\input texinfo @c $Id: latex2e.texi 613 2018-03-21 18:48:08Z jimhefferon $ @comment %**start of header (This is for running Texinfo on a region.) @setfilename latex2e.info @set UPDATED March 2018 @include common.texi @settitle @LaTeX{}2e unofficial reference manual (@value{UPDATED}) @comment %**end of header (This is for running Texinfo on a region.) @c latex 2.09 commands should all be present now, @c xx but latex2e stuff is missing. @c xx random list of a few of the missing items is at the end of this file @c @c xx ending a run with errors @c xx ctan, distributions, components of TeX @c xx classes and packages -- required, additional, useful; oberdiek; fonts @c @c xx merge http://ctan.org/pkg/latex-info (CTAN package latex-info) @c xx merge http://ctan.org/pkg/latex2e-reference @c xx merge permuted-index @c xx merge latex-manual from savannah @c xx merge display style math @c xx vertical mode, horizontal mode @c xx JH Discuss restricted execution @c @c xx The typeset source2e has an index with all kernel @c xx commands, though some are internal and shouldn't be included. @c xx classes.dtx et al. define additional commands. @c xx See also http://ctan.org/pkg/macros2e. @copying This document is an unofficial reference manual for @LaTeX{}, a document preparation system, version of @value{UPDATED}. This manual was originally translated from @file{LATEX.HLP} v1.0a in the VMS Help Library. The pre-translation version was written by George@tie{}D. Greenwade of Sam Houston State University. The @LaTeX{}@tie{}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{}}, by Sheldon Green, and @cite{@LaTeX{} Command Summary} (for @LaTeX{}@tie{}2.09) by L.@tie{}Botway and C.@tie{}Biemesderfer (published by the @TeX{} Users Group as @cite{@TeX{}niques} number 10), as reference material (no text was directly copied). Copyright 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 Karl Berry.@* Copyright 1988, 1994, 2007 Stephen Gilmore.@* Copyright 1994, 1995, 1996 Torsten Martinsen. @comment start of License 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. @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). @end ignore 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. 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 @end copying @dircategory TeX @direntry * LaTeX2e: (latex2e). Unofficial LaTeX reference manual. @end direntry @tex \global\hbadness=4444 % don't complain much @end tex @titlepage @title @LaTeX{}2e: An unofficial reference manual @subtitle @value{UPDATED} @author @url{@value{LTXREFMAN_HOME_PAGE}} @page @vskip 0pt plus 1filll @insertcopying @end titlepage @shortcontents @contents @c Best Effort Symbol @iftex @macro BES {utf8,math} @math{\math\} @end macro @macro BESU {utf8,math} @code{@backslashchar{}\math\} @end macro @end iftex @ifnottex @macro BES {utf8,math} @U{\utf8\} @end macro @macro BESU {utf8,math} @U{\utf8\} @end macro @end ifnottex @macro EnvIndex {env} @findex @r{environment}, @code{\env\} @findex @code{\env\} @r{environment} @end macro @macro PkgIndex {pkg} @cindex @r{package}, @code{\pkg\} @cindex @code{\pkg\} @r{package} @end macro @set NotInPlainTeX Not available in plain @TeX{}. @set NeedsAMSSymb @value{NotInPlainTeX} In @LaTeX{} you need to load the @file{amssymb} package. @set NeedsSTIX @value{NotInPlainTeX} In @LaTeX{} you need to load the @file{stix} package. @node Top @top @LaTeX{}2e: An unofficial reference manual This document is an unofficial reference manual (version of @value{UPDATED}) for @LaTeX{}2e, a document preparation system. @menu * About this document:: Bug reporting, etc. * Overview:: What is @LaTeX{}? * Document classes:: Some of the various classes available. * Fonts:: Italic, bold, typewriter, etc. * Layout:: Controlling the page layout. * Sectioning:: How to section properly. * Cross references:: Automatic referencing. * Environments:: Such as enumerate & itemize. * Line breaking:: Influencing line breaks. * Page breaking:: Influencing page breaks. * Footnotes:: How to produce footnotes. * Definitions:: Define your own commands, etc. * Counters:: Internal counters used by @LaTeX{}. * Lengths:: The length commands. * Making paragraphs:: Paragraph commands. * Math formulas:: How to create mathematical formulas. * Modes:: Paragraph, Math or LR modes. * Page styles:: Various styles of page layout. * Spaces:: Horizontal and vertical space. * Boxes:: Making boxes. * Color:: Defining and using colors. * Graphics:: Importing graphics from outside @LaTeX{}. * Special insertions:: Inserting reserved and special characters. * Splitting the input:: Dealing with big files by splitting. * Front/back matter:: Tables of contents, glossaries, indexes. * Letters:: The @code{letter} class. * Terminal input/output:: User interaction. * Command line:: System-independent command-line behavior. * Document templates:: Starter templates for various document classes. * Concept Index:: General index. * Command Index:: Alphabetical list of @LaTeX{} commands. @end menu @node About this document @chapter About this document @findex @url{@value{LTXREFMAN_HOME_PAGE}} @r{home page} This is an unofficial reference manual for the @LaTeX{}2e document preparation system, which is a macro package for the @TeX{} typesetting program (@pxref{Overview}). This document's home page is @url{@value{LTXREFMAN_HOME_PAGE}}. That page has links to the current output in various formats, sources, mailing list archives and subscriptions, and other infrastructure. @cindex @LaTeX{} vs.@: @LaTeX{}2e In this document, we will mostly just use `@LaTeX{}' rather than `@LaTeX{}2e', since the previous version of @LaTeX{}@tie{}(2.09) was frozen decades ago. @cindex unofficial nature of this manual @cindex @LaTeX{} Project team @findex @email{@value{LTXREFMAN_BUGS}} @r{email address} @LaTeX{} is currently maintained by a group of volunteers (@url{http://latex-project.org}). 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 bug reporting @cindex reporting bugs Do not send bug reports or anything else about this document to them. Instead, please send all comments to @email{@value{LTXREFMAN_BUGS}}. 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. @table @url @item http://ctan.org/pkg/latex-doc-ptr @findex latex-doc-ptr @r{document} Two pages of recommended references to @LaTeX{} documentation. @item http://ctan.org/pkg/first-latex-doc @findex first-latex-doc @r{document} Writing your first document, with a bit of both text and math. @item http://ctan.org/pkg/usrguide @findex usrguide @r{official documentation} 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: @item http://ctan.org/pkg/lshort @findex lshort @r{document} A short introduction to @LaTeX{}, translated to many languages. @item http://tug.org/begin.html Introduction to the @TeX{} system, including @LaTeX{}, with further references. @end table @node Overview @chapter Overview of @LaTeX{} @cindex overview of @LaTeX{} @cindex basics of @LaTeX{} @cindex Knuth, Donald E. @cindex Lamport, Leslie @cindex @LaTeX{} overview @LaTeX{} is a system for typesetting documents. It was originally created by Leslie Lamport and is now maintained by a group of volunteers (@url{http://latex-project.org}). It is widely used, particularly for complex and technical documents, such as those involving mathematics. @cindex macro package, @LaTeX{} as 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@tie{}E. Knuth's @TeX{} typesetting program (the technical term is that @LaTeX{} is a @dfn{macro package} for the @TeX{} engine). The user produces the output document by giving that input file to the @TeX{} engine. 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. @cindex Lamport @TeX{} @cindex pronunciation The name @LaTeX{} is short for ``Lamport @TeX{}''. It is pronounced LAH-teck or LAY-teck, or sometimes LAY-tecks. Inside a document, produce the logo with @code{\LaTeX}. Where use of the logo is not sensible, such as in plain text, write it as @samp{LaTeX}. @menu * Starting and ending:: The standard beginning and end of a document. * Output files:: Files produced. * @TeX{} engines:: Programs that can compile @TeX{} and @LaTeX{}. * @LaTeX{} command syntax:: General syntax of @LaTeX{} commands. @end menu @node Starting and ending @section Starting and ending @anchor{Starting & ending}@c old name @cindex starting and ending @cindex ending and starting @cindex hello, world @LaTeX{} files have a simple global structure, with a standard beginning and ending. Here is a ``hello, world'' example: @example \documentclass@{article@} \begin@{document@} Hello, \LaTeX\ world. \end@{document@} @end example @cindex document class, defined @noindent Here, the @samp{article} is the so-called @dfn{document class}, implemented in a file @file{article.cls}. Any document class can be used. A few document classes are defined by @LaTeX{} itself, and vast array of others are widely available. @xref{Document classes}. @cindex preamble, defined You can include other @LaTeX{} commands between the @code{\documentclass} and the @code{\begin@{document@}} commands. This area is called the @dfn{preamble}. The @code{\begin@{document@} ... \end@{document@}} is a so-called @cindex environment @dfn{environment}; the @samp{document} environment (and no others) is required in all @LaTeX{} documents (@pxref{document}). @LaTeX{} provides many environments itself, and many more are defined separately. @xref{Environments}. The following sections discuss how to produce PDF or other output from a @LaTeX{} input file. @node Output files @section Output files @LaTeX{} produces a main output file and at least two accessory files. The main output file's name ends in either @file{.dvi} or @file{.pdf}. @table @code @item .dvi @findex .dvi @r{file} @findex latex @r{command} @findex xdvi @r{command} @findex dvips @r{command} @findex dvipdfmx @r{command} @findex dvitype @r{command} If @LaTeX{} is invoked with the system command @command{latex} then it produces a DeVice Independent file, with extension @file{.dvi}. You can view this file with a command such as @command{xdvi}, or convert it to a PostScript @code{.ps} file with @command{dvips} or to a Portable Document Format @code{.pdf} file with @command{dvipdfmx}. The contents of the file can be dumped in human-readable form with @command{dvitype}. A vast array of other DVI utility programs are available (@url{http://mirror.ctan.org/dviware}). @item .pdf @findex .pdf @r{file} @cindex pdf@TeX{} @findex pdflatex @r{command} If @LaTeX{} is invoked via the system command @command{pdflatex}, among other commands (@pxref{@TeX{} engines}), then the main output is a Portable Document Format (PDF) file. Typically this is a self-contained file, with all fonts and images included. @end table @LaTeX{} also produces at least two additional files. @table @code @item .log @cindex transcript file @cindex log file @findex .log @r{file} 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. @item .aux @cindex auxiliary file @findex .aux @r{file} @cindex cross references, resolving @cindex forward references, resolving @cindex references, resolving forward Auxiliary information is used by @LaTeX{} for things such as cross references. For example, the first time that @LaTeX{} finds a forward reference---a cross reference to something that has not yet appeared in the source---it will appear in the output as a doubled question mark @code{??}. When the referred-to spot does eventually appear in the source then @LaTeX{} writes its location information to this @code{.aux} 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. @end table @findex .lof @r{file} @cindex list of figures file @findex .lot @r{file} @cindex list of tables file @findex .toc @r{file} @cindex table of contents file @cindex contents file @LaTeX{} may produce yet more files, characterized by the filename ending. These include a @code{.lof} file that is used to make a list of figures, a @code{.lot} file used to make a list of tables, and a @code{.toc} file used to make a table of contents. A particular class may create others; the list is open-ended. @node @TeX{} engines @section @TeX{} engines @cindex engines, @TeX{} @cindex implementations of @TeX{} @cindex UTF-8 @cindex Unicode input, native @cindex TrueType fonts @cindex OpenType fonts @LaTeX{} is defined to be a set of commands that are run by a @TeX{} implementation (@pxref{Overview}). This section gives a terse overview of the main programs. @table @code @item latex @itemx pdflatex @cindex pdf@TeX{} engine @findex etex @r{command} @cindex e-@TeX{} In @TeX{} Live (@url{http://tug.org/texlive}), if @LaTeX{} is invoked via either the system command @command{latex} or @command{pdflatex}, then the pdf@TeX{} engine is run (@url{http://ctan.org/pkg/pdftex}). When invoked as @command{latex}, the main output is a @file{.dvi} file; as @command{pdflatex}, the main output is a @file{.pdf} file. pdf@TeX{} incorporates the e-@TeX{} extensions to Knuth's original program (@url{http://ctan.org/pkg/etex}), 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}, but this is plain @TeX{} (and produces @file{.dvi}). In other @TeX{} distributions, @command{latex} may invoke e-@TeX{} rather than pdf@TeX{}. In any case, the e-@TeX{} extensions can be assumed to be available in @LaTeX{}. @item lualatex @findex lualatex @r{command} @cindex Lua@TeX{} If @LaTeX{} is invoked via the system command @command{lualatex}, the Lua@TeX{} engine is run (@url{http://ctan.org/pkg/luatex}). This program allows code written in the scripting language Lua (@url{http://luatex.org}) to interact with @TeX{}'s typesetting. Lua@TeX{} handles UTF-8 Unicode input natively, can handle OpenType and TrueType fonts, and produces a @file{.pdf} file by default. There is also @command{dvilualatex} to produce a @file{.dvi} file, but this is rarely used. @item xelatex @findex xelatex @r{command} @cindex Xe@TeX{} @findex .xdv @r{file} @findex xdvipdfmx If @LaTeX{} is invoked with the system command @command{xelatex}, the Xe@TeX{} engine is run (@url{http://tug.org/xetex}). 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 as output; it does not support DVI output. Internally, Xe@TeX{} creates an @code{.xdv} file, a variant of DVI, and translates that to PDF using the (@code{x})@code{dvipdfmx} program, but this process is automatic. The @code{.xdv} file is only useful for debugging. @end table Other variants of @LaTeX{} and @TeX{} exist, e.g., to provide additional support for Japanese and other languages ([u]p@TeX{}, @url{http://ctan.org/pkg/ptex}, @url{http://ctan.org/pkg/uptex}). @node @LaTeX{} command syntax @section @LaTeX{} command syntax @cindex command syntax @findex \ @r{character starting commands} @findex [...] @r{for optional arguments} @findex @{...@} @r{for required arguments} In the @LaTeX{} input file, a command name starts with a backslash character, @code{\}. The name itself then consists of either (a)@tie{}a string of letters or (b)@tie{}a single non-letter. @LaTeX{} commands names are case sensitive so that @code{\pagebreak} differs from @code{\Pagebreak} (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. 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{@{...@}}. Optional arguments are contained in square brackets, @code{[...]}. Generally, but not universally, if the command accepts an optional argument, it comes first, before any required arguments. Inside of an optional argument, to use the character close square bracket@tie{}(@code{]}) hide it inside curly braces, as in@tie{}@code{\item[closing bracket @{]@}]}. 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. @LaTeX{} has the convention that some commands have a @code{*} form that is related to the form without a @code{*}, such as @code{\chapter} and @code{\chapter*}. The exact difference in behavior varies from command to command. This manual describes all accepted options and @code{*}-forms for the commands it covers (barring unintentional omissions, a.k.a.@: bugs). @menu * Environment:: Area of the source with distinct behavior. * Declaration:: Change the value or meaning of a command. * \makeatletter and \makeatother:: Change the status of the at-sign character. @end menu @node Environment @subsection Environments Synopsis: @example \begin@{@var{environment name}@} ... \end@{@var{environment name}@} @end example 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@{verse@}} and @code{\end@{verse@}}. @example \begin@{verse@} There once was a man from Nantucket \\ ... \end@{verse@} @end example See@tie{}@ref{Environments} for a list of environments. The @var{environment name} at the beginning must exactly match that at the end. This includes the case where @var{environment name} ends in a star@tie{}(@code{*}); both the @code{\begin} and @code{\end} texts must include the star. 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). @example \begin@{tabular@}[t]@{r|l@} ... rows of table ... \end@{tabular@} @end example @node Declaration @subsection Command declarations A command that changes the value, or changes the meaning, of some other command or parameter. For instance, the @code{\mainmatter} command changes the setting of page numbers from roman numerals to arabic. @node \makeatletter and \makeatother @subsection @code{\makeatletter} and @code{\makeatother} Synopsis: @example \makeatletter ... definition of commands with @@ in their name .. \makeatother @end example Used to redefine internal @LaTeX{} commands. @code{\makeatletter} makes the at-sign character@tie{}@code{@@} have the category code of a letter, 11. @code{\makeatother} sets the category code of@tie{}@code{@@} to 12, its original value. As each character is read by @TeX{} for @LaTeX{}, it is assigned a character category code, or @cindex catcode @cindex character category code @cindex category code, character @dfn{catcode} for short. For instance, the backslash@tie{}@code{\} is assigned the catcode 0, for characters that start a command. These two commands alter the catcode assigned to @code{@@}. The alteration is needed because many of @LaTeX{}'s commands use @code{@@} in their name, to prevent users from accidentally defining a command that replaces one of @LaTeX{}'s own. Command names consist of a category@tie{}0 character, ordinarily backslash, followed by letters, category@tie{}11 characters (except that a command name can also consist of a category@tie{}0 character followed by a single non-letter symbol). So under the default category codes, user-defined commands cannot contain an @code{@@}. But @code{\makeatletter} and @code{\makeatother} allow users to define or redefine commands named with @code{@@}. Use these two commands inside a @file{.tex} file, in the preamble, when defining or redefining a command with @code{@@} in its name. Don't use them inside @file{.sty} or @file{.cls} files since the @code{\usepackage} and @code{\documentclass} commands set the at sign to have the character code of a letter. @PkgIndex{macros2e} For a comprehensive list of macros with an at-sign in their names see @url{http://ctan.org/pkg/macros2e}. These macros are mainly intended to package or class authors. The example below is typical. In the user's class file is a command @code{\thesis@@universityname}. The user wants to change the definition. These three lines should go in the preamble, before the @code{\begin@{document@}}. @example \makeatletter \renewcommand@{\thesis@@universityname@}@{Saint Michael's College@} \makeatother @end example @menu * \@@ifstar:: Define your own commands with *-variants. @end menu @node \@@ifstar @subsubsection @code{\@@ifstar} @findex \@@ifstar @cindex commands, star-variants @cindex star-variants, commands Synopsis: @example \newcommand@{\mycmd@}@{\@@ifstar@{\mycmd@@star@}@{\mycmd@@nostar@}@} \newcommand@{\mycmd@@nostar@}[@var{non-starred command number of args}]@{@var{body of non-starred command}@} \newcommand@{\mycmd@@star@}[@var{starred command number of args}]@{@var{body of starred command}@} @end example Many standard @LaTeX{} environments or commands have a variant with the same name but ending with a star character@tie{}@code{*}, an asterisk. Examples are the @code{table} and @code{table*} environments and the @code{\section} and @code{\section*} commands. When defining environments, following this pattern is straightforward because @code{\newenvironment} and @code{\renewenvironment} 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}, which peeks ahead to see if it is followed by a star. For instance, @LaTeX{} does not really have a @code{\section*} command; instead, the @code{\section} 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@@nostar} and @code{\mycmd@@star}. 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@tie{}@code{@@} must be enclosed inside a @code{\makeatletter ... \makeatother} block (@pxref{\makeatletter and \makeatother}). This example of @code{\@@ifstar} defines the command @code{\ciel} and a variant @code{\ciel*}. Both have one required argument. A call to @code{\ciel@{night@}} will return "starry night sky" while @code{\ciel*@{blue@}} will return "starry not blue sky". @example \newcommand*@{\ciel@@unstarred@}[1]@{starry #1 sky@} \newcommand*@{\ciel@@starred@}[1]@{starry not #1 sky@} \newcommand*@{\ciel@}@{\@@ifstar@{\ciel@@starred@}@{\ciel@@unstarred@}@} @end example In the next example, the starred variant takes a different number of arguments than does the unstarred one. With this definition, Agent 007's @code{``My name is \agentsecret*@{Bond@}, \agentsecret@{James@}@{Bond@}.''} is equivalent to @code{``My name is \textsc@{Bond@}, \textit@{James@} textsc@{Bond@}.''} @example \newcommand*@{\agentsecret@@unstarred@}[2]@{\textit@{#1@} \textsc@{#2@}@} \newcommand*@{\agentsecret@@starred@}[1]@{\textsc@{#1@}@} \newcommand*@{\agentsecret@}@{\@@ifstar@{\agentsecret@@starred@}@{\agentsecret@@unstarred@}@} @end example There are two sometimes more convenient ways to accomplish the work of @code{\@@ifstar}. The @file{suffix} package allows the construct @code{\newcommand\mycommand@{@var{unstarred version}@}} followed by @code{\WithSuffix\newcommand\mycommand*@{@var{starred version}@}}. And @LaTeX{}3 has the @file{xparse} package that allows this code. @example \NewDocumentCommand\foo@{s@}@{\IfBooleanTF#1 @{@var{starred version}@}% @{@var{unstarred version}@}% @} @end example @node Document classes @chapter Document classes @cindex document classes @cindex classes of documents @findex \documentclass The document's overall class is defined with this command, which is normally the first command in a @LaTeX{} source file. @example \documentclass[@var{options}]@{@var{class}@} @end example @findex article @r{class} @findex report @r{class} @findex book @r{class} @findex letter @r{class} @findex slides @r{class} The following document @var{class} names are built into @LaTeX{}. (Many other document classes are available as separate packages; @pxref{Overview}.) @table @code @item article For a journal article, a presentation, and miscellaneous general use. @item book Full-length books, including chapters and possibly including front matter, such as a preface, and back matter, such as an appendix (@pxref{Front/back matter}). @item letter Mail, optionally including mailing labels (@pxref{Letters}). @item report For documents of length between an @code{article} and a @code{book}, such as technical reports or theses, which may contain several chapters. @item slides For slide presentations---rarely used today. In its place the @code{beamer} package is perhaps the most prevalent (@pxref{beamer template}). @end table Standard @var{options} are described in the next section. @menu * Document class options:: Global options. * Additional packages:: Bring in packages. * Class and package construction:: Create new classes and packages. @end menu @node Document class options @section Document class options @cindex document class options @cindex options, document class @cindex class options @cindex global options You can specify so-called @dfn{global options} or @dfn{class options} to the @code{\documentclass} command by enclosing them in square brackets. To specify more than one @var{option}, separate them with a comma, as in: @example \documentclass[@var{option1},@var{option2},...]@{@var{class}@} @end example Here is the list of the standard class options. @findex 10pt @r{option} @findex 11pt @r{option} @findex 12pt @r{option} All of the standard classes except @code{slides} accept the following options for selecting the typeface size (default is @code{10pt}): @example 10pt 11pt 12pt @end example @findex a4paper @r{option} @findex a5paper @r{option} @findex b5paper @r{option} @findex executivepaper @r{option} @findex legalpaper @r{option} @findex letterpaper @r{option} All of the standard classes accept these options for selecting the paper size (these show height by width): @table @code @item a4paper 210 by 297@dmn{mm} (about 8.25 by 11.75@tie{}inches) @item a5paper 148 by 210@dmn{mm} (about 5.8 by 8.3@tie{}inches) @item b5paper 176 by 250@dmn{mm} (about 6.9 by 9.8@tie{}inches) @item executivepaper 7.25 by 10.5@tie{}inches @item legalpaper 8.5 by 14@tie{}inches @item letterpaper 8.5 by 11@tie{}inches (the default) @end table @findex \pdfpagewidth @findex \pdfpageheight @PkgIndex{geometry} When using one of the engines pdf@LaTeX{}, Lua@LaTeX{}, or Xe@LaTeX{} (@pxref{@TeX{} engines}), options other than @code{letterpaper} set the print area but you must also set the physical paper size. One way to do that is to put @code{\pdfpagewidth=\paperwidth} and @code{\pdfpageheight=\paperheight} in your document's preamble. @PkgIndex{geometry} The @code{geometry} package provides flexible ways of setting the print area and physical page size. @findex draft @r{option} @findex final @r{option} @findex fleqn @r{option} @findex landscape @r{option} @findex leqno @r{option} @findex openbib @r{option} @findex titlepage @r{option} @findex notitlepage @r{option} Miscellaneous other options: @table @code @item draft @itemx final @cindex black boxes, omitting Mark (@code{draft}) or do not mark (@code{final}) overfull boxes with a black box in the margin; default is @code{final}. @item fleqn @cindex flush left equations @cindex centered equations @cindex equations, flush left vs.@: centered Put displayed formulas flush left; default is centered. @item landscape @cindex landscape orientation @cindex portrait orientation Selects landscape format; default is portrait. @item leqno @cindex left-hand equation numbers @cindex right-hand equation numbers @cindex equation numbers, left vs.