.  <!-- c don't bother implementing in texinfo -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="778">\tilde</indexterm>\tilde</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="405">tilde accent, math</indexterm></cindex>
<para>Math tilde accent: <math>\tilde{x}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="779">\vec</indexterm>\vec</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="406">vector symbol, math</indexterm></cindex>
<para>Math vector symbol: <math>\vec{x}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="780">\widehat</indexterm>\widehat</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="407">wide hat accent, math</indexterm></cindex>
<para>Math wide hat accent: <math>\widehat{x+y}</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="781">\widetilde</indexterm>\widetilde</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="408">wide tilde accent, math</indexterm></cindex>
<para>Math wide tilde accent: <math>\widetilde{x+y}</math>.
</para>
</tableitem></tableentry></ftable>


</section>
<node name="Spacing-in-math-mode" spaces=" "><nodename>Spacing in math mode</nodename><nodenext automatic="on">Math miscellany</nodenext><nodeprev automatic="on">Math accents</nodeprev><nodeup automatic="on">Math formulas</nodeup></node>
<section spaces=" "><sectiontitle>Spacing in math mode</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="409">spacing within math mode</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="410">math mode, spacing</indexterm></cindex>

<para>In a <code>math</code> environment, &latex; ignores the spaces that you use
in the source, and instead puts in the spacing according to the normal
rules for mathematics texts.  
</para>
<para>Many math mode spacing definitions are expressed in terms of the math unit
<dfn>mu</dfn> given by 1 em = 18 mu, where the em is taken from the current
math symbols family (<pxref label="Units-of-length"><xrefnodename>Units of length</xrefnodename></pxref>).
&latex; provides the following commands for use in math mode:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">\;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="782">\;</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="783">\thickspace</indexterm></findex>
<para>Normally <code>5.0mu plus 5.0mu</code>.  The longer name is
<code>\thickspace</code>.  Math mode only.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\:</itemformat></item>
<itemx spaces=" "><itemformat command="code">\&gt;</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="784">\:</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="785">\&gt;</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="786">\medspace</indexterm></findex>
<para>Normally <code>4.0mu plus 2.0mu minus 4.0mu</code>.  The longer name is
<code>\medspace</code>.  Math mode only.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\,</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="787">\,</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="788">\thinspace</indexterm></findex>
<para>Normally <code>3mu</code>.  The longer name is <code>\thinspace</code>.  This can
be used in both math mode and text mode. <xref label="_005cthinspace"><xrefnodename>\thinspace</xrefnodename></xref>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\!</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="789">\!</indexterm></findex>
<para>A negative thin space. Normally <code>-3mu</code>.  Math mode only.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\quad</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="411">quad</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="790">\quad</indexterm></findex>
<para>This is 18<dmn>mu</dmn>, that is, 1<dmn>em</dmn>. This is often used for space
surrounding equations or expressions, for instance for the space between
two equations inside a <code>displaymath</code> environment.  It is available
in both text and math mode.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\qquad</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="791">\qquad</indexterm></findex>
<para>A length of 2 quads, that is, 36<dmn>mu</dmn> = 2<dmn>em</dmn>.  It is available in
both text and math mode.
</para></tableitem></tableentry></table>

<para>In this example a thinspace separates the function from the
infinitesimal.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\int_0^1 f(x)\,dx
</pre></example>


</section>
<node name="Math-miscellany" spaces=" "><nodename>Math miscellany</nodename><nodeprev automatic="on">Spacing in math mode</nodeprev><nodeup automatic="on">Math formulas</nodeup></node>
<section spaces=" "><sectiontitle>Math miscellany</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="412">math miscellany</indexterm></cindex>

<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="792">\*</indexterm>\*</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="413">discretionary multiplication</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="414">multiplication symbol, discretionary line break</indexterm></cindex>
<para>A <dfn>discretionary</dfn> multiplication symbol, at which a line break is
allowed. Without the break multiplication is implicitly indicated by a
space, while in the case of a break a <U>00D7</U> symbol is
printed immediately before the break. So
</para>
<example endspaces=" ">
<pre xml:space="preserve">\documentclass&lbrace;article&rbrace;
\begin&lbrace;document&rbrace;
Now \(A_3 = 0\), hence the product of all terms \(A_1\) 
through \(A_4\), that is \(A_1\* A_2\* A_3 \* A_4\), is 
equal to zero.
\end&lbrace;document&rbrace;
</pre></example>

<para>will make that sort of output<!-- c -->
<w> </w>(the ellipsis <samp>[&dots;]</samp> is here to show the line break at
the same place as in a &tex; output)<!-- c -->
:
</para>
<indentedblock endspaces=" ">
<para>Now <math>A_3 = 0</math>,
[&dots;]
<math>A_1</math>
through <math>A_4</math>, that is <math>A_1 A_2 \times</math>&linebreak;<math>A_3 A_4</math>, is
equal to zero.
</para></indentedblock>

</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="793">\cdots</indexterm>\cdots</itemformat></item>
</tableterm><tableitem><para>A horizontal ellipsis with the dots raised to the center of the line.
<tex endspaces=" ">
</tex>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="794">\ddots</indexterm>\ddots</itemformat></item>
</tableterm><tableitem><para>A diagonal ellipsis: <math>\ddots</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="795">\frac&lbrace;<var>num</var>&rbrace;&lbrace;<var>den</var>&rbrace;</indexterm>\frac&lbrace;<var>num</var>&rbrace;&lbrace;<var>den</var>&rbrace;</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="796">\frac</indexterm></findex>
<para>Produces the fraction <var>num</var> divided by <var>den</var>.
</para>

</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="797">\left <var>delim1</var> ... \right <var>delim2</var></indexterm>\left <var>delim1</var> ... \right <var>delim2</var></itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="798">\right</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="415">null delimiter</indexterm></cindex>
<para>The two delimiters need not match; <samp>.</samp> acts as a <dfn>null delimiter</dfn>,
producing no output.  The delimiters are sized according to the math
in between.  Example: <code>\left( \sum_&lbrace;i=1&rbrace;^&lbrace;10&rbrace; a_i \right]</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="799">\mathdollar</indexterm>\mathdollar</itemformat></item>
</tableterm><tableitem><para>Dollar sign in math mode: $.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="800">\mathellipsis</indexterm>\mathellipsis</itemformat></item>
</tableterm><tableitem><para>Ellipsis (spaced for text) in math mode: &dots;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="801">\mathparagraph</indexterm>\mathparagraph</itemformat></item>
</tableterm><tableitem><para>Paragraph sign (pilcrow) in math mode: <U>00B6</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="802">\mathsection</indexterm>\mathsection</itemformat></item>
</tableterm><tableitem><para>Section sign in math mode.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="803">\mathsterling</indexterm>\mathsterling</itemformat></item>
</tableterm><tableitem><para>Sterling sign in math mode: &pound;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="804">\mathunderscore</indexterm>\mathunderscore</itemformat></item>
</tableterm><tableitem><para>Underscore in math mode: _.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="805">\overbrace&lbrace;<var>math</var>&rbrace;</indexterm>\overbrace&lbrace;<var>math</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Generates a brace over <var>math</var>.
For example, <code>\overbrace&lbrace;x+\cdots+x&rbrace;^&lbrace;k \;\textrm&lbrace;times&rbrace;&rbrace;</code>.
</para>        
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="806">\overline&lbrace;<var>text</var>&rbrace;</indexterm>\overline&lbrace;<var>text</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Generates a horizontal line over <var>tex</var>.
For example, <code>\overline&lbrace;x+y&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="807">\sqrt[<var>root</var>]&lbrace;<var>arg</var>&rbrace;</indexterm>\sqrt[<var>root</var>]&lbrace;<var>arg</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Produces the representation of the square root of <var>arg</var>.  The
optional argument <var>root</var> determines what root to produce.  For
example, the cube root of <code>x+y</code> would be typed as
<code>\sqrt[3]&lbrace;x+y&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="808">\stackrel&lbrace;<var>text</var>&rbrace;&lbrace;<var>relation</var>&rbrace;</indexterm>\stackrel&lbrace;<var>text</var>&rbrace;&lbrace;<var>relation</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Puts <var>text</var> above <var>relation</var>.  For example,
<code>\stackrel&lbrace;f&rbrace;&lbrace;\longrightarrow&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="809">\underbrace&lbrace;<var>math</var>&rbrace;</indexterm>\underbrace&lbrace;<var>math</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Generates <var>math</var> with a brace underneath. For example, <code>\underbrace&lbrace;x+y+z&rbrace;_&lbrace;&gt;\,0&rbrace;</code>
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="810">\underline&lbrace;<var>text</var>&rbrace;</indexterm>\underline&lbrace;<var>text</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Causes <var>text</var>, which may be either math mode or not, to be
underlined.  The line is always below the text, taking account of
descenders.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="811">\vdots</indexterm>\vdots</itemformat></item>
</tableterm><tableitem><para>Produces a vertical ellipsis.
</para>
</tableitem></tableentry></ftable>


</section>
</chapter>
<node name="Modes" spaces=" "><nodename>Modes</nodename><nodenext automatic="on">Page styles</nodenext><nodeprev automatic="on">Math formulas</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Modes</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="416">modes</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="417">paragraph mode</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="418">math mode</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="419">left-to-right mode</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="420">LR mode</indexterm></cindex>

<para>When &latex; is processing your input text, it is always in one of three
modes:
</para>
<itemize commandarg="bullet" spaces=" " endspaces=" "><itemprepend><formattingcommand command="bullet"/></itemprepend>
<listitem><prepend>&bullet;</prepend>
<para>Paragraph mode
</para></listitem><listitem><prepend>&bullet;</prepend>
<para>Math mode
</para></listitem><listitem><prepend>&bullet;</prepend>
<para>Left-to-right mode, called LR mode for short
</para></listitem></itemize>

<para>Mode changes occur only when entering or leaving an environment, or when
&latex; is processing the argument of certain text-producing commands.
</para>
<para><dfn>Paragraph mode</dfn> is the most common; it&textrsquo;s the one &latex; is in
when processing ordinary text.  In this mode, &latex; breaks the
input text into lines and breaks the lines into pages.
</para>
<para>&latex; is in <dfn>math mode</dfn> when it&textrsquo;s generating a mathematical
formula, either displayed math or within a line.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="812">\mbox<r>, and LR mode</r></indexterm></findex>
<para>In <dfn>LR mode</dfn>, as in paragraph mode, &latex; considers the output
that it produces to be a string of words with spaces between them.
However, unlike paragraph mode, &latex; keeps going from left to
right; it never starts a new line in LR mode.  Even if you put a
hundred words into an <code>\mbox</code>, &latex; would keep typesetting
them from left to right inside a single box (and then most likely
complain because the resulting box was too wide to fit on the line).
&latex; is in LR mode when it starts making a box with an
<code>\mbox</code> command.  You can get it to enter a different mode inside
the box&textmdash;for example, you can make it enter math mode to put a
formula in the box.
</para>
<para>There are also several text-producing commands and environments for
making a box that put &latex; into paragraph mode.  The box made by
one of these commands or environments will be called a <code>parbox</code>.
When &latex; is in paragraph mode while making a box, it is said to
be in &textldquo;inner paragraph mode&textrdquo; (no page breaks).  Its normal paragraph
mode, which it starts out in, is called &textldquo;outer paragraph mode&textrdquo;.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator=":: ">\ensuremath</menunode><menudescription><pre xml:space="preserve">Ensure that math mode is active
</pre></menudescription></menuentry></menu>

<node name="_005censuremath" spaces=" "><nodename>\ensuremath</nodename><nodeup automatic="on">Modes</nodeup></node>
<section spaces=" "><sectiontitle><code>\ensuremath</code></sectiontitle>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\ensuremath&lbrace;<var>formula</var>&rbrace;
</pre></example>

<para>The <code>\ensuremath</code> command ensures that <var>formula</var> is typeset in
math mode whatever the current mode in which the command is used.
</para>
<para>For instance:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\documentclass&lbrace;report&rbrace;
\newcommand&lbrace;\ab&rbrace;&lbrace;\ensuremath&lbrace;(\delta, \varepsilon)&rbrace;&rbrace;
\begin&lbrace;document&rbrace;
Now, the \ab\ pair is equal to \(\ab = (\frac&lbrace;1&rbrace;&lbrace;\pi&rbrace;, 0)\), ...
\end&lbrace;document&rbrace;
</pre></example>

<para>One can redefine commands that can be used only in math mode so that
they ca be used in any mode like in the following example given for
<code>\leadsto</code>:
</para>
<!-- c Vincent 2 Karl : "Tous les chemins mènent à Rome" is a French saying -->
<!-- c meaning that there are many different ways to get the same result. I -->
<!-- c am not sure whether in English the given example is also funny. -->
<example endspaces=" ">
<pre xml:space="preserve">\documentclass&lbrace;report&rbrace;
\usepackage&lbrace;amssymb&rbrace;
\newcommand&lbrace;\originalMeaningOfLeadsTo&rbrace;&lbrace;&rbrace;
\let\originalMeaningOfLeadsTo\leadsto
\renewcommand\leadsto&lbrace;\ensuremath&lbrace;\originalMeaningOfLeadsTo&rbrace;&rbrace;
\begin&lbrace;document&rbrace;
All roads \leadsto\ Rome.
\end&lbrace;document&rbrace;
</pre></example>


</section>
</chapter>
<node name="Page-styles" spaces=" "><nodename>Page styles</nodename><nodenext automatic="on">Spaces</nodenext><nodeprev automatic="on">Modes</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Page styles</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="421">styles, page</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="422">page styles</indexterm></cindex>

<para>The <code>\documentclass</code> command determines the size and position of
the page&textrsquo;s head and foot.  The page style determines what goes in them.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::          ">\maketitle</menunode><menudescription><pre xml:space="preserve">Generate a title page.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::      ">\pagenumbering</menunode><menudescription><pre xml:space="preserve">Set the style used for page numbers.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::		">\pagestyle</menunode><menudescription><pre xml:space="preserve">Change the headings/footings style.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::      ">\thispagestyle</menunode><menudescription><pre xml:space="preserve">Change the headings/footings style for this page.
</pre></menudescription></menuentry></menu>


<node name="_005cmaketitle" spaces=" "><nodename>\maketitle</nodename><nodenext automatic="on">\pagenumbering</nodenext><nodeup automatic="on">Page styles</nodeup></node>
<section spaces=" "><sectiontitle><code>\maketitle</code></sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="423">titles, making</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="813">\maketitle</indexterm></findex>

<para>The <code>\maketitle</code> command generates a title on a separate title
page&textmdash;except in the <code>article</code> class, where the title is placed
at the top of the first page.  Information used to produce the title
is obtained from the following declarations:
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="814">\author&lbrace;<var>name</var> \and <var>name2</var>&rbrace;</indexterm>\author&lbrace;<var>name</var> \and <var>name2</var>&rbrace;</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="424">author, for titlepage</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="815">\\ <r>for <code>\author</code></r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="816">\and <r>for <code>\author</code></r></indexterm></findex>
<para>The <code>\author</code> command declares the document author(s), where the
argument is a list of authors separated by <code>\and</code> commands.  Use
<code>\\</code> to separate lines within a single author&textrsquo;s entry&textmdash;for
example, to give the author&textrsquo;s institution or address.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="817">\date&lbrace;<var>text</var>&rbrace;</indexterm>\date&lbrace;<var>text</var>&rbrace;</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="425">date, for titlepage</indexterm></cindex>
<para>The <code>\date</code> command declares <var>text</var> to be the document&textrsquo;s
date.  With no <code>\date</code> command, the current date (<pxref label="_005ctoday"><xrefnodename>\today</xrefnodename></pxref>)
is used.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="818">\thanks&lbrace;<var>text</var>&rbrace;</indexterm>\thanks&lbrace;<var>text</var>&rbrace;</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="426">thanks, for titlepage</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="427">credit footnote</indexterm></cindex>
<para>The <code>\thanks</code> command produces a <code>\footnote</code> to the title,
usually used for credit acknowledgements.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="819">\title&lbrace;<var>text</var>&rbrace;</indexterm>\title&lbrace;<var>text</var>&rbrace;</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="428">title, for titlepage</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="820">\\ <r>for <code>\title</code></r></indexterm></findex>
<para>The <code>\title</code> command declares <var>text</var> to be the title of the
document.  Use <code>\\</code> to force a line break, as usual.
</para>
</tableitem></tableentry></ftable>


</section>
<node name="_005cpagenumbering" spaces=" "><nodename>\pagenumbering</nodename><nodenext automatic="on">\pagestyle</nodenext><nodeprev automatic="on">\maketitle</nodeprev><nodeup automatic="on">Page styles</nodeup></node>
<section spaces=" "><sectiontitle><code>\pagenumbering</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="821">\pagenumbering</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="429">page numbering style</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\pagenumbering&lbrace;<var>style</var>&rbrace;
</pre></example>

<para>Specifies the style of page numbers, according to <var>style</var>; also
resets the page number to 1.  The <var>style</var> argument is one of
the following:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">arabic</itemformat></item>
</tableterm><tableitem><para>arabic numerals
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">roman</itemformat></item>
</tableterm><tableitem><para>lowercase Roman numerals
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">Roman</itemformat></item>
</tableterm><tableitem><para>uppercase Roman numerals
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">alph</itemformat></item>
</tableterm><tableitem><para>lowercase letters
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">Alph</itemformat></item>
</tableterm><tableitem><para>uppercase letters
</para></tableitem></tableentry></table>


</section>
<node name="_005cpagestyle" spaces=" "><nodename>\pagestyle</nodename><nodenext automatic="on">\thispagestyle</nodenext><nodeprev automatic="on">\pagenumbering</nodeprev><nodeup automatic="on">Page styles</nodeup></node>
<section spaces=" "><sectiontitle><code>\pagestyle</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="822">\pagestyle</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="430">header style</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="431">footer style</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="432">running header and footer style</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\pagestyle&lbrace;<var>style</var>&rbrace;
</pre></example>

<para>The <code>\pagestyle</code> command specifies how the headers and footers
are typeset from the current page onwards.  Values for <var>style</var>:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">plain</itemformat></item>
</tableterm><tableitem><para>Just a plain page number.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">empty</itemformat></item>
</tableterm><tableitem><para>Empty headers and footers, e.g., no page numbers.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">headings</itemformat></item>
</tableterm><tableitem><para>Put running headers on each page.  The document style specifies what
goes in the headers.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">myheadings</itemformat></item>
</tableterm><tableitem><para>Custom headers, specified via the <code>\markboth</code> or the
<code>\markright</code> commands.
</para>
</tableitem></tableentry></table>

<para>Here are the descriptions of <code>\markboth</code> and <code>\markright</code>:
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="823">\markboth&lbrace;<var>left</var>&rbrace;&lbrace;<var>right</var>&rbrace;</indexterm>\markboth&lbrace;<var>left</var>&rbrace;&lbrace;<var>right</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Sets both the left and the right heading.  A &textldquo;left-hand heading&textrdquo;
(<var>left</var>) is generated by the last <code>\markboth</code> command before
the end of the page, while a &textldquo;right-hand heading&textrdquo; (<var>right</var>) is
generated by the first <code>\markboth</code> or <code>\markright</code> that
comes on the page if there is one, otherwise by the last one before
the page.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="824">\markright&lbrace;<var>right</var>&rbrace;</indexterm>\markright&lbrace;<var>right</var>&rbrace;</itemformat></item>
</tableterm><tableitem><para>Sets the right heading, leaving the left heading unchanged.
</para>
</tableitem></tableentry></ftable>


</section>
<node name="_005cthispagestyle" spaces=" "><nodename>\thispagestyle</nodename><nodeprev automatic="on">\pagestyle</nodeprev><nodeup automatic="on">Page styles</nodeup></node>
<section spaces=" "><sectiontitle><code>\thispagestyle&lbrace;<var>style</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="825">\thispagestyle</indexterm></findex>

<para>The <code>\thispagestyle</code> command works in the same manner as the
<code>\pagestyle</code> command (see previous section) except that it
changes to <var>style</var> for the current page only.
</para>

</section>
</chapter>
<node name="Spaces" spaces=" "><nodename>Spaces</nodename><nodenext automatic="on">Boxes</nodenext><nodeprev automatic="on">Page styles</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Spaces</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="433">spaces</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="434">white space</indexterm></cindex>

<para>&latex; has many ways to produce white (or filled) space.
</para>
<menu endspaces=" ">
<menucomment><pre xml:space="preserve">Horizontal space 
</pre></menucomment><menuentry leadingtext="* "><menunode separator="::              ">\hspace</menunode><menudescription><pre xml:space="preserve">Fixed horizontal space.  
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">\hfill</menunode><menudescription><pre xml:space="preserve">Stretchable horizontal space.  
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::         ">\spacefactor</menunode><menudescription><pre xml:space="preserve">Stretchability of following space
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator=":: ">\(SPACE) after control sequence</menunode><menudescription><pre xml:space="preserve">Space (gobbling) after a control sequence.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           ">\thinspace</menunode><menudescription><pre xml:space="preserve">One-sixth of an em.  
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                   ">\/</menunode><menudescription><pre xml:space="preserve">Insert italic correction.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::  ">\hrulefill \dotfill</menunode><menudescription><pre xml:space="preserve">Stretchable horizontal rule or dots.
</pre></menudescription></menuentry><menucomment><pre xml:space="preserve">
Vertical space
</pre></menucomment><menuentry leadingtext="* "><menunode separator="::                    ">\addvspace</menunode><menudescription><pre xml:space="preserve">Add arbitrary vertical space if needed.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::  ">\bigskip \medskip \smallskip</menunode><menudescription><pre xml:space="preserve">Fixed vertical spaces.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                        ">\vfill</menunode><menudescription><pre xml:space="preserve">Infinitely stretchable vertical space.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                       ">\vspace</menunode><menudescription><pre xml:space="preserve">Add arbitrary vertical space.
</pre></menudescription></menuentry></menu>


<node name="_005chspace" spaces=" "><nodename>\hspace</nodename><nodenext automatic="on">\hfill</nodenext><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\hspace</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="826">\hspace</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\hspace&lbrace;<var>length</var>&rbrace;
\hspace*&lbrace;<var>length</var>&rbrace;
</pre></example>

<para>Add the horizontal space given by <var>length</var>.  The <var>length</var> is a
rubber length, that is, it may contain a <code>plus</code> or <code>minus</code>
component, in any unit that &latex; understands (<pxref label="Lengths"><xrefnodename>Lengths</xrefnodename></pxref>).
</para>
<para>This command can add both positive and negative space; adding negative
space is like backspacing.
</para>
<para>Normally when &tex; breaks a paragraph into lines it discards white
space (glues and kerns) that would come at the start of a line, so you
get an inter-word space or a line break between words but not both. This
command&textrsquo;s starred version <code>\hspace*&lbrace;...&rbrace;</code> puts a non-discardable
invisible item in front of the space, so the space appears in the
output.
</para>
<para>This example make a one-line paragraph that puts <samp>Name:</samp> an inch
from the right margin.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\noindent\makebox[\linewidth]&lbrace;\hspace&lbrace;\fill&rbrace;Name:\hspace&lbrace;1in&rbrace;&rbrace;
</pre></example>


</section>
<node name="_005chfill" spaces=" "><nodename>\hfill</nodename><nodenext automatic="on">\spacefactor</nodenext><nodeprev automatic="on">\hspace</nodeprev><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\hfill</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="827">\hfill</indexterm></findex>

<cindex index="cp" spaces=" "><indexterm index="cp" number="435">stretch, infinite horizontal</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="436">infinite horizontal stretch</indexterm></cindex>
<para>Produce a rubber length which has
no natural space but can stretch horizontally as far as
needed (<pxref label="Lengths"><xrefnodename>Lengths</xrefnodename></pxref>).
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="828">\fill</indexterm></findex>
<para>The command <code>\hfill</code> is equivalent to <code>\hspace&lbrace;\fill&rbrace;</code>.  For
space that does not disappear at line breaks use
<code>\hspace*&lbrace;\fill&rbrace;</code> instead (<pxref label="_005chspace"><xrefnodename>\hspace</xrefnodename></pxref>).
</para>

</section>
<node name="_005cspacefactor" spaces=" "><nodename>\spacefactor</nodename><nodenext automatic="on">\(SPACE) after control sequence</nodenext><nodeprev automatic="on">\hfill</nodeprev><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\spacefactor</code></sectiontitle>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\spacefactor=<var>integer</var>
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="829">\spacefactor</indexterm></findex>
<para>While &latex; is making the page, to give the lines the best appearance
it may stretch or shrink the gaps between words.  The
<code>\spacefactor</code> command (from Plain&nbsp;&tex;) allows you to
change the &latex;&textrsquo;s default behavior.
</para>
<para>After &latex; places each character, or rule or other box, it sets a
parameter called the <dfn>space factor</dfn>.  If the next thing in the input
is a space then this parameter affects how much of a horizontal gap
&latex; will have it span.  (This gap is not a character; it is called
<dfn>interword glue</dfn>.)  A larger space factor means that the glue gap
can stretch more and shrink less.
</para>
<para>Normally, the space factor is 1000; this value is in effect following
most characters, and any non-character box or math formula.  But it is
3000 after a period, exclamation mark, or question mark, it is 2000
after a colon, 1500 after a semicolon, 1250 after a comma, and 0 after a
right parenthesis or bracket, or closing double quote or single quote.
Finally, it is 999 after a capital letter.
</para>
<para>If the space factor&nbsp;<var>f</var> is 1000 then the glue gap will be the
font&textrsquo;s normal space value (for Computer Modern Roman 10 point this is
3.3333&nbsp;points).  Otherwise, if the space factor <var>f</var> is greater
than 2000 then &tex; adds the font&textrsquo;s extra space value (for Computer
Modern Roman 10 point this is 1.11111&nbsp;points), and then the font&textrsquo;s
normal stretch value is multiplied by <math>f /1000</math> and the normal
shrink value is multiplied by <math>1000/f</math> (for Computer Modern Roman
10 point these are 1.66666 and 1.11111&nbsp;points).  In short, compared
to a normal space, such as the space following a word ending in a
lowercase letter, inter-sentence spacing has a fixed extra space added
and then the space can stretch 3 times as much and shrink 1/3 as much.
</para>
<para>The rules for how &tex; uses space factors are even more complex
because they play two more roles.  In practice, there are two
consequences.  First, if a period or other punctuation is followed by a
close parenthesis or close double quote then its effect is still in
place, that is, the following glue will have increased stretch and
shrink.  Second, conversely, if punctuation comes after a capital letter
then its effect is not in place so you get an ordinary space.  For how
to adjust to this second case, for instance if an abbreviation does not
end in a capital letter, <pxref label="_005c_0028SPACE_0029-and-_005c_0040"><xrefnodename>\(SPACE) and \&arobase;</xrefnodename></pxref>.
</para>

<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::     ">\(SPACE) and \&arobase;</menunode><menudescription><pre xml:space="preserve">Space after a period.  
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::       ">\frenchspacing</menunode><menudescription><pre xml:space="preserve">Equal interword and inter-sentence space.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::       ">\normalsfcodes</menunode><menudescription><pre xml:space="preserve">Restore space factor settings to the default.
</pre></menudescription></menuentry></menu>


<node name="_005c_0028SPACE_0029-and-_005c_0040" spaces=" "><nodename trailingspaces=" ">\(SPACE) and \&arobase;</nodename><nodenext automatic="on">\frenchspacing</nodenext><nodeup automatic="on">\spacefactor</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\(SPACE)</code> and <code>\&arobase;</code>  </sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="830">\(SPACE)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="831">\TAB</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="832">\NEWLINE</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="833">\&arobase;</indexterm></findex>
<anchor name="_005cAT">\AT</anchor><!-- c old name -->

<para>Here, <code>\(SPACE)</code> means a backslash followed by a space.  These
commands mark a punctuation character, typically a period, as either
ending a sentence or as ending an abbreviation.
</para>
<para>By default, in justifying a line &latex; adjusts the space after a
sentence-ending period (or a question mark, exclamation point, comma, or
colon) more than the space between words.  <xref label="_005cspacefactor"><xrefnodename>\spacefactor</xrefnodename></xref>. As
described there, &latex; assumes that the period ends a sentence unless
it is preceded by a capital letter, in which case it takes that period
for part of an abbreviation.  Note that if a sentence-ending period is
immediately followed by a right parenthesis or bracket, or right single
or double quote, then the space effect of that period follows through
that parenthesis or quote.
</para>
<para>So: if you have a period ending an abbreviation whose last letter is not
a capital letter, and that abbreviation is not the last word in the
sentence, then follow that period with a backslash-space (<code>\ </code>) or
a tie (<code>~</code>) or a <code>\&arobase;</code>.  Examples are <code>Nat.\ Acad.\
Science</code>, and <code>Mr.~Bean</code>, and <code>(manure, etc.\&arobase;) for sale</code>
(note that in the last the <code>\&arobase;</code> comes before the closing parenthesis).
</para>
<para>In the opposite situation, if you have a capital letter followed by a
period that does end the sentence, then put <code>\&arobase;</code> before the
period.  For example, <code>book by the MAA\&arobase;.</code> will have correct
inter-sentence spacing after the period.
</para>
<para>For another use of <code>\(SPACE)</code>, <pxref label="_005c_0028SPACE_0029-after-control-sequence"><xrefnodename>\(SPACE) after control sequence</xrefnodename></pxref>.
</para>

</subsection>
<node name="_005cfrenchspacing" spaces=" "><nodename>\frenchspacing</nodename><nodenext automatic="on">\normalsfcodes</nodenext><nodeprev automatic="on">\(SPACE) and \&arobase;</nodeprev><nodeup automatic="on">\spacefactor</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\frenchspacing</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="834">\frenchspacing</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="835">\nonfrenchspacing</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="437">spacing, inter-sentence</indexterm></cindex>

<para>This declaration (from Plain &tex;) causes &latex; to treat
inter-sentence spacing in the same way as interword spacing.
</para>
<para>In justifying the text in a line, some typographic traditions, including
English, prefer to adjust the space between sentences (or after other
punctuation marks) more than the space between words.  Following this
declaration, all spaces are instead treated equally.
</para>
<para>Revert to the default behavior by declaring <code>\nonfrenchspacing</code>.
</para>

</subsection>
<node name="_005cnormalsfcodes" spaces=" "><nodename>\normalsfcodes</nodename><nodeprev automatic="on">\frenchspacing</nodeprev><nodeup automatic="on">\spacefactor</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\normalsfcodes</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="836">\normalsfcodes</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="438">spacing, inter-sentence</indexterm></cindex>

<para>Reset the &latex; space factor values to the default.
</para>

</subsection>
</section>
<node name="_005c_0028SPACE_0029-after-control-sequence" spaces=" "><nodename>\(SPACE) after control sequence</nodename><nodenext automatic="on">\thinspace</nodenext><nodeprev automatic="on">\spacefactor</nodeprev><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\ </code> after control sequence</sectiontitle>

<para>The <code>\ </code> command is often used after control sequences to keep
them from gobbling the space that follows, as in <samp>\TeX\ is nice</samp>.
And, under normal circumstances, <code>\</code><key>tab</key> and
<code>\</code><key>newline</key> are equivalent to <code>\ </code>. For another use of
<code>\ </code>, see also <ref label="_005c_0028SPACE_0029-and-_005c_0040"><xrefnodename>\(SPACE) and \&arobase;</xrefnodename></ref>.
</para>
<para>Some people prefer to use <code>&lbrace;&rbrace;</code> for the same purpose, as in
<code>\TeX&lbrace;&rbrace; is nice</code>. This has the advantage that you can always
write it the same way, namely <code>\TeX&lbrace;&rbrace;</code>, whether it is followed
by a space or by a punctuation mark. Compare:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\TeX\ is a nice system. \TeX, a nice system.&linebreak;
\TeX&lbrace;&rbrace; is a nice system. \TeX&lbrace;&rbrace;, a nice system.
</pre></example>

<cindex index="cp" spaces=" "><indexterm index="cp" number="439"><r>package</r>, <code>xspace</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="440"><code>xspace</code> <r>package</r></indexterm></cindex>

<para>Some individual commands, notably those defined with the <code>xspace</code>,
package do not follow the standard behavior.
</para>

</section>
<node name="_005cthinspace" spaces=" "><nodename>\thinspace</nodename><nodenext automatic="on">\/</nodenext><nodeprev automatic="on">\(SPACE) after control sequence</nodeprev><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\thinspace</code>: Insert 1/6<dmn>em</dmn></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="837">\thinspace</indexterm></findex>

<para><code>\thinspace</code> produces an unbreakable and unstretchable space that
is 1/6 of an em.  This is the proper space to use between nested
quotes, as in &textrsquo;<dmn></dmn>&textrdquo;.<!-- c Abuse @dmn, which is a thin space in Texinfo. -->
</para>

</section>
<node name="_005c_002f" spaces=" "><nodename>\/</nodename><nodenext automatic="on">\hrulefill \dotfill</nodenext><nodeprev automatic="on">\thinspace</nodeprev><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\/</code>: Insert italic correction</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="838">\/</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="441">italic correction</indexterm></cindex>

<para>The <code>\/</code> command produces an <dfn>italic correction</dfn>.  This is a
small space defined by the font designer for a given character,
to avoid the character colliding with whatever follows.  The italic
<i>f</i> character typically has a large italic correction value.
</para>
<para>If the following character is a period or comma, it&textrsquo;s not necessary to
insert an italic correction, since those punctuation symbols have a
very small height.  However, with semicolons or colons, as well as
normal letters, it can help. Compare
<tex endspaces=" ">
</tex>
<i>f: f;</i> (in the &tex; output, the &textlsquo;f&textrsquo;s are nicely separated)
with <i>f: f;</i>.
</para>
<para>When changing fonts with commands such as <code>\textit&lbrace;italic
text&rbrace;</code> or <code>&lbrace;\itshape italic text&rbrace;</code>, &latex; will
automatically insert an italic correction if appropriate (<pxref label="Font-styles"><xrefnodename>Font
styles</xrefnodename></pxref>).
</para>
<para>Despite the name, roman characters can also have an italic
correction.  Compare
<tex endspaces=" ">
</tex>
pdf&tex; (in the &tex; output, there is a small space after the &textlsquo;f&textrsquo;)
with pdf&tex;.
</para>
<para>There is no concept of italic correction in math mode; spacing is done
in a different way.
</para>

</section>
<node name="_005chrulefill-_005cdotfill" spaces=" "><nodename>\hrulefill \dotfill</nodename><nodenext automatic="on">\addvspace</nodenext><nodeprev automatic="on">\/</nodeprev><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\hrulefill \dotfill</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="839">\hrulefill</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="840">\dotfill</indexterm></findex>

<para>Produce an infinite rubber length (<pxref label="Lengths"><xrefnodename>Lengths</xrefnodename></pxref>) filled with a
horizontal rule (that is, a line) or with dots, instead of just white
space.
</para>
<para>When placed between blank lines this example creates a paragraph that is
left and right justified, where the space in the middle is filled with
evenly spaced dots.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\noindent Jack Aubrey\dotfill Melbury Lodge
</pre></example>

<para>To make the rule or dots go to the line&textrsquo;s end use <code>\null</code> at the
start or end.  
</para>
<para>To change the rule&textrsquo;s thickness, copy the definition and adjust it, as
with <code>\renewcommand&lbrace;\hrulefill&rbrace;&lbrace;\leavevmode\leaders\hrule height
1pt\hfill\kern\z&arobase;&rbrace;</code>, which changes the default thickness of
0.4<dmn>pt</dmn> to 1<dmn>pt</dmn>.  Similarly, adjust the dot spacing as with
<code>\renewcommand&lbrace;\dotfill&rbrace;&lbrace;\leavevmode\cleaders\hb&arobase;xt&arobase;
1.00em&lbrace;\hss .\hss &rbrace;\hfill\kern\z&arobase;&rbrace;</code>, which changes the default
length of 0.33<dmn>em</dmn> to 1.00<dmn>em</dmn>.
</para>

</section>
<node name="_005caddvspace" spaces=" "><nodename>\addvspace</nodename><nodenext automatic="on">\bigskip \medskip \smallskip</nodenext><nodeprev automatic="on">\hrulefill \dotfill</nodeprev><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\addvspace</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="841">\addvspace</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="442">vertical space</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="443">space, inserting vertical</indexterm></cindex>

<para><code>\addvspace&lbrace;<var>length</var>&rbrace;</code>
</para>
<para>Add a vertical space of height <var>length</var>, which is a rubber length
(<pxref label="Lengths"><xrefnodename>Lengths</xrefnodename></pxref>).  However, if vertical space has already been added to
the same point in the output by a previous <code>\addvspace</code> command
then this command will not add more space than what is needed to make
the natural length of the total vertical space equal to <var>length</var>.
</para>
<para>Use this command to adjust the vertical space above or below an
environment that starts a new paragraph.  For instance, a Theorem
environment is defined to begin and end with <code>\addvspace&lbrace;...&rbrace;</code>
so that two consecutive Theorem&textrsquo;s are separated by one vertical space,
not two.
</para>
<para>This command is fragile (<pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>).
</para>
<para>The error <samp>Something's wrong--perhaps a missing \item</samp> means that
you were not in vertical mode when you invoked this command; one way to
change that is to precede this command with a <code>\par</code> command.
</para>

</section>
<node name="_005cbigskip-_005cmedskip-_005csmallskip" spaces=" "><nodename>\bigskip \medskip \smallskip</nodename><nodenext automatic="on">\vfill</nodenext><nodeprev automatic="on">\addvspace</nodeprev><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\bigskip \medskip \smallskip</code></sectiontitle>

<para>These commands produce a given amount of space, specified by the
document class.
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="842">\bigskip</indexterm>\bigskip</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="843">\bigskipamount</indexterm></findex>
<para>The same as <code>\vspace&lbrace;\bigskipamount&rbrace;</code>, ordinarily about one line
space, with stretch and shrink (the default for the <code>book</code> and
<code>article</code> classes is <code>12pt plus 4pt minus 4pt</code>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="844">\medskip</indexterm>\medskip</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="845">\medskipamount</indexterm></findex>
<para>The same as <code>\vspace&lbrace;\medskipamount&rbrace;</code>, ordinarily about half of
a line space, with stretch and shrink (the default for the <code>book</code>
and <code>article</code> classes is <code>6pt plus 2pt minus 2pt</code>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="846">\smallskip</indexterm>\smallskip</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="847">\smallskipamount</indexterm></findex>
<para>The same as <code>\vspace&lbrace;\smallskipamount&rbrace;</code>, ordinarily about a
quarter of a line space, with stretch and shrink (the default for the
<code>book</code> and <code>article</code> classes is <code>3pt plus 1pt minus
1pt</code>).
</para>
</tableitem></tableentry></ftable>


</section>
<node name="_005cvfill" spaces=" "><nodename>\vfill</nodename><nodenext automatic="on">\vspace</nodenext><nodeprev automatic="on">\bigskip \medskip \smallskip</nodeprev><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\vfill</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="848">\vfill</indexterm></findex>

<cindex index="cp" spaces=" "><indexterm index="cp" number="444">stretch, infinite vertical</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="445">infinite vertical stretch</indexterm></cindex>

<para>End the current paragraph and insert a vertical rubber length
(<pxref label="Lengths"><xrefnodename>Lengths</xrefnodename></pxref>) that is infinite, so it can stretch or shrink as far
as needed.
</para>
<para>It is often used in the same way as <code>\vspace&lbrace;\fill&rbrace;</code>, except that
<code>\vfill</code> ends the current paragraph, whereas
<code>\vspace&lbrace;\fill&rbrace;</code> adds the infinite vertical space below its line
irrespective of the paragraph structure.  In both cases that space will
disappear at a page boundary; to circumvent this see&nbsp;<ref label="_005cvspace"><xrefnodename>\vspace</xrefnodename></ref>.
</para>
<para>In this example the page is filled, so the top and bottom lines contain
the text <samp>Lost Dog!</samp> and the third <samp>Lost Dog!</samp> is exactly
halfway between them.
</para> 
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;document&rbrace;
Lost Dog!
\vfill
Lost Dog!
\vfill
Lost Dog!
\end&lbrace;document&rbrace;
</pre></example>


</section>
<node name="_005cvspace" spaces=" "><nodename>\vspace</nodename><nodeprev automatic="on">\vfill</nodeprev><nodeup automatic="on">Spaces</nodeup></node>
<section spaces=" "><sectiontitle><code>\vspace&lbrace;<var>length</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="849">\vspace</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="446">vertical space</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="447">space, vertical</indexterm></cindex>

<para>Synopsis, one of these two:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\vspace&lbrace;<var>length</var>&rbrace;
\vspace*&lbrace;<var>length</var>&rbrace;
</pre></example>

<para>Add the vertical space <var>length</var>.  This can be negative or positive,
and is a rubber length (<pxref label="Lengths"><xrefnodename>Lengths</xrefnodename></pxref>).
</para>
<para>&latex; removes the vertical space from <code>\vspace</code> at a page
break, that is, at the top or bottom of a page.  The starred version
<code>\vspace*&lbrace;...&rbrace;</code> causes the space to stay.
</para>
<para>If <code>\vspace</code> is used in the middle of a paragraph (i.e., in
horizontal mode), the space is inserted <emph>after</emph> the line with
the <code>\vspace</code> command.  A new paragraph is not started.
</para>
<para>In this example the two questions will be evenly spaced vertically on
the page, with at least one inch of space below each.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;document&rbrace;
1) Who put the bomp in the bomp bah bomp bah bomp?
\vspace&lbrace;1in plus 1fill&rbrace;

2) Who put the ram in the rama lama ding dong?
\vspace&lbrace;1in plus 1fill&rbrace;
\end&lbrace;document&rbrace;
</pre></example>


</section>
</chapter>
<node name="Boxes" spaces=" "><nodename>Boxes</nodename><nodenext automatic="on">Color</nodenext><nodeprev automatic="on">Spaces</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Boxes</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="448">boxes</indexterm></cindex>

<para>All the predefined length parameters (<pxref label="Predefined-lengths"><xrefnodename>Predefined lengths</xrefnodename></pxref>) can be
used in the arguments of the box-making commands.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::               ">\mbox</menunode><menudescription><pre xml:space="preserve">Horizontal boxes.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator=":: ">\fbox and \framebox</menunode><menudescription><pre xml:space="preserve">Put a frame around a box.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">lrbox</menunode><menudescription><pre xml:space="preserve">An environment like <code>\sbox</code>.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">\makebox</menunode><menudescription><pre xml:space="preserve">Box, adjustable position.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::             ">\parbox</menunode><menudescription><pre xml:space="preserve">Box with text in paragraph mode.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           ">\raisebox</menunode><menudescription><pre xml:space="preserve">Raise or lower text.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">\savebox</menunode><menudescription><pre xml:space="preserve">Like <code>\makebox</code>, but save the text for later use.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::               ">\sbox</menunode><menudescription><pre xml:space="preserve">Like <code>\mbox</code>, but save the text for later use.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::             ">\usebox</menunode><menudescription><pre xml:space="preserve">Print saved text.
</pre></menudescription></menuentry></menu>


<node name="_005cmbox" spaces=" "><nodename>\mbox</nodename><nodenext automatic="on">\fbox and \framebox</nodenext><nodeup automatic="on">Boxes</nodeup></node>
<section spaces=" "><sectiontitle><code>\mbox&lbrace;<var>text&rbrace;</var></code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="850">\mbox</indexterm></findex>

<cindex index="cp" spaces=" "><indexterm index="cp" number="449">hyphenation, preventing</indexterm></cindex>
<para>The <code>\mbox</code> command creates a box just wide enough to hold the
text created by its argument.  The <var>text</var> is not broken into
lines, so it can be used to prevent hyphenation.
</para>

</section>
<node name="_005cfbox-and-_005cframebox" spaces=" "><nodename>\fbox and \framebox</nodename><nodenext automatic="on">lrbox</nodenext><nodeprev automatic="on">\mbox</nodeprev><nodeup automatic="on">Boxes</nodeup></node>
<section spaces=" "><sectiontitle><code>\fbox</code> and <code>\framebox</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="851">\fbox</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="852">\framebox</indexterm></findex>

<para>Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\fbox&lbrace;<var>text</var>&rbrace;
\framebox[<var>width</var>][<var>position</var>]&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>The <code>\fbox</code> and <code>\framebox</code> commands are like <code>\mbox</code>,
except that they put a frame around the outside of the box being created.
</para>
<para>In addition, the <code>\framebox</code> command allows for explicit
specification of the box width with the optional <var>width</var> argument
(a dimension), and positioning with the optional <var>position</var>
argument. <!-- c xxref -->
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="853">\fboxrule</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="854">\fboxsep</indexterm></findex>
<para>Both commands produce a rule of thickness <code>\fboxrule</code> (default
<code>0.4pt</code>), and leave a space of <code>\fboxsep</code> (default <code>3pt</code>)
between the rule and the contents of the box.
</para>
<para><xref label="_005cframebox-_0028picture_0029"><xrefnodename>\framebox (picture)</xrefnodename></xref>, for the <code>\framebox</code> command in the
<code>picture</code> environment.
</para>

</section>
<node name="lrbox" spaces=" "><nodename>lrbox</nodename><nodenext automatic="on">\makebox</nodenext><nodeprev automatic="on">\fbox and \framebox</nodeprev><nodeup automatic="on">Boxes</nodeup></node>
<section spaces=" "><sectiontitle><code>lrbox</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="855">lrbox</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;lrbox&rbrace;&lbrace;\<var>cmd</var>&rbrace; 
  <var>text </var>
\end&lbrace;lrbox&rbrace;
</pre></example>

<para>This is the environment form of <ref label="_005csbox"><xrefnodename>\sbox</xrefnodename><xrefinfoname><code>\sbox</code></xrefinfoname></ref>.
</para>
<para>The <var>text</var> inside the environment is saved in the box <code>\<var>cmd</var></code>,
which must have been declared with <code>\newsavebox</code>.
</para>

</section>
<node name="_005cmakebox" spaces=" "><nodename>\makebox</nodename><nodenext automatic="on">\parbox</nodenext><nodeprev automatic="on">lrbox</nodeprev><nodeup automatic="on">Boxes</nodeup></node>
<section spaces=" "><sectiontitle><code>\makebox</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="856">\makebox</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\makebox[<var>width</var>][<var>position</var>]&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>The <code>\makebox</code> command creates a box just wide enough to contain
the <var>text</var> specified.  The width of the box can be overridden by the
optional <var>width</var> argument.  The position of the text within the box
is determined by the optional <var>position</var> argument, which may take
the following values:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">c</itemformat></item>
</tableterm><tableitem><para>Centered (default).
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">l</itemformat></item>
</tableterm><tableitem><para>Flush left.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">r</itemformat></item>
</tableterm><tableitem><para>Flush right.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">s</itemformat></item>
</tableterm><tableitem><para>Stretch (justify) across entire <var>width</var>; <var>text</var> must contain
stretchable space for this to work.
</para></tableitem></tableentry></table>