@: right Put equation numbers on the left side of equations; default is the right side. @item openbib @cindex bibliography format, open Use ``open'' bibliography format. @item titlepage @itemx notitlepage @cindex title page, separate or run-in 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} class is @code{titlepage}, for the other classes it is @code{notitlepage}. @end table The following options are not available with the @code{slides} class. @findex onecolumn @r{option} @findex twocolumn @r{option} @findex oneside @r{option} @findex twoside @r{option} @findex openright @r{option} @findex openany @r{option} @table @code @item onecolumn @itemx twocolumn Typeset in one or two columns; default is @code{onecolumn}. @item oneside @itemx twoside @findex \evensidemargin @findex \oddsidemargin Selects one- or two-sided layout; default is @code{oneside}, except that in the @code{book} class the default is @code{twoside}. For one-sided printing, the text is centered on the page. For two-sided printing, the @code{\evensidemargin} (@code{\oddsidemargin}) parameter determines the distance on even (odd) numbered pages between the left side of the page and the text's left margin, with @code{\oddsidemargin} being 40% of the difference between @code{\paperwidth} and @code{\textwidth}, and @code{\evensidemargin} is the remainder. @item openright @itemx openany Determines if a chapter should start on a right-hand page; default is @code{openright} for @code{book}, and @code{openany} for @code{report}. @end table @findex clock @r{option to @code{slides} class} The @code{slides} class offers the option @code{clock} for printing the time at the bottom of each note. @node Additional packages @section Additional packages @cindex loading additional packages @cindex packages, loading additional @cindex additional packages, loading @findex \usepackage Load a package @var{pkg}, with the package options given in the comma-separated list @var{options}, as here. @example \usepackage[@var{options}]@{@var{pkg}@}. @end example To specify more than one package you can separate them with a comma, as in @code{\usepackage@{@var{pkg1},@var{pkg2},...@}}, or use multiple @code{\usepackage} commands. @cindex global options @cindex options, global Any options given in the @code{\documentclass} command that are unknown to the selected document class are passed on to the packages loaded with @code{\usepackage}. @node Class and package construction @section Class and package construction @cindex document class commands @cindex commands, document class @cindex new class commands 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} and begin your documents with @code{\documentclass@{smcmemo@}}. 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} is for a class. @cindex class and package difference @cindex difference between class and package Inside of a class or package file you can use the at-sign @code{@@} as a character in command names without having to surround the code containing that command with @code{\makeatletter} and @code{\makeatother}. @xref{\makeatletter and \makeatother}. 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} might have commands @code{\smc@@tolist}, @code{\smc@@fromlist}, etc. @menu * Class and package structure:: Layout of the file. * Class and package commands:: List of commands. @end menu @node Class and package structure @subsection Class and package structure @cindex class and package structure @cindex class file layout @cindex package file layout @cindex options, document class @cindex options, package @cindex class options @cindex package options A class file or package file typically has four parts. @enumerate In the @dfn{identification part}, the file says that it is a @LaTeX{} package or class and describes itself, using the @code{\NeedsTeXFormat} and @code{\ProvidesClass} or @code{\ProvidesPackage} commands. @item The @dfn{preliminary declarations part} 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} 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]@{smcmemo@}}, and therefore needs to define a command @code{\newcommand@{\setto@}[1]@{\def\@@tolist@{#1@}@}} used in that file. @item In the @dfn{handle options part} 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{class name}@}}, to modify the behavior of the class. An example is when you declare @code{\documentclass[11pt]@{article@}} to set the default document font size. @item Finally, in the @dfn{more declarations part} the class or package usually does most of its work: declaring new variables, commands and fonts, and loading other files. @end enumerate Here is a starting class file, which should be saved as @file{stub.cls} where @LaTeX{} can find it, for example in the same directory as the @file{.tex} file. @example \NeedsTeXFormat@{LaTeX2e@} \ProvidesClass@{stub@}[2017/07/06 stub to start building classes from] \DeclareOption*@{\PassOptionsToClass@{\CurrentOption@}@{article@}@} \ProcessOptions\relax \LoadClass@{article@} @end example @cindex class file example It identifies itself, handles the class options via the default of passing them all to the @code{article} class, and then loads the @code{article} class to provide the basis for this class's code. For more, see the official guide for class and package writers, the Class Guide, at @url{http://www.latex-project.org/help/documentation/clsguide.pdf} (much of the descriptions here derive from this document), or the tutorial @url{https://www.tug.org/TUGboat/tb26-3/tb84heff.pdf}. @node Class and package commands @subsection Class and package commands @cindex class and package commands @cindex commands, class and package These are the commands designed to help writers of classes or packages. @table @code @item \AtBeginDvi@{specials@} @findex \AtBeginDvi Save in a box register things that are written to the @file{.dvi} file at the beginning of the shipout of the first page of the document. @item \AtEndOfClass@{@var{code}@} @item \AtEndOfPackage@{@var{code}@} @findex \AtEndOfClass @findex \AtEndOfPackage Hook to insert @var{code} to be executed when @LaTeX{} finishes processing the current class or package. You can use these hooks multiple times; the @code{code} will be executed in the order that you called it. See also @ref{\AtBeginDocument}. @item \CheckCommand@{@var{cmd}@}[@var{num}][@var{default}]@{@var{definition}@} @item \CheckCommand*@{@var{cmd}@}[@var{num}][@var{default}]@{@var{definition}@} @findex \CheckCommand @findex \CheckCommand* @cindex new command, check Like @code{\newcommand} (@pxref{\newcommand & \renewcommand}) but does not define @var{cmd}; instead it checks that the current definition of @var{cmd} is exactly as given by @var{definition} and is or is not @cindex long command @dfn{long} as expected. A long command is a command that accepts @code{\par} within an argument. The @var{cmd} command is expected to be long with the unstarred version of @code{\CheckCommand}. Raises an error when the check fails. This allows you to check before you start redefining @code{cmd} yourself that no other package has already redefined this command. @item \ClassError@{@var{class name}@}@{@var{error text}@}@{@var{help text}@} @item \PackageError@{@var{package name}@}@{@var{error text}@}@{@var{help text}@} @item \ClassWarning@{@var{class name}@}@{@var{warning text}@} @item \PackageWarning@{@var{package name}@}@{@var{warning text}@} @item \ClassWarningNoLine@{@var{class name}@}@{@var{warning text}@} @item \PackageWarningNoLine@{@var{package name}@}@{@var{warning text}@} @item \ClassInfo@{@var{class name}@}@{@var{info text}@} @item \PackageInfo@{@var{package name}@}@{@var{info text}@} @item \ClassInfoNoLine@{@var{class name}@}@{@var{info text}@} @item \PackageInfoNoLine@{@var{package name}@}@{@var{info text}@} @findex \ClassError @findex \PackageError @findex \ClassWarning @findex \PackageWarning @findex \ClassWarningNoLine @findex \PackageWarningNoLine @findex \ClassInfo @findex \PackageInfo @findex \ClassInfoNoLine @findex \PackageInfoNoLine Produce an error message, or warning or informational messages. For @code{\ClassError} and @code{\PackageError} the message is @var{error text}, followed by @TeX{}'s @code{?} error prompt. If the user then asks for help by typing @code{h}, they see the @var{help text}. The four warning commands are similar except that they write @var{warning text} on the screen with no error prompt. The four info commands write @var{info text} only in the transcript file. The @code{NoLine} versions do not show the number of the line generating the message, while the other versions do show that number. To format the messages, including the @var{help text}: use @code{\protect} to stop a command from expanding, get a line break with @code{\MessageBreak}, and get a space with @code{\space} when a space character does not allow it, like after a command. Note that @LaTeX{} appends a period to the messages. @item \CurrentOption @findex \CurrentOption Expands to the name of the currently-being-processed option. Can only be used within the @var{code} argument of either @code{\DeclareOption} or @code{\DeclareOption*}. @item \DeclareOption@{@var{option}@}@{@var{code}@} @item \DeclareOption*@{@var{code}@} @findex \DeclareOption @findex \DeclareOption* @cindex class options @cindex package options @cindex options, class @cindex options, package Make an option available to a user, for invoking in their @code{\documentclass} command. For example, the @code{smcmemo} class could have an option allowing users to put the institutional logo on the first page with @code{\documentclass[logo]@{smcmemo@}}. The class file must contain @code{\DeclareOption@{logo@}@{@var{code}@}} (and later, @code{\ProcessOptions}). If you request an option that has not been declared, by default this will produce a warning like @code{Unused global option(s): [badoption].} Change this behaviour with the starred version @code{\DeclareOption*@{@var{code}@}}. For example, many classes extend an existing class, using a declaration such as @code{\LoadClass@{article@}}, and for passing extra options to the underlying class use code such as this. @example \DeclareOption*@{% \PassOptionsToClass@{\CurrentOption@}@{article@}% @} @end example Another example is that the class @code{smcmemo} may allow users to keep lists of memo recipients in external files. Then the user could invoke @code{\documentclass[math]@{smcmemo@}} and it will read the file @code{math.memo}. This code handles the file if it exists and otherwise passes the option to the @code{article} class. @example \DeclareOption*@{\InputIfFileExists@{\CurrentOption.memo@}@{@}@{% \PassOptionsToClass@{\CurrentOption@}@{article@}@}@} @end example @item \DeclareRobustCommand@{@var{cmd}@}[@var{num}][@var{default}]@{@var{definition}@} @item \DeclareRobustCommand*@{@var{cmd}@}[@var{num}][@var{default}]@{@var{definition}@} @findex \DeclareRobustCommand @findex \DeclareRobustCommand* @cindex new command, definition Like @code{\newcommand} and @code{\newcommand*} (@pxref{\newcommand & \renewcommand}) but these declare a robust command, even if some code within the @var{definition} is fragile. (For a discussion of robust and fragile commands @pxref{\protect}.) Use this command to define new robust commands or to redefine existing commands and make them robust. Unlike @code{\newcommand} these do not give an error if macro @var{cmd} already exists; instead, a log message is put into the transcript file if a command is redefined. Commands defined this way are a bit less efficient than those defined using @code{\newcommand} so unless the command's data is fragile and the command is used within a moving argument, use @code{\newcommand}. @PkgIndex{etoolbox} The @code{etoolbox} package offers commands @code{\newrobustcmd}, @code{\newrobustcmd*}, @code{\renewrobustcmd}, @code{\renewrobustcmd*}, @code{\providerobustcmd}, and @code{\providerobustcmd*} which are similar to @code{\newcommand}, @code{\newcommand*}, @code{\renewcommand}, @code{\renewcommand*}, @code{\providecommand}, and @code{\providecommand*}, but define a robust @var{cmd} with two advantages as compared to @code{\DeclareRobustCommand}: @enumerate @item They use the low-level e-@TeX{} protection mechanism rather than the higher level @LaTeX{} @code{\protect} mechanism, so they do not incur the slight loss of performance mentioned above, and @item They make the same distinction between @code{\new@dots{}}, @code{\renew@dots{}}, and @code{\provide@dots{}}, as the standard commands, so they do not just make a log message when you redefine @var{cmd} that already exists, in that case you need to use either @code{\renew@dots{}} or @code{\provide@dots{}} or you get an error. @end enumerate @item \IfFileExists@{@var{file name}@}@{@var{true code}@}@{@var{false code}@} @item \InputIfFileExists@{@var{file name}@}@{@var{true code}@}@{@var{false code}@} @findex \IfFileExists @findex \InputIfFileExists Execute @var{true code} if @LaTeX{} can find the file @file{@var{file name}} and @var{false code} otherwise. In the second case it inputs the file immediately after executing @var{true code}. Thus @code{\IfFileExists@{img.pdf@}@{\includegraphics@{img.pdf@}@}@{\typeout@{WARNING: img.pdf not found@}@}} will include the graphic @file{img.pdf} if it is found but otherwise just give a warning. 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@{./filename@}@{@var{true code}@}@{@var{false code}@}}. If you ask for a filename without a @code{.tex} extension then @LaTeX{} will first look for the file by appending the @code{.tex}; for more on how @LaTeX{} handles file extensions see @ref{\input}. @item \LoadClass[@var{options list}]@{@var{class name}@}[@var{release date}] @item \LoadClassWithOptions@{@var{class name}@}[@var{release date}] @findex \LoadClass @findex \LoadClassWithOptions Load a class, as with @code{\documentclass[@var{options list}]@{@var{class name}@}[@var{release info}]}. An example is @code{\LoadClass[twoside]@{article@}}. The @var{options list}, if present, is a comma-separated list. The @var{release date} is optional. If present it must have the form @var{YYYY/MM/DD}. @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. If you request a @var{release date} 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.} The command version @code{\LoadClassWithOptions} uses the list of options for the current class. This means it ignores any options passed to it via @code{\PassOptionsToClass}. This is a convenience command that lets you build classes on existing ones, such as the standard @code{article} class, without having to track which options were passed. @item \ExecuteOptions@{@var{options-list}@} @findex \ExecuteOptions For each option @var{option} in the @var{options-list}, in order, this command executes the command @code{\ds@@@var{option}}. If this command is not defined then that option is silently ignored. It can be used to provide a default option list before @code{\ProcessOptions}. For example, if in a class file you want the default to be 11pt fonts then you could specify @code{\ExecuteOptions@{11pt@}\ProcessOptions\relax}. @item \NeedsTeXFormat@{@var{format}@}[@var{format date}] @findex \NeedsTeXFormat 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@{LaTeX2e@}}. 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} 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'.} To specify a version of the format that you know to have certain features, include the optional @var{format date} on which those features were implemented. If present it must be in the form @code{YYYY/MM/DD}. If the format version installed on your system is earlier than @var{format date} then you get a warning like @samp{You have requested release `2038/01/20' of LaTeX, but only release `2016/02/01' is available.} @item \OptionNotUsed @findex \OptionNotUsed Adds the current option to the list of unused options. Can only be used within the @var{code} argument of either @code{\DeclareOption} or @code{\DeclareOption*}. @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@}}. @item \PassOptionsToClass@{@var{option list}@}@{@var{class name}@} @item \PassOptionsToPackage@{@var{option list}@}@{@var{package name}@} @findex \PassOptionsToClass @findex \PassOptionsToPackage Adds the options in the comma-separated list @var{option list} to the options used by any future @code{\RequirePackage} or @code{\usepackage} command for package @var{package name} or the class @var{class name}. 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.} (@LaTeX{} throws an error even if there is no conflict between the options.) 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]@{geometry@}\RequirePackage[margins=1in]@{geometry@}} with the single @code{\RequirePackage[landscape,margins=1in]@{geometry@}}. 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} loads the package @code{geometry}. Instead of @code{\RequirePackage@{foo@}\RequirePackage[draft]@{graphics@}} you must write @code{\PassOptionsToPackage@{draft@}@{graphics@} \RequirePackage@{foo@}}. (If @code{foo.sty} loads an option in conflict with what you want then you may have to look into altering its source.) 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} package with the option @code{draft} and also wants to use a class @code{foo} that loads the @code{graphicx} package, but without that option. The user could start their @LaTeX{} file with @code{\PassOptionsToPackage@{draft@}@{graphicx@}\documentclass@{foo@}}. @item \ProcessOptions @item \ProcessOptions*@var{\@@options} @findex \ProcessOptions @findex \ProcessOptions* Execute the code for each option that the user has invoked. Include it in the class file as @code{\ProcessOptions\relax} (because of the existence of the starred command). Options come in two types. @dfn{Local options} have been specified for this particular package in the @var{options} argument of @code{\PassOptionsToPackage@{@var{options}@}}, @code{\usepackage[@var{options}]}, or @code{\RequirePackage[@var{options}]}. @dfn{Global options} are those given by the class user in @code{\documentclass[@var{options}]} (If an option is specified both locally and globally then it is local.) When @code{\ProcessOptions} is called for a package @file{pkg.sty}, the following happens: @enumerate @item For each option @var{option} so far declared with @code{\DeclareOption}, it looks to see if that option is either a global or a local option for @code{pkg}. If so then it executes the declared code. This is done in the order in which these options were given in @file{pkg.sty}. @item For each remaining local option, it executes the command @code{\ds@@}@var{option} if it has been defined somewhere (other than by a @code{\DeclareOption}); otherwise, it executes the default option code given in @code{\DeclareOption*}. 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. @end enumerate When @code{\ProcessOptions} is called for a class it works in the same way except that all options are local, and the default @var{code} for @code{\DeclareOption*} is @code{\OptionNotUsed} rather than an error. The starred version @code{\ProcessOptions*} 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. @item \ProvidesClass@{@var{class name}@}[@var{release date} @var{brief additional information}] @item \ProvidesClass@{@var{class name}@}[@var{release date}] @item \ProvidesPackage@{@var{package name}@}[@var{release date} @var{brief additional information}] @item \ProvidesPackage@{@var{package name}@}[@var{release date}] @findex \ProvidesClass @findex \ProvidesPackage Identifies the class or package, printing a message to the screen and the log file. When a user writes @code{\documentclass@{smcmemo@}} then @LaTeX{} loads the file @file{smcmemo.cls}. Similarly, a user writing @code{\usepackage@{test@}} prompts @LaTeX{} to load the file @code{test.sty}. 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@{smcmemo@}}, and the file @file{smcmemo.cls} has the statement @code{\ProvidesClass@{xxx@}} then you get a warning like @code{You have requested document class `smcmemo', but the document class provides 'xxx'.} This warning does not prevent @LaTeX{} from processing the rest of the class file normally. 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}. 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} contains the line @code{\ProvidesClass@{smcmemo@}[2008/06/01 v1.0 SMC memo class]} and your document's first line is @code{\documentclass@{smcmemo@}} then you will see @code{Document Class: smcmemo 2008/06/01 v1.0 SMC memo class}. 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}, by using the optional arguments such as @code{\documentclass@{smcmemo@}[2018/10/12]} or @code{\usepackage@{foo@}[[2017/07/07]]}. (Note that package users only rarely include a date, and class users almost never do.) @item \ProvidesFile@{@var{file name}@}[@var{additional information}] @findex \ProvidesFile 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} for @var{file name} equal to @samp{test.config} and @var{additional information} equal to @samp{2017/10/12 config file for test.cls}. @item \RequirePackage[@var{option list}]@{@var{package name}@}[@var{release date}] @item \RequirePackageWithOptions@{@var{package name}@}[@var{release date}] @findex \RequirePackage @findex \RequirePackageWithOptions Load a package, like the document author command @code{\usepackage}. @xref{Additional packages}. An example is @code{\RequirePackage[landscape,margin=1in]@{geometry@}}. Note that the @LaTeX{} development team strongly recommends use of these commands over Plain@tie{}@TeX{}'s @code{\input}; see the Class Guide. The @var{option list}, if present, is a comma-separated list. The @var{release date}, if present, must have the form @var{YYYY/MM/DD}. If the release date of the package as installed on your system is earlier than @var{release date} 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}. The @code{\RequirePackageWithOptions} version uses the list of options for the current class. This means it ignores any options passed to it via @code{\PassOptionsToClass}. This is a convenience command to allow easily building classes on existing ones without having to track which options were passed. The difference between @code{\usepackage} and @code{\RequirePackage} is small. The @code{\usepackage} command is intended for the document file while @code{\RequirePackage} is intended for package and class files. Thus, using @code{\usepackage} before the @code{\documentclass} command causes @LaTeX{} to give error like @code{\usepackage before \documentclass}, but you can use @code{\RequirePackage} there. @end table @node Fonts @chapter Fonts @anchor{Typefaces}@c old name @cindex typefaces @cindex fonts Two important aspects of selecting a @dfn{font} are specifying a size and a style. The @LaTeX{} commands for doing this are described here. @menu * Font styles:: Select roman, italics, etc. * Font sizes:: Select point size. * Low-level font commands:: Select encoding, family, series, shape. @end menu @node Font styles @section Font styles @cindex font styles @cindex type styles @cindex styles of text The following type style commands are supported by @LaTeX{}. This first group of commands is typically used with an argument, as in @code{\textit@{@var{text}@}}. In the table below, the corresponding command in parenthesis is the ``declaration form'', which takes no arguments, as in @code{@{\itshape @var{text}@}}. The scope of the declaration form lasts until the next type style command or the end of the current group. These commands, in both the argument form and the declaration form, are cumulative; e.g., you can say either @code{\sffamily\bfseries} or @code{\bfseries\sffamily} to get bold sans serif. You can alternatively use an environment form of the declarations; for instance, @code{\begin@{ttfamily@}...\end@{ttfamily@}}. @findex \nocorrlist @findex \nocorr These font-switching commands automatically insert italic corrections if needed. (@xref{\/}, for the details of italic corrections.) Specifically, they insert the italic correction unless the following character is in the list @code{\nocorrlist}, which by default consists of a period and a comma. To suppress the automatic insertion of italic correction, use @code{\nocorr} at the start or end of the command argument, such as @code{\textit@{\nocorr text@}} or @code{\textsc@{text \nocorr@}}. @table @code @item \textrm (\rmfamily) @findex \textrm @findex \rmfamily Roman. @item \textit (\itshape) @findex \textit @findex \itshape Italics. @item \textmd (\mdseries) @findex \textmd @findex \mdseries Medium weight (default). @item \textbf (\bfseries) @findex \textbf @findex \bfseries Boldface. @item \textup (\upshape) @findex \textup @findex \upshape Upright (default). @item \textsl (\slshape) @findex \textsl @findex \slshape Slanted. @item \textsf (\sffamily) @findex \textsf @findex \sffamily Sans serif. @item \textsc (\scshape) @findex \textsc @findex \scshape Small caps. @item \texttt (\ttfamily) @findex \texttt @findex \ttfamily Typewriter. @item \textnormal (\normalfont) @findex \textnormal @findex \normalfont Main document font. @end table @cindex emphasis @findex \emph Although it also changes fonts, the @code{\emph@{@var{text}@}} command is semantic, for text to be emphasized, and should not be used as a substitute for @code{\textit}. For example, @code{\emph@{@var{start text} \emph@{@var{middle text}@} @var{end text}@}} will result in the @var{start text} and @var{end text} in italics, but @var{middle text} will be in roman. @LaTeX{} also provides the following commands, which unconditionally switch to the given style, that is, are @emph{not} cumulative. Also, they are used differently than the above commands: @code{@{\@var{cmd}...@}} instead of @code{\@var{cmd}@{...@}}. These are two unrelated constructs. @ftable @code @item \bf @cindex bold font Switch to bold face. @item \cal @cindex script letters for math @cindex calligraphic letters for math Switch to calligraphic letters for math. @item \it @cindex italic font Italics. @item \rm @cindex roman font Roman. @item \sc @cindex small caps font Small caps. @item \sf @cindex sans serif font Sans serif. @item \sl @cindex slanted font @cindex oblique font Slanted (oblique). @item \tt @cindex typewriter font @cindex monospace font @cindex fixed-width font Typewriter (monospace, fixed-width). @end ftable The @code{\em} command is the unconditional version of @code{\emph}. (Some people consider the unconditional font-switching commands, such as @code{\tt}, obsolete and that only the cumulative commands (@code{\texttt}) 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{description,,@code{description}}.) The following commands are for use in math mode. They are not cumulative, so @code{\mathbf@{\mathit@{@var{symbol}@}@}} does not create a boldface and italic @var{symbol}; instead, it will just be in italics. This is because typically math symbols need consistent typographic treatment, regardless of the surrounding environment. @table @code @item \mathrm @findex \mathrm Roman, for use in math mode. @item \mathbf @findex \mathbf Boldface, for use in math mode. @item \mathsf @findex \mathsf Sans serif, for use in math mode. @item \mathtt @findex \mathtt Typewriter, for use in math mode. @item \mathit @itemx (\mit) Italics, for use in math mode. @item \mathnormal @findex \mathnormal For use in math mode, e.g., inside another type style declaration. @item \mathcal @findex \mathcal Calligraphic letters, for use in math mode. @end table @findex \mathversion @cindex math, bold @cindex bold math In addition, the command @code{\mathversion@{bold@}} can be used for switching to bold letters and symbols in formulas. @code{\mathversion@{normal@}} restores the default. @findex \oldstylenums @cindex numerals, old-style @cindex old-style numerals @cindex lining numerals @PkgIndex{textcomp} Finally, the command @code{\oldstylenums@{@var{numerals}@}} will typeset so-called ``old-style'' numerals, which have differing heights and depths (and sometimes widths) from the standard ``lining'' numerals, which all have the same height as uppercase letters. @LaTeX{}'s default fonts support this, and will respect @code{\textbf} (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} package must be loaded, and sometimes package options are provided to make them the default. FAQ entry: @url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=osf}. @node Font sizes @section Font sizes @cindex font sizes @cindex typeface sizes @cindex sizes of text 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{11pt}, and @samp{12pt} document size options, respectively (@pxref{Document class options}). @findex \tiny @findex \scriptsize @findex \footnotesize @findex \small @findex \normalsize @findex \large @findex \Large @findex \LARGE @findex \huge @findex \Huge @multitable {@code{\normalsize} (default)} {24.88} {24.88} {24.88} @headitem Command @tab @code{10pt} @tab @code{11pt} @tab @code{12pt} @item @code{\tiny} @tab 5 @tab 6 @tab 6 @item @code{\scriptsize} @tab 7 @tab 8 @tab 8 @item @code{\footnotesize} @tab 8 @tab 9 @tab 10 @item @code{\small} @tab 9 @tab 10 @tab 10.95 @item @code{\normalsize} (default) @tab 10 @tab 10.95 @tab 12 @item @code{\large} @tab 12 @tab 12 @tab 14.4 @item @code{\Large} @tab 14.4 @tab 14.4 @tab 17.28 @item @code{\LARGE} @tab 17.28 @tab 17.28 @tab 20.74 @item @code{\huge} @tab 20.74 @tab 20.74 @tab 24.88 @item @code{\Huge} @tab 24.88 @tab 24.88 @tab 24.88 @end multitable The commands as listed here are ``declaration forms''. 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@{tiny@}...\end@{tiny@}}. @node Low-level font commands @section Low-level font commands @cindex low-level font commands @cindex font commands, low-level 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? @table @code @item \fontencoding@{@var{encoding}@} @findex \fontencoding Select the font encoding, the encoding of the output font. There are a large number of valid encodings. The most common are @code{OT1}, Knuth's original encoding for Computer Modern (the default), and @code{T1}, 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{https://ctan.org/pkg/encguide}. @item \fontfamily@{@var{family}@} @findex \fontfamily @cindex families, of fonts @cindex font catalogue Select the font family. The web page @url{http://www.tug.dk/FontCatalogue/} provides one way to browse through many of the fonts easily used with @LaTeX{}. Here are examples of some common families: @multitable {font} {Computer Modern Typewriter XXXX} @item @code{pag} @tab Avant Garde @item @code{fvs} @tab Bitstream Vera Sans @item @code{pbk} @tab Bookman @item @code{bch} @tab Charter @item @code{ccr} @tab Computer Concrete @item @code{cmr} @tab Computer Modern @item @code{cmss} @tab Computer Modern Sans Serif @item @code{cmtt} @tab Computer Modern Typewriter @item @code{pcr} @tab Courier @item @code{phv} @tab Helvetica @item @code{fi4} @tab Inconsolata @item @code{lmr} @tab Latin Modern @item @code{lmss} @tab Latin Modern Sans @item @code{lmtt} @tab Latin Modern Typewriter @item @code{pnc} @tab New Century Schoolbook @item @code{ppl} @tab Palatino @item @code{ptm} @tab Times @item @code{uncl} @tab Uncial @item @code{put} @tab Utopia @item @code{pzc} @tab Zapf Chancery @end multitable @item \fontseries@{@var{series}@} @findex \fontseries @cindex series, of fonts Select the font series. A @dfn{series} combines a @dfn{weight} and a @dfn{width}. Typically, a font supports only a few of the possible combinations. Some common combined series values include: @multitable {xx} {Medium (normal)xx} @item @code{m} @tab Medium (normal) @item @code{b} @tab Bold @item @code{c} @tab Condensed @item @code{bc} @tab Bold condensed @item @code{bx} @tab Bold extended @end multitable @cindex weights, of fonts The possible values for weight, individually, are: @multitable {xx} {Medium (normal) xx} @item @code{ul} @tab Ultra light @item @code{el} @tab Extra light @item @code{l} @tab Light @item @code{sl} @tab Semi light @item @code{m} @tab Medium (normal) @item @code{sb} @tab Semi bold @item @code{b} @tab Bold @item @code{eb} @tab Extra bold @item @code{ub} @tab Ultra bold @end multitable @cindex widths, of fonts The possible values for width, individually, are (the meaning and relationship of these terms varies with individual typefaces): @multitable {xx} {Ultra condensed} @item @code{uc} @tab Ultra condensed @item @code{ec} @tab Extra condensed @item @code{c} @tab Condensed @item @code{sc} @tab Semi condensed @item @code{m} @tab Medium @item @code{sx} @tab Semi expanded @item @code{x} @tab Expanded @item @code{ex} @tab Extra expanded @item @code{ux} @tab Ultra expanded @end multitable When forming the @var{series} string from the weight and width, drop the @code{m} that stands for medium weight or medium width, unless both weight and width are @code{m}, in which case use just one (@samp{@code{m}}). @item \fontshape@{@var{shape}@} @findex \fontshape @cindex shapes, of fonts Select font shape. Valid shapes are: @multitable {xx} {Slanted (oblique)xx} @item @code{n} @tab Upright (normal) @item @code{it} @tab Italic @item @code{sl} @tab Slanted (oblique) @item @code{sc} @tab Small caps @item @code{ui} @tab Upright italics @item @code{ol} @tab Outline @end multitable The two last shapes are not available for most font families, and small caps are often missing as well. @item \fontsize@{@var{size}@}@{@var{skip}@} @findex \fontsize @cindex font size @findex \baselineskip Set the font size and the line spacing. The unit of both parameters defaults to points (@code{pt}). The line spacing is the nominal vertical space between lines, baseline to baseline. It is stored in the parameter @code{\baselineskip}. The default @code{\baselineskip} for the Computer Modern typeface is 1.2 times the @code{\fontsize}. Changing @code{\baselineskip} directly is inadvisable since its value is reset every time a size change happens; see @code{\baselinestretch}, next. @item \baselinestretch @findex \baselinestretch @LaTeX{} multiplies the line spacing by the value of the @code{\baselinestretch} parameter; the default factor is 1. A change takes effect when @code{\selectfont} (see below) is called. You can make a line skip change happen for the entire document, for instance doubling it, by doing @code{\renewcommand@{\baselinestretch@}@{2.0@}} in the preamble. @PkgIndex{setspace} @cindex double spacing However, the best way to double-space a document is to use the @file{setspace} 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. @item \linespread@{@var{factor}@} @findex \linespread Equivalent to @code{\renewcommand@{\baselinestretch@}@{@var{factor}@}}, and therefore must be followed by @code{\selectfont} to have any effect. Best specified in the preamble, or use the @code{setspace} package, as just described. @item \selectfont @findex \selectfont The effects of the font commands described above do not happen until @code{\selectfont} is called, as in @code{\fontfamily@{@var{familyname}@}\selectfont}. It is often useful to put this in a macro:@* @code{\newcommand*@{\myfont@}@{\fontfamily@{@var{familyname}@}\selectfont@}}@* (@pxref{\newcommand & \renewcommand}). @item \usefont@{@var{enc}@}@{@var{family}@}@{@var{series}@}@{@var{shape}@} @findex \usefont The same as invoking @code{\fontencoding}, @code{\fontfamily}, @code{\fontseries} and @code{\fontshape} with the given parameters, followed by @code{\selectfont}. For example: @example \usefont@{ot1@}@{cmr@}@{m@}@{n@} @end example @end table @node Layout @chapter Layout @cindex layout commands Commands for controlling the general page layout. @menu * \onecolumn:: Use one-column layout. * \twocolumn:: Use two-column layout. * \flushbottom:: Make all text pages the same height. * \raggedbottom:: Allow text pages of differing height. * Page layout parameters:: @code{\headheight} @code{\footskip}. * Floats:: Figures, tables, etc. @end menu @node \onecolumn @section @code{\onecolumn} @findex \onecolumn @cindex one-column output Start a new page and produce single-column output. If the document is given the class option @code{onecolumn} then this is the default behavior (@pxref{Document class options}). This command is fragile (@pxref{\protect}). @node \twocolumn @section @code{\twocolumn} @findex \twocolumn @cindex multicolumn text @cindex two-column output Synopses: @example \twocolumn \twocolumn[@var{prelim one column text}] @end example Start a new page and produce two-column output. If the document is given the class option @code{twocolumn} then this is the default (@pxref{Document class options}). If the optional @var{prelim one column text} argument is present, it is typeset in one-column mode before the two-column typesetting starts. This command is fragile (@pxref{\protect}). These parameters control typesetting in two-column output: @ftable @code @item \columnsep The distance between columns. The default is 35pt. Change it with a command such as @code{\setlength@{\columnsep@}@{40pt@}} You must change it before the two column environment starts; in the preamble is a good place. @item \columnseprule 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@{\columnseprule@}@{0.4pt@}}, before the two-column environment starts. @item \columnwidth The width of a single column. In one-column mode this is equal to @code{\textwidth}. In two-column mode by default @LaTeX{} sets the width of each of the two columns to be half of @code{\textwidth} minus @code{\columnsep}. @end ftable In a two-column document, the starred environments @code{table*} and @code{figure*} are two columns wide, whereas the unstarred environments @code{table} and @code{figure} take up only one column (@pxref{figure} and @pxref{table}). @LaTeX{} places starred floats at the top of a page. The following parameters control float behavior of two-column output. @ftable @code @item \dbltopfraction 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*} or @code{figure*} environment must not exceed @code{0.7\textheight} . 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: @itemize @bullet @item Use the @code{[tp]} 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. @item Use the @code{[t!]} location specifier to override the effect of @code{\dbltopfraction} for this particular float. @item Increase the value of @code{\dbltopfraction} to a suitably large number, to avoid going to float pages so soon. @end itemize You can redefine it, for instance with @code{\renewcommand@{\dbltopfraction@}@{0.9@}}. @item \dblfloatpagefraction 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{}'s default is @code{0.5}. Change it with @code{\renewcommand}. @item \dblfloatsep 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} for a document set at @code{10pt} or @code{11pt}, and @code{14pt plus2pt minus4pt} for a document set at @code{12pt}. @item \dbltextfloatsep 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}. @item \dbltopnumber 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}. @end ftable @c From egreg at http://tex.stackexchange.com/a/142232/339 This example uses @code{\twocolumn}'s optional argument of to create a title that spans the two-column article: @example \documentclass[twocolumn]@{article@} \newcommand@{\authormark@}[1]@{\textsuperscript@{#1@}@} \begin@{document@} \twocolumn[@{% inside this optional argument goes one-column text \centering \LARGE The Title \\[1.5em] \large Author One\authormark@{1@}, Author Two\authormark@{2@}, Author Three\authormark@{1@} \\[1em] \normalsize \begin@{tabular@}@{p@{.2\textwidth@}@@@{\hspace@{2em@}@}p@{.2\textwidth@}@} \authormark@{1@}Department one &\authormark@{2@}Department two \\ School one &School two \end@{tabular@}\\[3em] % space below title part @}] Two column text here. @end example @node \flushbottom @section @code{\flushbottom} @findex \flushbottom 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. 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}. If you get that, one option is to change to @code{\raggedbottom} (@pxref{\raggedbottom}). Alternatively, you can adjust the @code{textheight} to make compatible pages, or you can add some vertical stretch glue between lines or between paragraphs, as in @code{\setlength@{\parskip@}@{0ex plus0.1ex@}}. Your last option is to, in a final editing stage, adjust the height of individual pages (@pxref{\enlargethispage}). The @code{\flushbottom} state is the default only if you select the @code{twoside} document class option (@pxref{Document class options}). @node \raggedbottom @section @code{\raggedbottom} @findex \raggedbottom @cindex stretch, omitting vertical 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{\flushbottom}. This is the default unless you select the @code{twoside} document class option (@pxref{Document class options}). @node Page layout parameters @section Page layout parameters @cindex page layout parameters @cindex parameters, page layout @cindex layout, page parameters for @cindex header, parameters for @cindex footer, parameters for @cindex running header and footer @ftable @code @item \columnsep @itemx \columnseprule @itemx \columnwidth @findex \columnsep @findex \columnseprule @findex \columnwidth 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} is in effect (@pxref{Document class options}). @xref{\twocolumn}. @item \headheight @findex \headheight Height of the box that contains the running head. The default in the @code{article}, @code{report}, and @code{book} classes is @samp{12pt}, at all type sizes. @item \headsep @findex \headsep Vertical distance between the bottom of the header line and the top of the main text. The default in the @code{article} and @code{report} classes is @samp{25pt}. In the @code{book} class the default is: if the document is set at 10pt then it is @samp{0.25in}, and at 11pt and 12pt it is @samp{0.275in}. @item \footskip @findex \footskip Distance from the baseline of the last line of text to the baseline of the page footer. The default in the @code{article} and @code{report} classes is @samp{30pt}. In the @code{book} class the default is: when the type size is 10pt the default is @samp{0.35in}, while at 11pt it is @samp{0.38in}, and at 12pt it is @samp{30pt}. @item \linewidth @findex \linewidth Width of the current line, decreased for each nested @code{list} (@pxref{list}). That is, the nominal value for @code{\linewidth} is to equal @code{\textwidth} but for each nested list the @code{\linewidth} is decreased by the sum of that list's @code{\leftmargin} and @code{\rightmargin} (@pxref{itemize}). @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}. @item \marginparpush @itemx \marginsep @itemx \marginparwidth @findex \marginparpush @findex \marginsep @findex \marginparwidth 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. Normally marginal notes appear on the outside of the page, but the declaration @code{\reversemarginpar} changes that (and @code{\normalmarginpar} changes it back). The defaults for @code{\marginparpush} in both @code{book} and @code{article} classes are: @samp{7pt} if the document is set at 12pt, and @samp{5pt} if the document is set at 11pt or 10pt. For @code{\marginsep}, in @code{article} class the default is @samp{10pt} except if the document is set at 10pt and in two-column mode where the default is @samp{11pt}. For @code{\marginsep} in @code{book} class the default is @samp{10pt} in two-column mode and @samp{7pt} in one-column mode. For @code{\marginparwidth} in both @code{book} and @code{article} classes, in two-column mode the default is 60% of @code{\paperwidth @minus{} \textwidth}, while in one-column mode it is 50% of that distance. @item \oddsidemargin @itemx \evensidemargin @findex \oddsidemargin @findex \evensidemargin The @code{\oddsidemargin} is the extra distance between the left side of the page and the text's left margin, on odd-numbered pages when the document class option @code{twoside} is chosen and on all pages when @code{oneside} is in effect. When @code{twoside} is in effect, on even-numbered pages the extra distance on the left is @code{evensidemargin}. @LaTeX{}'s default is that @code{\oddsidemargin} is 40% of the difference between @code{\paperwidth} and @code{\textwidth}, and @code{\evensidemargin} is the remainder. @item \paperheight @findex \paperheight 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]@{article@}} (@pxref{Document class options}). @item \paperwidth @findex \paperwidth 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]@{article@}} (@pxref{Document class options}). @item \textheight @findex \textheight 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} or @code{report} the default is @samp{43\baselineskip}, while for a @code{book} it is @samp{41\baselineskip}. At a type size of 11pt the default is @samp{38\baselineskip} for all document classes. At 12pt it is @samp{36\baselineskip} for all classes. @item \textwidth @findex \textwidth The full horizontal width of the entire page body. For an @code{article} or @code{report} document, the default is @samp{345pt} when the chosen type size is 10pt, the default is @samp{360pt} at 11pt, and it is @samp{390pt} at 12pt. For a @code{book} document, the default is @samp{4.5in} at a type size of 10pt, and @samp{5in} at 11pt or 12pt. In multi-column output, @code{\textwidth} remains the width of the entire page body, while @code{\columnwidth} is the width of one column (@pxref{\twocolumn}). In lists (@pxref{list}), @code{\textwidth} remains the width of the entire page body (and @code{\columnwidth} the width of the entire column), while @code{\linewidth} may decrease for nested lists. Inside a minipage (@pxref{minipage}) or @code{\parbox} (@pxref{\parbox}), all the width-related parameters are set to the specified width, and revert to their normal values at the end of the @code{minipage} or @code{\parbox}. @findex \hsize @findex \hsize This entry is included for completeness: @code{\hsize} is the @TeX{} primitive parameter used when text is broken into lines. It should not be used in normal @LaTeX{} documents. @item \topmargin @findex topmargin 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}, and then divided by two. @item \topskip @findex \topskip 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} at a type size of 10pt. @end ftable @node Floats @section Floats 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. @LaTeX{} can have a number of different classes of floating material. The default is the two classes, @code{figure} (@pxref{figure}) and @code{table} (@pxref{table}), but you can create a new class with the package @file{float}. 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. 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. @cindex placement of floats @cindex specifier, float placement 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} argument. The possible values are a sequence of the letters below. The default for both @code{figure} and @code{table}, in both @code{article} and @code{book} classes, is @code{tbp}. @table @code @item t (Top)---at the top of a text page. @item b (Bottom)---at the bottom of a text page. (However, @code{b} is not allowed for full-width floats (@code{figure*}) with double-column output. To ameliorate this, use the @file{stfloats} or @file{dblfloatfix} package, but see the discussion at caveats in the FAQ: @url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=2colfloat}. @item h (Here)---at the position in the text where the @code{figure} environment appears. However, @code{h} is not allowed by itself; @code{t} is automatically added. @cindex here, putting floats @PkgIndex{float} To absolutely force a float to appear ``here'', you can @code{\usepackage@{float@}} and use the @code{H} specifier which it defines. For further discussion, see the FAQ entry at @url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=figurehere}. @item p @cindex float page (Page of floats)---on a separate @dfn{float page}, which is a page containing no text, only floats. @item ! 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{!} specifier does @emph{not} mean ``put the float here''; see above. @end table Note: the order in which letters appear in the @var{placement} argument does not change the order in which @LaTeX{} tries to place the float; for instance, @code{btp} has the same effect as @code{tbp}. All that @var{placement} does is that if a letter is not present then the algorithm does not try that location. Thus, @LaTeX{}'s default of @code{tbp} is to try every location except placing the float where it occurs in the source. To prevent @LaTeX{} from moving floats to the end of the document or a chapter you can use a @code{\clearpage} command to start a new page and insert all pending floats. If a pagebreak is undesirable then you can use the @file{afterpage} package and issue @code{\afterpage@{\clearpage@}}. This will wait until the current page is finished and then flush all outstanding floats. @PkgIndex{flafter} @LaTeX{} can typeset a float before where it appears in the source (although on the same output page) if there is a @code{t} specifier in the @var{placement} parameter. If this is not desired, and deleting the @code{t} 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} package or using the command @findex \suppressfloats @code{\suppressfloats[t]}, which causes floats for the top position on this page to moved to the next page. Parameters relating to fractions of pages occupied by float and non-float text (change them with @code{\renewcommand@{@var{parameter}@}@{@var{decimal between 0 and 1}@}}): @ftable @code @item \bottomfraction @findex \bottomfraction The maximum fraction of the page allowed to be occupied by floats at the bottom; default @samp{.3}. @item \floatpagefraction @findex \floatpagefraction The minimum fraction of a float page that must be occupied by floats; default @samp{.5}. @item \textfraction @findex \textfraction 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}. @item \topfraction @findex \topfraction Maximum fraction at the top of a page that may be occupied before floats; default @samp{.7}. @end ftable Parameters relating to vertical space around floats (change them with @code{\setlength@{@var{parameter}@}@{@var{length expression}@}}): @ftable @code @item \floatsep @findex \floatsep Space between floats at the top or bottom of a page; default @samp{12pt plus2pt minus2pt}. @item \intextsep @findex \intextsep Space above and below a float in the middle of the main text; default @samp{12pt plus2pt minus2pt} for 10 point and 11 point documents, and @samp{14pt plus4pt minus4pt} for 12 point documents. @item \textfloatsep @findex \textfloatsep Space between the last (first) float at the top (bottom) of a page; default @samp{20pt plus2pt minus4pt}. @end ftable Counters relating to the number of floats on a page (change them with @code{\setcounter@{@var{ctrname}@}@{@var{natural number}@}}): @ftable @code @item bottomnumber @findex bottomnumber Maximum number of floats that can appear at the bottom of a text page; default 1. @item dbltopnumber @findex dbltopnumber Maximum number of full-sized floats that can appear at the top of a two-column page; default 2. @item topnumber @findex topnumber Maximum number of floats that can appear at the top of a text page; default 2. @item totalnumber @findex totalnumber Maximum number of floats that can appear on a text page; default 3. @end ftable The principal @TeX{}@tie{}FAQ entry relating to floats @url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=floats} contains suggestions for relaxing @LaTeX{}'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's article ``How to influence the position of float environments like figure and table in @LaTeX{}?'' (@url{http://latex-project.org/papers/tb111mitt-float.pdf}). @node Sectioning @chapter Sectioning @cindex sectioning commands Sectioning commands provide the means to structure your text into units: @ftable @code @item \part @item \chapter (@code{report} and @code{book} class only) @item \section @item \subsection @item \subsubsection @item \paragraph @item \subparagraph @end ftable All sectioning commands take the same general form, e.g., @example \chapter[@var{toctitle}]@{@var{title}@} @end example In addition to providing the heading @var{title} in the main text, the section title can appear in two other places: @enumerate @item The table of contents. @item The running head at the top of the page. @end enumerate 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} that, when given, specifies the text for these other places. @cindex @code{*}-form of sectioning commands Also, all sectioning commands have @code{*}-forms that print @var{title} as usual, but do not include a number and do not make an entry in the table of contents. For instance: @example \section*@{Preamble@} @end example @findex \appendix @cindex appendix, creating The @code{\appendix} command changes the way following sectional units are numbered. The @code{\appendix} command itself generates no text and does not affect the numbering of parts. The normal use of this command is something like @example \chapter@{A Chapter@} @dots{} \appendix \chapter@{The First Appendix@} @end example @findex secnumdepth @r{counter} @cindex section numbers, printing @anchor{Sectioning/secnumdepth} The @code{secnumdepth} counter controls printing of section numbers. The setting @example \setcounter@{secnumdepth@}@{@var{level}@} @end example @noindent suppresses heading numbers at any depth @math{> @var{level}}, where @code{chapter} is level zero. The default @code{secnumdepth} is 3 in @LaTeX{}'s @file{article} class and 2 in the @file{book} and @file{report} classes. (@xref{\setcounter}.) @menu * \@@startsection:: Redefine layout of start of sections, subsections, etc. @end menu @node \@@startsection @section @code{\@@startsection} @findex \@@startsection @cindex section, redefining Synopsis: @example \@@startsection@{@var{name}@}@{@var{level}@}@{@var{indent}@}@{@var{beforeskip}@}@{@var{afterskip}@}@{@var{style}@} @end example Used to help redefine the behavior of commands that start sectioning divisions such as @code{\section} or @code{\subsection}. Note that the @file{titlesec} package makes manipulation of sectioning easier. Further, while most requirements for sectioning commands can be satisfied with @code{\@@startsection}, some cannot. For instance, in the standard @LaTeX{} @code{book} and @code{report} classes the commands @code{\chapter} and @code{\report} are not constructed in this way. To make such a command you may want to use the @code{\secdef} command. @c xx define, and make a cross reference to, secdef. Technically, @code{\@@startsection} has the form @example \@@startsection@{@var{name}@}@{@var{level}@}@{@var{indent}@}@{@var{beforeskip}@}@{@var{afterskip}@}@{@var{style}@}*[@var{toctitle}]@{@var{title}@} @end example @noindent (the star@tie{}@code{*} is optional), so that issuing @example \renewcommand@{\section@}@{\@@startsection@{@var{name}@}@{@var{level}@}@{@var{indent}@}@{@var{beforeskip}@}@{@var{afterskip}@}@{@var{style}@}@} @end example @noindent redefines @code{\section} to have the form @code{\section*[@var{toctitle}]@{@var{title}@}} (here too, the star@tie{}@code{*} is optional). @xref{Sectioning}. This implies that when you write a command like @code{\renewcommand@{section@}@{...