<para><code>\makebox</code> is also used within the <code>picture</code> environment
<pxref label="_005cmakebox-_0028picture_0029"><xrefnodename>\makebox (picture)</xrefnodename></pxref>.
</para>

</section>
<node name="_005cparbox" spaces=" "><nodename>\parbox</nodename><nodenext automatic="on">\raisebox</nodenext><nodeprev automatic="on">\makebox</nodeprev><nodeup automatic="on">Boxes</nodeup></node>
<section spaces=" "><sectiontitle><code>\parbox</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="857">\parbox</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\parbox[<var>position</var>][<var>height</var>][<var>inner-pos</var>]&lbrace;<var>width</var>&rbrace;&lbrace;<var>text</var>&rbrace;
</pre></example>

<cindex index="cp" spaces=" "><indexterm index="cp" number="450">paragraph mode</indexterm></cindex>
<para>The <code>\parbox</code> command produces a box whose contents are created
in <dfn>paragraph mode</dfn>.  It should be used to make a box small
pieces of text, with nothing fancy inside.  In particular, you
shouldn&textrsquo;t use any paragraph-making environments inside a
<code>\parbox</code> argument.  For larger pieces of text, including ones
containing a paragraph-making environment, you should use a
<code>minipage</code> environment (<pxref label="minipage"><xrefnodename>minipage</xrefnodename></pxref>).
</para>
<para><code>\parbox</code> has two mandatory arguments:
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="var">width</itemformat></item>
</tableterm><tableitem><para>the width of the parbox;
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">text</itemformat></item>
</tableterm><tableitem><para>the text that goes inside the parbox.
</para></tableitem></tableentry></table>

<para>By default &latex; will position vertically a parbox so its center
lines up with the center of the surrounding text line.  When the
optional <var>position</var> argument is present and equal either to <samp>t</samp>
or <samp>b</samp>, this allows you respectively to align either the top or
bottom line in the parbox with the baseline of the surrounding text. You
may also specify <samp>m</samp> for <var>position</var> to get the default
behaviour.
</para>
<para>The optional <var>height</var> argument overrides the natural height of the box.
</para>
<para>The <var>inner-pos</var> argument controls the placement of the text inside
the box, as follows; if it is not specified, <var>position</var> is used.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">t</itemformat></item>
</tableterm><tableitem><para>text is placed at the top of the box.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">c</itemformat></item>
</tableterm><tableitem><para>text is centered in the box.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">b</itemformat></item>
</tableterm><tableitem><para>text is placed at the bottom of the box.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">s</itemformat></item>
</tableterm><tableitem><para>stretch vertically; the text must contain vertically stretchable space
for this to work.
</para></tableitem></tableentry></table>


</section>
<node name="_005craisebox" spaces=" "><nodename>\raisebox</nodename><nodenext automatic="on">\savebox</nodenext><nodeprev automatic="on">\parbox</nodeprev><nodeup automatic="on">Boxes</nodeup></node>
<section spaces=" "><sectiontitle><code>\raisebox</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="858">\raisebox</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\raisebox&lbrace;<var>distance</var>&rbrace;[<var>height</var>][<var>depth</var>]&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>The <code>\raisebox</code> command raises or lowers <var>text</var>.  The first
mandatory argument specifies how high <var>text</var> is to be raised (or
lowered if it is a negative amount).  <var>text</var> itself is processed
in LR mode.
</para>
<para>The optional arguments <var>height</var> and <var>depth</var> are dimensions.  If
they are specified, &latex; treats <var>text</var> as extending a certain
distance above the baseline (<var>height</var>) or below (<var>depth</var>),
ignoring its natural height and depth.
</para>

</section>
<node name="_005csavebox" spaces=" "><nodename>\savebox</nodename><nodenext automatic="on">\sbox</nodenext><nodeprev automatic="on">\raisebox</nodeprev><nodeup automatic="on">Boxes</nodeup></node>
<section spaces=" "><sectiontitle><code>\savebox</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="859">\savebox</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\savebox&lbrace;<var>\boxcmd</var>&rbrace;[<var>width</var>][<var>pos</var>]&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>This command typeset <var>text</var> in a box just as with <code>\makebox</code>
(<pxref label="_005cmakebox"><xrefnodename>\makebox</xrefnodename></pxref>), except that instead of printing the resulting box,
it saves it in the box labeled <var>\boxcmd</var>, which must have been
declared with <code>\newsavebox</code> (<pxref label="_005cnewsavebox"><xrefnodename>\newsavebox</xrefnodename></pxref>).
</para>

</section>
<node name="_005csbox" spaces=" "><nodename>\sbox</nodename><nodenext automatic="on">\usebox</nodenext><nodeprev automatic="on">\savebox</nodeprev><nodeup automatic="on">Boxes</nodeup></node>
<section spaces=" "><sectiontitle><code>\sbox&lbrace;<var>\boxcmd</var>&rbrace;&lbrace;<var>text</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="860">\sbox</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\sbox&lbrace;<var>\boxcmd</var>&rbrace;&lbrace;<var>text</var>&rbrace;
</pre></example>

<para><code>\sbox</code> types <var>text</var> in a box just as with <code>\mbox</code>
(<pxref label="_005cmbox"><xrefnodename>\mbox</xrefnodename></pxref>) except that instead of the resulting box being
included in the normal output, it is saved in the box labeled
<var>\boxcmd</var>.  <var>\boxcmd</var> must have been previously declared with
<code>\newsavebox</code> (<pxref label="_005cnewsavebox"><xrefnodename>\newsavebox</xrefnodename></pxref>).
</para>

</section>
<node name="_005cusebox" spaces=" "><nodename>\usebox</nodename><nodeprev automatic="on">\sbox</nodeprev><nodeup automatic="on">Boxes</nodeup></node>
<section spaces=" "><sectiontitle><code>\usebox&lbrace;<var>\boxcmd</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="861">\usebox</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usebox&lbrace;<var>\boxcmd</var>&rbrace;
</pre></example>

<para><code>\usebox</code> produces the box most recently saved in the bin
<var>\boxcmd</var> by a <code>\savebox</code> command (<pxref label="_005csavebox"><xrefnodename>\savebox</xrefnodename></pxref>).
</para>

</section>
</chapter>
<node name="Color" spaces=" "><nodename>Color</nodename><nodenext automatic="on">Graphics</nodenext><nodeprev automatic="on">Boxes</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Color</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="451">color</indexterm></cindex>

<para>You can add color to text, rules, etc.  You can also have color in a box
or on an entire page and write text on top of it.
</para>
<para>Color support comes as an additional package.  So all the commands below
will only work if your document preamble contains
<code>\usepackage&lbrace;color&rbrace;</code>, that brings in the standard package.
</para>
<para>Many other packages also supplement &latex;&textrsquo;s color abilities.
Particularly worth mentioning is <file>xcolor</file>, which is widely used and
significantly extends the capabilities described here, including adding
<samp>HTML</samp> and <samp>Hsb</samp> color models.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::       ">Color package options</menunode><menudescription><pre xml:space="preserve">Options when you load the standard package.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                ">Color models</menunode><menudescription><pre xml:space="preserve">How colors are represented.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::          ">Commands for color</menunode><menudescription><pre xml:space="preserve">The available commands.
</pre></menudescription></menuentry></menu>


<node name="Color-package-options" spaces=" "><nodename>Color package options</nodename><nodenext automatic="on">Color models</nodenext><nodeup automatic="on">Color</nodeup></node>
<section spaces=" "><sectiontitle>Color package options</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="452">color package options</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="453">options, color package</indexterm></cindex>

<para>Synopsis (must be in the document preamble):
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usepackage[<var>comma-separated option list</var>]&lbrace;color&rbrace;
</pre></example>

<para>When you load the <file>color</file> package there are two kinds of available
options.
</para>
<para>The first specifies the <dfn>printer driver</dfn>.  &latex; doesn&textrsquo;t contain
information about different output systems but instead depends on
information stored in a file.  Normally you should not specify the
driver option in the document, and instead rely on your system&textrsquo;s
default. One advantage of this is that it makes the document portable
across systems.  For completeness we include a list of the drivers.  The
currently relevant ones are: <file>dvipdfmx</file>, <file>dvips</file>,
<file>dvisvgm</file>, <file>luatex</file>, <file>pdftex</file>, <file>xetex</file>.  The two
<file>xdvi</file> and <file>oztex</file> are essentially aliases for <file>dvips</file>
(and <file>xdvi</file> is monochrome).  Ones that should not be used for new
systems are: <file>dvipdf</file>, <file>dvipdfm</file>, <file>dviwin</file>,
<file>dvipsone</file>, <file>emtex</file>, <file>pctexps</file>, <file>pctexwin</file>,
<file>pctexhp</file>, <file>pctex32</file>, <file>truetex</file>, <file>tcidvi</file>,
<file>vtex</file> (and <file>dviwindo</file> is an alias for <file>dvipsone</file>).
</para>
<para>The second kind of options, beyond the drivers, are below.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<beforefirstitem>
</beforefirstitem><tableentry><tableterm><item spaces=" "><itemformat command="code">monochrome</itemformat></item>
</tableterm><tableitem><para>Disable the color commands, so that they do not generate errors but do
not generate color either.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">dvipsnames</itemformat></item>
</tableterm><tableitem><para>Make available a list of 68 color names that are often used,
particularly in legacy documents.  These color names were originally
provided by the <file>dvips</file> driver, giving the option name.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">nodvipsnames</itemformat></item>
</tableterm><tableitem><para>Do not load that list of color names, saving &latex; a tiny amount of
memory space.
</para>
</tableitem></tableentry></table>


</section>
<node name="Color-models" spaces=" "><nodename>Color models</nodename><nodenext automatic="on">Commands for color</nodenext><nodeprev automatic="on">Color package options</nodeprev><nodeup automatic="on">Color</nodeup></node>
<section spaces=" "><sectiontitle>Color models</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="454">color models</indexterm></cindex>

<para>A <dfn>color model</dfn> is a way of representing colors.  &latex;&textrsquo;s
capabilities depend on the printer driver.  However, the <file>pdftex</file>,
<file>xetex</file>, and <file>luatex</file> printer drivers are today by far the
most commonly used.  The models below work for those drivers.  All but
one of these is also supported by essentially all other printer drivers
used today.
</para>
<para>Note that color combination can be additive or subtractive.  Additive
mixes colors of light, so that for instance combining full intensities
of red, green, and blue produces white.  Subtractive mixes pigments,
such as with inks, so that combining full intensity of cyan, magenta,
and yellow makes black.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">cmyk</itemformat></item>
</tableterm><tableitem><para>A comma-separated list with four real numbers between 0 and 1,
inclusive.  The first number is the intensity of cyan, the second is
magenta, and the others are yellow and black.  A number value of 0 means
minimal intensity, while a 1 is for full intensity.  This model is often
used in color printing.  It is a subtractive model.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">gray</itemformat></item>
</tableterm><tableitem><para>A single real number between 0 and 1, inclusive.  The colors are shades
of grey.  The number 0 produces black while 1 gives white.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">rgb</itemformat></item>
</tableterm><tableitem><para>A comma-separated list with three real numbers between 0 and 1,
inclusive.  The first number is the intensity of the red component, the
second is green, and the third the blue.  A number value of 0 means that
none of that component is added in, while a 1 means full intensity.
This is an additive model.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">RGB</itemformat></item>
</tableterm><tableitem><para>(<file>pdftex</file>, <file>xetex</file>, <file>luatex</file> drivers) A comma-separated
list with three integers between 0 and 255, inclusive.  This model is a
convenience for using <code>rgb</code> since outside of &latex; colors are
often described in a red-green-blue model using numbers in this range.
The values entered here are converted to the <code>rgb</code> model by
dividing by 255.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">named</itemformat></item>
</tableterm><tableitem><para>Colors are accessed by name, such as <samp>PrussianBlue</samp>.  The list of
names depends on the driver, but all support the names <samp>black</samp>,
<samp>blue</samp>, <samp>cyan</samp>, <samp>green</samp>, <samp>magenta</samp>, <samp>red</samp>,
<samp>white</samp>, and <samp>yellow</samp> (See the <code>dvipsnames</code> option in
<ref label="Color-package-options"><xrefnodename>Color package options</xrefnodename></ref>).
</para>
</tableitem></tableentry></table>


</section>
<node name="Commands-for-color" spaces=" "><nodename>Commands for color</nodename><nodeprev automatic="on">Color models</nodeprev><nodeup automatic="on">Color</nodeup></node>
<section spaces=" "><sectiontitle>Commands for color</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="455">color package commands</indexterm></cindex>

<para>These are the commands available with the <file>color</file> package.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::            ">Define colors</menunode><menudescription><pre xml:space="preserve">Give a color a name.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::             ">Colored text</menunode><menudescription><pre xml:space="preserve">Text or rules in color.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">Colored boxes</menunode><menudescription><pre xml:space="preserve">A box of color, to write over.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">Colored pages</menunode><menudescription><pre xml:space="preserve">A whole page colored.
</pre></menudescription></menuentry></menu>


<node name="Define-colors" spaces=" "><nodename>Define colors</nodename><nodenext automatic="on">Colored text</nodenext><nodeup automatic="on">Commands for color</nodeup></node>
<subsection spaces=" "><sectiontitle>Define colors</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="456">color</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="457">define color</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="458">color, define</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\definecolor&lbrace;<var>name</var>&rbrace;&lbrace;<var>model</var>&rbrace;&lbrace;<var>specification</var>&rbrace;
</pre></example>

<para>Give the name <var>name</var> to the color.  For example, after
<code>\definecolor&lbrace;silver&rbrace;&lbrace;rgb&rbrace;&lbrace;0.75,0.75,0.74&rbrace;</code> you can use that
color name with <code>Hi ho, \textcolor&lbrace;silver&rbrace;&lbrace;Silver&rbrace;!</code>.
</para>
<para>This example gives the color a more abstract name, so it could change and
not be misleading.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\definecolor&lbrace;logocolor&rbrace;&lbrace;RGB&rbrace;&lbrace;145,92,131&rbrace;    % RGB needs pdflatex
\newcommand&lbrace;\logo&rbrace;&lbrace;\textcolor&lbrace;logocolor&rbrace;&lbrace;Bob's Big Bagels&rbrace;&rbrace;
</pre></example>

<para>Often a document&textrsquo;s colors are defined in the preamble, or in the class
or style, rather than in the document body.
</para>

</subsection>
<node name="Colored-text" spaces=" "><nodename>Colored text</nodename><nodenext automatic="on">Colored boxes</nodenext><nodeprev automatic="on">Define colors</nodeprev><nodeup automatic="on">Commands for color</nodeup></node>
<subsection spaces=" "><sectiontitle>Colored text</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="459">color</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="460">colored text</indexterm></cindex>

<para>Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\textcolor&lbrace;<var>name</var>&rbrace;&lbrace;...&rbrace;
\textcolor[<var>color model</var>]&lbrace;<var>color specification</var>&rbrace;&lbrace;...&rbrace;
</pre></example>

<para>or
</para>
<example endspaces=" ">
<pre xml:space="preserve">\color&lbrace;<var>name</var>&rbrace;
\color[<var>color model</var>]&lbrace;<var>specification</var>&rbrace;
</pre></example>

<para>The affected text gets the color.  This line
</para>
<example endspaces=" ">
<pre xml:space="preserve">\textcolor&lbrace;magenta&rbrace;&lbrace;My name is Ozymandias, king of kings:&rbrace; Look on my works, ye Mighty, and despair!
</pre></example>

<para>causes the first half to be in magenta while the rest is in black.  You
can use a color declared with <code>\definecolor</code> in exactly the same
way that we just used the builtin color <samp>magenta</samp>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\definecolor&lbrace;MidlifeCrisisRed&rbrace;&lbrace;rgb&rbrace;&lbrace;1.0,0.11,0.0&rbrace;
I'm thinking about getting a \textcolor&lbrace;MidlifeCrisisRed&rbrace;&lbrace;sports car&rbrace;.
</pre></example>

<para>The two <code>\textcolor</code> and <code>\color</code> differ in that the first is
a command form, enclosing the text to be colored as an argument.  Often
this form is more convenient, or at least more explicit.  The second
form is a declaration, as in <code>The moon is made of &lbrace;\color&lbrace;green&rbrace;
green&rbrace; cheese</code>, so it is in effect until the end of the current group
or environment.  This is sometimes useful when writing macros or as
below where it colors everything inside the <code>center</code> environment,
including the vertical and horizontal lines.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;center&rbrace; \color&lbrace;blue&rbrace;
  \begin&lbrace;tabular&rbrace;&lbrace;l|r&rbrace;
    UL &amp;UR \\ \hline
    LL &amp;LR 
  \end&lbrace;tabular&rbrace;
\end&lbrace;center&rbrace;
</pre></example>

<para>You can use color in equations.  A document might have
<code>\definecolor&lbrace;highlightcolor&rbrace;&lbrace;RGB&rbrace;&lbrace;225,15,0&rbrace;</code> in the
preamble, and then contain this equation.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;equation&rbrace;
  \int_a^b \textcolor&lbrace;highlightcolor&rbrace;&lbrace;f'(x)&rbrace;\,dx=f(b)-f(a)
\end&lbrace;equation&rbrace;
</pre></example>

<para>Typically the colors used in a document are declared in a class or style
but sometimes you want a one-off.  Those are the second forms in the
synopses.
</para>
<example endspaces=" ">
<pre xml:space="preserve">Colors of \textcolor[rgb]&lbrace;0.33,0.14,0.47&rbrace;&lbrace;Purple&rbrace; and &lbrace;\color[rgb]&lbrace;0.72,0.60,0.37&rbrace; Gold&rbrace; for the team
</pre></example>

<para>The format of <var>color specification </var> depends on the color model
(<pxref label="Color-models"><xrefnodename>Color models</xrefnodename></pxref>).  For instance, while <code>rgb</code> takes three
numbers, <code>gray</code> takes only one.
</para>
<example endspaces=" ">
<pre xml:space="preserve">The selection was \textcolor[gray]&lbrace;0.5&rbrace;&lbrace;grayed out&rbrace;.
</pre></example>

<para>Colors inside colors do not combine.  Thus
</para>
<example endspaces=" ">
<pre xml:space="preserve">\textcolor&lbrace;green&rbrace;&lbrace;kind of \textcolor&lbrace;blue&rbrace;&lbrace;blue&rbrace;&rbrace;
</pre></example>

<para>has a final word that is blue, not a combination of blue and green.
</para>
<!-- c xx address coloring a line of a table? -->


</subsection>
<node name="Colored-boxes" spaces=" "><nodename>Colored boxes</nodename><nodenext automatic="on">Colored pages</nodenext><nodeprev automatic="on">Colored text</nodeprev><nodeup automatic="on">Commands for color</nodeup></node>
<subsection spaces=" "><sectiontitle>Colored boxes</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="461">color</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="462">colored boxes</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="463">box, colored</indexterm></cindex>

<para>Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\colorbox&lbrace;<var>name</var>&rbrace;&lbrace;...&rbrace;
\colorbox[<var>model name</var>]&lbrace;<var>box background color specification</var>&rbrace;&lbrace;...&rbrace;
</pre></example>

<para>or
</para>
<example endspaces=" ">
<pre xml:space="preserve">\fcolorbox&lbrace;<var>frame color</var>&rbrace;&lbrace;<var>box background color</var>&rbrace;&lbrace;...&rbrace;
\fcolorbox[<var>model name</var>]&lbrace;<var>frame color specification</var>&rbrace;&lbrace;<var>box background color specification</var>&rbrace;&lbrace;...&rbrace;
</pre></example>

<para>Make a box with the stated background color.  The <code>\fcolorbox</code>
command puts a frame around the box.  For instance this
</para>
<example endspaces=" ">
<pre xml:space="preserve">Name:~\colorbox&lbrace;cyan&rbrace;&lbrace;\makebox[5cm][l]&lbrace;\strut&rbrace;&rbrace;
</pre></example>

<para>makes a cyan-colored box that is five centimeters long and gets its
depth and height from the <code>\strut</code> (so the depth is
<code>-.3\baselineskip</code> and the height is <code>\baselineskip</code>).  This
puts white text on a blue background.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\colorbox&lbrace;blue&rbrace;&lbrace;\textcolor&lbrace;white&rbrace;&lbrace;Welcome to the machine.&rbrace;&rbrace;
</pre></example>

<para>The <code>\fcolorbox</code> commands use the same parameters as <code>\fbox</code>
(<pxref label="_005cfbox-and-_005cframebox"><xrefnodename>\fbox and \framebox</xrefnodename></pxref>), <code>\fboxrule</code> and <code>\fboxsep</code>, to
set the thickness of the rule and the boundary between the box interior
and the surrounding rule.  &latex;&textrsquo;s defaults are <code>0.4pt</code> and
<code>3pt</code>, respectively.
</para>
<para>This example changes the thickness of the border to 0.8 points.  Note
that it is surrounded by curly braces so that the change ends at the end
of the second line.
</para>
<example endspaces=" ">
<pre xml:space="preserve">&lbrace;\setlength&lbrace;\fboxrule&rbrace;&lbrace;0.8pt&rbrace;
\fcolorbox&lbrace;black&rbrace;&lbrace;red&rbrace;&lbrace;Under no circumstances turn this knob.&rbrace;&rbrace;
</pre></example>


</subsection>
<node name="Colored-pages" spaces=" "><nodename>Colored pages</nodename><nodeprev automatic="on">Colored boxes</nodeprev><nodeup automatic="on">Commands for color</nodeup></node>
<subsection spaces=" "><sectiontitle>Colored pages</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="464">color</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="465">colored page</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="466">page, colored</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="467">background, colored</indexterm></cindex>

<para>Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\pagecolor&lbrace;<var>name</var>&rbrace;
\pagecolor[<var>color model</var>]&lbrace;<var>color specification</var>&rbrace;
\nopagecolor
</pre></example>

<para>The first two set the background of the page, and all subsequent pages,
to the color.  For an explanation of the specification in the second
form <pxref label="Colored-text"><xrefnodename>Colored text</xrefnodename></pxref>.  The third returns the background to normal,
which is a transparent background.  (If that is not supported use
<code>\pagecolor&lbrace;white&rbrace;</code>, although that will make a white background
rather than the default transparent background.)
</para>
<example endspaces=" ">
<pre xml:space="preserve"> ...
\pagecolor&lbrace;cyan&rbrace;
 ...
\nopagecolor
</pre></example>


</subsection>
</section>
</chapter>
<node name="Graphics" spaces=" "><nodename>Graphics</nodename><nodenext automatic="on">Special insertions</nodenext><nodeprev automatic="on">Color</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Graphics</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="468">graphics</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="469">graphics package</indexterm></cindex>

<para>You can use graphics such as PNG or PDF files in your &latex; document.
You need an additional package, which comes standard with &latex;.
This example is the short how-to.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\include&lbrace;graphicx&rbrace;  % goes in the preamble
  ...
\includegraphics[width=0.5\linewidth]&lbrace;plot.pdf&rbrace;
</pre></example>