@}}, the @code{\@@startsection@{...@}} must come last in the definition. See the examples below. @table @var @item name @anchor{\@@startsection/name} Name of the counter used to number the sectioning header. This counter must be defined separately. Most commonly this is either @code{section}, @code{subsection}, or @code{paragraph}. Although in those three cases the counter name is the same as the sectioning command itself, using the same name is not required. Then @code{\the}@var{name} displays the title number and @code{\}@var{name}@code{mark} is for the page headers. See the third example below. @item level @anchor{\@@startsection/level} An integer giving the depth of the sectioning command: 0 for @code{chapter} (only applies to the standard @code{book} and @code{report} classes), 1 for @code{section}, 2 for @code{subsection}, 3 for @code{subsubsection}, 4 for @code{paragraph}, and 5 for @code{subparagraph}. In the @code{book} and @code{report} classes @code{part} has level -1, while in the @code{article} class @code{part} has level 0. If @var{level} is less than or equal to the value of @code{secnumdepth} then the titles for this sectioning command will be numbered. For instance, in an @code{article}, if @code{secnumdepth} is 1 then a @code{\section@{Introduction@}} command will produce output like ``1 Introduction'' while @code{\subsection@{Discussion@}} will produce output like ``Discussion'', without the number prefix. @xref{Sectioning/secnumdepth}. If @var{level} is less than or equal to the value of @var{tocdepth} then the table of contents will have an entry for this sectioning unit. For instance, in an @code{article}, if @var{tocdepth} is 1 then the table of contents will list sections but not subsections. @c xx add, and cross reference to, tocdepth @item indent @anchor{\@@startsection/indent} 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}. A negative indentation such as @code{-\parindent} will move the title into the left margin. @item beforeskip @anchor{\@@startsection/beforeskip} The absolute value of this length is the amount of vertical space that is inserted before this sectioning unit'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} is @code{-1pt plus -2pt minus -3pt}.) For example, if @var{beforeskip} is @code{-3.5ex plus -1ex minus -0.2ex} 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} and @code{minus}, is good practice here since it gives @LaTeX{} more flexibility in making up the page (@pxref{Lengths}). The full accounting of the vertical space between the baseline of the line prior to this sectioning unit's header and the baseline of the header is that it is the sum of the @code{\parskip} of the text font, the @code{\baselineskip} of the title font, and the absolute value of the @var{beforeskip}. 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.) @item afterskip @anchor{\@@startsection/afterskip} This is a length. If @var{afterskip} is non-negative then this is the vertical space inserted after the sectioning unit'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} is @code{-1pt plus -2pt minus -3pt}.) As with @var{beforeskip}, using a rubber length, with @code{plus} and @code{minus} components, is good practice here since it gives @LaTeX{} more flexibility in putting together the page. If @code{afterskip} is non-negative then the full accounting of the vertical space between the baseline of the sectioning unit's header and the baseline of the first line of the following paragraph is that it is the sum of the @code{\parskip} of the title font, the @code{\baselineskip} of the text font, and the value of @var{after}. That space is typically rubber so it may stretch or shrink. (Note that because the sign of @code{afterskip} changes the sectioning unit header's from standalone to run-in, you cannot use a negative @code{afterskip} to cancel part of the @code{\parskip}.) @item style @anchor{\@@startsection/style} Controls the styling of the title. See the examples below. Typical commands to use here are @code{\centering}, @code{\raggedright}, @code{\normalfont}, @code{\hrule}, or @code{\newpage}. The last command in @var{style} may be one such as @code{\MakeUppercase} or @code{\fbox} that takes one argument. The section title will be supplied as the argument to this command. For instance, setting @var{style} to @code{\bfseries\MakeUppercase} would produce titles that are bold and upper case. @end table These are @LaTeX{}'s defaults for the first three sectioning units that are defined with @code{\@@startsection}, for the @file{article}, @file{book}, and @file{report} classes. @multitable @columnfractions .10 .30 .30 .30 @headitem @tab @code{section} @tab @code{subsection} @tab @code{subsubsection} @item @ref{\@@startsection/name,@var{name},@var{name}} @tab section @tab subsection @tab subsubsection @item @ref{\@@startsection/level,@var{level},@var{level}} @tab 1 @tab 2 @tab 3 @item @ref{\@@startsection/indent,@var{indent},@var{indent}} @tab @code{0pt} @tab @code{0pt} @tab @code{0pt} @item @ref{\@@startsection/beforeskip,@var{beforeskip},@var{beforeskip}} @tab @code{-3.5ex plus -1ex minus -0.2ex} @tab @code{-3.25ex plus -1ex minus -0.2ex} @tab @code{-3.25ex plus -1ex minus -0.2ex} @item @ref{\@@startsection/afterskip,@var{afterskip},@var{afterskip}} @tab @code{2.3ex plus 0.2ex} @tab @code{1.5ex plus 0.2ex} @tab @code{1.5ex plus 0.2ex} @item @ref{\@@startsection/style,@var{style},@var{style}} @tab @code{\normalfont\Large\bfseries} @tab @code{\normalfont\large\bfseries} @tab @code{\normalfont\normalsize\bfseries} @end multitable 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} command and a @code{\makeatother}. (Probably the error message @code{You can't use `\spacefactor' in vertical mode.} means that you forgot this.) @xref{\makeatletter and \makeatother}. This will put section titles in large boldface type, centered. It says @code{\renewcommand} because @LaTeX{}'s standard classes have already defined a @code{\section}. For the same reason it does not define a @code{section} counter, or the commands @code{\thesection} and @code{\l@@section}. @example \renewcommand\section@{% \@@startsection@{section@}% @ref{\@@startsection/name,@var{name},@var{name}} @{1@}% @ref{\@@startsection/level,@var{level},@var{level}} @{0pt@}% @ref{\@@startsection/indent,@var{indent},@var{indent}} @{-3.5ex plus -1ex minus -.2ex@}% @ref{\@@startsection/beforeskip,@var{beforeskip},@var{beforeskip}} @{2.3ex plus.2ex@}% @ref{\@@startsection/afterskip,@var{afterskip},@var{afterskip}} @{\centering\normalfont\Large\bfseries@}% @ref{\@@startsection/style,@var{style},@var{style}} @} @end example This will put @code{subsection} titles in small caps type, inline with the paragraph. @example \renewcommand\subsection@{% \@@startsection@{subsection@}% @ref{\@@startsection/name,@var{name},@var{name}} @{2@}% @ref{\@@startsection/level,@var{level},@var{level}} @{0em@}% @ref{\@@startsection/indent,@var{indent},@var{indent}} @{-1ex plus 0.1ex minus -0.05ex@}% @ref{\@@startsection/beforeskip,@var{beforeskip},@var{beforeskip}} @{-1em plus 0.2em@}% @ref{\@@startsection/afterskip,@var{afterskip},@var{afterskip}} @{\scshape@}% @ref{\@@startsection/style,@var{style},@var{style}} @} @end example The prior examples redefined existing sectional unit title commands. This defines a new one, illustrating the needed counter and macros to display that counter. @c From https://groups.google.com/forum/#!searchin/comp.text.tex/startsection%7Csort:relevance/comp.text.tex/sB-nTS-oL08/ZZeKYdG0llMJ @example \setcounter@{secnumdepth@}@{6@}% show counters this far down \newcounter@{subsubparagraph@}[subparagraph]% counter for numbering \renewcommand@{\thesubsubparagraph@}% how to display @{\thesubparagraph.\@@arabic\c@@subsubparagraph@}% numbering \newcommand@{\subsubparagraph@}@{\@@startsection @{subsubparagraph@}% @{6@}% @{0em@}% @{\baselineskip@}% @{0.5\baselineskip@}% @{\normalfont\normalsize@}@} \newcommand*\l@@subsubparagraph@{\@@dottedtocline@{6@}@{10em@}@{5em@}@}% for toc \newcommand@{\subsubparagraphmark@}[1]@{@}% for page headers @end example @node Cross references @chapter Cross references @cindex cross references One reason for numbering things such as figures and equations is to refer the reader to them, as in ``See Figure~3 for more details.'' @cindex label 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} like @code{\label@{eq:GreensThm@}} and refer to it with @code{See equation~\ref@{eq:GreensThm@}}. @LaTeX{} writes the information from the labels to a file with the same name as the file containing the @code{\label@{...@}} but with an @file{.aux} extension. (The information has the format @code{\newlabel@{@var{label}@}@{@{@var{currentlabel}@}@{@var{pagenumber}@}@}} where @var{currentlabel} is the current value of the macro @code{\@@currentlabel} that is usually updated whenever you call @code{\refstepcounter@{@var{counter}@}}.) @cindex forward reference @cindex reference, forward The most common side effect of the prior paragraph happens when your document has a @dfn{forward reference}, a @code{\ref@{@var{key}@}} that appears earlier than the associated @code{\label@{@var{key}@}}; see the example in the @code{\pageref@{...@}} description. @LaTeX{} gets the information for references from the @file{.aux} 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.} and in the output the reference will appear as two question marks@tie{}@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. @menu * \label:: Assign a symbolic name to a piece of text. * \pageref:: Refer to a page number. * \ref:: Refer to a section, figure or similar. @end menu @node \label @section @code{\label} @findex \label Synopsis: @example \label@{@var{key}@} @end example Assign a reference number to @var{key}. In ordinary text @code{\label@{@var{key}@}} assigns to @var{key} the number of the current sectional unit. Inside an environment with numbering, such as a @code{table} or @code{theorem} environment, @code{\label@{@var{key}@}} assigns to @var{key} the number of that environment. Retrieve the assigned number with the @code{\ref@{@var{key}@}} command (@pxref{\ref}). A key name can consist of any sequence of letters, digits, or common punctuation characters. Upper and lowercase letters are distinguished, as usual. 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: @table @code @item ch for chapters @item sec for lower-level sectioning commands @item fig for figures @item tab for tables @item eq for equations @end table Thus, @code{\label@{fig:Euler@}} is a label for a figure with a portrait of the great man. In this example below the key @code{sec:test} will get the number of the current section and the key @code{fig:test} will get the number of the figure. (Incidentally, put labels after captions in figures and tables.) @example \section@{section name@} \label@{sec:test@} This is Section~\ref@{sec:test@}. \begin@{figure@} ... \caption@{caption text@} \label@{fig:test@} \end@{figure@} See Figure~\ref@{fig:test@}. @end example @node \pageref @section @code{\pageref@{@var{key}@}} @findex \pageref @cindex cross referencing with page number @cindex page number, cross referencing Synopsis: @example \pageref@{@var{key}@} @end example Produce the page number of the place in the text where the corresponding @code{\label}@{@var{key}@} command appears. In this example the @code{\label@{eq:main@}} 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.) @example The main result is formula~\ref@{eq:main@} on page~\pageref@{eq:main@}. ... \begin@{equation@} \label@{eq:main@} \mathbf@{P@}=\mathbf@{NP@} \end@{equation@} @end example @node \ref @section @code{\ref@{@var{key}@}} @findex \ref @cindex cross referencing, symbolic @cindex section number, cross referencing @cindex equation number, cross referencing @cindex figure number, cross referencing @cindex footnote number, cross referencing Synopsis: @example \ref@{@var{key}@} @end example Produces the number of the sectional unit, equation, footnote, figure, @dots{}, of the corresponding @code{\label} command (@pxref{\label}). It does not produce any text, such as the word `Section' or `Figure', just the bare number itself. In this example, the @code{\ref@{popular@}} produces @samp{2}. Note that it is a forward reference since it comes before @code{\label@{popular@}}. @example The most widely-used format is item number~\ref@{popular@}. \begin@{enumerate@} \item Plain \TeX \item \label@{popular@} \LaTeX \item Con\TeX t \end@{enumerate@} @end example @node Environments @chapter Environments @cindex environments @findex \begin @findex \end @LaTeX{} provides many environments for delimiting certain behavior. An environment begins with @code{\begin} and ends with @code{\end}, like this: @example \begin@{@var{environment-name}@} ... \end@{@var{environment-name}@} @end example The @var{environment-name} at the beginning must exactly match that at the end. For instance, the input @code{\begin@{table*@}...\end@{table@}} will cause an error like: @samp{! LaTeX Error: \begin@{table*@} on input line 5 ended by \end@{table@}.} @cindex group, and environments Environments are executed within a group. @menu * abstract:: Produce an abstract. * array:: Math arrays. * center:: Centered lines. * description:: Labelled lists. * displaymath:: Formulas that appear on their own line. * document:: Enclose the whole document. * enumerate:: Numbered lists. * eqnarray:: Sequences of aligned equations. * equation:: Displayed equation. * figure:: Floating figures. * filecontents:: Writing multiple files from the source. * flushleft:: Flushed left lines. * flushright:: Flushed right lines. * itemize:: Bulleted lists. * letter:: Letters. * list:: Generic list environment. * math:: In-line math. * minipage:: Miniature page. * picture:: Picture with text, arrows, lines and circles. * quotation and quote:: Include a quotation. * tabbing:: Align text arbitrarily. * table:: Floating tables. * tabular:: Align text in columns. * thebibliography:: Bibliography or reference list. * theorem:: Theorems, lemmas, etc. * titlepage:: For hand crafted title pages. * verbatim:: Simulating typed input. * verse:: For poetry and other things. @end menu @node abstract @section @code{abstract} @EnvIndex{abstract} @cindex abstracts Synopsis: @example \begin@{abstract@} ... \end@{abstract@} @end example Produce an abstract, possibly of multiple paragraphs. This environment is only defined in the @code{article} and @code{report} document classes (@pxref{Document classes}). Using the example below in the @code{article} class produces a displayed paragraph. Document class option @code{titlepage} causes the abstract to be on a separate page (@pxref{Document class options}); this is the default only in the @code{report} class. @example \begin@{abstract@} 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@{abstract@} @end example The next example produces a one column abstract in a two column document (for a more flexible solution, use the package @file{abstract}). @c Adopted from http://www.tex.ac.uk/FAQ-onecolabs.html @example \documentclass[twocolumn]@{article@} ... \begin@{document@} \title@{Babe Ruth as Cultural Progenitor: a Atavistic Approach@} \author@{Smith \\ Jones \\ Robinson\thanks@{Railroad tracking grant.@}@} \twocolumn[ \begin@{@@twocolumnfalse@} \maketitle \begin@{abstract@} Ruth was not just the Sultan of Swat, he was the entire swat team. \end@{abstract@} \end@{@@twocolumnfalse@} ] @{ % by-hand insert a footnote at page bottom \renewcommand@{\thefootnote@}@{\fnsymbol@{footnote@}@} \footnotetext[1]@{Thanks for all the fish.@} @} @end example @node array @section @code{array} @EnvIndex{array} @cindex arrays, math Synopsis: @example \begin@{array@}@{@var{cols}@} @var{column 1 entry} &@var{column 2 entry} ... &@var{column n entry} \\ ... \end@{array@} @end example or @example \begin@{array@}[@var{pos}]@{@var{cols}@} @var{column 1 entry} &@var{column 2 entry} ... &@var{column n entry} \\ ... \end@{array@} @end example 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} (@pxref{equation}). Column entries are separated by an ampersand@tie{}(@code{&}). Rows are terminated with double-backslashes (@pxref{\\}). The required argument @var{cols} describes the number of columns, their alignment, and the formatting of the intercolumn regions. See @ref{tabular} for the complete description of @var{cols}, and of the other common features of the two environments, including the optional @var{pos} argument. There are two ways that @code{array} diverges from @code{tabular}. The first is that @code{array} entries are typeset in math mode, in textstyle (except if the @var{cols} definition specifies the column with @code{p@{...@}}, which causes the entry to be typeset in text mode). The second is that, instead of @code{tabular}'s parameter @code{\tabcolsep}, @LaTeX{}'s intercolumn space in an @code{array} is governed by @findex \arraycolsep @code{\arraycolsep}, which gives half the width between columns. The default for this is @samp{5pt}. @PkgIndex{amsmath} To obtain arrays with braces the standard is to use the @file{amsmath} package. It comes with environments @code{pmatrix} for an array surrounded by parentheses@tie{}@code{(...)}, @code{bmatrix} for an array surrounded by square brackets@tie{}@code{[...]}, @code{Bmatrix} for an array surrounded by curly braces@tie{}@code{@{...@}}, @code{vmatrix} for an array surrounded by vertical bars@tie{}@code{|...|}, and @code{Vmatrix} for an array surrounded by double vertical bars@tie{}@code{||...||}, along with a number of other array constructs. Here is an example of an array: @example \begin@{equation@} \begin@{array@}@{cr@} \sqrt@{y@} &12.3 \\ x^2 &3.4 \end@{array@} \end@{equation@} @end example The next example works if @code{\usepackage@{amsmath@}} is in the preamble: @example \begin@{equation@} \begin@{vmatrix@}@{cc@} a &b \\ c &d \end@{vmatrix@}=ad-bc \end@{equation@} @end example @node center @section @code{center} @EnvIndex{center} @cindex centering text, environment for Synopsis: @example \begin@{center@} ... text ... \end@{center@} @end example 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{\\}). @findex \\ @r{(for @code{center})} 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. This environment inserts space above and below the text body. See @ref{\centering} to avoid such space, for example inside a @code{figure} environment. This example produces three centered lines. There is extra vertical space between the last two lines. @example \begin@{center@} A Thesis Submitted in Partial Fufillment \\ of the Requirements of \\[0.5ex] the School of Environmental Engineering \end@{center@} @end example In this example, depending on the page'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. @example \begin@{center@} 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@{center@} @end example A double backslash after the final line is optional. @menu * \centering:: Declaration form of the @code{center} environment. @end menu @node \centering @subsection @code{\centering} @findex \centering @cindex centering text, declaration for A declaration that causes material in its scope to be centered. It is most often used inside an environment such as @code{figure}, or in a @code{parbox}. Unlike the @code{center} environment, the @code{\centering} command does not add vertical space above and below the text. It also does not start a new paragraph; it simply changes how @LaTeX{} formats paragraph units. If @code{ww @{\centering xx \\ yy@} zz} is surrounded by blank lines then @LaTeX{} will create a paragraph whose first line @samp{ww xx} is centered and whose second line, not centered, contains @samp{yy zz}. Usually what is desired is for the scope of the declaration to contain a blank line or the @code{\end} command of an environment such as @code{figure} or @code{table} that ends the paragraph unit. Thus, if @code{@{\centering xx \\ yy\par@} zz} is surrounded by blank lines then it makes a new paragraph with two centered lines @samp{xx} and @samp{yy}, followed by a new paragraph with @samp{zz} that is formatted as usual. See also the following example. This example's @code{\centering} causes the graphic to be horizontally centered. @example \begin@{figure@} \centering \includegraphics[width=0.6\textwidth]@{ctan_lion.png@} \caption@{CTAN Lion@} \label@{fig:CTANLion@} \end@{figure@} @end example The scope of the @code{\centering} ends with the @code{\end@{figure@}}. @node description @section @code{description} @EnvIndex{description} @cindex labelled lists, creating @cindex description lists, creating Synopsis: @example \begin@{description@} \item[@var{label of first item}] text of first item \item[@var{label of second item}] text of second item ... \end@{description@} @end example Environment to make a labeled list of items. Each item's @var{label} 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}. This example shows the environment used for a sequence of definitions. The labels @samp{lama} and @samp{llama} come out in boldface with their left edges aligned on the left margin. @example \begin@{definition@} \item[lama] A priest. \item[llama] A beast. \end@{definition@} @end example @findex \item Start list items with the @code{\item} command (@pxref{\item}). Use the optional labels, as in @code{\item[Main point]}, because there is no sensible default. Following the @code{\item} is optional text, which may contain multiple paragraphs. @cindex bold typewriter, avoiding @cindex typewriter labels in lists Since the labels are in bold style, if the label text calls for a font change given in argument style (see @ref{Font styles}) then it will come out bold. For instance, if the label text calls for typewriter with @code{\item[\texttt@{label text@}]} 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[@{\tt label text@}]}. Similarly, get the standard roman font with @code{\item[@{\rm label text@}]}. For other major @LaTeX{} labelled list environments, see @ref{itemize} and @ref{enumerate}. Unlike those environments, nesting @code{description} environments does not change the default label; it is boldface and flush left at all levels. For information about list layout parameters, including the default values, and for information about customizing list layout, see @ref{list}. The package @file{enumitem} is useful for customizing lists. This example changes the description labels to small caps. @example \renewcommand@{\descriptionlabel@}[1]@{% @{\hspace@{\labelsep@}\textsc@{#1@}@}@} @end example @node displaymath @section @code{displaymath} @c http://tex.stackexchange.com/questions/40492/what-are-the-differences-between-align-equation-and-displaymath @EnvIndex{displaymath} Synopsis: @example \begin@{displaymath@} @var{math text} \end@{displaymath@} @end example 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}; see @ref{Document class options}. In the @code{displaymath} environment no equation number is added to the math text. One way to get an equation number is to use the @code{equation} environment (@pxref{equation}). @LaTeX{} will not break the @var{math text} across lines. @PkgIndex{amsmath} Note that the @file{amsmath} 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. The construct @code{\[@var{math text}\]} is essentially a synonym for @code{\begin@{displaymath@}@var{math text}\end@{displaymath@}} 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} will likely be unique. (The construct @code{$$@var{math text}$$} from Plain@tie{}@TeX{} is sometimes mistakenly used as a synonym for @code{displaymath}. It is not a synonym, because the @code{displaymath} environment checks that it isn't started in math mode and that it ends in math mode begun by the matching environment start, because the @code{displaymath} environment has different vertical spacing, and because the @code{displaymath} environment honors the @code{fleqn} option.) The output from this example is centered and alone on its line. @example \begin@{displaymath@} \int_1^2 x^2\,dx=7/3 \end@{displaymath@} @end example Also, the integral sign is larger than the inline version @code{\( \int_1^2 x^2\,dx=7/3 \)} produces. @node document @section @code{document} @EnvIndex{document} The @code{document} environment encloses the entire body of a document. It is required in every @LaTeX{} document. @xref{Starting and ending}. @menu * \AtBeginDocument:: Hook for commands at the start of the document. * \AtEndDocument:: Hook for commands at the end of the document. @end menu @node \AtBeginDocument @subsection @code{\AtBeginDocument} @findex \AtBeginDocument @cindex beginning of document hook Synopsis: @example \AtBeginDocument@{@var{code}@} @end example Save @var{code} and execute it when @code{\begin@{document@}} 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. You can issue this command more than once; the successive code lines will be executed in the order that you gave them. @node \AtEndDocument @subsection @code{\AtEndDocument} @findex \AtEndDocument @cindex end of document hook Synopsis: @example \AtEndDocument@{@var{code}@} @end example Save @var{code} and execute it near the end of the document. Specifically, it is executed when @code{\end@{document@}} 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} at the appropriate point in @var{code}. You can issue this command more than once; the successive code lines will be executed in the order that you gave them. @node enumerate @section @code{enumerate} @EnvIndex{enumerate} @cindex lists of items, numbered Synopsis: @example \begin@{enumerate@} \item[@var{optional label of first item}] text of first item \item[@var{optional label of second item}] text of second item ... \end@{enumerate@} @end example 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{2.