<para>To use the commands described here your document preamble must contain
either <code>\usepackage&lbrace;graphicx&rbrace;</code> or
<code>\usepackage&lbrace;graphics&rbrace;</code>. Most of the time, <file>graphicx</file> is the
better choice.
</para>
<para>Graphics come in two main types, raster and vector.  &latex; can use
both.  In raster graphics the file contains an entry for each location
in an array, describing what color it is.  An example is a photograph,
in JPG format.  In vector graphics, the file contains a list of
instructions such as <samp>draw a circle with this radius and that
center</samp>.  An example is a line drawing produced by the Asymptote
program, in PDF format.  Generally vector graphics are more useful
because you can rescale their size without pixelation or other problems,
and because they often have a smaller size.
</para>
<para>There are systems particularly well-suited to make graphics for a
&latex; document.  For example, these allow you to use the same fonts
as in your document.  &latex; comes with a <code>picture</code> environment
(<pxref label="picture"><xrefnodename>picture</xrefnodename></pxref>) that has simple capabilities.  Besides that, there are
other ways to include the graphic-making commands in the document.  Two
such systems are the PSTricks and TikZ packages.  There are also systems
external to &latex;, that generate a graphic that you include using the
commands of this chapter.  Two that use a programming language are
Asymptote and MetaPost.  One that uses a graphical interface is Xfig.
Full description of these systems is outside the scope of this document;
see their documentation.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::         ">Graphics package options</menunode><menudescription><pre xml:space="preserve">Options when you load the package.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::   ">Graphics package configuration</menunode><menudescription><pre xml:space="preserve">Where to look for files, which file types.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">Commands for graphics</menunode><menudescription><pre xml:space="preserve">The available commands.
</pre></menudescription></menuentry></menu>


<node name="Graphics-package-options" spaces=" "><nodename>Graphics package options</nodename><nodenext automatic="on">Graphics package configuration</nodenext><nodeup automatic="on">Graphics</nodeup></node>
<section spaces=" "><sectiontitle>Graphics package options</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="470">graphics package options</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="471">options, graphics package</indexterm></cindex>

<para>Synopsis (must be in the document preamble):
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usepackage[<var>comma-separated option list</var>]&lbrace;graphics&rbrace;
</pre></example>

<para>or
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usepackage[<var>comma-separated option list</var>]&lbrace;graphicx&rbrace;
</pre></example>

<para>The <code>graphicx</code> package has a format for optional arguments to the
<code>\includegraphics</code> command that is convenient (it is the key-value
format), so it is the better choice for new documents.  When you load
the <file>graphics</file> or <file>graphicx</file> package with <code>\usepackage</code>
there are two kinds of available options.
</para>
<para>The first is that &latex; does not contain information about different
output systems but instead depends on information stored in a
<dfn>printer driver</dfn> file.  Normally you should not specify the driver
option in the document, and instead rely on your system&textrsquo;s default. One
advantage of this is that it makes the document portable across systems.
</para>
<para>For completeness here is a list of the drivers.  The currently relevant
ones are: <file>dvipdfmx</file>, <file>dvips</file>, <file>dvisvgm</file>, <file>luatex</file>,
<file>pdftex</file>, <file>xetex</file>.  The two <file>xdvi</file> and <file>oztex</file> are
essentially aliases for <file>dvips</file> (and <file>xdvi</file> is monochrome).
Ones that should not be used for new systems are: <file>dvipdf</file>,
<file>dvipdfm</file>, <file>dviwin</file>, <file>dvipsone</file>, <file>emtex</file>,
<file>pctexps</file>, <file>pctexwin</file>, <file>pctexhp</file>, <file>pctex32</file>,
<file>truetex</file>, <file>tcidvi</file>, <file>vtex</file> (and <file>dviwindo</file> is an
alias for <file>dvipsone</file>).  These are stored in files with a
<file>.def</file> extension, such as <file>pdftex.def</file>.
</para>
<para>The second kind of options are below.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">demo</itemformat></item>
</tableterm><tableitem><para>Instead of an image file, &latex; puts in a 150&nbsp;pt by 100&nbsp;pt
rectangle (unless another size is specified in the
<code>\includegraphics</code> command).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">draft</itemformat></item>
</tableterm><tableitem><para>For each graphic file, it is not shown but instead the file name is
printed in a box of the correct size.  In order to determine the size,
the file must be present.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">final</itemformat></item>
</tableterm><tableitem><para>(Default) Override any previous <code>draft</code> option, so that the
document shows the contents of the graphic files.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">hiderotate</itemformat></item>
</tableterm><tableitem><para>Do not show rotated text.  (This allows for the possibility that a
previewer does not have the capability to rotate text.)
<!-- c what does it show? -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">hidescale</itemformat></item>
</tableterm><tableitem><para>Do not show scaled text.  (This allows for the possibility that a
previewer does not have the capability to scale.)
<!-- c what does it show? -->
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">hiresbb</itemformat></item>
</tableterm><tableitem><para>In a PS or EPS file the graphic size may be specified in two ways.  The
<code>%%BoundingBox</code> lines describe the graphic size using integer
multiples of a PostScript point, that is, integer multiples of 1/72
inch.  A later addition to the PostScript language allows decimal
multiples, such as 1.23, in <code>%%HiResBoundingBox</code> lines.  This
option has &latex; to read the size from the latter.
</para>
</tableitem></tableentry></table>


</section>
<node name="Graphics-package-configuration" spaces=" "><nodename>Graphics package configuration</nodename><nodenext automatic="on">Commands for graphics</nodenext><nodeprev automatic="on">Graphics package options</nodeprev><nodeup automatic="on">Graphics</nodeup></node>
<section spaces="  "><sectiontitle>Graphics package configuration</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="472">graphics</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="473">graphics package</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="474">configuration, graphics package</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="475">EPS files</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="476">JPEG files</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="477">JPG files</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="478">PDF graphic files</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="479">PNG files</indexterm></cindex>

<para>These commands configure the way &latex; searches the file system for
the graphic.
</para>
<para>The behavior of file system search code is necessarily platform
dependent.  In this document we cover Linux, Macintosh, and Windows, as
those systems are typically configured.  For other situations consult
the documentation in <file>grfguide.pdf</file>, or the &latex; source, or your
&tex; distribution&textrsquo;s documentation.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::         ">\graphicspath</menunode><menudescription><pre xml:space="preserve">Directories to search.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::   ">\DeclareGraphicsExtensions</menunode><menudescription><pre xml:space="preserve">File types, such as JPG or EPS.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::         ">\DeclareGraphicsRule</menunode><menudescription><pre xml:space="preserve">How to handle file types.
</pre></menudescription></menuentry></menu>


<node name="_005cgraphicspath" spaces=" "><nodename>\graphicspath</nodename><nodenext automatic="on">\DeclareGraphicsExtensions</nodenext><nodeup automatic="on">Graphics package configuration</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\graphicspath</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="862">\graphicspath</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\graphicspath&lbrace;<var>list of dir names inside curly brackets</var>&rbrace;
</pre></example>

<para>Declare a list of directories to search for graphics files.  This allows
you to later say something like <code>\includegraphics&lbrace;lion.png&rbrace;</code>
instead of having to give its path.
</para>
<para>&latex; always looks for graphic files first in the current directory.
The declaration below tells the system to then look in the subdirectory
<file>pix</file>, and then <file>../pix</file>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usepackage&lbrace;graphicx&rbrace;   % or graphics; put in preamble
  ...
\graphicspath&lbrace; &lbrace;pix/&rbrace; &lbrace;../pix/&rbrace; &rbrace;
</pre></example>

<para>The <code>\graphicspath</code> declaration is optional.  If you don&textrsquo;t include
it then &latex;&textrsquo;s default is to search all of the places that it
usually looks for a file (it uses &latex;&textrsquo;s <code>\input&arobase;path</code>).  In
particular, in this case one of the places it looks is the current
directory.
</para>
<para>Enclose each directory name in curly braces; for example, above it says
<samp><code>&lbrace;pix&rbrace;</code></samp>.  Do this even if there is only one directory.
Each directory name must end in a forward slash, <file>/</file>.  This is true
even on Windows, where good practice is to use forward slashes for all
the directory separators since it makes the document portable to other
platforms.  If you have spaces in your directory name then use double
quotes, as with <code>&lbrace;&quot;my docs/&quot;&rbrace;</code>. Getting one of these rules wrong
will cause &latex; to report <code>Error: File `<var>filename</var>' not
found</code>.
</para>
<para>Basically, the algorithm is that with this example, after looking in the
current directory,
</para>
<example endspaces=" ">
<pre xml:space="preserve">\graphicspath&lbrace; &lbrace;pix/&rbrace; &lbrace;../pix/&rbrace; &rbrace;
...
\usepackage&lbrace;lion.png&rbrace;
</pre></example>

<para>for each of the listed directories, &latex; concatenates it with the
file name and searches for the result, checking for <file>pix/lion.png</file>
and then <file>../pix/lion.png</file>.  This algorithm means that the
<code>\graphicspath</code> command does not recursively search subdirectories:
if you issue <code>\graphicspath&lbrace;&lbrace;a/&rbrace;&rbrace;</code> and the graphic is in
<file>a/b/lion.png</file> then &latex; will not find it.  It also means that
you can use absolute paths such as
<code>\graphicspath&lbrace;&lbrace;/home/jim/logos/&rbrace;&rbrace;</code> or
<code>\graphicspath&lbrace;&lbrace;C:/Users/Albert/Pictures/&rbrace;&rbrace;</code>.  However, using
these means that the document is not portable.  (You could preserve
portability by adjusting your &tex; system settings configuration file
parameter <code>TEXINPUTS</code>; see the documentation of your system.)
</para>
<para>You can use <code>\graphicspath</code> in the preamble or in the document
body.  You can use it more than once.  For debugging, show its value
with <code>\makeatletter\typeout&lbrace;\Ginput&arobase;path&rbrace;\makeatother</code>.
</para>
<para>The directories are taken with respect to the base file.  That is,
suppose that you are working on a document based on <file>book/book.tex</file>
and it contains <code>\include&lbrace;chapters/chap1&rbrace;</code>.  If in
<file>chap1.tex</file> you put <code>\graphicspath&lbrace;&lbrace;plots/&rbrace;&rbrace;</code> then
&latex; will not search for graphics in <file>book/chapters/plots</file>, but
instead in <file>book/plots</file>.
</para>

</subsection>
<node name="_005cDeclareGraphicsExtensions" spaces=" "><nodename>\DeclareGraphicsExtensions</nodename><nodenext automatic="on">\DeclareGraphicsRule</nodenext><nodeprev automatic="on">\graphicspath</nodeprev><nodeup automatic="on">Graphics package configuration</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\DeclareGraphicsExtensions</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="863">\DeclareGraphicsExtensions</indexterm></findex>

<para>Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\DeclareGraphicsExtensions&lbrace;<var>comma-separated list of file extensions</var>&rbrace;
</pre></example>

<para>Declare the filename extensions to try.  This allows you to specify the
order in which to choose graphic formats when you include graphic files
by giving the filename without the extension, as in
<code>\includegraphics&lbrace;functionplot&rbrace;</code>.
</para>
<para>In this example, &latex; will find files in the PNG format before PDF
files.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\DeclareGraphicsExtensions&lbrace;.png,PNG,.pdf,.PDF&rbrace;
  ...
\includegraphics&lbrace;lion&rbrace;   % will find <file>lion.png</file> before <file>lion.pdf</file> 
</pre></example>

<para>Because the file name <file>lion</file> does not have a period, &latex; uses
the extension list.  For each directory in the graphics path
(<pxref label="_005cgraphicspath"><xrefnodename>\graphicspath</xrefnodename></pxref>), &latex; will try the extensions in the order
given.  If it does not find such a file after trying all the directories
and extensions then it reports <samp>! LaTeX Error: File `<file>lion</file>'
not found</samp>.  Note that you must include the periods at the start of the
extensions.
</para>
<para>Because Linux and Macintosh filenames are case sensitive, the list of
file extensions is case sensitive on those platforms.  The Windows
platform is not case sensitive.
</para>
<para>You are not required to include <code>\DeclareGraphicsExtensions</code> in
your document; the printer driver has a sensible default.  For example,
the most recent <file>pdftex.def</file> has the extension list
<samp><code>.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPEG,.JBIG2,.JB2</code></samp>.
</para>
<para>You can use this command in the preamble or in the document body.  You
can use it more than once.  For debugging, show its value with
<code>\makeatletter\typeout&lbrace;\Gin&arobase;extensions&rbrace;\makeatother</code>.
</para>

</subsection>
<node name="_005cDeclareGraphicsRule" spaces=" "><nodename>\DeclareGraphicsRule</nodename><nodeprev automatic="on">\DeclareGraphicsExtensions</nodeprev><nodeup automatic="on">Graphics package configuration</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\DeclareGraphicsRule</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="864">\DeclareGraphicsRule</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\DeclareGraphicsRule&lbrace;<var>extension</var>&rbrace;&lbrace;<var>type</var>&rbrace;&lbrace;<var>size-file extension</var>&rbrace;&lbrace;<var>command</var>&rbrace;
</pre></example>

<para>Declare how to handle graphic files whose names end in <var>extension</var>.
</para>
<para>This example declares that all files with names have the form
<file>filename-without-dot.mps</file> will be treated as output from MetaPost,
meaning that the printer driver will use its MetaPost-handling code to
input the file.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\DeclareGraphicsRule&lbrace;.mps&rbrace;&lbrace;mps&rbrace;&lbrace;.mps&rbrace;&lbrace;&rbrace;
</pre></example>

<para>This
</para>
<example endspaces=" ">
<pre xml:space="preserve">\DeclareGraphicsRule&lbrace;*&rbrace;&lbrace;mps&rbrace;&lbrace;*&rbrace;&lbrace;&rbrace;
</pre></example>

<para>tells &latex; that it should handle as MetaPost output any file with an
extension not covered by another rule, so it covers <file>filename.1</file>,
<file>filename.2</file>, etc.
</para>
<para>This describes the four arguments.
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="var">extension</itemformat></item>
</tableterm><tableitem><para>The file extension to which this rule applies. The extension is anything
after and including the first dot in the filename.  Use the Kleene star,
<code>*</code>, to denote the default behaviour for all undeclared extensions.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">type</itemformat></item>
</tableterm><tableitem><para>The type of file involved.  This type is a string that must be defined
in the printer driver. For instance, files with extensions <file>.ps</file>,
<file>.eps</file>, or <file>.ps.gz</file> may all be classed as type <code>eps</code>.
All files of the same type will be input with the same internal command
by the printer driver. For example, the file types that <file>pdftex</file>
recognizes are: <code>jpg</code>, <code>jbig2</code>, <code>mps</code>, <code>pdf</code>,
<code>png</code>, <code>tif</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">size-file extension</itemformat></item>
</tableterm><tableitem><para>The extension of the file to be read to determine the size of the
graphic, if there is such a file. It may be the same as <var>extension</var>
but it may be different.
</para>
<para>As an example, consider a PostScript graphic.  To make it smaller, it
might be compressed into a <file>.ps.gz</file> file.  Compressed files are not
easily read by &latex; so you can put the bounding box information in a
separate file. If <var>size-file extension</var> is empty then you must
specify size information in the arguments of <code>\includegraphics</code>.
</para>
<para>If the driver file has a procedure for reading size files for
<code>type</code> then that will be used, otherwise it will use the procedure
for reading <file>.eps</file> files.  (Thus you may specify the size of bitmap
files in a file with a PostScript style <code>%%BoundingBox</code> line if no
other format is available.)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">command</itemformat></item>
</tableterm><tableitem><para>A command that will be applied to the
file. This is very often left blank. This command must start with a
single backward quote.  Thus,
<code>\DeclareGraphicsRule&lbrace;.eps.gz&rbrace;&lbrace;eps&rbrace;&lbrace;.eps.bb&rbrace;&lbrace;`gunzip -c
#1&rbrace;</code> specifies that any file with the extension <file>.eps.gz</file> should
be treated as an <code>eps</code> file, with the the BoundingBox information
stored in the file with extension <file>.eps.bb</file>, and that the command
<code>gunzip -c</code> will run on your platform to decompresses the file.
</para>
<para>Such a command is specific to your platform.  In addition, your &tex;
system must allow you to run external commands; as a security measure
modern systems restrict running commands unless you explicitly allow it.
See the documentation for your &tex; distribution.
</para>
</tableitem></tableentry></table>

</subsection>
</section>
<node name="Commands-for-graphics" spaces=" "><nodename>Commands for graphics</nodename><nodeprev automatic="on">Graphics package configuration</nodeprev><nodeup automatic="on">Graphics</nodeup></node>
<section spaces=" "><sectiontitle>Commands for graphics</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="480">graphics package commands</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="481">commands, graphics package</indexterm></cindex>

<para>These are the commands available with the <file>graphics</file> and
<file>graphicx</file> packages.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::     ">\includegraphics</menunode><menudescription><pre xml:space="preserve">Using a graphic in your document.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           ">\rotatebox</menunode><menudescription><pre xml:space="preserve">Rotating boxes, including graphics.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">\scalebox</menunode><menudescription><pre xml:space="preserve">Scaling boxes, including graphics.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::           ">\resizebox</menunode><menudescription><pre xml:space="preserve">Scaling boxes, including graphics, to a set size.
</pre></menudescription></menuentry></menu>


<node name="_005cincludegraphics" spaces=" "><nodename>\includegraphics</nodename><nodenext automatic="on">\rotatebox</nodenext><nodeup automatic="on">Commands for graphics</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\includegraphics</code></sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="482">graphics</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="483">graphics package</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="484">including graphics</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="485">importing graphics</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="486">EPS files</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="487">JPEG files</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="488">JPG files</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="489">PDF graphic files</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="490">PNG files</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="865">\includegraphics</indexterm></findex>

<para>Synopses for <file>graphics</file> package:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\includegraphics&lbrace;<var>filename</var>&rbrace;
\includegraphics[<var>urx</var>,<var>ury</var>]&lbrace;<var>filename</var>&rbrace;
\includegraphics[<var>llx</var>,<var>lly</var>][<var>urx</var>,<var>ury</var>]&lbrace;<var>filename</var>&rbrace;
\includegraphics*&lbrace;<var>filename</var>&rbrace;
\includegraphics*[<var>urx</var>,<var>ury</var>]&lbrace;<var>filename</var>&rbrace;
\includegraphics*[<var>llx</var>,<var>lly</var>][<var>urx</var>,<var>ury</var>]&lbrace;<var>filename</var>&rbrace;
</pre></example>

<para>Synopses for <file>graphicx</file> package:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\includegraphics&lbrace;<var>filename</var>&rbrace;
\includegraphics[<var>key-value list</var>]&lbrace;<var>filename</var>&rbrace;
\includegraphics*&lbrace;<var>filename</var>&rbrace;
\includegraphics*[<var>key-value list</var>]&lbrace;<var>filename</var>&rbrace;
</pre></example>

<para>Include a graphics file.  The starred form <code>\includegraphics*</code> will
clip the graphic to the size specified, while for the unstarred form any
part of the graphic that is outside the box of the specified size will
over-print the surrounding area.
</para>
<para>This 
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usepackage&lbrace;graphicx&rbrace;  % in preamble
  ...
\begin&lbrace;center&rbrace;
  \includegraphics&lbrace;plot.pdf&rbrace;
\end&lbrace;center&rbrace;
</pre></example>

<para>will incorporate into the document the graphic in <file>plot.pdf</file>,
centered and at its nominal size.  You can also give a path to the file,
as with <code>\includegraphics&lbrace;graphics/plot.pdf&rbrace;</code>.  To specify a list
of locations to search for the file, <pxref label="_005cgraphicspath"><xrefnodename>\graphicspath</xrefnodename></pxref>.
</para>
<para>If your filename includes spaces then put it in double quotes, as with
<code>\includegraphics&lbrace;&quot;sister picture.jpg&quot;&rbrace;</code>.
</para>
<para>The <code>\includegraphics&lbrace;<var>filename</var>&rbrace;</code> command decides on the
type of graphic by splitting <var>filename</var> on the first dot.  You can
use <var>filename</var> with no dot, as in <code>\includegraphics&lbrace;turing&rbrace;</code>
and then &latex; tries a sequence of extensions such as <code>.png</code> and
<code>.pdf</code> until it finds a file with that extension
(<pxref label="_005cDeclareGraphicsExtensions"><xrefnodename>\DeclareGraphicsExtensions</xrefnodename></pxref>).
</para>
<para>If your file name contains dots before the extension then you can hide
them with curly braces, as in
<code>\includegraphics&lbrace;&lbrace;plot.2018.03.12.a&rbrace;.pdf&rbrace;</code>.  Or, if you use
the <file>graphicx</file> package then you can use the options <code>type</code> and
<code>ext</code>; see below.  This and other filename issues are also handled
with the package <file>grffile</file>.
</para>
<para>This example puts a graphic in a figure environment so &latex; can
move it to the next page if fitting it on the current page is awkward
(<pxref label="figure"><xrefnodename>figure</xrefnodename></pxref>).
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;figure&rbrace;
  \centering
  \includegraphics[width=3cm]&lbrace;lungxray.jpg&rbrace;
  \caption&lbrace;The evidence is overwhelming: don't smoke.&rbrace;  \label&lbrace;fig:xray&rbrace;
\end&lbrace;figure&rbrace;
</pre></example>

<para>This places a graphic that will not float, so it is sure to appear at
this point in the document even if makes &latex; stretch the text or
resort to blank areas on the page.  It will be centered and will have a
caption.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\usepackage&lbrace;caption&rbrace;  % in preamble
  ...
\begin&lbrace;center&rbrace;
  \includegraphics&lbrace;pix/nix.png&rbrace;
  \captionof&lbrace;figure&rbrace;&lbrace;The spirit of the night&rbrace; \label&lbrace;pix:nix&rbrace;  % if you want a caption  
\end&lbrace;center&rbrace;
</pre></example>

<para>This example puts a box with a graphic side by side with one having
text, with the two vertically centered.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcommand*&lbrace;\vcenteredhbox&rbrace;[1]&lbrace;\begingroup
                                \setbox0=\hbox&lbrace;#1&rbrace;\parbox&lbrace;\wd0&rbrace;&lbrace;\box0&rbrace;\endgroup&rbrace;
  ...
\begin&lbrace;center&rbrace;
  \vcenteredhbox&lbrace;\includegraphics[width=0.4\textwidth]&lbrace;plot&rbrace;&rbrace;
  \hspace&lbrace;1em&rbrace;
  \vcenteredhbox&lbrace;\begin&lbrace;minipage&rbrace;&lbrace;0.4\textwidth&rbrace;
                   \begin&lbrace;displaymath&rbrace;
                     f(x)=x\cdot \sin (1/x)
                   \end&lbrace;displaymath&rbrace;
                 \end&lbrace;minipage&rbrace;&rbrace;
\end&lbrace;center&rbrace;
</pre></example>