}, etc. Each @code{enumerate} list environment must have at least one item; having none causes the @LaTeX{} error @samp{Something's wrong--perhaps a missing \item}. 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.} and @samp{2.}. @example \begin@{enumerate@} \item Johnny Hayes (USA) \item Charles Hefferon (RSA) \end@{enumerate@} @end example @findex \item Start list items with the @code{\item} command (@pxref{\item}). If you give @code{\item} an optional argument by following it with square brackets, as in @code{\item[Interstitial label]}, then the next item will continue the interrupted sequence (@pxref{\item}). That is, you will get labels like @samp{1.}, then @samp{Interstitial label}, then @samp{2.}. Following the @code{\item} is optional text, which may contain multiple paragraphs. Enumerations may be nested within other @code{enumerate} environments, or within any paragraph-making environment such as @code{itemize} (@pxref{itemize}), up to four levels deep. This gives @LaTeX{}'s default for the format at each nesting level, where 1 is the top level, the outermost level. @enumerate @item arabic number followed by a period: @samp{1.}, @samp{2.},@tie{}@dots{} @item lower case letter inside parentheses: @samp{(a)}, @samp{(b)}@tie{}@dots{} @item lower case roman numeral followed by a period: @samp{i.}, @samp{ii.},@tie{}@dots{} @item upper case letter followed by a period: @samp{A.}, @samp{B.},@tie{}@dots{} @end enumerate @findex \enumi @findex \enumii @findex \enumiii @findex \enumiv The @code{enumerate} environment uses the counters @code{\enumi} through @code{\enumiv} (@pxref{Counters}). For other major @LaTeX{} labeled list environments, see @ref{description} and @ref{itemize}. For information about list layout parameters, including the default values, and for information about customizing list layout, see @ref{list}. The package @file{enumitem} is useful for customizing lists. @findex \labelenumi @findex \labelenumii @findex \labelenumiii @findex \labelenumiv To change the format of the label use @code{\renewcommand} (@pxref{\newcommand & \renewcommand}) on the commands @code{\labelenumi} through @code{\labelenumiv}. For instance, this first level list will be labelled with uppercase letters, in boldface, and without a trailing period. @findex \Alph @r{example} @example \renewcommand@{\labelenumi@}@{\textbf@{\Alph@{enumi@}@}@} \begin@{enumerate@} \item Shows as boldface A \item Shows as boldface B \end@{enumerate@} @end example For a list of counter-labeling commands see @ref{\alph \Alph \arabic \roman \Roman \fnsymbol}. @node eqnarray @section @code{eqnarray} @EnvIndex{eqnarray} @cindex equations, aligning @cindex aligning equations @cindex align @r{environment, from @code{amsmath}} @cindex amsmath @r{package, replacing @code{eqnarray}} @cindex Madsen, Lars First, a caveat: the @code{eqnarray} environment is depreciated. It has infelicities that cannot be overcome, including spacing that is inconsistent with other mathematics elements (see the article ``Avoid eqnarray!''@: by Lars Madsen @url{http://tug.org/TUGboat/tb33-1/tb103madsen.pdf}). New documents should include the @file{amsmath} package and use the displayed mathematics environments provided there, such as the @code{align} environment. Nevertheless, for completeness and for a reference when working with old documents, a synopsis: @example \begin@{eqnarray@} @var{first formula left} &@var{first formula middle} &@var{first formula right} \\ ... \end@{eqnarray@} @end example or @example \begin@{eqnarray*@} @var{first formula left} &@var{first formula middle} &@var{first formula right} \\ ... \end@{eqnarray*@} @end example @findex \\ @r{(for @code{eqnarray})} 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. It is similar to a three-column @code{array} environment, with items within a row separated by an ampersand@tie{}(@code{&}), and with rows separated by double backslash@tie{} @code{\\}). @findex \\* @r{(for @code{eqnarray})} The starred form of line break (@code{\\*}) can also be used to separate equations, and will disallow a page break there (@pxref{\\}). @findex \nonumber @cindex equation numbers, omitting The unstarred form @code{eqnarray} places an equation number on every line (using the @code{equation} counter), unless that line contains a @code{\nonumber} command. The starred form @code{eqnarray*} omits equation numbering, while otherwise being the same. @findex \lefteqn The command @code{\lefteqn} is used for splitting long formulas across lines. It typesets its argument in display style flush left in a box of zero width. This example shows three lines. The first two lines make an inequality, while the third line has not entry on the left side. @example \begin@{eqnarray*@} \lefteqn@{x_1+x_2+\cdots+x_n@} \\ &\leq &y_1+y_2+\cdots+y_n \\ &= &z+y_3+\cdots+y_n \end@{eqnarray*@} @end example @node equation @section @code{equation} @EnvIndex{equation} @cindex equations, environment for @cindex formulas, environment for Synopsis: @example \begin@{equation@} math text \end@{equation@} @end example Make a @code{displaymath} environment (@pxref{displaymath}) with an equation number in the right margin. The equation number is generated using the @code{equation} counter. You should have no blank lines between @code{\begin@{equation@}} and @code{\begin@{equation@}}, or @LaTeX{} will tell you that there is a missing dollar sign,@tie{}$@code{$}. Note that the @file{amsmath} package has extensive displayed equation facilities. Those facilities are the best approach for such output in new documents. @node figure @section @code{figure} @EnvIndex{figure} @cindex inserting figures @cindex figures, inserting Synopsis: @example \begin@{figure@}[@var{placement}] figure body \caption[@var{loftitle}]@{@var{title}@} \label@{@var{label@}} \end@{figure@} @end example or @example \begin@{figure*@}[@var{placement}] figure body \caption[@var{loftitle}]@{@var{title}@} \label@{@var{label@}} \end@{figure*@} @end example A class of floats (@pxref{Floats}). Because they cannot be split across pages, they are not typeset in sequence with the normal text but instead are ``floated'' to a convenient place, such as the top of a following page. For the possible values of @var{placement} and their effect on the float placement algorithm, see @ref{Floats}. The starred form @code{figure*} is used when a document is in double-column mode (@pxref{\twocolumn}). 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} @code{b} in @ref{Floats}. The figure body is typeset in a @code{parbox} of width @code{\textwidth} and so it can contain text, commands, etc. The label is optional; it is used for cross references (@pxref{Cross references}). @findex \caption The optional @code{\caption} command specifies caption text for the figure. By default it is numbered. If @var{loftitle} is present, it is used in the list of figures instead of @var{title} (@pxref{Tables of contents}). This example makes a figure out of a graphic. It requires one of the packages @file{graphics} or @file{graphicx}. 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. @example \begin@{figure@}[t] \centering \includegraphics[width=0.5\textwidth]@{CTANlion.png@} \caption@{The CTAN lion, by Duane Bibby@} \end@{figure@} @end example @node filecontents @section @code{filecontents}: Write an external file @EnvIndex{filecontents} @EnvIndex{filecontents*} @cindex external files, writing @cindex writing external files Synopsis: @example \begin@{filecontents@}@{@var{filename}@} @var{text} \end@{filecontents@} @end example or @example \begin@{filecontents*@}@{@var{filename}@} @var{text} \end@{filecontents*@} @end example Create a file named @var{filename} and fill it with @var{text}. The unstarred version of the environment @code{filecontents} prefixes the content of the created file with a header; see the example below. The starred version @code{filecontents*} does not include the header. This environment can be used anywhere in the preamble, although it often appears before the @code{\documentclass} 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} references in the file, again to make it self-contained. The environment checks whether a file of that name already exists and if so, does not do anything. There is a @file{filecontents} package that redefines the @code{filecontents} environment so that instead of doing nothing in that case, it will overwrite the existing file. For example, this document @example \documentclass@{article@} \begin@{filecontents@}@{JH.sty@} \newcommand@{\myname@}@{Jim Hef@{@}feron@} \end@{filecontents@} \usepackage@{JH@} \begin@{document@} Article by \myname. \end@{document@} @end example produces this file @file{JH.sty}. @example %% LaTeX2e file `JH.sty' %% generated by the `filecontents' environment %% from source `test' on 2015/10/12. %% \newcommand@{\myname@}@{Jim Hef@{@}feron@} @end example @node flushleft @section @code{flushleft} @EnvIndex{flushleft} @cindex left-justifying text, environment for @cindex ragged right text, environment for @example \begin@{flushleft@} @var{line1} \\ @var{line2} \\ ... \end@{flushleft@} @end example @findex \\ @r{for @code{flushleft}} The @code{flushleft} 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{\\}. @menu * \raggedright:: Declaration form of the @code{flushleft} environment. @end menu @node \raggedright @subsection @code{\raggedright} @findex \raggedright @cindex ragged right text @cindex left-justifying text @cindex justification, ragged right The @code{\raggedright} declaration corresponds to the @code{flushleft} environment. This declaration can be used inside an environment such as @code{quote} or in a @code{parbox}. Unlike the @code{flushleft} environment, the @code{\raggedright} command does not start a new paragraph; it only changes how @LaTeX{} formats paragraph units. To affect a paragraph unit's format, the scope of the declaration must contain the blank line or @code{\end} command that ends the paragraph unit. @node flushright @section @code{flushright} @EnvIndex{flushright} @cindex ragged left text, environment for @cindex right-justifying text, environment for @example \begin@{flushright@} @var{line1} \\ @var{line2} \\ ... \end@{flushright@} @end example @findex \\ (for @code{flushright}) The @code{flushright} 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{\\}. @menu * \raggedleft:: Declaration form of the @code{flushright} environment. @end menu @node \raggedleft @subsection @code{\raggedleft} @findex \raggedleft @cindex ragged left text @cindex justification, ragged left @cindex right-justifying text The @code{\raggedleft} declaration corresponds to the @code{flushright} environment. This declaration can be used inside an environment such as @code{quote} or in a @code{parbox}. Unlike the @code{flushright} environment, the @code{\raggedleft} command does not start a new paragraph; it only changes how @LaTeX{} formats paragraph units. To affect a paragraph unit's format, the scope of the declaration must contain the blank line or @code{\end} command that ends the paragraph unit. @node itemize @section @code{itemize} @EnvIndex{itemize} @findex \item @cindex lists of items @cindex unordered lists @cindex bulleted lists Synopsis: @example \begin@{itemize@} \item[@var{optional label of first item}] text of first item \item[@var{optional label of second item}] text of second item ... \end@{itemize@} @end example The @code{itemize} environment produces an ``unordered'', ``bulleted'' list. The format of the label numbering depends on the nesting level of this environment; see below. Each @code{itemize} list environment must have at least one item; having none causes the @LaTeX{} error @samp{Something's wrong--perhaps a missing \item}. This example gives a two-item list. As a top-level list each label would come out as a bullet, @bullet{}. @example \begin@{itemize@} \item Pencil and watercolor sketch by Cassandra \item Rice portrait \end@{itemize@} @end example @findex \item Start list items with the @code{\item} command (@pxref{\item}). If you give @code{\item} an optional argument by following it with square brackets, as in @code{\item[Optional label]}, 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{description} environment. Following the @code{\item} is optional text, which may contain multiple paragraphs. @findex \labelitemi @findex \labelitemii @findex \labelitemiii @findex \labelitemiv 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} (@pxref{enumerate}). The @code{itemize} environment uses the commands @code{\labelitemi} through @code{\labelitemiv} 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. @enumerate @item @bullet{} (bullet, from @code{\textbullet}) @item @b{-@w{-}} (bold en-dash, from @code{\normalfont\bfseries\textendash}) @item * (asterisk, from @code{\textasteriskcentered}) @iftex @item @math{\cdot} (centered dot, from @code{\textperiodcentered}) @end iftex @ifnottex @item . (centered dot, rendered here as a period, from @code{\textperiodcentered}) @end ifnottex @end enumerate Change the labels with @code{\renewcommand}. For instance, this makes the first level use diamonds. @example \renewcommand@{\labelitemi@}@{$\diamond$@} @end example @findex \leftmargin @findex \leftmargini @findex \leftmarginii @findex \leftmarginiii @findex \leftmarginiv @findex \leftmarginv @findex \leftmarginvi The distance between the left margin of the enclosing environment and the left margin of the @code{itemize} list is determined by the parameters @code{\leftmargini} through @code{\leftmarginvi}. (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} in level 1 (@code{2em} in two-column mode), @code{2.2em} in level 2, @code{1.87em} in level 3, and @code{1.7em} in level 4, with smaller values for more deeply nested levels. For other major @LaTeX{} labeled list environments, see @ref{description} and @ref{enumerate}. For information about list layout parameters, including the default values, and for information about customizing list layout, see @ref{list}. The package @file{enumitem} is useful for customizing lists. This example greatly reduces the margin space for outermost itemized lists. @example \setlength@{\leftmargini@}@{1.25em@} % default 2.5em @end example @findex \parskip @r{example} Especially for lists with short items, it may be desirable to elide space between items. Here is an example defining an @code{itemize*} environment with no extra spacing between items, or between paragraphs within a single item (@code{\parskip} is not list-specific, @pxref{\parskip}): @example \newenvironment@{itemize*@}% @{\begin@{itemize@}% \setlength@{\itemsep@}@{0pt@}% \setlength@{\parsep@}@{0pt@}@}% \setlength@{\parskip@}@{0pt@}@}% @{\end@{itemize@}@} @end example @node letter @section @code{letter} environment: writing letters @EnvIndex{letter} This environment is used for creating letters. @xref{Letters}. @node list @section @code{list} @EnvIndex{list} @cindex lists of items, generic Synopsis: @example \begin@{list@}@{@var{labeling}@}@{@var{spacing}@} \item[@var{optional label of first item}] text of first item \item[@var{optional label of second item}] text of second item ... \end@{list@} @end example The @code{list} environment is a generic environment for constructing more specialized lists. It is most often used to create lists via the @code{description}, @code{enumerate}, and @code{itemize} environments (@pxref{description}, @ref{enumerate}, and @ref{itemize}). Also, many standard @LaTeX{} environments that are not visually lists are constructed using @code{list}, including @code{quotation}, @code{quote}, @code{center}, @code{verbatim}, and plenty more (@pxref{quotation and quote}, @pxref{center}, @pxref{flushright}). @PkgIndex{enumitem} The third-party package @code{enumitem} is useful for customizing lists. Here, we describe the @code{list} environment by defining a new custom environment. @example \newcounter@{namedlistcounter@} % number the items \newenvironment@{named@} @{\begin@{list@} @{Item~\Roman@{namedlistcounter@}.@} % labeling argument @{\usecounter@{namedlistcounter@} % spacing argument \setlength@{\leftmargin@}@{3.5em@}@} % still spacing arg @} @{\end@{list@}@} \begin@{named@} \item Shows as ``Item~I.'' \item[Special label.] Shows as ``Special label.'' \item Shows as ``Item~II.'' \end@{named@} @end example The @code{list} environment's mandatory first argument, @var{labeling}, specifies the default labeling of list items. It can contain text and @LaTeX{} commands, as above where it contains both @samp{Item} and @samp{\Roman@{...@}}. @LaTeX{} forms the label by putting the @var{labeling} argument in a box of width @code{\labelwidth}. 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} an optional argument by including square braces and the text, as in the above @code{\item[Special label.]}; @pxref{\item}. @findex \makelabel The label box is constructed by the command @code{\makelabel}. 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} environment add @code{\newcommand@{\namedmakelabel@}[1]@{\textsc@{#1@}@}}, and between the @code{\setlength} command and the parenthesis that closes the @var{spacing} argument also add @code{\let\makelabel\namedmakelabel}. Then the items will be typeset in small caps. Similarly, changing the second code line to @code{\let\makelabel\fbox} puts the labels inside a framed box. Another example is at the bottom of this entry. The mandatory second argument @var{spacing} can have a list of commands to redefine the spacing parameters for the list, such as @code{\setlength@{\labelwidth@}@{2em@}}. If this argument is empty, i.e., @code{@{@}}, then the list will have the default spacing given below. To number the items using a counter, put @code{\usecounter@{@var{countername}@}} in this argument (@pxref{\usecounter}). Below are the spacing parameters for list formatting. See also the figure below. Each is a length (@pxref{Lengths}). The vertical spaces are normally rubber lengths, with @code{plus} and @code{minus} components, to give @TeX{} flexibility in setting the page. Change each with a command such as @code{\setlength@{itemsep@}@{2pt plus1pt minus1pt@}}. For some effects these lengths should be zero or negative. Default values for derived environments such as @code{itemize} can be changed from the values shown here for the basic @code{list}. @ftable @code @item \itemindent Extra horizontal space indentation, beyond @code{leftmargin}, of the first line each item. Its default value is @code{0pt}. @item \itemsep Vertical space between items, beyond the @code{\parsep}. The defaults for the first three levels in @LaTeX{}'s @samp{article}, @samp{book}, and @samp{report} classes at 10 point size are: @code{4pt plus2pt minus1pt}, @code{\parsep} (that is, @code{2pt plus1pt minus1pt}), and @code{\topsep} (that is, @code{2pt plus1pt minus1pt}). The defaults at 11 point are: @code{4.5pt plus2pt minus1pt}, @code{\parsep} (that is, @code{2pt plus1pt minus1pt}), and @code{topsep} (that is, @code{2pt plus1pt minus1pt}). The defaults at 12 point are: @code{5pt plus2.5pt minus1pt}, @code{\parsep} (that is, @code{2.5pt plus1pt minus1pt}), and @code{\topsep} (that is, @code{2.5pt plus1pt minus1pt}). @item \labelsep Horizontal space between the label and text of an item. The default for @LaTeX{}'s @samp{article}, @samp{book}, and @samp{report} classes is @code{0.5em}. @item \labelwidth Horizontal width. The box containing the label is nominally this wide. If @code{\makelabel} 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} returns text of width less than or equal to @code{\labelwidth} then @LaTeX{}'s default is that the label is typeset flush right in a box of this width. The left edge of the label box is @code{\leftmargin}+@code{\itemindent}-@code{\labelsep}-@code{\labelwidth} from the left margin of the enclosing environment. The default for @LaTeX{}'s @samp{article}, @samp{book}, and @samp{report} classes at the top level is @code{\leftmargini}-@code{\labelsep}, (which is @code{2em} in one column mode and @code{1.5em} in two column mode). At the second level it is @code{\leftmarginii}-@code{\labelsep}, and at the third level it is @code{\leftmarginiii}-@code{\labelsep}. These definitions make the label's left edge coincide with the left margin of the enclosing environment. @item \leftmargin 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. In the standard @LaTeX{} document classes, a top-level list has this set to the value of @code{\leftmargini}, while a list that is nested inside a top-level list has this margin set to @code{\leftmarginii}. More deeply nested lists get the values of @code{\leftmarginiii} through @code{\leftmarginvi}. (Nesting greater than level five generates the error message @samp{Too deeply nested}.) The defaults for the first three levels in @LaTeX{}'s @samp{article}, @samp{book}, and @samp{report} classes are: @code{\leftmargini} is @code{2.5em} (in two column mode, @code{2em}), @code{\leftmarginii} is @code{2.2em}, and @code{\leftmarginiii} is @code{1.87em}. @item \listparindent Horizontal space of additional line indentation, beyond @code{\leftmargin}, for second and subsequent paragraphs within a list item. A negative value makes this an ``outdent''. Its default value is @code{0pt}. @item \parsep Vertical space between paragraphs within an item. In the @samp{book} and @samp{article} classes The defaults for the first three levels in @LaTeX{}'s @samp{article}, @samp{book}, and @samp{report} classes at 10 point size are: @code{4pt plus2pt minus1pt}, @code{2pt plus1pt minus1pt}, and @code{0pt}. The defaults at 11 point size are: @code{4.5pt plus2pt minus1pt}, @code{2pt plus1pt minus1pt}, and @code{0pt}. The defaults at 12 point size are: @code{5pt plus2.5pt minus1pt}, @code{2.5pt plus1pt minus1pt}, and @code{0pt}. @item \partopsep Vertical space added, beyond @code{\topsep}+@code{\parskip}, 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.) The defaults for the first three levels in @LaTeX{}'s @samp{article}, @samp{book}, and @samp{report} classes at 10 point size are: @code{2pt plus1 minus1pt}, @code{2pt plus1pt minus1pt}, and @code{1pt plus0pt minus1pt}. The defaults at 11 point are: @code{3pt plus1pt minus1pt}, @code{3pt plus1pt minus1pt}, and @code{1pt plus0pt minus1pt}). The defaults at 12 point are: @code{3pt plus2pt minus3pt}, @code{3pt plus2pt minus2pt}, and @code{1pt plus0pt minus1pt}. @item \rightmargin Horizontal space between the right margin of the list and the right margin of the enclosing environment. Its default value is @code{0pt}. It must be non-negative. @item \topsep Vertical space added to both the top and bottom of the list, in addition to @code{\parskip} (@pxref{\parskip}). The defaults for the first three levels in @LaTeX{}'s @samp{article}, @samp{book}, and @samp{report} classes at 10 point size are: @code{8pt plus2pt minus4pt}, @code{4pt plus2pt minus1pt}, and @code{2pt plus1pt minus1pt}. The defaults at 11 point are: @code{9pt plus3pt minus5pt}, @code{4.5pt plus2pt minus1pt}, and @code{2pt plus1pt minus1pt}. The defaults at 12 point are: @code{10pt plus4pt minus6pt}, @code{5pt plus2.5pt minus1pt}, and @code{2.5pt plus1pt minus1pt}. @end ftable This shows the horizontal and vertical distances. @float @image{latex2e-figures/list,3.21in,,,.png} @end float The lengths shown are listed below. The key relationship is that the right edge of the bracket for @var{h1} equals the right edge of the bracket for @var{h4}, so that the left edge of the label box is at @var{h3}+@var{h4}-(@var{h0}+@var{h1}). @table @var @item v0 @math{@code{@\topsep} + @code{@\parskip}} if the list environment does not start a new paragraph, and @code{\topsep}+@code{\parskip}+@code{\partopsep} if it does @item v1 @code{\parsep} @item v2 @code{\itemsep}+@code{\parsep} @item v3 Same as @var{v0}. (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.) @item h1 @code{\labelsep} @item h2 @code{\listparindent} @item h3 @code{\leftmargin} @item h4 @code{\itemindent} @item h5 @code{\rightmargin} @end table The list's left and right margins, shown above as @var{h3} and @var{h5}, 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} (@pxref{Page layout parameters}). For instance, set the list's left margin to be one quarter of the distance between the left and right margins of the enclosing environment with @code{\setlength@{\leftmargin@}@{0.25\linewidth@}}. Page breaking in a list structure is controlled by the three parameters below. For each, the @LaTeX{} default is @code{-\@@lowpenalty}, that is, @code{-51}. Because it is negative, it somewhat encourages a page break at each spot. Change it with, e.g., @code{\@@beginparpenalty=9999}; a value of 10000 prohibits a page break. @ftable @code @item \@@beginparpenalty The page breaking penalty for breaking before the list (default @code{-51}). @item \@@itempenalty The page breaking penalty for breaking before a list item (default @code{-51}). @item \@@endparpenalty The page breaking penalty for breaking after a list (default @code{-51}). @end ftable 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. @example \usepackage@{color@} \newcounter@{cnt@} \newcommand@{\makeredlabel@}[1]@{\textcolor@{red@}@{#1.