<para>If you use the <file>graphics</file> package then the only options involve the
size of the graphic (but see <ref label="_005crotatebox"><xrefnodename>\rotatebox</xrefnodename></ref> and <ref label="_005cscalebox"><xrefnodename>\scalebox</xrefnodename></ref>).
When one optional argument is present then it is
<code>[<var>urx</var>,<var>ury</var>]</code> and it gives the coordinates of the top
right corner of the image, as a pair of &tex; dimensions (<pxref label="Units-of-length"><xrefnodename>Units
of length</xrefnodename></pxref>).  If the units are omitted they default to <code>bp</code>.  In
this case, the lower left corner of the image is assumed to be at (0,0).
If two optional arguments are present then the leading one is
<code>[<var>llx</var>,<var>lly</var>]</code>, specifying the coordinates of the image&textrsquo;s
lower left.  Thus, <code>\includegraphics[1in,0.618in]&lbrace;...&rbrace;</code> calls for
the graphic to be placed so it is 1&nbsp;inch wide and 0.618&nbsp;inches
tall and so its origin is at (0,0).
</para>
<para>The <file>graphicx</file> package gives you many more options.  Specify them
in a key-value form, as here.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;center&rbrace;
  \includegraphics[width=1in,angle=90]&lbrace;lion&rbrace;
  \hspace&lbrace;2em&rbrace;
  \includegraphics[angle=90,width=1in]&lbrace;lion&rbrace;
\end&lbrace;center&rbrace;
</pre></example>

<para>The options are read left-to-right. So the first graphic above is made
one inch wide and then rotated, while the second is rotated and then
made one inch wide.  Thus, unless the graphic is perfectly square, the
two will end with different widths and heights.
</para>
<para>There are many options.  The primary ones are listed first.
</para>
<para>Note that a graphic is placed by &latex; into a box, which is
traditionally referred to as its bounding box (distinct from the
PostScript BoundingBox described below).  The graphic&textrsquo;s printed area may
go beyond this box, or sit inside this box, but when &latex; makes up a
page it puts together boxes and this is the box allocated for the
graphic.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">width</itemformat></item>
</tableterm><tableitem><para>The graphic will be shown so its bounding box is this width.  An example
is <code>\includegraphics[width=1in]&lbrace;plot&rbrace;</code>.  You can use the standard
&tex; dimensions (<pxref label="Units-of-length"><xrefnodename>Units of length</xrefnodename></pxref>) and also convenient is
<code>\linewidth</code>, or in a two-column document, <code>\columnwidth</code>
(<pxref label="Page-layout-parameters"><xrefnodename>Page layout parameters</xrefnodename></pxref>).  An example is that by using the
<file>calc</file> package you can make the graphic be 1&nbsp;cm narrow than
the width of the text with
<code>\includegraphics[width=\linewidth-1.0cm]&lbrace;hefferon.jpg&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">height</itemformat></item>
</tableterm><tableitem><para>The graphic will be shown so its bounding box is this height.  You can
use the standard &tex; dimensions (<pxref label="Units-of-length"><xrefnodename>Units of length</xrefnodename></pxref>), and also
convenient are <code>\pageheight</code> and <code>\textheight</code> (<pxref label="Page-layout-parameters"><xrefnodename>Page
layout parameters</xrefnodename></pxref>).  For instance,
<code>\includegraphics[height=0.25\textheight]&lbrace;godel&rbrace;</code> will make the
graphic be a quarter of the height of the text area.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">totalheight</itemformat></item>
</tableterm><tableitem><para>The graphic will be shown so its bounding box has this height plus
depth.  This differs from the height if the graphic was rotated. For
instance, if it has been rotated by -90 then it will have zero height
but a large depth.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">keepaspectratio</itemformat></item>
</tableterm><tableitem><para>If set to <code>true</code>, or just specified as with
<code>\includegraphics[...,keepaspectratio,...]&lbrace;...&rbrace;</code> and you give as
options both <code>width</code> and <code>height</code> (or <code>totalheight</code>),
then &latex; will make the graphic is as large as possible without
distortion. That is, &latex; will ensure that neither is the graphic
wider than <code>width</code> nor taller than <code>height</code> (or
<code>totalheight</code>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">scale</itemformat></item>
</tableterm><tableitem><para>Factor by which to scale the graphic.  Specifying
<code>\includegraphics[scale=2.0]&lbrace;...&rbrace;</code> makes the graphic twice its
nominal size.  This number may be any value; a number between 1
and&nbsp;0 will shrink the graphic and a negative number will reflect
it.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">angle</itemformat></item>
</tableterm><tableitem><para>Rotate the picture.  The angle is taken in degrees and counterclockwise.
The graphic is rotated about its <code>origin</code>; see that option.  For a
complete description of how rotated material is typeset,
<pxref label="_005crotatebox"><xrefnodename>\rotatebox</xrefnodename></pxref>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">origin</itemformat></item>
</tableterm><tableitem><para>The point of the graphic about which the rotation happens.  Possible
values are any string containing one or two of: <code>l</code> for left,
<code>r</code> for right, <code>b</code> for bottom, <code>c</code> for center, <code>t</code>
for top, and <code>B</code> for baseline.  Thus,
<code>\includegraphics[angle=180,origin=c]&lbrace;moon&rbrace;</code> will turn the
picture upside down from the center, while
<code>\includegraphics[angle=180,origin=lB]&lbrace;LeBateau&rbrace;</code> will turn its
picture upside down about its left baseline.  (The character <code>c</code>
gives the horizontal center in <code>bc</code> or <code>tc</code>, but gives the
vertical center in <code>lc</code> or <code>rc</code>.)  The default is <code>lB</code>.
</para>
<para>To rotate about an arbitrary point, <pxref label="_005crotatebox"><xrefnodename>\rotatebox</xrefnodename></pxref>.
</para>
</tableitem></tableentry></table>

<para>These are lesser-used options.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">viewport</itemformat></item>
</tableterm><tableitem><para>Pick out a subregion of the graphic to show.  Takes four arguments,
separated by spaces and given in &tex; dimensions, as with
<code>\includegraphics[.., viewport=0in 0in 1in 0.618in]&lbrace;...&rbrace;</code>.  The
dimensions default to big points,&nbsp;<code>bp</code>.  They are taken
relative to the origin specified by the bounding box.  See also the
<code>trim</code> option.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">trim</itemformat></item>
</tableterm><tableitem><para>Gives parts of the graphic to not show.  Takes four arguments, separated
by spaces, that are given in &tex; dimensions, as with
<code>\includegraphics[.., trim= 0in 0.1in 0.2in 0.3in, ...]&lbrace;...&rbrace;</code>.
These give the amounts of the graphic not to show, that is, &latex;
will crop the picture by 0&nbsp;inches on the left, 0.1&nbsp;inches on
the bottom, 0.2&nbsp;inches on the right, and 0.3&nbsp;inches on the
top.  See also the <code>viewport</code> option.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">clip</itemformat></item>
</tableterm><tableitem><para>If set to <code>true</code>, or just specified as with
<code>\includegraphics[...,clip,...]&lbrace;...&rbrace;</code>, then the graphic is
cropped to the bounding box.  You can get this effect by instead using
the starred form of the command, as
<code>\includegraphics*[...]&lbrace;...&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">page</itemformat></item>
</tableterm><tableitem><para>Give the page number of a multi-page PDF file.  The default is
<code>page=1</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">pagebox</itemformat></item>
</tableterm><tableitem><para>Specifies which bounding box to use for PDF files from among
<code>mediabox</code>, <code>cropbox</code>, <code>bleedbox</code>, <code>trimbox</code>, or
<code>artbox</code>.  PDF files do not have the BoundingBox that PostScript
files have, but may specify up to four predefined rectangles. The
MediaBox gives the boundaries of the physical medium. The CropBox is the
region to which the contents of the page are to be clipped when
displayed.  The BleedBox is the region to which the contents of the page
should be clipped in production. The TrimBox is the intended dimensions
of the finished page.  The ArtBox is the extent of the page&textrsquo;s meaningful
content.  The driver will set the image size based on CropBox if
present, otherwise it will not use one of the others, with a
driver-defined order of preference.  MediaBox is always present.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">interpolate</itemformat></item>
</tableterm><tableitem><para>Enable or disable interpolation of raster images by the viewer.  Can be
set with <code>interpolate=true</code> or just specified as with
<code>\includegraphics[...,interpolate,...]&lbrace;...&rbrace;</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">quiet</itemformat></item>
</tableterm><tableitem><para>Do not write information to the log.  You can set it with
<code>quiet=true</code> or just specified it with
<code>\includegraphics[...,quite,...]&lbrace;...&rbrace;</code>,
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">draft</itemformat></item>
</tableterm><tableitem><para>If you set it with <code>draft=true</code> or just specified it with
<code>\includegraphics[...,draft,...]&lbrace;...&rbrace;</code>, then the graphic will not
appear in the document, possibly saving color printer ink.  Instead,
&latex; will put an empty box of the correct size with the filename
printed in it.
</para>
</tableitem></tableentry></table>

<para>These options address the bounding box for Encapsulated PostScript
graphic files, which have a size specified with a line
<code>%%BoundingBox</code> that appears in the file.  It has four values,
giving the lower <math>x</math> coordinate, lower <math>y</math> coordinate, upper
<math>x</math> coordinate, and upper <math>y</math> coordinate.  The units are
PostScript points, equivalent to &tex;&textrsquo;s big points, 1/72&nbsp;inch.
For example, if an <file>.eps</file> file has the line <code>%%BoundingBox 10
20 40 80</code> then its natural size is 30/72&nbsp;inch wide by
60/72&nbsp;inch tall.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">bb</itemformat></item>
</tableterm><tableitem><para>Specify the bounding box of the displayed region.  The argument is four
dimensions separated by spaces, as with <code>\includegraphics[.., bb=
0in 0in 1in 0.618in]&lbrace;...&rbrace;</code>.  Usually <code>\includegraphics</code> reads the
BoundingBox numbers from the EPS file automatically, so this option is
only useful if the bounding box is missing from that file or if you want
to change it.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">bbllx, bblly, bburx, bbury</itemformat></item>
</tableterm><tableitem><para>Set the bounding box.  These four are obsolete, but are retained for
compatibility with old packages.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">natwidth, natheight</itemformat></item>
</tableterm><tableitem><para>An alternative for <code>bb</code>.  Setting
<code>\includegraphics[...,natwidth=1in,natheight=0.618in,...]&lbrace;...&rbrace;</code>
is the same as setting <code>bb=0 0 1in 0.618in</code>.
</para> 
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">hiresbb</itemformat></item>
</tableterm><tableitem><para>If set to <code>true</code>, or just specified as with
<code>\includegraphics[...,hiresbb,...]&lbrace;...&rbrace;</code>, then &latex; will look
for <code>%%HiResBoundingBox</code> lines instead of <code>%%BoundingBox</code>
lines.  (The <code>BoundingBox</code> lines use only natural numbers while the
<code>HiResBoundingBox</code> lines use decimals; both use units equivalent to
&tex;&textrsquo;s big points, 1/72&nbsp;inch.) To override a prior setting of
<code>true</code>, you can set it to <code>false</code>.
</para>
</tableitem></tableentry></table>

<para>These following options allow a user to override &latex;&textrsquo;s method of
choosing the graphic type based on the filename extension.  An example
is that <code>\includegraphics[type=png,ext=.xxx,read=.xxx]&lbrace;lion&rbrace;</code>
will read the file <file>lion.xxx</file> as though it were
<file>lion.png</file>. For more on these, <pxref label="_005cDeclareGraphicsRule"><xrefnodename>\DeclareGraphicsRule</xrefnodename></pxref>.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">type</itemformat></item>
</tableterm><tableitem><para>Specify the graphics type.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">ext</itemformat></item>
</tableterm><tableitem><para>Specify the graphics extension.
Only use this in conjunction with the option <code>type</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">read</itemformat></item>
</tableterm><tableitem><para>Specify the file extension of the read file.
Only use this in conjunction with the option <code>type</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">command</itemformat></item>
</tableterm><tableitem><para>Specify a command to be applied to this file.
Only use this in conjunction with the option <code>type</code>.
<!-- c write18 and restricted execution. -->
</para>
</tableitem></tableentry></table>


</subsection>
<node name="_005crotatebox" spaces=" "><nodename>\rotatebox</nodename><nodenext automatic="on">\scalebox</nodenext><nodeprev automatic="on">\includegraphics</nodeprev><nodeup automatic="on">Commands for graphics</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\rotatebox</code></sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="491">rotation</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="492">rotating graphics</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="493">rotating text</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="866">\rotatebox</indexterm></findex>

<para>Synopsis for <file>graphics</file> package:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\rotatebox&lbrace;<var>angle</var>&rbrace;&lbrace;<var>material</var>&rbrace;
</pre></example>

<para>Synopses for <file>graphicx</file> package:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\rotatebox&lbrace;<var>angle</var>&rbrace;&lbrace;<var>material</var>&rbrace;
\rotatebox[<var>key-value list</var>]&lbrace;<var>angle</var>&rbrace;&lbrace;<var>material</var>&rbrace;
</pre></example>

<para>Put <var>material</var> in a box and rotate it <var>angle</var> degrees counterclockwise. 
</para>
<para>This example rotates the table column heads forty five degrees.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;tabular&rbrace;&lbrace;ll&rbrace;
  \rotatebox&lbrace;45&rbrace;&lbrace;Character&rbrace; &amp;\rotatebox&lbrace;45&rbrace;&lbrace;NATO phonetic&rbrace;   \\
  A                         &amp;AL-FAH  \\
  B                         &amp;BRAH-VOH
\end&lbrace;tabular&rbrace;
</pre></example>

<para>The <var>material</var> can be anything that goes in a box, including a graphic.
</para>
<example endspaces=" ">
<pre xml:space="preserve">  \rotatebox[origin=c]&lbrace;45&rbrace;&lbrace;\includegraphics[width=1in]&lbrace;lion&rbrace;&rbrace;
</pre></example>

<para>To place the rotated material, the first step is that &latex; sets
<var>material</var> in a box, with a reference point on the left baseline.
The second step is the rotation, by default about the reference point.
The third step is that &latex; computes a box to bound the rotated
material.  Fourth, &latex; moves this box horizontally so that the left
edge of this new bounding box coincides with the left edge of the box
from the first step (they need not coincide vertically).  This new
bounding box, in its new position, is what &latex; uses as the box when
typesetting this material.
</para>
<para>If you use the <file>graphics</file> package then the rotation is about the
reference point of the box.  If you use the <file>graphicx</file> package then
then these are the options that can go in the <var>key-value list</var>, but
note that you can get the same effect without needing this package,
except for the <code>x</code> and <code>y</code> options (<pxref label="_005cincludegraphics"><xrefnodename>\includegraphics</xrefnodename></pxref>).
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">origin</itemformat></item>
</tableterm><tableitem><para>The point of the <var>material</var>&textrsquo;s box about which the rotation happens.
Possible values are any string containing one or two of: <code>l</code> for
left, <code>r</code> for right, <code>b</code> for bottom, <code>c</code> for center,
<code>t</code> for top, and <code>B</code> for baseline.  Thus,
<code>\includegraphics[angle=180,origin=c]&lbrace;moon&rbrace;</code> will turn the
picture upside down from the center, while
<code>\includegraphics[angle=180,origin=lB]&lbrace;LeBateau&rbrace;</code> will turn its
picture upside down about its left baseline.  (The character <code>c</code>
gives the horizontal center in <code>bc</code> or <code>tc</code> but gives the
vertical center in <code>lc</code> or <code>rc</code>.)  The default is <code>lB</code>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">x, y</itemformat></item>
</tableterm><tableitem><para>Specify an arbitrary point of rotation with
<code>\rotatebox[x=<var>&tex; dimension</var>,y=<var>&tex;
dimension</var>]&lbrace;...&rbrace;</code> (<pxref label="Units-of-length"><xrefnodename>Units of length</xrefnodename></pxref>).  These give the offset
from the box&textrsquo;s reference point.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">units</itemformat></item>
</tableterm><tableitem><para>This key allows you to change the default of degrees counterclockwise.
Setting <code>units=-360</code> changes the direction to degrees clockwise and
setting <code>units=6.283185</code> changes to radians counterclockwise.
</para>
</tableitem></tableentry></table>


</subsection>
<node name="_005cscalebox" spaces=" "><nodename>\scalebox</nodename><nodenext automatic="on">\resizebox</nodenext><nodeprev automatic="on">\rotatebox</nodeprev><nodeup automatic="on">Commands for graphics</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\scalebox</code></sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="494">graphics, scaling</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="495">graphics, resizing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="496">scaling</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="497">resizing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="498">text, scaling</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="499">text, resizing</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="867">\scalebox</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="868">\reflectbox</indexterm></findex>

<para>Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\scalebox&lbrace;<var>horizontal factor</var>&rbrace;&lbrace;<var>material</var>&rbrace;
\scalebox&lbrace;<var>horizontal factor</var>&rbrace;[<var>vertical factor</var>]&lbrace;<var>material</var>&rbrace;
\reflectbox&lbrace;<var>material</var>&rbrace;
</pre></example>

<para>Scale the <var>material</var>.
</para>
<para>This example halves the size, both horizontally and vertically, of the
first text and doubles the size of the second.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\scalebox&lbrace;0.5&rbrace;&lbrace;DRINK ME&rbrace; and \scalebox&lbrace;2.0&rbrace;&lbrace;Eat Me&rbrace;
</pre></example>

<para>If you do not specify the optional <var>vertical factor</var> then it
defaults to the same value as the <var>horizontal factor</var>.
</para>
<para>You can use this command to resize a graphic, as with
<code>\scalebox&lbrace;0.5&rbrace;&lbrace;\includegraphics&lbrace;lion&rbrace;&rbrace;</code>.  If you use the
<file>graphicx</file> package then you can accomplish the same thing with
optional arguments to <code>\includegraphics</code>
(<pxref label="_005cincludegraphics"><xrefnodename>\includegraphics</xrefnodename></pxref>).
</para>
<para>The <code>\reflectbox</code> command abbreviates
<code>\scalebox&lbrace;-1&rbrace;[1]&lbrace;<var>material</var>&rbrace;</code>.  Thus, <code>Able was
I\reflectbox&lbrace;Able was I&rbrace;</code> will show the phrase <samp>Able was I</samp>
immediately followed by its mirror reflection.
</para>

</subsection>
<node name="_005cresizebox" spaces=" "><nodename>\resizebox</nodename><nodeprev automatic="on">\scalebox</nodeprev><nodeup automatic="on">Commands for graphics</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\resizebox</code></sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="500">graphics, scaling</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="501">graphics, resizing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="502">scaling</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="503">resizing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="504">text, scaling</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="505">text, resizing</indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="869">\resizebox</indexterm></findex>

<para>Synopses:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\resizebox&lbrace;<var>horizontal length</var>&rbrace;&lbrace;<var>vertical length</var>&rbrace;&lbrace;<var>material</var>&rbrace;
\resizebox*&lbrace;<var>horizontal length</var>&rbrace;&lbrace;<var>vertical length</var>&rbrace;&lbrace;<var>material</var>&rbrace;
</pre></example>

<para>Given a size, such as <code>3cm</code>, transform <var>material</var> to make it
that size.  If either <var>horizontal length</var> or <var>vertical length</var>
is an exclamation point&nbsp;<code>!</code>  then the other argument is used
to determine a scale factor for both directions.
</para>
<para>This example makes the graphic be a half inch wide and scales it
vertically by the same factor to keep it from being distorted.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\resizebox&lbrace;0.5in&rbrace;&lbrace;!&rbrace;&lbrace;\includegraphics&lbrace;lion&rbrace;&rbrace;
</pre></example>

<para>The unstarred form <code>\resizebox</code> takes <var>vertical length</var> to be
the box&textrsquo;s height while the starred form <code>\resizebox*</code> takes it to
be height+depth.  For instance, make the text have a height+depth of a
quarter inch with <code>\resizebox*&lbrace;!&rbrace;&lbrace;0.25in&rbrace;&lbrace;\parbox&lbrace;1in&rbrace;&lbrace;This
box has both height and depth.&rbrace;&rbrace;</code>.
</para>
<para>You can use <code>\depth</code>, <code>\height</code>, <code>\totalheight</code>, and
<code>\width</code> to refer to the original size of the box.  Thus, make the
text two inches wide but keep the original height with
<code>\resizebox&lbrace;2in&rbrace;&lbrace;\height&rbrace;&lbrace;Two inches&rbrace;</code>.
</para>

</subsection>
</section>
</chapter>
<node name="Special-insertions" spaces=" "><nodename>Special insertions</nodename><nodenext automatic="on">Splitting the input</nodenext><nodeprev automatic="on">Graphics</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Special insertions</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="506">special insertions</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="507">insertions of special characters</indexterm></cindex>

<para>&latex; provides commands for inserting characters that have a
special meaning do not correspond to simple characters you can type.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::         ">Reserved characters</menunode><menudescription><pre xml:space="preserve">Inserting <samp># $ % &amp; &lbrace; &rbrace; _ ~ ^ \</samp>
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::        ">Upper and lower case</menunode><menudescription><pre xml:space="preserve">Make text upper or lower case.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::    ">Symbols by font position</menunode><menudescription><pre xml:space="preserve">Inserting font symbols by number.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                ">Text symbols</menunode><menudescription><pre xml:space="preserve">Inserting other non-letter symbols in text.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                     ">Accents</menunode><menudescription><pre xml:space="preserve">Inserting accents.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::      ">Additional Latin letters</menunode><menudescription><pre xml:space="preserve">Inserting other non-English characters.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                       ">\rule</menunode><menudescription><pre xml:space="preserve">Inserting lines and rectangles.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                      ">\today</menunode><menudescription><pre xml:space="preserve">Inserting today&textrsquo;s date.
</pre></menudescription></menuentry></menu>


<node name="Reserved-characters" spaces=" "><nodename>Reserved characters</nodename><nodenext automatic="on">Upper and lower case</nodenext><nodeup automatic="on">Special insertions</nodeup></node>
<section spaces=" "><sectiontitle>Reserved characters</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="508">reserved characters</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="509">characters, reserved</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="510">special characters</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="511">characters, special</indexterm></cindex>
<para>&latex; sets aside the following characters for special purposes (for
example, the percent sign&nbsp;<code>%</code> is for comments) so they are
called <dfn>reserved characters</dfn> or <dfn>special characters</dfn>.
</para>
<example endspaces=" ">
<pre xml:space="preserve"># $ % &amp; &lbrace; &rbrace; _ ~ ^ \ 
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="870">\#</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="871">\$</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="872">\%</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="873">\&amp;</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="874">\_</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="875">\&lbrace;</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="876">\&rbrace;</indexterm></findex>
<para>If you want a reserved character to be printed as itself, in the text
body font, for all but the final three characters in that list simply
put a backslash&nbsp;<code>\</code> in front of the character.  Thus,
<code>\$1.23</code> will produce&nbsp;<code>$1.23</code> in your output.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="877">\~</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="878">\^</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="879">\textbackslash</indexterm></findex>
<para>As to the last three characters, to get a tilde in the text body font
use <code>\~&lbrace;&rbrace;</code> (omitting the curly braces would result in the next
character receiving a tilde accent).  Similarly, to get a get a text
body font circumflex use <code>\^&lbrace;&rbrace;</code>.  A text body font backslash
results from <code>\textbackslash&lbrace;&rbrace;</code>.
</para>
<para>To produce the reserved characters in a typewriter font use
<code>\verb!!</code>, as below.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\begin&lbrace;center&rbrace;
  \# \$ \% \&amp; \&lbrace; \&rbrace; \_ \~&lbrace;&rbrace; \^&lbrace;&rbrace; \textbackslash \\
  \verb!# $ % &amp; &lbrace; &rbrace; _ ~ ^ \!
\end&lbrace;center&rbrace;
</pre></example>

<para>In that example the double backslash&nbsp;<code>\\</code> is only there to
split the lines.
</para>

</section>
<node name="Upper-and-lower-case" spaces=" "><nodename>Upper and lower case</nodename><nodenext automatic="on">Symbols by font position</nodenext><nodeprev automatic="on">Reserved characters</nodeprev><nodeup automatic="on">Special insertions</nodeup></node>
<section spaces=" "><sectiontitle>Upper and lower case</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="512">Upper case</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="513">Lower case</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="514">characters, case</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\uppercase&lbrace;<var>text</var>&rbrace;
\lowercase&lbrace;<var>text</var>&rbrace;
\MakeUppercase&lbrace;<var>text</var>&rbrace;
\MakeLowercase&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>Change the case of characters.  The &tex; primitives commands
<code>\uppercase</code> and <code>\lowercase</code> only work for American
characters. The &latex; commands <code>\MakeUppercase</code> and
<code>\MakeLowercase</code> commands also change characters accessed by
commands such as <code>\ae</code> or <code>\aa</code>.  The commands
<code>\MakeUppercase</code> and <code>\MakeLowercase</code> are robust but they have
moving arguments (<pxref label="_005cprotect"><xrefnodename>\protect</xrefnodename></pxref>).
</para>
<para>These commands do not change the case of letters used in the name of a
command within <var>text</var>.  But they do change the case of every other
Latin letter inside the argument <var>text</var>.  Thus,
<code>\MakeUppercase&lbrace;Let $y=f(x)$</code>&rbrace; produces <samp>LET Y=F(X)</samp>.  Another
example is that the name of an environment will be changed, so that
<code>\MakeUppercase&lbrace;\begin&lbrace;tabular&rbrace; ... \end&lbrace;tabular&rbrace;&rbrace;</code> will
produce an error because the first half is changed to
<code>\begin&lbrace;TABULAR&rbrace;</code>.
</para>
<para>&latex; uses the same fixed table for changing case throughout a
document, The table used is designed for the font encoding T1; this
works well with the standard &tex; fonts for all Latin alphabets but
will cause problems when using other alphabets.
</para>
<para>To change the case of text that results from a macro inside <var>text</var>
you need to do expansion.  Here the <code>\Schoolname</code> produces
<samp>COLLEGE OF MATHEMATICS</samp>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\newcommand&lbrace;\schoolname&rbrace;&lbrace;College of Mathematics&rbrace;
\newcommand&lbrace;\Schoolname&rbrace;&lbrace;\expandafter\MakeUppercase
<w>                           </w>\expandafter&lbrace;\schoolname&rbrace;&rbrace;
</pre></example>

<cindex index="cp" spaces=" "><indexterm index="cp" number="515"><r>package</r>, <code>textcase</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="516"><code>textcase</code> <r>package</r></indexterm></cindex>

<para>The <file>textcase</file> package brings some of the missing feature of the
standard &latex; commands <code>\MakeUppercase</code> and
<code>\MakeLowerCase</code>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="517"><r>package</r>, <code>mfirstuc</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="518"><code>mfirstuc</code> <r>package</r></indexterm></cindex>
 
<para>To uppercase only the first letter of words, you can use the package
<file>mfirstuc</file>.
</para>

</section>
<node name="Symbols-by-font-position" spaces=" "><nodename>Symbols by font position</nodename><nodenext automatic="on">Text symbols</nodenext><nodeprev automatic="on">Upper and lower case</nodeprev><nodeup automatic="on">Special insertions</nodeup></node>
<section spaces=" "><sectiontitle>Symbols by font position</sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="880">\symbol</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="519">accessing any character of a font</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="520">font symbols, by number</indexterm></cindex>

<para>You can access any character of the current font using its number with
the <code>\symbol</code> command. For example, the visible space character
used in the <code>\verb*</code> command has the code decimal 32, so it can be
typed as <code>\symbol&lbrace;32&rbrace;</code>.
</para>
<para>You can also specify numbers in octal (base 8) by using a <code>'</code>
prefix, or hexadecimal (base 16) with a <code>&quot;</code> prefix, so the previous
example could also be written as <code>\symbol&lbrace;'40&rbrace;</code> or
<code>\symbol&lbrace;&quot;20&rbrace;</code>.
</para>

</section>
<node name="Text-symbols" spaces=" "><nodename>Text symbols</nodename><nodenext automatic="on">Accents</nodenext><nodeprev automatic="on">Symbols by font position</nodeprev><nodeup automatic="on">Special insertions</nodeup></node>
<section spaces=" "><sectiontitle>Text symbols</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="521">text symbols</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="522">symbols, text</indexterm></cindex>

<findex index="fn" spaces=" "><indexterm index="fn" number="881">textcomp <r>package</r></indexterm></findex>
<para>&latex; provides commands to generate a number of non-letter symbols
in running text.  Some of these, especially the more obscure ones, are
not available in OT1; you may need to load the <code>textcomp</code> package.
</para>
<ftable commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="882">\copyright</indexterm>\copyright</itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="883">\textcopyright</indexterm>\textcopyright</itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="523">copyright symbol</indexterm></cindex>
<para>The copyright symbol, &copyright;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="884">\dag</indexterm>\dag</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="524">dagger, in text</indexterm></cindex>
<para>The dagger symbol (in text).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="885">\ddag</indexterm>\ddag</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="525">double dagger, in text</indexterm></cindex>
<para>The double dagger symbol (in text).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="886">\LaTeX</indexterm>\LaTeX</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="526">&latex; logo</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="527">logo, &latex;</indexterm></cindex>
<para>The &latex; logo.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="887">\LaTeXe</indexterm>\LaTeXe</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="528">&latex;2e logo</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="529">logo, &latex;2e</indexterm></cindex>
<para>The &latex;2e logo.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="888">\guillemotleft <r>(&laquo;)</r></indexterm>\guillemotleft <r>(&laquo;)</r></itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="889">\guillemotright <r>(&raquo;)</r></indexterm>\guillemotright <r>(&raquo;)</r></itemformat></itemx>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="890">\guilsinglleft <r>(&lsaquo;)</r></indexterm>\guilsinglleft <r>(&lsaquo;)</r></itemformat></itemx>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="891">\guilsinglright <r>(&rsaquo;)</r></indexterm>\guilsinglright <r>(&rsaquo;)</r></itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="530">double guillemets</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="531">single guillemets</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="532">left angle quotation marks</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="533">right angle quotation marks</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="534">double angle quotation marks</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="535">single angle quotation marks</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="536">French quotation marks</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="537">quotation marks, French</indexterm></cindex>
<para>Double and single angle quotation marks, commonly used in French:
&laquo;, &raquo;, &lsaquo;, &rsaquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="892">\ldots</indexterm>\ldots</itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="893">\dots</indexterm>\dots</itemformat></itemx>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="894">\textellipsis</indexterm>\textellipsis</itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="538">ellipsis</indexterm></cindex>
<para>An ellipsis (three dots at the baseline): &textlsquo;&dots;&textrsquo;.  <code>\ldots</code>
and <code>\dots</code> also work in math mode.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="895">\lq</indexterm>\lq</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="539">left quote</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="540">opening quote</indexterm></cindex>
<para>Left (opening) quote: &textlsquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="896">\P</indexterm>\P</itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="897">\textparagraph</indexterm>\textparagraph</itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="541">paragraph symbol</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="542">pilcrow</indexterm></cindex>
<para>Paragraph sign (pilcrow): <U>00B6</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="898">\pounds</indexterm>\pounds</itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="899">\textsterling</indexterm>\textsterling</itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="543">pounds symbol</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="544">sterling symbol</indexterm></cindex>
<para>English pounds sterling: &pound;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="900">\quotedblbase <r>(&bdquo;)</r></indexterm>\quotedblbase <r>(&bdquo;)</r></itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="901">\quotesinglbase <r>(&sbquo;)</r></indexterm>\quotesinglbase <r>(&sbquo;)</r></itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="545">double low-9 quotation mark</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="546">single low-9 quotation mark</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="547">low-9 quotation marks, single and double</indexterm></cindex>
<para>Double and single quotation marks on the baseline:
&bdquo; and &sbquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="902">\rq</indexterm>\rq</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="548">right quote</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="549">closing quote</indexterm></cindex>
<para>Right (closing) quote: &textrsquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="903">\S</indexterm>\S</itemformat></item>
</tableterm><tableitem><para>\itemx \textsection
<cindex index="cp" spaces=" "><indexterm index="cp" number="550">section symbol</indexterm></cindex>
Section sign: <U>00A7</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="904">\TeX</indexterm>\TeX</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="551">&tex; logo</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="552">logo, &tex;</indexterm></cindex>
<para>The &tex; logo.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="905">\textasciicircum</indexterm>\textasciicircum</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="553">circumflex, ASCII, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="554">ASCII circumflex, in text</indexterm></cindex>
<para>ASCII circumflex: ^.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="906">\textasciitilde</indexterm>\textasciitilde</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="555">tilde, ASCII, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="556">ASCII tilde, in text</indexterm></cindex>
<para>ASCII tilde: ~.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="907">\textasteriskcentered</indexterm>\textasteriskcentered</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="557">asterisk, centered, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="558">centered asterisk, in text</indexterm></cindex>
<para>Centered asterisk: *.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="908">\textbackslash</indexterm>\textbackslash</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="559">backslash, in text</indexterm></cindex>
<para>Backslash: \.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="909">\textbar</indexterm>\textbar</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="560">vertical bar, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="561">bar, vertical, in text</indexterm></cindex>
<para>Vertical bar: |.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="910">\textbardbl</indexterm>\textbardbl</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="562">vertical bar, double, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="563">bar, double vertical, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="564">double vertical bar, in text</indexterm></cindex>
<para>Double vertical bar.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="911">\textbigcircle</indexterm>\textbigcircle</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="565">big circle symbols, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="566">circle symbol, big, in text</indexterm></cindex>
<para>Big circle symbol.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="912">\textbraceleft</indexterm>\textbraceleft</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="567">left brace, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="568">brace, left, in text</indexterm></cindex>
<para>Left brace: &lbrace;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="913">\textbraceright</indexterm>\textbraceright</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="569">right brace, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="570">brace, right, in text</indexterm></cindex>
<para>Right brace: &rbrace;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="914">\textbullet</indexterm>\textbullet</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="571">bullet, in text</indexterm></cindex>
<para>Bullet: &bullet;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="915">\textcircled&lbrace;<var>letter</var>&rbrace;</indexterm>\textcircled&lbrace;<var>letter</var>&rbrace;</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="572">circled letter, in text</indexterm></cindex>
<para><var>letter</var> in a circle, as in &registered;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="916">\textcompwordmark</indexterm>\textcompwordmark</itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="917">\textcapitalcompwordmark</indexterm>\textcapitalcompwordmark</itemformat></itemx>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="918">\textascendercompwordmark</indexterm>\textascendercompwordmark</itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="573">composite word mark, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="574">cap height</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="575">ascender height</indexterm></cindex>
<para>Composite word mark (invisible).  The <code>\textcapital...</code> form
has the cap height of the font, while the <code>\textascender...</code> form
has the ascender height.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="919">\textdagger</indexterm>\textdagger</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="576">dagger, in text</indexterm></cindex>
<para>Dagger: <math>\dag</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="920">\textdaggerdbl</indexterm>\textdaggerdbl</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="577">dagger, double, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="578">double dagger, in text</indexterm></cindex>
<para>Double dagger: <math>\ddag</math>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="921">\textdollar <r>(or <code>\$</code>)</r></indexterm>\textdollar <r>(or <code>\$</code>)</r></itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="579">dollar sign</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="580">currency, dollar</indexterm></cindex>
<para>Dollar sign: $.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="922">\textemdash <r>(or <code>---</code>)</r></indexterm>\textemdash <r>(or <code>---</code>)</r></itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="581">em-dash</indexterm></cindex>
<para>Em-dash: &textmdash; (for punctuation).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="923">\textendash <r>(or <code>--</code>)</r></indexterm>\textendash <r>(or <code>--</code>)</r></itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="582">e-dash</indexterm></cindex>
<para>En-dash: &textndash; (for ranges).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="924">\texteuro</indexterm>\texteuro</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="583">euro symbol</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="584">currency, euro</indexterm></cindex>
<para>The Euro symbol: &euro;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="925">\textexclamdown <r>(or <code>!`</code>)</r></indexterm>\textexclamdown <r>(or <code>!`</code>)</r></itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="585">exclamation point, upside-down</indexterm></cindex>
<para>Upside down exclamation point: &iexcl;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="926">\textgreater</indexterm>\textgreater</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="586">greater than symbol, in text</indexterm></cindex>
<para>Greater than: &gt;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="927">\textless</indexterm>\textless</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="587">less than symbol, in text</indexterm></cindex>
<para>Less than: &lt;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="928">\textleftarrow</indexterm>\textleftarrow</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="588">arrow, left, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="589">left arrow, in text</indexterm></cindex>
<para>Left arrow.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="929">\textordfeminine</indexterm>\textordfeminine</itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="930">\textordmasculine</indexterm>\textordmasculine</itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="590">feminine ordinal symbol</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="591">masculine ordinal symbol</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="592">ordinals, feminine and masculine</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="593">Spanish ordinals, feminine and masculine</indexterm></cindex>
<para>Feminine and masculine ordinal symbols: &ordf;, &ordm;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="931">\textperiodcentered</indexterm>\textperiodcentered</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="594">period, centered, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="595">centered period, in text</indexterm></cindex>
<para>Centered period: <U>00B7</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="932">\textquestiondown <r>(or <code>?`</code>)</r></indexterm>\textquestiondown <r>(or <code>?`</code>)</r></itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="596">question mark, upside-down</indexterm></cindex>
<para>Upside down question mark: &iquest;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="933">\textquotedblleft <r>(or <code>``</code>)</r></indexterm>\textquotedblleft <r>(or <code>``</code>)</r></itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="597">left quote, double</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="598">double left quote</indexterm></cindex>
<para>Double left quote: &textldquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="934">\textquotedblright <r>(or <code>''</code>)</r></indexterm>\textquotedblright <r>(or <code>''</code>)</r></itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="599">right quote, double</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="600">double right quote</indexterm></cindex>
<para>Double right quote: &textrdquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="935">\textquoteleft <r>(or <code>`</code>)</r></indexterm>\textquoteleft <r>(or <code>`</code>)</r></itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="601">left quote, single</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="602">single left quote</indexterm></cindex>
<para>Single left quote: &textlsquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="936">\textquoteright <r>(or <code>'</code>)</r></indexterm>\textquoteright <r>(or <code>'</code>)</r></itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="603">right quote, single</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="604">single right quote</indexterm></cindex>
<para>Single right quote: &textrsquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="937">\textquotesingle</indexterm>\textquotesingle</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="605">quote, single straight</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="606">straight single quote</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="607">single quote, straight</indexterm></cindex>
<para>Straight single quote.  (From TS1 encoding.)
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="938">\textquotestraightbase</indexterm>\textquotestraightbase</itemformat></item>
<itemx spaces=" "><itemformat command="code"><indexterm index="fn" number="939">\textquotestraightdblbase</indexterm>\textquotestraightdblbase</itemformat></itemx>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="608">quote, straight base</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="609">straight quote, base</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="610">double quote, straight base</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="611">straight double quote, base</indexterm></cindex>
<para>Single and double straight quotes on the baseline.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="940">\textregistered</indexterm>\textregistered</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="612">registered symbol</indexterm></cindex>
<para>Registered symbol: &registered;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="941">\textrightarrow</indexterm>\textrightarrow</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="613">arrow, right, in text</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="614">right arrow, in text</indexterm></cindex>
<para>Right arrow.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="942">\textthreequartersemdash</indexterm>\textthreequartersemdash</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="615">three-quarters em-dash</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="616">em-dash, three-quarters</indexterm></cindex>
<para>&textldquo;Three-quarters&textrdquo; em-dash, between en-dash and em-dash.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="943">\texttrademark</indexterm>\texttrademark</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="617">trademark symbol</indexterm></cindex>
<para>Trademark symbol: <U>2122</U>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="944">\texttwelveudash</indexterm>\texttwelveudash</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="618">two-thirds em-dash</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="619">em-dash, two-thirds</indexterm></cindex>
<para>&textldquo;Two-thirds&textrdquo; em-dash, between en-dash and em-dash.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="945">\textunderscore</indexterm>\textunderscore</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="620">underscore, in text</indexterm></cindex>
<para>Underscore: _.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code"><indexterm index="fn" number="946">\textvisiblespace</indexterm>\textvisiblespace</itemformat></item>
</tableterm><tableitem><cindex index="cp" spaces=" "><indexterm index="cp" number="621">visible space symbol, in text</indexterm></cindex>
<para>Visible space symbol.
</para>
</tableitem></tableentry></ftable>


</section>
<node name="Accents" spaces=" "><nodename>Accents</nodename><nodenext automatic="on">Additional Latin letters</nodenext><nodeprev automatic="on">Text symbols</nodeprev><nodeup automatic="on">Special insertions</nodeup></node>
<section spaces=" "><sectiontitle>Accents</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="622">accents</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="623">characters, accented</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="624">letters, accented</indexterm></cindex>

<cindex index="cp" spaces=" "><indexterm index="cp" number="625"><r>package</r>, <code>babel</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="626"><code>babel</code> <r>package</r></indexterm></cindex>

<cindex index="cp" spaces=" "><indexterm index="cp" number="627">multilingual support</indexterm></cindex>
<para>&latex; has wide support for many of the world&textrsquo;s scripts and
languages, through the <code>babel</code> package and related support.  This
section does not attempt to cover all that support.  It merely lists
the core &latex; commands for creating accented characters.
</para>
<para>The <code>\capital...</code> commands produce alternative forms for use with
capital letters.  These are not available with OT1.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">\&quot;</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitaldieresis</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="947">\&quot; <r>(umlaut accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="948">\capitaldieresis</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="628">umlaut accent</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="629">dieresis accent</indexterm></cindex>
<para>Produces an umlaut (dieresis), as in <accent type="uml">o</accent>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\'</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitalacute</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="949">\' <r>(acute accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="950">\capitalacute</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="630">acute accent</indexterm></cindex>
<para>Produces an acute accent, as in <accent type="acute">o</accent>.  In the <code>tabbing</code>
environment, pushes current column to the right of the previous column
(<pxref label="tabbing"><xrefnodename>tabbing</xrefnodename></pxref>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\.</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="951">\. <r>(dot-over accent)</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="631">dot accent</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="632">dot-over accent</indexterm></cindex>
<para>Produces a dot accent over the following, as in <accent type="dotaccent">o</accent>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\=</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitalmacron</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="952">\= <r>(macron accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="953">\capitalmacron</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="633">macron accent</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="634">overbar accent</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="635">bar-over accent</indexterm></cindex>
<para>Produces a macron (overbar) accent over the following, as in <accent type="macr">o</accent>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\^</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitalcircumflex</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="954">\^ <r>(circumflex accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="955">\capitalcircumflex</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="636">circumflex accent</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="637">hat accent</indexterm></cindex>
<para>Produces a circumflex (hat) accent over the following, as in <accent type="circ">o</accent>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\`</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitalgrave</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="956">\` <r>(grave accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="957">\capitalgrave</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="638">grave accent</indexterm></cindex>
<para>Produces a grave accent over the following, as in <accent type="grave">o</accent>.  In the
<code>tabbing</code> environment, move following text to the right margin
(<pxref label="tabbing"><xrefnodename>tabbing</xrefnodename></pxref>).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\~</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitaltilde</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="958">\~ <r>(tilde accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="959">\capitaltilde</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="639">tilde accent</indexterm></cindex>
<para>Produces a tilde accent over the following, as in <accent type="tilde">n</accent>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\b</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="960">\b <r>(bar-under accent)</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="640">bar-under accent</indexterm></cindex>
<para>Produces a bar accent under the following, as in <accent type="ubaraccent">o</accent>. See
also <code>\underbar</code> hereinafter.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\c</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitalcedilla</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="961">\c <r>(cedilla accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="962">\capitalcedilla</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="641">cedilla accent</indexterm></cindex>
<para>Produces a cedilla accent under the following, as in <accent type="cedil">c</accent>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\d</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitaldotaccent</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="963">\d <r>(dot-under accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="964">\capitaldotaccent</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="642">dot-under accent</indexterm></cindex>
<para>Produces a dot accent under the following, as in <accent type="udotaccent">o</accent>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\H</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitalhungarumlaut</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="965">\H <r>(Hungarian umlaut accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="966">\capitalhungarumlaut</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="643">hungarian umlaut accent</indexterm></cindex>
<para>Produces a long Hungarian umlaut accent over the following, as in <accent type="doubleacute">o</accent>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\i</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="967">\i <r>(dotless i)</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="644">dotless i</indexterm></cindex>
<para>Produces a dotless i, as in &textlsquo;<dotless>i</dotless>&textrsquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\j</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="968">\j <r>(dotless j)</r></indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="645">dotless j</indexterm></cindex>
<para>Produces a dotless j, as in &textlsquo;<dotless>j</dotless>&textrsquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\k</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitalogonek</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="969">\k <r>(ogonek)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="970">\capitalogonek</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="646">ogonek</indexterm></cindex>
<para>Produces a letter with ogonek, as in &textlsquo;<accent type="ogon">o</accent>&textrsquo;.  Not available in
the OT1 encoding.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\r</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitalring</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="971">\r <r>(ring accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="972">\capitalring</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="647">ring accent</indexterm></cindex>
<para>Produces a ring accent, as in &textlsquo;<accent type="ring">o</accent>&textrsquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\t</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitaltie</itemformat></itemx>
<itemx spaces=" "><itemformat command="code">\newtie</itemformat></itemx>
<itemx spaces=" "><itemformat command="code">\capitalnewtie</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="973">\t <r>(tie-after accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="974">\capitaltie</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="975">\newtie</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="976">\capitalnewtie</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="648">tie-after accent</indexterm></cindex>
<para>Produces a tie-after accent, as in &textlsquo;<accent type="tieaccent">oo</accent>&textrsquo;.  The
<code>\newtie</code> form is centered in its box.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\u</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitalbreve</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="977">\u <r>(breve accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="978">\capitalbreve</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="649">breve accent</indexterm></cindex>
<para>Produces a breve accent, as in &textlsquo;<accent type="breve">o</accent>&textrsquo;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\underbar</itemformat></item>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="979">\underbar</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="650">underbar</indexterm></cindex>
<para>Not exactly an accent, this produces a bar under the argument text.
The argument is always processed in horizontal mode.  The bar is
always a fixed position under the baseline, thus crossing through
descenders.  See also <code>\underline</code> in <ref label="Math-miscellany"><xrefnodename>Math miscellany</xrefnodename></ref>.
See also <code>\b</code> above.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\v</itemformat></item>
<itemx spaces=" "><itemformat command="code">\capitalcaron</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="980">\v <r>(breve accent)</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="981">\capitalcaron</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="651">hacek accent</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="652">check accent</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="653">caron accent</indexterm></cindex>
<para>Produces a h<accent type="acute" bracketed="off">a</accent><accent type="caron">c</accent>ek (check, caron) accent, as in &textlsquo;<accent type="caron">o</accent>&textrsquo;.
</para>
</tableitem></tableentry></table>