@}@} \newenvironment@{redlabel@} @{\begin@{list@} @{\arabic@{cnt@}@} @{\usecounter@{cnt@} \setlength@{\labelwidth@}@{0em@} \setlength@{\labelsep@}@{0.5em@} \setlength@{\leftmargin@}@{1.5em@} \setlength@{\itemindent@}@{0.5em@} % equals \labelwidth+\labelsep \let\makelabel=\makeredlabel @} @} @{\end@{list@} @} @end example @menu * \item:: An entry in a list. * trivlist:: A restricted form of @code{list}. @end menu @node \item @subsection @code{\item}: An entry in a list Synopsis: @example \item text of item @end example or @example \item[@var{optional-label}] text of item @end example An entry in a list. The entries are prefixed by a label, whose default depends on the list type. Because the optional label is surrounded by square brackets @samp{[...]}, if you have an item whose text starts with @samp{[}, you have to to hide the bracket inside curly braces, as in: @code{\item @{[@} is an open square bracket}; otherwise, @LaTeX{} will think it marks the start of an optional label. 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, @{]@}]}. @xref{@LaTeX{} command syntax}. In this example the enumerate list has two items that use the default label and one that uses the optional label. @example \begin@{enumerate@} \item Moe \item[sometimes] Shemp \item Larry \end@{enumerate@} @end example The first item is labelled @samp{1.}, the second item is labelled @samp{sometimes}, and the third item is labelled @samp{2.}. Because of the optional label in the second item, the third item is not labelled@tie{}@samp{3.}. @node trivlist @subsection @code{trivlist}: A restricted form of @code{list} Synopsis: @example \begin@{trivlist@} ... \end@{trivlist@} @end example A restricted version of the list environment, in which margins are not indented and an @code{\item} without an optional argument produces no text. It is most often used in macros, to define an environment where the @code{\item} command as part of the environment's definition. For instance, the @code{center} environment is defined essentially like this: @example \newenvironment@{center@} @{\begin@{trivlist@}\centering\item\relax@} @{\end@{trivlist@}@} @end example Using @code{trivlist} 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. Specifically, @code{trivlist} uses the current values of the list parameters (@pxref{list}), except that @code{\parsep} is set to the value of @code{\parskip}, and @code{\leftmargin}, @code{\labelwidth}, and @code{\itemindent} are set to zero. This example outputs the items as two paragraphs, except that (by default) they have no paragraph indent and are vertically separated. @example \begin@{trivlist@} \item The \textit@{Surprise@} is not old; no one would call her old. \item She has a bluff bow, lovely lines. \end@{trivlist@} @end example @node math @section @code{math} @EnvIndex{math} @cindex in-line formulas Synopsis: @example \begin@{math@} @var{math} \end@{math@} @end example The @code{math} environment inserts given @var{math} material within the running text. @code{\(...\)} and @code{$...$} are synonyms. @xref{Math formulas}. @node minipage @section @code{minipage} @EnvIndex{minipage} @cindex minipage, creating a @example \begin@{minipage@}[@var{position}][@var{height}][@var{inner-pos}]@{@var{width}@} @var{text} \end@{minipage@} @end example The @code{minipage} environment typesets its body @var{text} in a block that will not be broken across pages. This is similar to the @code{\parbox} command (@pxref{\parbox}), but unlike @code{\parbox}, other paragraph-making environments can be used inside a minipage. @c (xxref positions) The arguments are the same as for @code{\parbox} (@pxref{\parbox}). @cindex indentation of paragraphs, in minipage @cindex paragraph indentation, in minipage @findex \parindent By default, paragraphs are not indented in the @code{minipage} environment. You can restore indentation with a command such as @code{\setlength@{\parindent@}@{1pc@}} command. @cindex footnotes in figures @cindex figures, footnotes in Footnotes in a @code{minipage} environment are handled in a way that is particularly useful for putting footnotes in figures or tables. A @code{\footnote} or @code{\footnotetext} command puts the footnote at the bottom of the minipage instead of at the bottom of the page, and it uses the @code{\mpfootnote} counter instead of the ordinary @code{footnote} counter (@pxref{Counters}). However, don't put one minipage inside another if you are using footnotes; they may wind up at the bottom of the wrong minipage. @node picture @section @code{picture} @EnvIndex{picture} @cindex creating pictures @cindex pictures, creating @example \begin@{picture@}(@var{width},@var{height})(@var{xoffset},@var{yoffset}) @dots{} @var{picture commands} @dots{} \end@{picture@} @end example @findex \unitlength The @code{picture} 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---a number like @code{5}, @code{0.3} or @code{-3.1416}. A coordinate specifies a length in multiples of the unit length @code{\unitlength}, so if @code{\unitlength} has been set to @code{1cm}, then the coordinate 2.54 specifies a length of 2.54 centimeters. You should only change the value of @code{\unitlength}, using the @code{\setlength} command, outside of a @code{picture} environment. The default value is @code{1pt}. @PkgIndex{picture} The @code{picture} package redefine the @code{picture} environment so that everywhere a number is used in a @var{picture commands} to specify a coordinate, one can use alternatively a length. Be aware however that this will prevent scaling those lengths by changing @code{\unitlength}. @cindex position, in picture A @dfn{position} is a pair of coordinates, such as @code{(2.4,-5)}, specifying the point with x-coordinate @code{2.4} and y-coordinate @code{-5}. 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. The @code{picture} environment has one mandatory argument which is a position (@var{width},@var{height}), which specifies the size of the picture. The environment produces a rectangular box with these @var{width} and @var{height}. The @code{picture} environment also has an optional position argument (@var{xoffset},@var{yoffset}), 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} has been set to @code{1mm}, the command @example \begin@{picture@}(100,200)(10,20) @end example @noindent 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. The environment'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's nominal size is used by @LaTeX{} in determining how much room to leave for it. Everything that appears in a picture is drawn by the @code{\put} command. The command @example \put (11.3,-.3)@{...@} @end example @noindent puts the object specified by @code{...} in the picture, with its reference point at coordinates @math{(11.3,-.3)}. The reference points for various objects will be described below. @findex lR box The @code{\put} command creates an @dfn{LR box}. You can put anything that can go in an @code{\mbox} (@pxref{\mbox}) in the text argument of the @code{\put} command. When you do this, the reference point will be the lower left corner of the box. The @code{picture} commands are described in the following sections. @menu * \circle:: Draw a circle. * \makebox (picture):: Draw a box of the specified size. * \framebox (picture):: Draw a box with a frame around it. * \dashbox:: Draw a dashed box. * \frame:: Draw a frame around an object. * \line:: Draw a straight line. * \linethickness:: Set the line thickness. * \thicklines:: A heavier line thickness. * \thinlines:: The default line thickness. * \multiput:: Draw multiple instances of an object. * \oval:: Draw an ellipse. * \put:: Place an object at a specified place. * \shortstack:: Make a pile of objects. * \vector:: Draw a line with an arrow. @end menu @node \circle @subsection @code{\circle} @findex \circle Synopsis: @example \circle[*]@{@var{diameter}@} @end example The @code{\circle} command produces a circle with a diameter as close to the specified one as possible. The @code{*}-form of the command draws a solid circle. Circles up to 40@dmn{pt} can be drawn. @node \makebox (picture) @subsection @code{\makebox} @findex \makebox @r{(for @code{picture})} Synopsis: @example \makebox(@var{width},@var{height})[@var{position}]@{@var{text}@} @end example The @code{\makebox} command for the picture environment is similar to the normal @code{\makebox} command except that you must specify a @var{width} and @var{height} in multiples of @code{\unitlength}. The optional argument, @code{[@var{position}]}, specifies the quadrant that your @var{text} appears in. You may select up to two of the following: @table @code @item t Moves the item to the top of the rectangle. @item b Moves the item to the bottom. @item l Moves the item to the left. @item r Moves the item to the right. @end table @xref{\makebox}. @node \framebox (picture) @subsection @code{\framebox} @findex \framebox Synopsis: @example \framebox(@var{width},@var{height})[@var{pos}]@{...@} @end example The @code{\framebox} command is like @code{\makebox} (see previous section), except that it puts a frame around the outside of the box that it creates. @findex \fboxrule @findex \fboxsep The @code{\framebox} command produces a rule of thickness @code{\fboxrule}, and leaves a space @code{\fboxsep} between the rule and the contents of the box. @node \dashbox @subsection @code{\dashbox} @findex \dashbox Draws a box with a dashed line. Synopsis: @example \dashbox@{@var{dlen}@}(@var{rwidth},@var{rheight})[@var{pos}]@{@var{text}@} @end example @code{\dashbox} creates a dashed rectangle around @var{text} in a @code{picture} environment. Dashes are @var{dlen} units long, and the rectangle has overall width @var{rwidth} and height @var{rheight}. The @var{text} is positioned at optional @var{pos}. @c xxref positions. A dashed box looks best when the @var{rwidth} and @var{rheight} are multiples of the @var{dlen}. @node \frame @subsection @code{\frame} @findex \frame Synopsis: @example \frame@{@var{text}@} @end example The @code{\frame} command puts a rectangular frame around @var{text}. The reference point is the bottom left corner of the frame. No extra space is put between the frame and the object. @node \line @subsection @code{\line} @findex \line Synopsis: @example \line(@var{xslope},@var{yslope})@{@var{length}@} @end example The @code{\line} command draws a line with the given @var{length} and slope @var{xslope}/@var{yslope}. @cindex @code{pict2e} package @cindex graphics packages Standard @LaTeX{} can only draw lines with @math{@var{slope} = x/y}, where @math{x} and @math{y} have integer values from @minus{}6 through@tie{}6. For lines of any slope, and plenty of other shapes, see @code{pict2e} and many other packages on CTAN. @node \linethickness @subsection @code{\linethickness} @findex \linethickness The @code{\linethickness@{@var{dim}@}} command declares the thickness of horizontal and vertical lines in a picture environment to be @var{dim}, which must be a positive length. @code{\linethickness} does not affect the thickness of slanted lines, circles, or the quarter circles drawn by @code{\oval}. @node \thicklines @subsection @code{\thicklines} @findex \thicklines The @code{\thicklines} command is an alternate line thickness for horizontal and vertical lines in a picture environment; cf.@tie{}@ref{\linethickness} and @ref{\thinlines}. @node \thinlines @subsection @code{\thinlines} @findex \thinlines The @code{\thinlines} command is the default line thickness for horizontal and vertical lines in a picture environment; cf.@tie{}@ref{\linethickness} and @ref{\thicklines}. @node \multiput @subsection @code{\multiput} @findex \multiput Synopsis: @example \multiput(@var{x},@var{y})(@var{delta_x},@var{delta_y})@{@var{n}@}@{@var{obj}@} @end example The @code{\multiput} command copies the object @var{obj} in a regular pattern across a picture. @var{obj} is first placed at position @math{(x,y)}, then at @math{(x+\delta x,y+\delta y)}, and so on, @var{n} times. @node \oval @subsection @code{\oval} @findex \oval Synopsis: @example \oval(@var{width},@var{height})[@var{portion}] @end example The @code{\oval} command produces a rectangle with rounded corners. The optional argument @var{portion} allows you to produce only half of the oval via the following: @table @code @item t selects the top half; @item b selects the bottom half; @item r selects the right half; @item l selects the left half. @end table It is also possible to produce only one quarter of the oval by setting @var{portion} to @code{tr}, @code{br}, @code{bl}, or @code{tl}. The ``corners'' of the oval are made with quarter circles with a maximum radius of 20@dmn{pt}, so large ``ovals'' will look more like boxes with rounded corners. @node \put @subsection @code{\put} @findex \put Synopsis: @example \put(@var{xcoord},@var{ycoord})@{ ... @} @end example The @code{\put} command places the material specified by the (mandatory) argument in braces at the given coordinate, (@var{xcoord},@var{ycoord}). @node \shortstack @subsection @code{\shortstack} @findex \shortstack Synopsis: @example \shortstack[@var{position}]@{...\\...\\...@} @end example The @code{\shortstack} command produces a stack of objects. The valid positions are: @table @code @item r Move the objects to the right of the stack. @item l Move the objects to the left of the stack @item c Move the objects to the centre of the stack (default) @end table @findex \\ @r{(for @code{\shortstack} objects)} Objects are separated with @code{\\}. @node \vector @subsection @code{\vector} @findex \vector Synopsis: @example \vector(@var{xslope},@var{yslope})@{@var{length}@} @end example The @code{\vector} command draws a line with an arrow of the specified length and slope. The @math{@var{xslope}} and @math{@var{yslope}} values must lie between @minus{}4 and +4, inclusive. @node quotation and quote @section @code{quotation} and @code{quote} @EnvIndex{quotation} @cindex quoted text with paragraph indentation, displaying @cindex displaying quoted text with paragraph indentation @cindex paragraph indentations in quoted text @EnvIndex{quote} @cindex quoted text without paragraph indentation, displaying @cindex displaying quoted text without paragraph indentation @cindex paragraph indentations in quoted text, omitting Synopsis: @example \begin@{quotation@} @var{text} \end@{quotation@} @end example or @example \begin@{quote@} @var{text} \end@{quote@} @end example Include a quotation. In both environments, margins are indented on both sides by @code{\leftmargin} and the text is justified at both. As with the main text, leaving a blank line produces a new paragraph. To compare the two: in the @code{quotation} environment, paragraphs are indented by 1.5@dmn{em} and the space between paragraphs is small, @code{0pt plus 1pt}. In the @code{quote} environment, paragraphs are not indented and there is vertical space between paragraphs (it is the rubber length @code{\parsep}). Thus, the @code{quotation} 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} may be more suitable for a short quotation or a sequence of short quotations. @example \begin@{quotation@} \it Four score and seven years ago ... shall not perish from the earth. \hspace@{1em plus 1fill@}---Abraham Lincoln \end@{quotation@} @end example @node tabbing @section @code{tabbing} @EnvIndex{tabbing} @cindex tab stops, using @cindex lining text up using tab stops @cindex alignment via tabbing Synopsis: @example \begin@{tabbing@} @var{row1col1} \= @var{row1col2} ... \\ @var{row2col1} \> @var{row2col2} ... \\ ... \end@{tabbing@} @end example The @code{tabbing} 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. This example has a first line where the tab stops are set to explicit widths, ended by a @code{\kill} command (which is described below): @example \begin@{tabbing@} \hspace@{0.75in@} \= \hspace@{0.40in@} \= \hspace@{0.40in@} \kill Ship \> Guns \> Year \\ \textit@{Sophie@} \> 14 \> 1800 \\ \textit@{Polychrest@} \> 24 \> 1803 \\ \textit@{Lively@} \> 38 \> 1804 \\ \textit@{Surprise@} \> 28 \> 1805 \\ \end@{tabbing@} @end example Both the @code{tabbing} environment and the more widely-used @code{tabular} environment put text in columns. The most important distinction is that in @code{tabular} the width of columns is determined automatically by @LaTeX{}, while in @code{tabbing} the user sets the tab stops. Another distinction is that @code{tabular} generates a box, but @code{tabbing} can be broken across pages. Finally, while @code{tabular} can be used in any mode, @code{tabbing} can be used only in paragraph mode and it starts a new paragraph. A @code{tabbing} 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} command at the beginning of a tabbed row. The right margin of the @code{tabbing} environment is the end of line, so that the width of the environment is @code{\linewidth}. @cindex row, @r{tabbing} The @code{tabbing} environment contains a sequence of @dfn{tabbed rows}. The first tabbed row begins immediately after @code{\begin@{tabbing@}} and each row ends with @code{\\} or @code{\kill}. The last row may omit the @code{\\} and end with just @code{\end@{tabbing@}}. At any point the @code{tabbing} environment has a current tab stop pattern, a sequence of @math{@var{n} > 0} tab stops, numbered 0, 1, etc. These create @var{n} corresponding columns. Tab stop@tie{}0 is always the left margin, defined by the enclosing environment. Tab stop number@tie{}@var{i} is set if it is assigned a horizontal position on the page. Tab stop number@tie{}@var{i} can only be set if all the stops 0, @dots{}, @math{i-1} have already been set; normally later stops are to the right of earlier ones. By default any text typeset in a @code{tabbing} environment is typeset ragged right and left-aligned on the current tab stop. Typesetting is done in LR mode (@pxref{Modes}). The following commands can be used inside a @code{tabbing} environment. They are all fragile (@pxref{\protect}). @ftable @code @item \\ @r{(tabbing)} End a tabbed line and typeset it. @item \= @r{(tabbing)} Sets a tab stop at the current position. @item \> @r{(tabbing)} @findex \> Advances to the next tab stop. @item \< Put following text to the left of the local margin (without changing the margin). Can only be used at the start of the line. @item \+ Moves the left margin of the next and all the following commands one tab stop to the right, beginning tabbed line if necessary. @item \- Moves the left margin of the next and all the following commands one tab stop to the left, beginning tabbed line if necessary. @item \' @r{(tabbing)} Moves everything that you have typed so far in the current column, i.e., everything from the most recent @code{\>}, @code{\<}, @code{\'}, @code{\\}, or @code{\kill} command, to the previous column and aligned to the right, flush against the current column's tab stop. @item \` @r{(tabbing)} Allows you to put text flush right against any tab stop, including tab stop@tie{}0. However, it can't move text to the right of the last column because there's no tab stop there. The @code{\`} command moves all the text that follows it, up to the @code{\\} or @code{\end@{tabbing@}} command that ends the line, to the right margin of the @code{tabbing} environment. There must be no @code{\>} or @code{\'} command between the @code{\`} and the @code{\\} or @code{\end@{tabbing@}} command that ends the line. @item \a @r{(tabbing)} @findex \a' @r{(acute accent in tabbing)} @findex \a` @r{(grave accent in tabbing)} @findex \a= @r{(macron accent in tabbing)} In a @code{tabbing} environment, the commands @code{\=}, @code{\'} and @code{\`} do not produce accents as usual (@pxref{Accents}). Instead, use the commands @code{\a=}, @code{\a'} and @code{\a`}. @item \kill Sets tab stops without producing text. Works just like @code{\\} except that it throws away the current line instead of producing output for it. Any @code{\=}, @code{\+} or @code{\-} commands in that line remain in effect. @item \poptabs @findex \poptabs Restores the tab stop positions saved by the last @code{\pushtabs}. @item \pushtabs Saves all current tab stop positions. Useful for temporarily changing tab stop positions in the middle of a @code{tabbing} environment. @item \tabbingsep Distance of the text moved by @code{\'} to left of current tab stop. @end ftable This example typesets a Pascal function: @example \begin@{tabbing@} function \= fact(n : integer) : integer;\\ \> begin \= \+ \\ \> if \= n > 1 then \+ \\ fact := n * fact(n-1) \- \\ else \+ \\ fact := 1; \-\- \\ end;\\ \end@{tabbing@} @end example The output looks like this: @example function fact(n : integer) : integer; begin if n > 1 then fact := n * fact(n-1); else fact := 1; end; @end example @PkgIndex{algorithm2e} @PkgIndex{listings} @PkgIndex{minted} @PkgIndex{fancyvrb} (The above example is just for illustration of the environment. To actually typeset computer code in typewriter like this, a verbatim environment (@pxref{verbatim}) would normally suffice. For pretty-printed code, there are quite a few packages, including @code{algorithm2e}, @code{fancyvrb}, @code{listings}, and @code{minted}.) @node table @section @code{table} @EnvIndex{table} @cindex tables, creating @cindex creating tables Synopsis: @example \begin@{table@}[@var{placement}] table body \caption[@var{loftitle}]@{@var{title}@} \label@{@var{label@}} \end@{table@} @end example A class of floats (@pxref{Floats}). Because they cannot be split across pages, they are not typeset in sequence with the normal text but instead are ``floated'' to a convenient place, such as the top of a following page. For the possible values of @var{placement} and their effect on the float placement algorithm, see @ref{Floats}. The table body is typeset in a @code{parbox} of width @code{\textwidth} and so it can contain text, commands, etc. The label is optional; it is used for cross references (@pxref{Cross references}). @findex \caption The optional @code{\caption} command specifies caption text for the table. By default it is numbered. If @var{lottitle} is present, it is used in the list of tables instead of @var{title} (@pxref{Tables of contents}). 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. @example \begin@{table@}[b] \centering \begin@{tabular@}@{r|p@{2in@}@} \hline One &The loneliest number \\ Two &Can be as sad as one. It's the loneliest number since the number one. \end@{tabular@} \caption@{Cardinal virtues@} \label@{tab:CardinalVirtues@} \end@{table@} @end example @node tabular @section @code{tabular} @EnvIndex{tabular} @cindex lines in tables @cindex lining text up in tables Synopsis: @example \begin@{tabular@}[@var{pos}]@{@var{cols}@} column 1 entry &column 2 entry ... &column n entry \\ ... \end@{tabular@} @end example @noindent or @example \begin@{tabular*@}@{@var{width}@}[@var{pos}]@{@var{cols}@} column 1 entry &column 2 entry ... &column n entry \\ ... \end@{tabular*@} @end example 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. @example \begin@{tabular@}@{l|l@} \textit@{Player name@} &\textit@{Career home runs@} \\ \hline Hank Aaron &755 \\ Babe Ruth &714 \end@{tabular@} @end example The vertical format of two left-aligned columns, with a vertical bar between them, is specified in @code{tabular}'s argument @code{@{l|l@}}. @findex & Columns are separated with an ampersand @code{&}. A horizontal rule between two rows is created with @code{\hline}. @findex \\ @r{for @code{tabular}} The end of each row is marked with a double backslash@tie{}@code{\\}. This @code{\\} is optional after the last row unless an @code{\hline} command follows, to put a rule below the table. The required and optional arguments to @code{tabular} consist of: @table @var @item width Required for @code{tabular*}, not allowed for @code{tabular}. Specifies the width of the @code{tabular*} environment. The space between columns should be rubber, as with @code{@@@{\extracolsep@{\fill@}@}}, 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 ...} warning. @item pos Optional. Specifies the table'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} aligns the table so its top row matches the baseline of the surrounding text, and @code{b} aligns on the bottom row. This only has an effect if there is other text. In the common case of a @code{tabular} alone in a @code{center} environment this option makes no difference. @item cols Required. Specifies the formatting of columns. It consists of a sequence of the following specifiers, corresponding to the types of column and intercolumn material. @table @code @item l A column of left-aligned items. @item r A column of right-aligned items. @item c A column of centered items. @item | A vertical line the full height and depth of the environment. @item @@@{@var{text or space}@} This inserts @var{text or space} at this location in every row. The @var{text or space} material is typeset in LR mode. This text is fragile (@pxref{\protect}). This specifier is optional: with no @@-expression, @LaTeX{}'s @code{book}, @code{article}, and @code{report} classes will put on either side of each column a space of length @code{\tabcolsep}, which by default is @samp{6pt}. That is, by default adjacent columns are separated by 12pt (so @code{\tabcolsep} 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{@@@{...@}} or @code{|} there. If you override the default and use an @@-expression then you must insert any desired space yourself, as in @code{@@@{\hspace@{1em@}@}}. An empty expression @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. @example \begin@{flushleft@} \begin@{tabular@}@{@@@{@}l@} ... \end@{tabular@} \end@{flushleft@} @end example This example shows text, a decimal point, between the columns, arranged so the numbers in the table are aligned on that decimal point. @example \begin@{tabular@}@{r@@@{$.