</section>
<node name="Additional-Latin-letters" spaces=" "><nodename>Additional Latin letters</nodename><nodenext automatic="on">\rule</nodenext><nodeprev automatic="on">Accents</nodeprev><nodeup automatic="on">Special insertions</nodeup></node>
<section spaces=" "><sectiontitle>Additional Latin letters</sectiontitle>

<anchor name="Non_002dEnglish-characters">Non-English characters</anchor>
<cindex index="cp" spaces=" "><indexterm index="cp" number="654">Latin letters, additional</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="655">letters, additional Latin</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="656">extended Latin</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="657">special characters</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="658">non-English characters</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="659">characters, non-English</indexterm></cindex>

<para>Here are the basic &latex; commands for inserting letters (beyond
A&textndash;Z) extending the Latin alphabet, used primarily in languages other
than English.
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">\aa</itemformat></item>
<itemx spaces=" "><itemformat command="code">\AA</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="982">\aa (&aring;)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="983">\AA (&Aring;)</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="660">aring</indexterm></cindex>
<para>&aring; and &Aring;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ae</itemformat></item>
<itemx spaces=" "><itemformat command="code">\AE</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="984">\ae (&aelig;)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="985">\AE (&AElig;)</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="661">ae ligature</indexterm></cindex>
<para>&aelig; and &AElig;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\dh</itemformat></item>
<itemx spaces=" "><itemformat command="code">\DH</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="986">\dh (&eth;)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="987">\DH (&ETH;)</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="662">Icelandic eth</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="663">eth, Icelandic letter</indexterm></cindex>
<para>Icelandic letter eth: &eth; and &ETH;. Not available with <sc>OT1</sc>
encoding, you need the <file>fontenc</file> package to select an alternate
font encoding, such as <sc>T1</sc>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\dj</itemformat></item>
<itemx spaces=" "><itemformat command="code">\DJ</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="988">\dj</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="989">\DJ</indexterm></findex>
<para>Crossed d and D, a.k.a.&noeos; capital and small letter d with stroke.  Not
available with <sc>OT1</sc> encoding, you need the <file>fontenc</file> package to
select an alternate font encoding, such as <sc>T1</sc>.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ij</itemformat></item>
<itemx spaces=" "><itemformat command="code">\IJ</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="990">\ij (ij)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="991">\IJ (IJ)</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="664">ij letter, Dutch</indexterm></cindex>
<para>ij and IJ (except somewhat closer together than appears here).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\l</itemformat></item>
<itemx spaces=" "><itemformat command="code">\L</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="992">\l (&lslash;)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="993">\L (&Lslash;)</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="665">polish l</indexterm></cindex>
<para>&lslash; and &Lslash;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ng</itemformat></item>
<itemx spaces=" "><itemformat command="code">\NG</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="994">\ng</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="995">\NG</indexterm></findex>
<para>Lappish letter eng, also used in phonetics.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\o</itemformat></item>
<itemx spaces=" "><itemformat command="code">\O</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="996">\o (&oslash;)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="997">\O (&Oslash;)</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="666">oslash</indexterm></cindex>
<para>&oslash; and &Oslash;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\oe</itemformat></item>
<itemx spaces=" "><itemformat command="code">\OE</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="998">\oe (&oelig;)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="999">\OE (&OElig;)</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="667">oe ligature</indexterm></cindex>
<para>&oelig; and &OElig;.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\ss</itemformat></item>
<itemx spaces=" "><itemformat command="code">\SS</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="1000">\ss (&szlig;)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="1001">\SS (SS)</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="668">es-zet German letter</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="669">sharp S letters</indexterm></cindex>
<para>&szlig; and SS.
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">\th</itemformat></item>
<itemx spaces=" "><itemformat command="code">\TH</itemformat></itemx>
</tableterm><tableitem><findex index="fn" spaces=" "><indexterm index="fn" number="1002">\th (&thorn;)</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="1003">\TH (&THORN;)</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="670">Icelandic thorn</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="671">thorn, Icelandic letter</indexterm></cindex>
<para>Icelandic letter thorn: &thorn; and &THORN;. Not available with <sc>OT1</sc>
encoding, you need the <file>fontenc</file> package to select an alternate
font encoding, such as <sc>T1</sc>.
</para>
</tableitem></tableentry></table>


</section>
<node name="_005crule" spaces=" "><nodename>\rule</nodename><nodenext automatic="on">\today</nodenext><nodeprev automatic="on">Additional Latin letters</nodeprev><nodeup automatic="on">Special insertions</nodeup></node>
<section spaces=" "><sectiontitle><code>\rule</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1004">\rule</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\rule[<var>raise</var>]&lbrace;<var>width</var>&rbrace;&lbrace;<var>thickness</var>&rbrace;
</pre></example>

<para>The <code>\rule</code> command produces <dfn>rules</dfn>, that is, lines or
rectangles.  The arguments are:
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="var">raise</itemformat></item>
</tableterm><tableitem><para>How high to raise the rule (optional).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">width</itemformat></item>
</tableterm><tableitem><para>The length of the rule (mandatory).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">thickness</itemformat></item>
</tableterm><tableitem><para>The thickness of the rule (mandatory).
</para></tableitem></tableentry></table>


</section>
<node name="_005ctoday" spaces=" "><nodename>\today</nodename><nodeprev automatic="on">\rule</nodeprev><nodeup automatic="on">Special insertions</nodeup></node>
<section spaces=" "><sectiontitle><code>\today</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1005">\today</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="672">date, today&textrsquo;s</indexterm></cindex>

<para>The <code>\today</code> command produces today&textrsquo;s date, in the format
<samp><var>month</var> <var>dd</var>, <var>yyyy</var></samp>; for example, <samp>July 4, 1976</samp>.
It uses the predefined counters <code>\day</code>, <code>\month</code>, and
<code>\year</code> (<pxref label="_005cday-_005cmonth-_005cyear"><xrefnodename>\day \month \year</xrefnodename></pxref>) to do this.  It is not
updated as the program runs.
</para>
<para>Multilingual packages like <file>babel</file> or classes like <file>lettre</file>,
among others, will localize <code>\today</code>. For example, the following
will output <samp>4 juillet 1976</samp>:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\year=1976 \month=7 \day=4
\documentclass&lbrace;minimal&rbrace;
\usepackage[french]&lbrace;babel&rbrace;
\begin&lbrace;document&rbrace;
\today
\end&lbrace;document&rbrace;
</pre></example>

<cindex index="cp" spaces=" "><indexterm index="cp" number="673"><r>package</r>, <code>datetime</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="674"><code>datetime</code> <r>package</r></indexterm></cindex>

<para>The <code>datetime</code> package, among others, can produce a wide variety
of other date formats.
</para>

</section>
</chapter>
<node name="Splitting-the-input" spaces=" "><nodename>Splitting the input</nodename><nodenext automatic="on">Front/back matter</nodenext><nodeprev automatic="on">Special insertions</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Splitting the input</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="675">splitting the input file</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="676">input file</indexterm></cindex>

<para>A large document requires a lot of input.  Rather than putting the whole
input in a single large file, it&textrsquo;s more efficient to split it into
several smaller ones.  Regardless of how many separate files you use,
there is one that is the 
<cindex index="cp" spaces=" "><indexterm index="cp" number="677">root file</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="678">file, root</indexterm></cindex>
<dfn>root file</dfn>; it is the one whose name you type
when you run &latex;.
</para>
<para><xref label="filecontents"><xrefnodename>filecontents</xrefnodename></xref>, for an environment that allows bundling an
external file to be created with the main document.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::            ">\include</menunode><menudescription><pre xml:space="preserve">Conditionally include a file.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::        ">\includeonly</menunode><menudescription><pre xml:space="preserve">Determine which files are included.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::              ">\input</menunode><menudescription><pre xml:space="preserve">Unconditionally include a file.
</pre></menudescription></menuentry></menu>


<node name="_005cinclude" spaces=" "><nodename>\include</nodename><nodenext automatic="on">\includeonly</nodenext><nodeup automatic="on">Splitting the input</nodeup></node>
<section spaces=" "><sectiontitle><code>\include</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1006">\include</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\include&lbrace;<var>file</var>&rbrace;
</pre></example>

<para>If no <code>\includeonly</code> command is present, the <code>\include</code>
command executes <code>\clearpage</code> to start a new page
(<pxref label="_005cclearpage"><xrefnodename>\clearpage</xrefnodename></pxref>), then reads <var>file</var>, then does another
<code>\clearpage</code>.
</para>
<para>Given an <code>\includeonly</code> command, the <code>\include</code> actions are
only run if <var>file</var> is listed as an argument to
<code>\includeonly</code>.  See <ref label="_005cincludeonly"><xrefnodename>\includeonly</xrefnodename></ref>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="679">nested <code>\include</code>, not allowed</indexterm></cindex>
<para>The <code>\include</code> command may not appear in the preamble or in a file
read by another <code>\include</code> command.
</para>

</section>
<node name="_005cincludeonly" spaces=" "><nodename>\includeonly</nodename><nodenext automatic="on">\input</nodenext><nodeprev automatic="on">\include</nodeprev><nodeup automatic="on">Splitting the input</nodeup></node>
<section spaces=" "><sectiontitle><code>\includeonly</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1007">\includeonly</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\includeonly&lbrace;<var>file1</var>,<var>file2</var>,...&rbrace;
</pre></example>

<para>The <code>\includeonly</code> command controls which files will be read by
subsequent <code>\include</code> commands.  The list of filenames is
comma-separated. Each element <var>file1</var>, <var>file2</var>, &dots; must
exactly match a filename specified in a <code>\include</code> command for the
selection to be effective.
</para>
<para>This command can only appear in the preamble.
</para>

</section>
<node name="_005cinput" spaces=" "><nodename>\input</nodename><nodeprev automatic="on">\includeonly</nodeprev><nodeup automatic="on">Splitting the input</nodeup></node>
<section spaces=" "><sectiontitle><code>\input</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1008">\input</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\input&lbrace;<var>file</var>&rbrace;
</pre></example>

<para>The <code>\input</code> command causes the specified <var>file</var> to be read
and processed, as if its contents had been inserted in the current
file at that point.
</para>
<para>If <var>file</var> does not end in <samp>.tex</samp> (e.g., <samp>foo</samp> or
<samp>foo.bar</samp>), it is first tried with that extension (<samp>foo.tex</samp>
or <samp>foo.bar.tex</samp>).  If that is not found, the original <var>file</var>
is tried (<samp>foo</samp> or <samp>foo.bar</samp>).
</para>

</section>
</chapter>
<node name="Front_002fback-matter" spaces=" "><nodename>Front/back matter</nodename><nodenext automatic="on">Letters</nodenext><nodeprev automatic="on">Splitting the input</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Front/back matter</sectiontitle>

<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::">Tables of contents</menunode><menudescription><pre xml:space="preserve">
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::">Glossaries</menunode><menudescription><pre xml:space="preserve">
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::">Indexes</menunode><menudescription><pre xml:space="preserve">
</pre></menudescription></menuentry></menu>


<node name="Tables-of-contents" spaces=" "><nodename>Tables of contents</nodename><nodenext automatic="on">Glossaries</nodenext><nodeup automatic="on">Front/back matter</nodeup></node>
<section spaces=" "><sectiontitle>Tables of contents</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="680">table of contents, creating</indexterm></cindex>

<findex index="fn" spaces=" "><indexterm index="fn" number="1009">\tableofcontents</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="1010">.toc <r>file</r></indexterm></findex>
<para>A table of contents is produced with the <code>\tableofcontents</code>
command.  You put the command right where you want the table of
contents to go; &latex; does the rest for you.  A previous run must
have generated a <file>.toc</file> file.
</para>
<para>The <code>\tableofcontents</code> command produces a heading, but it does
not automatically start a new page.  If you want a new page after the
table of contents, write a <code>\newpage</code> command after the
<code>\tableofcontents</code> command.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="1011">\listoffigures</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="1012">\listoftables</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="1013">.lof <r>file</r></indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="1014">.lot <r>file</r></indexterm></findex>
<para>The analogous commands <code>\listoffigures</code> and <code>\listoftables</code>
produce a list of figures and a list of tables (from <file>.lof</file> and
<file>.lot</file> files), respectively.  Everything works exactly the same
as for the table of contents.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="1015">\nofiles</indexterm></findex>
<para>The command <code>\nofiles</code> overrides these commands, and
<emph>prevents</emph> any of these lists from being generated.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::    ">\addcontentsline</menunode><menudescription><pre xml:space="preserve">Add an entry to table of contents, etc.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::      ">\addtocontents</menunode><menudescription><pre xml:space="preserve">Add text directly to table of contents file, etc.
</pre></menudescription></menuentry></menu>


<node name="_005caddcontentsline" spaces=" "><nodename>\addcontentsline</nodename><nodenext automatic="on">\addtocontents</nodenext><nodeup automatic="on">Tables of contents</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\addcontentsline</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1016">\addcontentsline</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="681">table of contents entry, manually adding</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\addcontentsline&lbrace;<var>ext</var>&rbrace;&lbrace;<var>unit</var>&rbrace;&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>The <code>\addcontentsline</code> command adds an entry to the specified list
or table where:
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="var">ext</itemformat></item>
</tableterm><tableitem><para>The filename extension of the file on which information is to be written,
typically one of: <code>toc</code> (table of contents), <code>lof</code> (list of
figures), or <code>lot</code> (list of tables).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">unit</itemformat></item>
</tableterm><tableitem><para>The name of the sectional unit being added, typically one of the
following, matching the value of the <var>ext</var> argument:
</para>
<table commandarg="code" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="code">toc</itemformat></item>
</tableterm><tableitem><para>The name of the sectional unit: <code>part</code>, <code>chapter</code>,
<code>section</code>, <code>subsection</code>, <code>subsubsection</code>.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">lof</itemformat></item>
</tableterm><tableitem><para>For the list of figures: <code>figure</code>.
</para></tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="code">lot</itemformat></item>
</tableterm><tableitem><para>For the list of tables: <code>table</code>.
</para></tableitem></tableentry></table>

</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">text</itemformat></item>
</tableterm><tableitem><para>The text of the entry.
</para></tableitem></tableentry></table>

<findex index="fn" spaces=" "><indexterm index="fn" number="1017">\contentsline</indexterm></findex>
<para>What is written to the <file>.<var>ext</var></file> file is the command
<code>\contentsline&lbrace;<var>unit</var>&rbrace;&lbrace;<var>text</var>&rbrace;&lbrace;<var>num</var>&rbrace;</code>, where
<code><var>num</var></code> is the current value of counter <code><var>unit</var></code>.
</para>
<!-- c xx how hardwired are these values?  other unit names? -->


</subsection>
<node name="_005caddtocontents" spaces=" "><nodename>\addtocontents</nodename><nodeprev automatic="on">\addcontentsline</nodeprev><nodeup automatic="on">Tables of contents</nodeup></node>
<subsection spaces=" "><sectiontitle><code>\addtocontents</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1018">\addtocontents&lbrace;<var>ext</var>&rbrace;&lbrace;<var>text</var>&rbrace;</indexterm></findex>

<para>The <code>\addtocontents</code>&lbrace;<var>ext</var>&rbrace;&lbrace;<var>text</var>&rbrace; command adds text
(or formatting commands) directly to the <file>.<var>ext</var></file> file that
generates the table of contents or lists of figures or tables.
</para>
<table commandarg="var" spaces=" " endspaces=" ">
<tableentry><tableterm><item spaces=" "><itemformat command="var">ext</itemformat></item>
</tableterm><tableitem><para>The extension of the file on which information is to be written,
typically one of: <file>toc</file> (table of contents), <file>lof</file> (list of
figures), or <file>lot</file> (list of tables).
</para>
</tableitem></tableentry><tableentry><tableterm><item spaces=" "><itemformat command="var">text</itemformat></item>
</tableterm><tableitem><para>The text to be written.
</para></tableitem></tableentry></table>


</subsection>
</section>
<node name="Glossaries" spaces=" "><nodename>Glossaries</nodename><nodenext automatic="on">Indexes</nodenext><nodeprev automatic="on">Tables of contents</nodeprev><nodeup automatic="on">Front/back matter</nodeup></node>
<section spaces=" "><sectiontitle>Glossaries</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="682">glossaries</indexterm></cindex>

<findex index="fn" spaces=" "><indexterm index="fn" number="1019">\makeglossary</indexterm></findex>
<para>The command <code>\makeglossary</code> enables creating glossaries.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="1020">\glossary</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="683"><file>.glo</file> file</indexterm></cindex>
<para>The command <code>\glossary&lbrace;<var>text</var>&rbrace;</code> writes a glossary entry for
<var>text</var> to an auxiliary file with the <file>.glo</file> extension.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="1021">\glossaryentry</indexterm></findex>
<para>Specifically, what gets written is the command
<code>\glossaryentry&lbrace;<var>text</var>&rbrace;&lbrace;<var>pageno</var>&rbrace;</code>, where
<var>pageno</var> is the current <code>\thepage</code> value.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="684">glossary <r>package</r></indexterm></cindex>
<para>The <code>glossary</code> package on CTAN provides support for fancier
glossaries.
</para>

</section>
<node name="Indexes" spaces=" "><nodename>Indexes</nodename><nodeprev automatic="on">Glossaries</nodeprev><nodeup automatic="on">Front/back matter</nodeup></node>
<section spaces=" "><sectiontitle>Indexes</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="685">indexes</indexterm></cindex>

<findex index="fn" spaces=" "><indexterm index="fn" number="1022">\makeindex</indexterm></findex>
<para>The command <code>\makeindex</code> enables creating indexes.  Put this in
the preamble.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="1023">\index</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="686"><file>.idx</file> file</indexterm></cindex>
<para>The command <code>\index&lbrace;<var>text</var>&rbrace;</code> writes an index entry for
<var>text</var> to an auxiliary file named with the <file>.idx</file> extension.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="1024">\indexentry</indexterm></findex>
<para>Specifically, what gets written is the command
<code>\indexentry&lbrace;<var>text</var>&rbrace;&lbrace;<var>pageno</var>&rbrace;</code>, where <var>pageno</var>
is the current <code>\thepage</code> value.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="687">&textlsquo;see&textrsquo; and &textlsquo;see also&textrsquo; index entries</indexterm></cindex>
<cindex index="cp" spaces="  "><indexterm index="cp" number="688">index entries, &textlsquo;see&textrsquo; and &textlsquo;see also&textrsquo;</indexterm></cindex>
<para>To generate a index entry for &textlsquo;bar&textrsquo; that says &textlsquo;See foo&textrsquo;, use a
vertical bar: <code>\index&lbrace;bar|see&lbrace;foo&rbrace;&rbrace;</code>.  Use <code>seealso</code>
instead of <code>see</code> to make a &textlsquo;See also&textrsquo; entry.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="1025">\seename</indexterm></findex>
<findex index="fn" spaces=" "><indexterm index="fn" number="1026">\alsoname</indexterm></findex>
<para>The text &textlsquo;See&textrsquo; is defined by the macro <code>\seename</code>, and &textlsquo;See also&textrsquo;
by the macro <code>\alsoname</code>.  These can be redefined for other
languages.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="689"><command>makeindex</command> program</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="690"><command>xindy</command> program</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="691"><file>.ind</file> file</indexterm></cindex>
<para>The generated <file>.idx</file> file is then sorted with an external
command, usually either <command>makeindex</command>
(<url><urefurl>http://mirror.ctan.org/indexing/makeindex</urefurl></url>) or (the
multi-lingual) <command>xindy</command> (<url><urefurl>http://xindy.sourceforge.net</urefurl></url>).
This results in a <file>.ind</file> file, which can then be read to typeset
the index.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="1027">\printindex</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="692"><r>package</r>, <code>makeidx</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="693"><code>makeidx</code> <r>package</r></indexterm></cindex>

<para>The index is usually generated with the <code>\printindex</code> command.
This is defined in the <code>makeidx</code> package, so
<code>\usepackage&lbrace;makeidx&rbrace;</code> needs to be in the preamble.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="1028">\indexspace</indexterm></findex>
<para>The rubber length <code>\indexspace</code> is inserted before each new
letter in the printed index; its default value is <samp>10pt plus5pt
minus3pt</samp>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="694"><r>package</r>, <code>showidx</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="695"><code>showidx</code> <r>package</r></indexterm></cindex>

<para>The <code>showidx</code> package causes each index entries to be shown in
the margin on the page where the entry appears.  This can help in
preparing the index.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="696"><r>package</r>, <code>multind</code></indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="697"><code>multind</code> <r>package</r></indexterm></cindex>

<para>The <code>multind</code> package supports multiple indexes.  See also the
&tex; FAQ entry on this topic,
<url><urefurl>http://www.tex.ac.uk/cgi-bin/texfaq2html?label=multind</urefurl></url>.
</para>

</section>
</chapter>
<node name="Letters" spaces=" "><nodename>Letters</nodename><nodenext automatic="on">Terminal input/output</nodenext><nodeprev automatic="on">Front/back matter</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Letters</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="698">letters, writing</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="699">writing letters</indexterm></cindex>

<para>Synopsis: 
</para>
<example endspaces=" ">
<pre xml:space="preserve">\documentclass&lbrace;letter&rbrace;
\address&lbrace;<var>sender address</var>&rbrace;
\signature&lbrace;<var>sender name</var>&rbrace;
\begin&lbrace;document&rbrace;
\begin&lbrace;letter&rbrace;&lbrace;<var>recipient address</var>&rbrace;
\opening&lbrace;<var>salutation</var>&rbrace;
  <var>letter body</var>
\closing&lbrace;<var>closing text</var>&rbrace;
\end&lbrace;letter&rbrace;
...  more letters ...
\end&lbrace;document&rbrace;
</pre></example>

<para>Produce one or more letters.  
</para>
<para>Each letter is in a separate <code>letter</code> environment, whose argument
<var>recipient address</var> often contains multiple lines separated with a
double backslash&nbsp;(<code>\\</code>).  For example, you might have:
</para>
<example endspaces=" ">
<pre xml:space="preserve"> \begin&lbrace;letter&rbrace;&lbrace;Mr. Joe Smith \\ 
      2345 Princess St. \\ 
      Edinburgh, EH1 1AA&rbrace;
   ...
 \end&lbrace;letter&rbrace;
</pre></example>