$@}l@} $3$ &$14$ \\ $9$ &$80665$ \end@{tabular@} @end example @findex \extracolsep An @code{\extracolsep@{@var{wd}@}} command in an @@-expression causes an extra space of width @var{wd} to appear to the left of all subsequent columns, until countermanded by another @code{\extracolsep} command. Unlike ordinary intercolumn space, this extra space is not suppressed by an @@-expression. An @code{\extracolsep} command can be used only in an @@-expression in the @code{cols} argument. Below, @LaTeX{} inserts the right amount of intercolumn space to make the entire table 4 inches wide. @example \begin@{center@} \begin@{tabular*@}@{4in@}@{l@@@{\ \ldots\extracolsep@{\fill@}@}l@} Seven times down, eight times up &such is life! \end@{tabular*@} \end@{center@} @end example To insert commands that are automatically executed before a given column, load the @code{array} package and use the @code{>@{...@}} specifier. @c xx should fully explain array, tabularx, and all other base packages... @item p@{@var{wd}@} Each item in the column is typeset in a parbox of width @var{wd}. Note that a line break double backslash @code{\\} may not appear in the item, except inside an environment like @code{minipage}, @code{array}, or @code{tabular}, or inside an explicit @code{\parbox}, or in the scope of a @code{\centering}, @code{\raggedright}, or @code{\raggedleft} declaration (when used in a @code{p}-column element these declarations must appear inside braces, as with @code{@{\centering .. \\ ..@}}). Otherwise @LaTeX{} will misinterpret the double backslash as ending the row. @item *@{@var{num}@}@{@var{cols}@} Equivalent to @var{num} copies of @var{cols}, where @var{num} is a positive integer and @var{cols} is a list of specifiers. Thus @code{\begin@{tabular@}@{|*@{3@}@{l|r@}|@}} is equivalent to @code{\begin@{tabular@}@{|l|rl|rl|r|@}}. Note that @var{cols} may contain another @code{*}-expression. @end table @end table Parameters that control formatting: @c xx defaults, own node (xref from array)? @ftable @code @item \arrayrulewidth A length that is the thickness of the rule created by @code{|}, @code{\hline}, and @code{\vline} in the @code{tabular} and @code{array} environments. The default is @samp{.4pt}. Change it as in @code{\setlength@{\arrayrulewidth@}@{0.8pt@}}. @item \arraystretch A factor by which the spacing between rows in the @code{tabular} and @code{array} environments is multiplied. The default is @samp{1}, for no scaling. Change it as @code{\renewcommand@{\arraystretch@}@{1.2@}}. @item \doublerulesep A length that is the distance between the vertical rules produced by the @code{||} specifier. The default is @samp{2pt}. @item \tabcolsep A length that is half of the space between columns. The default is @samp{6pt}. Change it with @code{\setlength}. @end ftable The following commands can be used inside the body of a @code{tabular} environment, the first two inside an entry and the second two between lines: @menu * \multicolumn:: Make an item spanning several columns. * \vline:: Draw a vertical line. * \cline:: Draw a horizontal line spanning some columns. * \hline:: Draw a horizontal line spanning all columns. @end menu @node \multicolumn @subsection @code{\multicolumn} @findex \multicolumn Synopsis: @example \multicolumn@{@var{numcols}@}@{@var{cols}@}@{@var{text}@} @end example Make an @code{array} or @code{tabular} entry that spans several columns. The first argument @var{numcols} gives the number of columns to span. The second argument @var{cols} specifies the formatting of the entry, with @code{c} for centered, @code{l} for flush left, or @code{r} for flush right. The third argument @var{text} gives the contents of that entry. In this example, in the first row, the second and third columns are spanned by the single heading @samp{Name}. @example \begin@{tabular@}@{lccl@} \textit@{ID@} &\multicolumn@{2@}@{c@}@{\textit@{Name@}@} &\textit@{Age@} \\ \hline % row one 978-0-393-03701-2 &O'Brian &Patrick &55 \\ % row two ... \end@{tabular@} @end example What counts as a column is:@tie{}the column format specifier for the @code{array} or @code{tabular} environment is broken into parts, where each part (except the first) begins with @code{l}, @code{c}, @code{r}, or@tie{}@code{p}. So from @code{\begin@{tabular@}@{|r|ccp@{1.5in@}|@}} the parts are @code{|r|}, @code{c}, @code{c}, and@tie{}@code{p@{1.5in@}|}. The @var{cols} argument overrides the @code{array} or @code{tabular} environment's intercolumn area default adjoining this multicolumn entry. To affect that area, this argument can contain vertical bars @code{|} indicating the placement of vertical rules, and @code{@@@{...@}} expressions. Thus if @var{cols} is @samp{|c|} 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. @example \begin@{tabular@}@{|cc|c|c|@} \multicolumn@{1@}@{r@}@{w@} % entry one &\multicolumn@{1@}@{|r|@}@{x@} % entry two &\multicolumn@{1@}@{|r@}@{y@} % entry three &z % entry four \end@{tabular@} @end example Before the first entry the output will not have a vertical rule because the @code{\multicolumn} has the @var{cols} specifier @samp{r} with no initial vertical bar. Between entry one and entry two there will be a vertical rule; although the first @var{cols} does not have an ending vertical bar, the second @var{cols} does have a starting one. Between entry two and entry three there is a single vertical rule; despite that the @var{cols} in both of the surrounding @code{multicolumn}'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} in the entry three @code{\multicolumn} leaves it out, and that takes precedence. Finally, following entry four there is a vertical rule because of the default. The number of spanned columns @var{numcols} can be 1. Besides giving the ability to change the horizontal alignment, this also is useful to override for one row the @code{tabular} definition's default intercolumn area specification, including the placement of vertical rules. In the example below, in the @code{tabular} definition the first column is specified to default to left justified but in the first row the entry is centered with @code{\multicolumn@{1@}@{c@}@{\textsc@{Period@}@}}. Also in the first row, the second and third columns are spanned by a single entry with @code{\multicolumn@{2@}@{c@}@{\textsc@{Span@}@}}, overriding the specification to center those two columns on the page range en-dash. @example \begin@{tabular@}@{l|r@@@{--@}l@} \multicolumn@{1@}@{c@}@{\textsc@{Period@}@} &multicolumn@{2@}@{c@}@{\textsc@{Span@}@} \\ \hline Baroque &1600 &1760 \\ Classical &1730 &1820 \\ Romantic &1780 &1910 \\ Impressionistic &1875 &1925 \end@{tabular@} @end example Note that although the @code{tabular} specification by default puts a vertical rule between the first and second columns, because there is no vertical bar in the @var{cols} of either of the first row's @code{\multicolumn} commands, no rule appears in the first row. @node \vline @subsection @code{\vline} @findex \vline Draw a vertical line in a @code{tabular} or @code{array} environment extending the full height and depth of an entry's row. Can also be used in an @@-expression, although its synonym vertical bar@tie{}@code{|} is more common. This command is rarely used in the body of a table; typically a table's vertical lines are specified in @code{tabular}'s @var{cols} argument and overridden as needed with @code{\multicolumn}. This example illustrates some pitfalls. In the first line's second entry the @code{\hfill} moves the @code{\vline} 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{@{c|cc@}} specifier coming before the one produced by the @code{\vline\hfill}. In contrast, the first line's third entry shows the usual way to put a vertical bar between two columns. In the second line, the @code{ghi} is the widest entry in its column so in the @code{\vline\hfill} the @code{\hfill} has no effect and the vertical line in that entry appears immediately next to the @code{g}, with no whitespace. @example \begin@{tabular@}@{c|cc@} x &\vline\hfill y &\multicolumn@{1@}@{|r@}@{z@} \\ abc &def &\vline\hfill ghi \end@{tabular@} @end example @node \cline @subsection @code{\cline} @findex \cline Synopsis: @example \cline@{@var{i}-@var{j}@} @end example Draw a horizontal rule in an @code{array} or @code{tabular} environment beginning in column @var{i} and ending in column @var{j}. The dash@tie{}@code{-} must appear in the mandatory argument. To span a single column use the number twice. 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. @example \begin@{tabular@}@{llrr@} a &b &c &d \\ \cline@{1-1@} \cline@{3-4@} e &f &g &h \end@{tabular@} @end example @node \hline @subsection @code{\hline} @findex \hline Draws a horizontal line the width of the enclosing @code{tabular} or @code{array} environment. It's most commonly used to draw a line at the top, bottom, and between the rows of a table. 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}, the @code{tabular} second row's line ending double backslash@tie{}@code{\\} is required. @example \begin@{tabular@}@{ll@} \hline\hline Baseball &Red Sox \\ Basketball &Celtics \\ \hline \end@{tabular@} @end example @node thebibliography @section @code{thebibliography} @EnvIndex{thebibliography} @cindex bibliography, creating (manually) Synopsis: @example \begin@{thebibliography@}@{@var{widest-label}@} \bibitem[@var{label}]@{@var{cite_key@}} ... \end@{thebibliography@} @end example The @code{thebibliography} environment produces a bibliography or reference list. In the @code{article} class, this reference list is labelled @samp{References} and the label is stored in macro @code{\refname}; in the @code{report} class, it is labelled @samp{Bibliography} and the label is stored in macro @code{\bibname}. You can change the label by redefining the command @code{\refname} or @code{\bibname}, whichever is applicable depending on the class: @itemize @item @findex \bibname For standard classes whose top level sectioning is @code{\chapter} (such as @file{book} and @file{report}), the label is in the macro @code{\bibname}; @item @findex \refname For standard classes whose the top level sectioning is @code{\section} (such as @file{article}), the label is in macro @code{\refname}. @end itemize @PkgIndex{babel} Typically it is neither necessary nor desirable to directly redefine @code{\refname} or @code{\bibname}; language support packages like @file{babel} do this. The mandatory @var{widest-label} argument is text that, when typeset, is as wide as the widest item label produced by the @code{\bibitem} commands. It is typically given as @code{9} for bibliographies with less than 10 references, @code{99} for ones with less than 100, etc. @menu * \bibitem:: Specify a bibliography item. * \cite:: Refer to a bibliography item. * \nocite:: Include an item in the bibliography. * Using BibTeX:: Automatic generation of bibliographies. @end menu @node \bibitem @subsection @code{\bibitem} @findex \bibitem Synopsis: @example \bibitem[@var{label}]@{@var{cite_key}@} @end example The @code{\bibitem} command generates an entry labelled by @var{label}. If the @var{label} argument is missing, a number is automatically generated using the @code{enumi} counter. The @var{cite_key} is a @cindex citation key @dfn{citation key} consisting in any sequence of letters, numbers, and punctuation symbols not containing a comma. This command writes an entry to the @file{.aux} file containing the item's @var{cite_key} and @var{label}. When the @file{.aux} file is read by the @code{\begin@{document@}} command, the item's @var{label} is associated with @code{cite_key}, causing references to @var{cite_key} with a @code{\cite} command (@pxref{\cite}) to produce the associated @var{label}. @node \cite @subsection @code{\cite} @findex \cite Synopsis: @example \cite[@var{subcite}]@{@var{keys}@} @end example The @var{keys} argument is a list of one or more citation keys (@pxref{\bibitem}), separated by commas. This command generates an in-text citation to the references associated with @var{keys} by entries in the @file{.aux} file. The text of the optional @var{subcite} argument appears after the citation. For example, @code{\cite[p.~314]@{knuth@}} might produce @samp{[Knuth, p.@tie{}314]}. @node \nocite @subsection @code{\nocite} @findex \nocite Synopsis: @example @code{\nocite@{@var{keys}@}} @end example The @code{\nocite} command produces no text, but writes @var{keys}, which is a list of one or more citation keys, to the @file{.aux} file. @node Using BibTeX @subsection Using Bib@TeX{} @cindex using Bib@TeX{} @cindex bib@TeX{}, using @cindex bibliography, creating (automatically) @findex \bibliographystyle @findex \bibliography 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't use the @code{thebibliography} environment (@pxref{thebibliography}). Instead, you include the lines @example \bibliographystyle@{@var{bibstyle}@} \bibliography@{@var{bibfile1},@var{bibfile2}@} @end example The @code{\bibliographystyle} command does not produce any output of its own. Rather, it defines the style in which the bibliography will be produced: @var{bibstyle} refers to a file @var{bibstyle}@file{.bst}, which defines how your citations will look. The standard @var{bibstyle} names distributed with Bib@TeX{} are: @table @code @item alpha Sorted alphabetically. Labels are formed from name of author and year of publication. @item plain Sorted alphabetically. Labels are numeric. @item unsrt Like @code{plain}, but entries are in order of citation. @item abbrv Like @code{plain}, but more compact labels. @end table In addition, numerous other Bib@TeX{} style files exist tailored to the demands of various publications. See @url{http://mirror.ctan.org/biblio/bibtex/contrib}. The @code{\bibliography} command is what actually produces the bibliography. The argument to @code{\bibliography} refers to files named @file{@var{bibfile1}.bib}, @file{@var{bibfile2}.bib}, @dots{}, which should contain your database in Bib@TeX{} format. Only the entries referred to via @code{\cite} and @code{\nocite} will be listed in the bibliography. @node theorem @section @code{theorem} @EnvIndex{theorem} @cindex theorems, typesetting Synopsis: @example \begin@{theorem@} @var{theorem-text} \end@{theorem@} @end example The @code{theorem} environment produces ``Theorem @var{n}'' in boldface followed by @var{theorem-text}, where the numbering possibilities for @var{n} are described under @code{\newtheorem} (@pxref{\newtheorem}). @node titlepage @section @code{titlepage} @EnvIndex{titlepage} @cindex making a title page @cindex title pages, creating Synopsis: @example \begin@{titlepage@} ... text and spacing ... \end@{titlepage@} @end example Create a title page, a page with no printed page number or heading. The following page will be numbered page one. To instead produce a standard title page without a @code{titlepage} environment you can use @code{\maketitle} (@pxref{\maketitle}). Notice in this example that all formatting, including vertical spacing, is left to the author. @example \begin@{titlepage@} \vspace*@{\stretch@{1@}@} \begin@{center@} @{\huge\bfseries Thesis \\[1ex] title@} \\[6.5ex] @{\large\bfseries Author name@} \\ \vspace@{4ex@} Thesis submitted to \\[5pt] \textit@{University name@} \\[2cm] in partial fulfilment for the award of the degree of \\[2cm] \textsc@{\Large Doctor of Philosophy@} \\[2ex] \textsc@{\large Mathematics@} \\[12ex] \vfill Department of Mathematics \\ Address \\ \vfill \today \end@{center@} \vspace@{\stretch@{2@}@} \end@{titlepage@} @end example @node verbatim @section @code{verbatim} @EnvIndex{verbatim} @cindex verbatim text @cindex simulating typed text @cindex typed text, simulating @cindex code, typesetting @cindex computer programs, typesetting Synopsis: @example \begin@{verbatim@} @var{literal-text} \end@{verbatim@} @end example The @code{verbatim} environment is a paragraph-making environment in which @LaTeX{} produces exactly what you type in; for instance the @code{\} character produces a printed @samp{\}. It turns @LaTeX{} into a typewriter with carriage returns and blanks having the same effect that they would on a typewriter. The @code{verbatim} environment uses a monospaced typewriter-like font (@code{\tt}). @menu * \verb:: The macro form of the @code{verbatim} environment. @end menu @node \verb @subsection @code{\verb} @findex \verb @cindex verbatim text, inline Synopsis: @example \verb@var{char}@var{literal-text}@var{char} \verb*@var{char}@var{literal-text}@var{char} @end example The @code{\verb} command typesets @var{literal-text} as it is input, including special characters and spaces, using the typewriter (@code{\tt}) font. No spaces are allowed between @code{\verb} or @code{\verb*} and the delimiter @var{char}, which begins and ends the verbatim text. The delimiter must not appear in @var{literal-text}. @cindex visible space The @code{*}-form differs only in that spaces are printed with a ``visible space'' character. @tex (Namely, {\tt\char`\ }.) @end tex @node verse @section @code{verse} @EnvIndex{verse} @cindex poetry, an environment for Synopsis: @example \begin@{verse@} @var{line1} \\ @var{line2} \\ ... \end@{verse@} @end example The @code{verse} environment is designed for poetry, though you may find other uses for it. @findex \\ @r{for @code{verse}} 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{\\}, and use one or more blank lines to separate the stanzas. @node Line breaking @chapter Line breaking @cindex line breaking @cindex breaking lines 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). @LaTeX{} usually does the line (and page) breaking in the text body for you but in some environments you manually force line breaks. @menu * \\:: Start a new line. * \obeycr & \restorecr:: Make each input line start a new output line. * \newline:: Break the line * \- (hyphenation):: Insert explicit hyphenation. * \discretionary:: Insert explicit hyphenation with control of hyphen character. * \fussy:: Be fussy about line breaking. * \sloppy:: Be sloppy about line breaking. * \hyphenation:: Tell @LaTeX{} how to hyphenate a word. * \linebreak & \nolinebreak:: Forcing & avoiding line breaks. @end menu @node \\ @section @code{\\} @findex \\ @r{force line break} @cindex new line, starting @cindex line break, forcing Synopsis: @example \\[@var{morespace}] @end example or @example \\*[@var{morespace}] @end example Start a new line. The optional argument @var{morespace} 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. 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} or @code{array} environment. Under ordinary circumstances (e.g., outside of a @code{p@{...@}} column in a @code{tabular} environment) the @code{\newline} command is a synonym for @code{\\} (@pxref{\newline}). In addition to starting a new line, the starred form @code{\\*} tells @LaTeX{} not to start a new page between the two lines, by issuing a @code{\nobreak}. @example \title@{My story: \\[0.25in] a tale of woe@} @end example @node \obeycr & \restorecr @section @code{\obeycr} & @code{\restorecr} @findex \obeycr @findex \restorecr @cindex new line, output as input The @code{\obeycr} command makes a return in the input file (@samp{^^M}, internally) the same as @code{\\} (followed by @code{\relax}). So each new line in the input will also be a new line in the output. @code{\restorecr} restores normal line-breaking behavior. @node \newline @section @code{\newline} @findex \newline @cindex new line, starting (paragraph mode) In ordinary text this is equivalent to double-backslash (@pxref{\\}); it breaks a line, with no stretching of the text before it. Inside a @code{tabular} or @code{array} environment, in a column with a specifier producing a paragraph box, like typically @code{p@{...@}}, @code{\newline} 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{\\} or its equivalent @code{\tabularnewline}. This will print @samp{Name:} and @samp{Address:} as two lines in a single cell of the table. @example \begin@{tabular@}@{p@{1in@}@{\hspace@{2in@}@}p@{1in@}@} Name: \newline Address: &Date: \\ \hline \end@{tabular@} @end example The @samp{Date:} will be baseline-aligned with @samp{Name:}. @node \- (hyphenation) @section @code{\-} (discretionary hyphen) @findex \- @r{(hyphenation)} @cindex hyphenation, forcing The @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{\-} command is used for the exceptional cases. When you insert @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. @node \discretionary @section @code{\discretionary} (generalized hyphenation point) @cindex hyphenation, discretionary @cindex discretionary hyphenation Synopsis: @example \discretionary@{@var{pre-break-text}@}@{@var{post-break-text}@}@{@var{no-break-text}@} @end example @c xxx TODO, complete this node, see LaTeX-fr @node \fussy @section @code{\fussy} @findex \fussy The declaration @code{\fussy} (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. This command cancels the effect of a previous @code{\sloppy} command (@pxref{\sloppy}). @node \sloppy @section @code{\sloppy} @findex \sloppy The declaration @code{\sloppy} makes @TeX{} less fussy about line breaking. This will avoid overfull boxes, at the cost of loose interword spacing. Lasts until a @code{\fussy} command is issued (@pxref{\fussy}). @node \hyphenation @section @code{\hyphenation} @findex \hyphenation @cindex hyphenation, defining Synopsis: @example \hyphenation@{@var{word-one} @var{word-two}@} @end example The @code{\hyphenation} command declares allowed hyphenation points with a @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} commands accumulate. Some examples (the default @TeX{} hyphenation patterns misses the hyphenations in these words): @example \hyphenation@{ap-pen-dix col-umns data-base data-bases@} @end example @node \linebreak & \nolinebreak @section @code{\linebreak} & @code{\nolinebreak} @findex \linebreak @findex \nolinebreak @cindex line breaks, forcing @cindex line breaks, preventing Synopses: @example \linebreak[@var{priority}] \nolinebreak[@var{priority}] @end example By default, the @code{\linebreak} (@code{\nolinebreak}) command forces (prevents) a line break at the current position. For @code{\linebreak}, the spaces in the line are stretched out so that it extends to the right margin as usual. With the optional argument @var{priority}, you can convert the command from a demand to a request. The @var{priority} must be a number from 0 to@tie{}4. The higher the number, the more insistent the request. @node Page breaking @chapter Page breaking @cindex page breaking @cindex breaking pages @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. @menu * \cleardoublepage:: Start a new right-hand page. * \clearpage:: Start a new page. * \newpage:: Start a new page. * \enlargethispage:: Enlarge the current page a bit. * \pagebreak & \nopagebreak:: Forcing & avoiding page breaks. @end menu @node \cleardoublepage @section @code{\cleardoublepage} @findex \cleardoublepage @cindex starting on a right-hand page The @code{\cleardoublepage} 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. @node \clearpage @section @code{\clearpage} @findex \clearpage @cindex flushing floats and starting a page @cindex starting a new page and clearing floats The @code{\clearpage} 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. @node \newpage @section @code{\newpage} @findex \newpage @cindex new page, starting @cindex starting a new page The @code{\newpage} command ends the current page, but does not clear floats (@pxref{\clearpage}). @node \enlargethispage @section @code{\enlargethispage} @findex \enlargethispage @cindex enlarge current page @code{\enlargethispage@{size@}} @code{\enlargethispage*@{size@}} Enlarge the @code{\textheight} for the current page by the specified amount; e.g., @code{\enlargethispage@{\baselineskip@}} will allow one additional line. 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}. @node \pagebreak & \nopagebreak @section @code{\pagebreak} & @code{\nopagebreak} @findex \pagebreak @findex \nopagebreak @cindex page break, forcing @cindex page break, preventing Synopses: @example \pagebreak[@var{priority}] \nopagebreak[@var{priority}] @end example By default, the @code{\pagebreak} (@code{\nopagebreak}) command forces (prevents) a page break at the current position. With @code{\pagebreak}, the vertical space on the page is stretched out where possible so that it extends to the normal bottom margin. With the optional argument @var{priority}, you can convert the @code{\pagebreak} command from a demand to a request. The number must be a number from 0 to@tie{}4. The higher the number, the more insistent the request is. @node Footnotes @chapter Footnotes @cindex footnotes, creating Place a numbered footnote at the bottom of the current page, as here. @example No@"{e}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@{I wouldn't know, I don't read footnotes.@} @end example You can place multiple footnotes on a page. If the text becomes too long it will flow to the next page. You can also produce footnotes by combining the @code{\footnotemark} and the @code{\footnotetext} commands, which is useful in special circumstances. To make bibliographic references come out as footnotes you need to include a bibliographic style with that behavior. @menu * \footnote:: Insert a footnote. * \footnotemark:: Insert footnote mark only. * \footnotetext:: Insert footnote text only. * Footnotes in a table:: Table footnotes. * Footnotes in section headings:: Chapter or section titles. * Footnotes of footnotes:: Multiple classes of footnotes. * Multiple reference to footnotes:: Referring to a footnote more than once. * Footnote parameters:: Parameters for footnote formatting. @end menu @node \footnote @section @code{\footnote} @findex \footnote Synopsis: @example \footnote[@var{number}]@{@var{text}@} @end example Place a numbered footnote @var{text} at the bottom of the current page. @example There are over a thousand footnotes in Gibbon's \textit@{Decline and Fall of the Roman Empire@}.\footnote@{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.''@} @end example The optional argument @var{number} 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. @cindex footnotes, symbols instead of numbers @findex \fnsymbol@r{, and footnotes} @findex \@@fnsymbol Change how @LaTeX{} shows the footnote counter with something like @code{\renewcommand@{\thefootnote@}@{\fnsymbol@{footnote@}@}}, which uses a sequence of symbols (@pxref{\alph \Alph \arabic \roman \Roman \fnsymbol}). 