<para>The start of the <code>letter</code> environment resets the page number to 1,
and the footnote number to 1 also.
</para>
<para>The <var>sender address</var> and <var>sender name</var> are common to all of the
letters, whether there is one or more, so these are best put in the
preamble.  As with the recipient address, often <var>sender address</var>
contains multiple lines separated by a double
backslash&nbsp;(<code>\\</code>).  &latex; will put the <var>sender name</var>
under the closing, after a vertical space for the traditional
hand-written signature; it also can contain multiple lines.
</para>
<para>Each <code>letter</code> environment body begins with a required <code>\opening</code> command
such as <code>\opening&lbrace;Dear Madam or Sir:&rbrace;</code>.  The <var>letter body</var>
text is ordinary &latex; so it can contain everything from
enumerated lists to displayed math, except that commands such as
<code>\chapter</code> that make no sense in a letter are turned off.  Each
<code>letter</code> environment body typically ends with a <code>\closing</code>
command such as <code>\closing&lbrace;Yours,&rbrace;</code>.
</para>
<findex index="fn" spaces=" "><indexterm index="fn" number="1029">\\ <r>for letters</r></indexterm></findex>
<para>Additional material may come after the <code>\closing</code>.  You can say who
is receiving a copy of the letter with a command like <code>\cc&lbrace;the
Boss \\ the Boss's Boss&rbrace;</code>.  There&textrsquo;s a similar <code>\encl</code> command for
a list of enclosures.  And, you can add a postscript with <code>\ps</code>.
</para>
<para>&latex;&textrsquo;s default is to indent the signature and the <code>\closing</code>
above it by a length of <code>\longindentation</code>.  By default this is
<code>0.5\textwidth</code>. To make them flush left, put
<code>\setlength&lbrace;\longindentation&rbrace;&lbrace;0em&rbrace;</code> in your preamble.
</para>
<para>To set a fixed date use something like
<code>\renewcommand&lbrace;\today&rbrace;&lbrace;2015-Oct-12&rbrace;</code>.  If put in your preamble
then it will apply to all the letters.
</para>
<para>This example shows only one <code>letter</code> environment.  The three lines
marked as optional are typically omitted.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\documentclass&lbrace;letter&rbrace;
\address&lbrace;Sender's street \\ Sender's town&rbrace;
\signature&lbrace;Sender's name \\ Sender's title&rbrace;
% optional: \location&lbrace;Mailbox 13&rbrace;
% optional: \telephone&lbrace;(102) 555-0101&rbrace;
\begin&lbrace;document&rbrace;
\begin&lbrace;letter&rbrace;&lbrace;Recipient's name \\ Recipient's address&rbrace;
\opening&lbrace;Sir:&rbrace;
% optional: \thispagestyle&lbrace;firstpage&rbrace;
I am not interested in entering a business arrangement with you.
\closing&lbrace;Your most humble, etc.,&rbrace;
\end&lbrace;letter&rbrace;
\end&lbrace;document&rbrace;
</pre></example>

<para>These commands are used with the <code>letter</code> class.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::                       ">\address</menunode><menudescription><pre xml:space="preserve">Sender&textrsquo;s return address.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                            ">\cc</menunode><menudescription><pre xml:space="preserve">Carbon copy list.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                       ">\closing</menunode><menudescription><pre xml:space="preserve">Saying goodbye.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                          ">\encl</menunode><menudescription><pre xml:space="preserve">List of enclosed material.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                      ">\location</menunode><menudescription><pre xml:space="preserve">Sender&textrsquo;s organizational location.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                    ">\makelabels</menunode><menudescription><pre xml:space="preserve">Make address labels.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                          ">\name</menunode><menudescription><pre xml:space="preserve">Sender&textrsquo;s name, for the return address.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                       ">\opening</menunode><menudescription><pre xml:space="preserve">Saying hello.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                            ">\ps</menunode><menudescription><pre xml:space="preserve">Adding a postscript.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                     ">\signature</menunode><menudescription><pre xml:space="preserve">Sender&textrsquo;s signature.
<!-- c ?Not user-level? * \stopbreaks and \startbreaks::   Disallow and allow page breaks. -->
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::                     ">\telephone</menunode><menudescription><pre xml:space="preserve">Sender&textrsquo;s phone number.
</pre></menudescription></menuentry></menu>


<node name="_005caddress" spaces=" "><nodename>\address</nodename><nodenext automatic="on">\cc</nodenext><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\address</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1030">\address</indexterm></findex>

<para>Synopsis: 
</para>
<example endspaces=" ">
<pre xml:space="preserve">\address&lbrace;<var>senders address</var>&rbrace;
</pre></example>

<para>Specifies the return address as it appears on the letter and on the
envelope.  Separate multiple lines in <var>senders address</var> with a
double backslash&nbsp;<code>\\</code>.
</para>
<para>Because it can apply to multiple letters this declaration is often put
in the preamble.  However, it can go anywhere, including inside an
individual <code>letter</code> environment.
</para>
<para>This command is optional: without the <code>\address</code> declaration the
letter is formatted with some blank space on top, for copying onto
pre-printed letterhead paper.  (<xref label="Overview"><xrefnodename>Overview</xrefnodename></xref>, for details on your
local implementation.)  With the <code>\address</code> declaration, it is
formatted as a personal letter.
</para>
<para>Here is an example.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\address&lbrace;Stephen Maturin \\
         The Grapes of the Savoy&rbrace;
</pre></example>


</section>
<node name="_005ccc" spaces=" "><nodename>\cc</nodename><nodenext automatic="on">\closing</nodenext><nodeprev automatic="on">\address</nodeprev><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\cc</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1031">\cc</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="700">cc list, in letters</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\cc&lbrace;<var>first name</var> \\ 
     ... &rbrace;
</pre></example>

<para>Produce a list of names to which copies of the letter were sent.  This
command is optional.  If it appears then typically it comes after
<code>\closing</code>.  Separate multiple lines with a double
backslash&nbsp;<code>\\</code>, as in:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\cc&lbrace;President \\
    Vice President&rbrace;
</pre></example>


</section>
<node name="_005cclosing" spaces=" "><nodename>\closing</nodename><nodenext automatic="on">\encl</nodenext><nodeprev automatic="on">\cc</nodeprev><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\closing</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1032">\closing</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="701">letters, ending</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="702">closing letters</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\closing&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>Usually at the end of a letter, above the handwritten signature, there
is a <code>\closing</code> (although this command is optional).  For example,
</para>
<example endspaces=" ">
<pre xml:space="preserve">\closing&lbrace;Regards,&rbrace;
</pre></example>


</section>
<node name="_005cencl" spaces=" "><nodename>\encl</nodename><nodenext automatic="on">\location</nodenext><nodeprev automatic="on">\closing</nodeprev><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\encl</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1033">\encl</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="703">enclosure list</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\encl&lbrace;<var>first enclosed object</var> \\ 
       ... &rbrace;
</pre></example>

<para>Produce a list of things included with the letter. This command is
optional; when it is used, it typically is put after <code>\closing</code>.
Separate multiple lines with a double backslash&nbsp;<code>\\</code>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\encl&lbrace;License \\
       Passport &rbrace;
</pre></example>


</section>
<node name="_005clocation" spaces=" "><nodename>\location</nodename><nodenext automatic="on">\makelabels</nodenext><nodeprev automatic="on">\encl</nodeprev><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\location</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1034">\location</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\location&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>The <var>text</var> appears centered at the bottom of the each page.  It only
appears if the page style is <code>firstpage</code>.
</para>

</section>
<node name="_005cmakelabels" spaces=" "><nodename>\makelabels</nodename><nodenext automatic="on">\name</nodenext><nodeprev automatic="on">\location</nodeprev><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\makelabels</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1035">\makelabels</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\makelabels
</pre></example>

<para>Create a sheet of address labels from the recipient addresses, one for
each letter. This sheet will be output before the letters, with the idea
that you can copy it to a sheet of peel-off labels.  This command goes
in the preamble.
</para>
<para>Customize the labels by redefining the commands <code>\startlabels</code>,
<code>\mlabel</code>, and <code>\returnaddress</code> in the preamble.  The command
<code>\startlabels</code> sets the width, height, number of columns, etc., of
the page onto which the labels are printed.  The command
<code>\mlabel&lbrace;<var>sender address</var>&rbrace;&lbrace;<var>recipient address</var>&rbrace;</code>
produces the two labels (or one, if you choose to ignore the <var>sender
address</var>). The <var>sender address</var> is the value returned by the macro
<code>\returnaddress</code> while <var>recipient address</var> is the value passed
in the argument to the <code>letter</code> environment.  By default
<code>\mlabel</code> ignores the first argument, the <var>sender address</var>.
</para>
<!-- c xxx TODO, align on latex2e-fr.texi, see https://mail.gna.org/public/latexrefman-discuss/2015-10/msg00000.html -->

</section>
<node name="_005cname" spaces=" "><nodename>\name</nodename><nodenext automatic="on">\opening</nodenext><nodeprev automatic="on">\makelabels</nodeprev><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\name</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1036">\name</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\name&lbrace;<var>name</var>&rbrace;
</pre></example>

<para>Sender&textrsquo;s name, used for printing on the envelope together with the
return address.
</para>

</section>
<node name="_005copening" spaces=" "><nodename>\opening</nodename><nodenext automatic="on">\ps</nodenext><nodeprev automatic="on">\name</nodeprev><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\opening</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1037">\opening</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="704">letters, starting</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\opening&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>This command is required.  It starts a letter, following the
<code>\begin&lbrace;letter&rbrace;&lbrace;...&rbrace;</code>. The mandatory argument <var>text</var> is the
text that starts your letter.  For instance:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\opening&lbrace;Dear John:&rbrace;
</pre></example>


</section>
<node name="_005cps" spaces=" "><nodename>\ps</nodename><nodenext automatic="on">\signature</nodenext><nodeprev automatic="on">\opening</nodeprev><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\ps</code></sectiontitle>
<findex index="fn" spaces=" "><indexterm index="fn" number="1038">\ps</indexterm></findex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="705">postscript, in letters</indexterm></cindex>

<para>Synopsis:
</para>
<example endspaces=" "> 
<pre xml:space="preserve">\ps&lbrace;<var>text</var>&rbrace;
</pre></example>

<para>Add a postscript.  This command is optional and usually is used after
<code>\closing</code>.
</para>
<example endspaces=" ">
<pre xml:space="preserve">\ps&lbrace;P.S. After you have read this letter, burn it. Or eat it.&rbrace;
</pre></example>


</section>
<node name="_005csignature" spaces=" "><nodename>\signature</nodename><nodenext automatic="on">\telephone</nodenext><nodeprev automatic="on">\ps</nodeprev><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\signature</code></sectiontitle>

<para>Synopsis:
</para>
<example endspaces=" "> 
<pre xml:space="preserve">\signature&lbrace;<var>first line</var> \\
            ... &rbrace;
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="1039">\signature</indexterm></findex>

<para>The sender&textrsquo;s name.  This command is optional, although its inclusion is
usual.
</para>
<para>The argument text appears at the end of the letter, after the closing
and after a vertical space for the traditional hand-written
signature. Separate multiple lines with a double
backslash&nbsp;<code>\\</code>.  For example:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\signature&lbrace;J Fred Muggs \\
           White House&rbrace;
</pre></example>

<para>&latex;&textrsquo;s default for the vertical space from the <code>\closing</code> text
down to the <code>\signature</code> text is <code>6\medskipamount</code>, which is
six times 0.7<dmn>em</dmn>.
</para>
<para>This command is usually in the preamble, to apply to all the letters in
the document.  To have it apply to one letter only, put it inside a
<code>letter</code> environment and before the <code>\closing</code>.
</para>
<para>You can include a graphic in the signature, for instance with
<code>\signature&lbrace;\vspace&lbrace;-6\medskipamount&rbrace;\includegraphics&lbrace;sig.png&rbrace;\\
My name&rbrace;</code> (this requires writing <code>\usepackage&lbrace;graphicx&rbrace;</code> in the
preamble).
</para>

<!-- c I think this is not a user-level command; it is used to keep from breaking -->
<!-- c the page between the closing and the signature -->
<!-- c @node \stopbreaks and \startbreaks -->
<!-- c @section @code{\stopbreaks} and @code{\startbreaks} -->

<!-- c @findex \startbreak -->
<!-- c @findex \stopbreaks -->

<!-- c @example  -->
<!-- c @code{\stopbreaks} -->
<!-- c text -->
<!-- c @code{\startbreaks} -->
<!-- c @end example -->

<!-- c The @code{\stopbreaks} inhibits page breaking.  The @code{\startbreaks} resumes -->
<!-- c normal page breaking. -->
<!-- c -->
<!-- c -->
</section>
<node name="_005ctelephone" spaces=" "><nodename>\telephone</nodename><nodeprev automatic="on">\signature</nodeprev><nodeup automatic="on">Letters</nodeup></node>
<section spaces=" "><sectiontitle><code>\telephone</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1040">\telephone</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\telephone&lbrace;<var>number</var>&rbrace;
</pre></example>

<para>The sender&textrsquo;s telephone number.  This is typically in the preamble, where
it applies to all letters.  This only appears if the <code>firstpage</code>
pagestyle is selected.  If so, it appears on the lower right of the
page.
</para>

</section>
</chapter>
<node name="Terminal-input_002foutput" spaces=" "><nodename>Terminal input/output</nodename><nodenext automatic="on">Command line</nodenext><nodeprev automatic="on">Letters</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Terminal input/output</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="706">input/output, to terminal</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="707">terminal input/output</indexterm></cindex>

<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::             ">\typein</menunode><menudescription><pre xml:space="preserve">Read text from the terminal.
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::            ">\typeout</menunode><menudescription><pre xml:space="preserve">Write text to the terminal.
</pre></menudescription></menuentry></menu>


<node name="_005ctypein" spaces=" "><nodename>\typein</nodename><nodenext automatic="on">\typeout</nodenext><nodeup automatic="on">Terminal input/output</nodeup></node>
<section spaces=" "><sectiontitle><code>\typein[<var>cmd</var>]&lbrace;<var>msg</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1041">\typein</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\typein[\<var>cmd</var>]&lbrace;<var>msg</var>&rbrace;
</pre></example>

<para><code>\typein</code> prints <var>msg</var> on the terminal and causes &latex; to
stop and wait for you to type a line of input, ending with return.  If
the optional <code>\<var>cmd</var></code> argument is omitted, the typed input is
processed as if it had been included in the input file in place of the
<code>\typein</code> command.  If the <code>\<var>cmd</var></code> argument is present, it
must be a command name.  This command name is then defined or
redefined to be the typed input.
</para>

</section>
<node name="_005ctypeout" spaces=" "><nodename>\typeout</nodename><nodeprev automatic="on">\typein</nodeprev><nodeup automatic="on">Terminal input/output</nodeup></node>
<section spaces=" "><sectiontitle><code>\typeout&lbrace;<var>msg</var>&rbrace;</code></sectiontitle>

<findex index="fn" spaces=" "><indexterm index="fn" number="1042">\typeout</indexterm></findex>

<para>Synopsis:
</para>
<example endspaces=" ">
<pre xml:space="preserve">\typeout&lbrace;<var>msg</var>&rbrace;
</pre></example>

<para>Prints <code>msg</code> on the terminal and in the <code>log</code> file.
Commands in <code>msg</code> that are defined with <code>\newcommand</code> or
<code>\renewcommand</code> (among others) are replaced by their definitions
before being printed.
</para>
<para>&latex;&textrsquo;s usual rules for treating multiple spaces as a single space
and ignoring spaces after a command name apply to <code>msg</code>.  A
<code>\space</code> command in <code>msg</code> causes a single space to be
printed, independent of surrounding spaces.  A <code>^^J</code> in
<code>msg</code> prints a newline.
</para>

</section>
</chapter>
<node name="Command-line" spaces=" "><nodename>Command line</nodename><nodenext automatic="on">Document templates</nodenext><nodeprev automatic="on">Terminal input/output</nodeprev><nodeup automatic="on">Top</nodeup></node>
<chapter spaces=" "><sectiontitle>Command line</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="708">command line</indexterm></cindex>

<findex index="fn" spaces=" "><indexterm index="fn" number="1043">.tex, <r>default extension</r></indexterm></findex>
<para>The input file specification indicates the file to be formatted;
&tex; uses <file>.tex</file> as a default file extension.  If you omit the
input file entirely, &tex; accepts input from the terminal.  You can
also specify arbitrary &latex; input by starting with a backslash.
For example, this processes <file>foo.tex</file> without pausing after every
error:
</para>
<example endspaces=" ">
<pre xml:space="preserve">latex '\nonstopmode\input foo.tex'
</pre></example>

<findex index="fn" spaces=" "><indexterm index="fn" number="1044">--help <r>command-line option</r></indexterm></findex>
<para>With many, but not all, implementations, command-line options can also
be specified in the usual Unix way, starting with <samp>-</samp> or
<samp>--</samp>.  For a list of those options, try <samp>latex --help</samp>.
</para>
<cindex index="cp" spaces=" "><indexterm index="cp" number="709"><samp>*</samp> prompt</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="710">prompt, <samp>*</samp></indexterm></cindex>
<findex index="fn" spaces=" "><indexterm index="fn" number="1045">\stop</indexterm></findex>
<para>If &latex; stops in the middle of the document and gives you a
<samp>*</samp> prompt, it is waiting for input.  You can type <code>\stop</code>
(and return) and it will prematurely end the document.
</para>
<para><xref label="TeX-engines"><xrefnodename>&tex; engines</xrefnodename></xref>, for other system commands invoking &latex;.
</para>

</chapter>
<node name="Document-templates" spaces=" "><nodename>Document templates</nodename><nodenext automatic="on">Concept Index</nodenext><nodeprev automatic="on">Command line</nodeprev><nodeup automatic="on">Top</nodeup></node>
<appendix spaces=" "><sectiontitle>Document templates</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="711">document templates</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="712">templates, document</indexterm></cindex>

<para>Although not reference material, perhaps these document templates will
be useful.  Additional template resources are listed at
<url><urefurl>http://tug.org/interest.html#latextemplates</urefurl></url>.
</para>
<menu endspaces=" ">
<menuentry leadingtext="* "><menunode separator="::">beamer template</menunode><menudescription><pre xml:space="preserve">
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::">book template</menunode><menudescription><pre xml:space="preserve">
</pre></menudescription></menuentry><menuentry leadingtext="* "><menunode separator="::">tugboat template</menunode><menudescription><pre xml:space="preserve">
</pre></menudescription></menuentry></menu>


<node name="beamer-template" spaces=" "><nodename>beamer template</nodename><nodenext automatic="on">book template</nodenext><nodeup automatic="on">Document templates</nodeup></node>
<section spaces=" "><sectiontitle><code>beamer</code> template</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="713"><code>beamer</code> template and class</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="714">template, <code>beamer</code></indexterm></cindex>

<para>The <code>beamer</code> class creates presentation slides.  It has a vast
array of features, but here is a basic template:
</para>
<verbatim xml:space="preserve">
\documentclass{beamer}

\title{Beamer Class template}
\author{Alex Author}
\date{July 31, 2007}

\begin{document}

\maketitle

% without [fragile], any {verbatim} code gets mysterious errors.
\begin{frame}[fragile]
 \frametitle{First Slide}

\begin{verbatim}
  This is \verbatim!
\end{verbatim}

\end{frame}

\end{document}
</verbatim>

<para>One web resource for this:
<url><urefurl>http://robjhyndman.com/hyndsight/beamer/</urefurl></url>.
</para>

</section>
<node name="book-template" spaces=" "><nodename>book template</nodename><nodenext automatic="on">tugboat template</nodenext><nodeprev automatic="on">beamer template</nodeprev><nodeup automatic="on">Document templates</nodeup></node>
<section spaces=" "><sectiontitle><code>book</code> template</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="715">template, <code>book</code></indexterm></cindex>

<verbatim xml:space="preserve">
\documentclass{book}
\title{Book Class Template}
\author{Alex Author}

\begin{document}
\maketitle

\chapter{First}
Some text.

\chapter{Second}
Some other text.

\section{A subtopic}
The end.
\end{document}
</verbatim>


</section>
<node name="tugboat-template" spaces=" "><nodename>tugboat template</nodename><nodeprev automatic="on">book template</nodeprev><nodeup automatic="on">Document templates</nodeup></node>
<section spaces=" "><sectiontitle><code>tugboat</code> template</sectiontitle>

<cindex index="cp" spaces=" "><indexterm index="cp" number="716">template, TUGboat</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="717">TUGboat template</indexterm></cindex>
<cindex index="cp" spaces=" "><indexterm index="cp" number="718"><code>ltugboat</code> class</indexterm></cindex>

<para><cite>TUGboat</cite> is the journal of the &tex; Users Group,
<url><urefurl>http://tug.org/TUGboat</urefurl></url>.
</para>
<verbatim xml:space="preserve">
\documentclass{ltugboat}

\usepackage{graphicx}
\usepackage{ifpdf}
\ifpdf
\usepackage[breaklinks,hidelinks]{hyperref}
\else
\usepackage{url}
\fi

%%% Start of metadata %%%

\title{Example \TUB\ article}

% repeat info for each author.
\author{First Last}
\address{Street Address \\ Town, Postal \\ Country}
\netaddress{user (at) example dot org}
\personalURL{http://example.org/~user/}

%%% End of metadata %%%

\begin{document}

\maketitle

\begin{abstract}
This is an example article for \TUB{}.
Please write an abstract.
\end{abstract}

\section{Introduction}

This is an example article for \TUB, linked from
\url{http://tug.org/TUGboat/location.html}.

We recommend the \texttt{graphicx} package for image inclusions, and the
\texttt{hyperref} package if active urls are desired (in the \acro{PDF}
output).  Nowadays \TUB\ is produced using \acro{PDF} files exclusively.

The \texttt{ltugboat} class provides these abbreviations (and many more):
% verbatim blocks are often better in \small
\begin{verbatim}[\small]
\AllTeX \AMS \AmS \AmSLaTeX \AmSTeX \aw \AW
\BibTeX \CTAN \DTD \HTML
\ISBN \ISSN \LaTeXe
\mf \MFB
\plain \POBox \PS
\SGML \TANGLE \TB \TP
\TUB \TUG \tug
\UNIX \XeT \WEB \WEAVE

\, \bull \Dash \dash \hyph

\acro{FRED} -&gt; {\small[er] fred}  % please use!
\cs{fred}   -&gt; \fred
\meta{fred} -&gt; &lt;fred&gt;
\nth{n}     -&gt; 1st, 2nd, ...
\sfrac{3/4} -&gt; 3/4
\booktitle{Book of Fred}
\end{verbatim}

For references to other \TUB\ issue, please use the format
\textsl{volno:issno}, e.g., ``\TUB\ 32:1'' for our \nth{100} issue.

This file is just a template.  The \TUB\ style documentation is the
\texttt{ltubguid} document at \url{http://ctan.org/pkg/tugboat}.  (For
\CTAN\ references, where sensible we recommend that form of url, using
\texttt{/pkg/}; or, if you need to refer to a specific file location,
\texttt{http://mirror.ctan.org/\textsl{path}}.)

Email \verb|tugboat@tug.org| if problems or questions.

\bibliographystyle{plain}  % we recommend the plain bibliography style
\nocite{book-minimal}      % just making the bibliography non-empty
\bibliography{xampl}       % xampl.bib comes with BibTeX

\makesignature
\end{document}
</verbatim>


</section>
</appendix>
<node name="Concept-Index" spaces=" "><nodename>Concept Index</nodename><nodenext automatic="on">Command Index</nodenext><nodeprev automatic="on">Document templates</nodeprev><nodeup automatic="on">Top</nodeup></node>
<unnumbered spaces=" "><sectiontitle>Concept Index</sectiontitle>

<printindex value="cp" line=" cp"></printindex>

<!-- c The name of the `Command Index' node must NOT be altered for ltx-help.el. -->
</unnumbered>
<node name="Command-Index" spaces=" "><nodename>Command Index</nodename><nodeprev automatic="on">Concept Index</nodeprev><nodeup automatic="on">Top</nodeup></node>
<unnumbered spaces=" "><sectiontitle>Command Index</sectiontitle>

<printindex value="fn" line=" fn"></printindex>

</unnumbered>
<bye></bye>
</texinfo>