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@{footnote@}@{0@}}. By default @LaTeX{} uses arabic numbers. @LaTeX{}'s default puts many restrictions on where you can use a @code{\footnote}; for instance, you cannot use it in an argument to a sectioning command such as @code{\chapter} (it can only be used in outer paragraph mode). There are some workarounds; see following sections. @c xx mention packages that fix this @cindex Footnotes, in a minipage @cindex mpfootnote counter In a @code{minipage} environment the @code{\footnote} command uses the @code{mpfootnote} counter instead of the @code{footnote} 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{minipage}. @node \footnotemark @section @code{\footnotemark} @findex \footnotemark Synopsis, one of: @example \footnotemark \footnotemark[@var{number}] @end example Put the current footnote number in the text. (See@tie{}@ref{\footnotetext} for giving the text of the footnote separately.) The version with the optional argument @var{number} uses that number to determine the mark printed. This command can be used in inner paragraph mode. This example gives the same institutional affiliation to both the first and third authors (@code{\thanks} is a version of @code{footnote}). @example \title@{A Treatise on the Binomial Theorem@} \author@{J Moriarty\thanks@{University of Leeds@} \and A C Doyle\thanks@{Durham University@} \and S Holmes\footnotemark[1]@} \begin@{document@} \maketitle @end example If you use @code{\footnotemark} without the optional argument then it increments the footnote counter but if you use the optional @var{number} then it does not. This produces several consecutive footnote markers referring to the same footnote. @example The first theorem\footnote@{Due to Gauss.@} and the second theorem\footnotemark[\value@{footnote@}] and the third theorem.\footnotemark[\value@{footnote@}] @end example @node \footnotetext @section @code{\footnotetext} @findex \footnotetext Synopsis, one of: @example \footnotetext@{@var{text}@} \footnotetext[@var{number}]@{@var{text}@} @end example Place @var{text} at the bottom of the page as a footnote. This command can come anywhere after the @code{\footnotemark} command. The optional argument @var{number} changes the displayed footnote number. The @code{\footnotetext} command must appear in outer paragraph mode. @node Footnotes in a table @section Footnotes in a table @cindex Footnotes, in a table Inside a @code{table} environment the @code{\footnote} 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. @example \begin@{center@} \begin@{tabular@}@{l|l@} \textsc@{Ship@} &\textsc@{Book@} \\ \hline \textit@{HMS Sophie@} &Master and Commander \\ \textit@{HMS Polychrest@} &Post Captain \\ \textit@{HMS Lively@} &Post Captain \\ \textit@{HMS Surprise@} &A number of books\footnote@{Starting with HMS Surprise.@} \end@{tabular@} \end@{center@} @end example The solution is to surround the @code{tabular} environment with a @code{minipage} environment, as here (@pxref{minipage}). @example \begin@{center@} \begin@{minipage@}@{.5\textwidth@} ... tabular material ... \end@{minipage@} \end@{center@} @end example The same technique will work inside a floating @code{table} environment (@pxref{table}). To get the footnote at the bottom of the page use the @file{tablefootnote} package, as illustrated in this example. If you put @code{\usepackage@{tablefootnote@}} in the preamble and use the code shown then the footnote appears at the bottom and is numbered in sequence with other footnotes. @example \begin@{table@} \centering \begin@{tabular@}@{l|l@} \textsc@{Date@} &\textsc@{Campaign@} \\ \hline 1862 &Fort Donelson \\ 1863 &Vicksburg \\ 1865 &Army of Northern Virginia\footnote@{Ending the war.@} \end@{tabular@} \caption@{Forces captured by US Grant@} \end@{table@} @end example @node Footnotes in section headings @section Footnotes in section headings @cindex footnotes, in section headings @cindex table of contents, avoiding footnotes Putting a footnote in a section heading, as in: @example \section@{Full sets\protect\footnote@{This material due to ...@}@} @end example @PkgIndex{footmisc} @cindex @code{stable} option to @code{footmisc} package @noindent 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} with the @code{stable} option. @example \usepackage[stable]@{footmisc@} ... \begin@{document@} ... \section@{Full sets\footnote@{This material due to ...@}@} @end example Note that the @code{\protect} is gone; including it would cause the footnote to reappear on the table of contents. @node Footnotes of footnotes @section Footnotes of footnotes Particularly in the humanities, authors can have multiple classes of footnotes, including having footnotes of footnotes. The package @file{bigfoot} extends @LaTeX{}'s default footnote mechanism in many ways, including allow these two, as in this example. @example \usepackage@{bigfoot@} \DeclareNewFootnote@{Default@} \DeclareNewFootnote@{from@}[alph] % create class \footnotefrom@{@} ... \begin@{document@} ... The third theorem is a partial converse of the second.\footnotefrom@{First noted in Wilson.\footnote@{Second edition only.@}@} ... @end example @node Multiple reference to footnotes @section Multiple references to footnotes You can refer to a single footnote more than once. This example uses the package @file{cleverref}. @c from SE user Jake http://tex.stackexchange.com/a/10116/339 @example \usepackage@{cleveref@}[2012/02/15] % this version of package or later \crefformat@{footnote@}@{#2\footnotemark[#1]#3@} ... \begin@{document@} ... The theorem is from Evers.\footnote@{\label@{fn:TE@}Tinker and Evers, 1994.@} The corollary is from Chance.\footnote@{Evers and Chance, 1990.@} But the key lemma is from Tinker.\cref@{fn:TE@} ... @end example This solution will work with the package @file{hyperref}. See@tie{}@ref{\footnotemark} for a simpler solution in the common case of multiple authors with the same affiliation. @node Footnote parameters @section Footnote parameters @cindex footnote parameters @cindex parameters, for footnotes @ftable @code @item \footnoterule Produces the rule separating the main text on a page from the page's footnotes. Default dimensions: @code{0.4pt} thick (or wide), and @code{0.4\columnwidth} long in the standard document classes (except @code{slides}, where it does not appear). @item \footnotesep The height of the strut placed at the beginning of the footnote. By default, this is set to the normal strut for @code{\footnotesize} fonts (@pxref{Font sizes}), therefore there is no extra space between footnotes. This is @samp{6.65pt} for @samp{10pt}, @samp{7.7pt} for @samp{11pt}, and @samp{8.4pt} for @samp{12pt}. @end ftable @node Definitions @chapter Definitions @cindex definitions @LaTeX{} has support for making new commands of many different kinds. @c xx everything in this chapter needs examples. @c xx Add DeclareRobustCommand (see clsguide.pdf) @menu * \newcommand & \renewcommand:: (Re)define a new command. * \providecommand:: Define a new command, if name not used. * \newcounter:: Define a new counter. * \newlength:: Define a new length. * \newsavebox:: Define a new box. * \newenvironment & \renewenvironment:: Define a new environment. * \newtheorem:: Define a new theorem-like environment. * \newfont:: Define a new font name. * \protect:: Using tricky commands. * \ignorespaces & \ignorespacesafterend:: Discard extra spaces. @end menu @node \newcommand & \renewcommand @section @code{\newcommand} & @code{\renewcommand} @findex \newcommand @cindex commands, defining new ones @cindex commands, redefining @cindex defining a new command @cindex new commands, defining @code{\newcommand} and @code{\renewcommand} define and redefine a command, respectively. Synopses: @example \newcommand@{\@var{cmd}@}[@var{nargs}][@var{optargdefault}]@{@var{defn}@} \newcommand*@{\@var{cmd}@}[@var{nargs}][@var{optargdefault}]@{@var{defn}@} \renewcommand@{\@var{cmd}@}[@var{nargs}][@var{optargdefault}]@{@var{defn}@} \renewcommand*@{\@var{cmd}@}[@var{nargs}][@var{optargdefault}]@{@var{defn}@} @end example @cindex starred form, defining new commands @cindex *-form, defining new commands The starred form of these two commands requires that the arguments not contain multiple paragraphs of text (not @code{\long}, in plain @TeX{} terms). @table @var @item cmd Required; @code{\@var{cmd}} is the command name. For @code{\newcommand}, it must not be already defined and must not begin with @code{\end}. For @code{\renewcommand}, it must already be defined. @item nargs 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. @item optargdefault Optional; if this argument is present then the first argument of defined command @code{\@var{cmd}} is optional, with default value @var{optargdefault} (which may be the empty string). If this argument is not present then @code{\@var{cmd}} does not take an optional argument. @cindex positional parameter That is, if @code{\@var{cmd}} is used with square brackets following, as in @code{\@var{cmd}[@var{myval}]}, then within @var{defn} the first @dfn{positional parameter} @code{#1} expands @var{myval}. On the other hand, if @code{\@var{cmd}} is called without square brackets following, then within @var{defn} the positional parameter @code{#1} expands to the default @var{optargdefault}. In either case, any required arguments will be referred to starting with @code{#2}. Omitting @code{[@var{myval}]} in a call is different from having the square brackets with no contents, as in @code{[]}. The former results in @code{#1} expanding to @var{optargdefault}; the latter results in @code{#1} expanding to the empty string. @item defn The text to be substituted for every occurrence of @code{\@var{cmd}}; the positional parameter @code{#@var{n}} in @var{defn} is replaced by the text of the @var{n}th argument. @end table @TeX{} ignores spaces in the source following an alphabetic control sequence, as in @samp{\cmd }. If you actually want a space there, one solution is to type @code{@{@}} after the command (@samp{\cmd@{@} }; another solution is to use an explicit control space (@samp{\cmd\ }). A simple example of defining a new command: @code{\newcommand@{\RS@}@{Robin Smith@}} results in @code{\RS} being replaced by the longer text. Redefining an existing command is similar: @code{\renewcommand@{\qedsymbol@}@{@{\small QED@}@}}. Here's a command definition with one required argument: @example \newcommand@{\defref@}[1]@{Definition~\ref@{#1@}@} @end example @noindent Then, @code{\defref@{def:basis@}} expands to @code{Definition~\ref@{def:basis@}}, which will ultimately expand to something like @samp{Definition~3.14}. An example with two required arguments: @code{\newcommand@{\nbym@}[2]@{$#1 \times #2$@}} is invoked as @code{\nbym@{2@}@{k@}}. An example with an optional argument: @example \newcommand@{\salutation@}[1][Sir or Madam]@{Dear #1:@} @end example @noindent Then, @code{\salutation} gives @samp{Dear Sir or Madam:} while @code{\salutation[John]} gives @samp{Dear John:}. And @code{\salutation[]} gives @samp{Dear :}. The braces around @var{defn} do not define a group, that is, they do not delimit the scope of the result of expanding @var{defn}. So @code{\newcommand@{\shipname@}[1]@{\it #1@}} is problematic; in this sentence, @example The \shipname@{Monitor@} met the \shipname@{Merrimac@}. @end example @noindent the words @samp{met the} would incorrectly be in italics. Another pair of braces in the definition is needed, like this: @code{\newcommand@{\shipname@}[1]@{@{\it #1@}@}}. Those braces are part of the definition and thus do define a group. @node \providecommand @section @code{\providecommand} @findex \providecommand @cindex commands, defining new ones @cindex defining a new command @cindex new commands, defining Defines a command, as long as no command of this name already exists. Synopses: @example \providecommand@{@var{cmd}@}[@var{nargs}][@var{optargdefault}]@{@var{defn}@} \providecommand*@{@var{cmd}@}[@var{nargs}][@var{optargdefault}]@{@var{defn}@} @end example If no command of this name already exists then this has the same effect as @code{\newcommand} (@pxref{\newcommand & \renewcommand}). 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. @node \newcounter @section @code{\newcounter}: Allocating a counter @findex \newcounter @cindex counters, defining new Synopsis, one of: @example \newcounter@{@var{countername}@} \newcounter@{@var{countername}@}[@var{supercounter}] @end example Globally defines a new counter named @var{countername} and initialize the new counter to zero. The name @var{countername} must consists of letters only, and does not begin with a backslash. This name must not already be in use by another counter. When you use the optional argument @code{[@var{supercounter}]} then @var{countername} will be numbered within, or subsidiary to, the existing counter @var{supercounter}. For example, ordinarily @code{subsection} is numbered within @code{section} so that any time @var{supercounter} is incremented with @code{\stepcounter} (@pxref{\stepcounter}) or @code{\refstepcounter} (@pxref{\refstepcounter}) then @var{countername} is reset to zero. @xref{Counters}, for more information about counters. @node \newlength @section @code{\newlength}: Allocating a length @findex \newlength @cindex lengths, allocating new @cindex rubber lengths, defining new @cindex skip register, plain @TeX{} @cindex glue register, plain @TeX{} Allocate a new @dfn{length} register. Synopsis: @example \newlength@{\@var{arg}@} @end example This command takes one required argument, which must begin with a backslash (@samp{\}). It creates a new length register named @code{\@var{arg}}, which is a place to hold (rubber) lengths such as @code{1in plus.2in minus.1in} (what plain @TeX{} calls a @code{skip} register). The register gets an initial value of zero. The control sequence @code{\@var{arg}} must not already be defined. @xref{Lengths}, for more about lengths. @node \newsavebox @section @code{\newsavebox}: Allocating a box @findex \newsavebox @cindex box, allocating new Allocate a ``bin'' for holding a box. Synopsis: @example \newsavebox@{\@var{cmd}@} @end example Defines @code{\@var{cmd}} to refer to a new bin for storing boxes. Such a box is for holding typeset material, to use multiple times (@pxref{Boxes}) or to measure or manipulate. The name @code{\@var{cmd}} must start with a backslash (@samp{\}), and must not be already defined. The allocation of a box is global. This command is fragile (@pxref{\protect}). @node \newenvironment & \renewenvironment @section @code{\newenvironment} & @code{\renewenvironment} @findex \newenvironment @findex \renewenvironment @cindex environments, defining @cindex defining new environments @cindex redefining environments These commands define or redefine an environment @var{env}, that is, @code{\begin@{@var{env}@} @var{body} \end@{@var{env}@}}. Synopses: @example \newenvironment@{@var{env}@}[@var{nargs}][@var{optargdefault}]@{@var{begdefn}@}@{@var{enddefn}@} \newenvironment*@{@var{env}@}[@var{nargs}][@var{optargdefault}]@{@var{begdefn}@}@{@var{enddefn}@} \renewenvironment@{@var{env}@}[@var{nargs}][@var{optargdefault}]@{@var{begdefn}@}@{@var{enddefn}@} \renewenvironment*@{@var{env}@}[@var{nargs}][@var{optargdefault}]@{@var{begdefn}@}@{@var{enddefn}@} @end example @cindex @code{*}-form of environment commands 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. @table @var @item env Required; the environment name. It consists only of letters or the @code{*} character, and thus does not begin with backslash (@code{\}). It must not begin with the string @code{end}. For @code{\newenvironment}, the name @var{env} must not be the name of an already existing environment, and also the command @code{\@var{env}} must be undefined. For @code{\renewenvironment}, @var{env} must be the name of an existing environment. @item nargs 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}, as in @code{\begin@{@var{env}@}@{@var{arg1}@}@dots{}@{@var{argn}@}}. 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. @item optargdefault Optional; if this argument is present then the first argument of the defined environment is optional, with default value @var{optargdefault} (which may be the empty string). If this argument is not present then the environment does not take an optional argument. That is, when @code{[@var{optargdefault}]} is present in the environment definition, if @code{\begin@{@var{env}@}} is used with square brackets following, as in @code{\begin@{@var{env}@}[@var{myval}]}, then, within @var{begdefn}, the positional parameter @code{#1} expands to @var{myval}. If @code{\begin@{@var{env}@}} is called without square brackets following, then, within within @var{begdefn}, the positional parameter @code{#1} expands to the default @var{optargdefault}. In either case, any required arguments will be referred to starting with @code{#2}. Omitting @code{[@var{myval}]} in the call is different from having the square brackets with no contents, as in @code{[]}. The former results in @code{#1} expanding to @var{optargdefault}; the latter results in @code{#1} expanding to the empty string. @item begdefn Required; the text expanded at every occurrence of @code{\begin@{@var{env}@}}. Within @var{begdef}, the @var{n}th positional parameter (i.e., @code{#@var{n}}) is replaced by the text of the @var{n}th argument. @item enddefn Required; the text expanded at every occurrence of @code{\end@{@var{env}@}}. This may not contain any positional parameters, so @code{#@var{n}} cannot be used here (but see the final example below). @end table All environments, that is to say the @var{begdefn} code, the environment body and the @var{enddefn} code, are processed within a group. Thus, in the first example below, the effect of the @code{\small} is limited to the quote and does not extend to material following the environment. This example gives an environment like @LaTeX{}'s @code{quotation} except that it will be set in smaller type: @example \newenvironment@{smallquote@}@{% \small\begin@{quotation@} @}@{% \end@{quotation@} @} @end example This one shows the use of arguments; it gives a quotation environment that cites the author: @example \newenvironment@{citequote@}[1][Shakespeare]@{% \begin@{quotation@} \noindent\textit@{#1@}: @}@{% \end@{quotation@} @} @end example @noindent The author's name is optional, and defaults to @samp{Shakespeare}. In the document, use the environment like this: @example \begin@{citequote@}[Lincoln] ... \end@{citequote@} @end example The final example shows how to save the value of an argument to use in @var{enddefn}, in this case in a box (@pxref{\sbox}): @example \newsavebox@{\quoteauthor@} \newenvironment@{citequote@}[1][Shakespeare]@{% \sbox\quoteauthor@{#1@}% \begin@{quotation@} @}@{% \hspace@{1em plus 1fill@}---\usebox@{\quoteauthor@} \end@{quotation@} @} @end example @node \newtheorem @section @code{\newtheorem} @findex \newtheorem @cindex theorems, defining @cindex defining new theorems @cindex theorem-like environment @cindex environment, theorem-like Define a new theorem-like environment. Synopses: @example \newtheorem@{@var{name}@}@{@var{title}@} \newtheorem@{@var{name}@}@{@var{title}@}[@var{numbered_within}] \newtheorem@{@var{name}@}[@var{numbered_like}]@{@var{title}@} @end example Using the first form, @code{\newtheorem@{@var{name}@}@{@var{title}@}} creates an environment that will be labelled with @var{title}. See the first example below. The second form @code{\newtheorem@{@var{name}@}@{@var{title}@}[@var{numbered_within}]} creates an environment whose counter is subordinate to the existing counter @var{numbered_within} (its counter will be reset when @var{numbered_within} is reset). The third form @code{\newtheorem@{@var{name}@}[@var{numbered_like}]@{@var{title}@}}, with optional argument between the two required arguments, will create an environment whose counter will share the previously defined counter @var{numbered_like}. You can specify one of @var{numbered_within} and @var{numbered_like}, or neither, but not both. This command creates a counter named @var{name}. In addition, unless the optional argument @var{numbered_like} is used, inside of the theorem-like environment the current @code{\ref} value will be that of @code{\the@var{numbered_within}} (@pxref{\ref}). This declaration is global. It is fragile (@pxref{\protect}). Arguments: @table @var @item name The name of the environment. It must not begin with a backslash (@samp{\}). It must not be the name of an existing environment; indeed, the command name @code{\@var{name}} must not already be defined as anything. @item title The text printed at the beginning of the environment, before the number. For example, @samp{Theorem}. @item numbered_within Optional; the name of an already defined counter, usually a sectional unit such as @code{chapter} or @code{section}. When the @var{numbered_within} counter is reset then the @var{name} environment's counter will also be reset. If this optional argument is not used then the command @code{\the@var{name}} is set to @code{\arabic@{@var{name}@}}. @item numbered_like Optional; the name of an already defined theorem-like environment. The new environment will be numbered in sequence with @var{numbered_like}. @end table Without any optional arguments the environments are numbered sequentially. The example below has a declaration in the preamble that results in @samp{Definition@tie{}1} and @samp{Definition@tie{}2} in the output. @example \newtheorem@{defn@}@{Definition@} \begin@{document@} \section@{...@} \begin@{defn@} First def \end@{defn@} \section@{...@} \begin@{defn@} Second def \end@{defn@} @end example Because the next example specifies the optional argument @var{numbered_within} to @code{\newtheorem} as @code{section}, the example, with the same document body, gives @samp{Definition@tie{}1.1} and @samp{Definition@tie{}2.1}. @example \newtheorem@{defn@}@{Definition@}[section] \begin@{document@} \section@{...@} \begin@{defn@} First def \end@{defn@} \section@{...@} \begin@{defn@} Second def \end@{defn@} @end example In the next example there are two declarations in the preamble, the second of which calls for the new @code{thm} environment to use the same counter as @code{defn}. It gives @samp{Definition@tie{}1.1}, followed by @samp{Theorem@tie{}2.1} and @samp{Definition@tie{}2.2}. @example \newtheorem@{defn@}@{Definition@}[section] \newtheorem@{thm@}[defn]@{Theorem@} \begin@{document@} \section@{...@} \begin@{defn@} First def \end@{defn@} \section@{...@} \begin@{thm@} First thm \end@{thm@} \begin@{defn@} Second def \end@{defn@} @end example @node \newfont @section @code{\newfont}: Define a new font (obsolete) @findex \newfont @cindex fonts, new commands for @cindex defining new fonts @code{\newfont}, now obsolete, defines a command that will switch fonts. Synopsis: @example \newfont@{\@var{cmd}@}@{@var{font description}@} @end example This defines a control sequence @code{\@var{cmd}} that will change the current font. @LaTeX{} will look on your system for a file named @file{@var{fontname}.tfm}. The control sequence must must not already be defined. It must begin with a backslash (@samp{\}). @findex .fd @r{file} 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 ``New Font Selection Scheme'', either by using @file{.fd} files or through the use of an engine that can access system fonts such as Xe@LaTeX{} (@pxref{@TeX{} engines}). @c xx explain nfss somewhere @cindex at clause, in font definitions @cindex design size, in font definitions But since it is part of @LaTeX{}, here is an explanation: the @var{font description} consists of a @var{fontname} and an optional @dfn{at clause}; this can have the form either @code{at @var{dimen}} or @code{scaled @var{factor}}, where a @var{factor} of @samp{1000} means no scaling. For @LaTeX{}'s purposes, all this does is scale all the character and other font dimensions relative to the font's design size, which is a value defined in the @file{.tfm} file. This example defines two equivalent fonts and typesets a few characters in each: @example \newfont@{\testfontat@}@{cmb10 at 11pt@} \newfont@{\testfontscaled@}@{cmb10 scaled 1100@} \testfontat abc \testfontscaled abc @end example @node \protect @section @code{\protect} @findex \protect @cindex fragile commands @cindex robust commands All @LaTeX{} commands are either @dfn{fragile} or @dfn{robust}. 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}. For example, when @LaTeX{} runs the @code{\section@{@var{section name}@}} command it writes the @var{section name} text to the @file{.aux} 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 moving arguments @dfn{moving argument}. 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@{...@}} command (@pxref{figure}), in the @code{\thanks@{...@}} command (@pxref{\maketitle}), and in @@-expressions in the @code{tabular} and @code{array} environments (@pxref{tabular}). If you get strange errors from commands used in moving arguments, try preceding it with @code{\protect}. Every fragile commands must be protected with their own @code{\protect}. Although usually a @code{\protect} command doesn't hurt, length commands are robust and should not be preceded by a @code{\protect} command. Nor can a @code{\protect} command be used in the argument to @code{\addtocounter} or @code{\setcounter} command. In this example the @code{\caption} command gives a mysterious error about an extra curly brace. Fix the problem by preceding each @code{\raisebox} command with @code{\protect}. @example \begin@{figure@} ... \caption@{Company headquarters of A\raisebox@{1pt@}@{B@}\raisebox@{-1pt@}@{C@}@} \end@{figure@} @end example In the next example the @code{\tableofcontents} command gives an error because the @code{\(..\)} in the section title expands to illegal @TeX{} in the @file{.toc} file. You can solve this by changing @code{\(..\)} to @code{\protect\(..\protect\)}. @example \begin@{document@} \tableofcontents ... \section@{Einstein's \( e=mc^2 \)@} ... @end example @node \ignorespaces & \ignorespacesafterend @section @code{\ignorespaces & \ignorespacesafterend} @findex \ignorespaces @findex \ignorespacesafterend @cindex spaces, ignore around commands @cindex commands, ignore spaces Synopsis: @example \ignorespaces @end example or @example \ignorespacesafterend @end example 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. The @code{ignorespaces} is often used when defining commands via @code{\newcommand}, or @code{\newenvironment}, or @code{\def}. 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} list, users must not put any space between the command and the question text. @example \newcommand@{\points@}[1]@{\makebox[0pt]@{\makebox[10em][l]@{#1~pts@}@} \begin@{enumerate@} \item\points@{10@}no extra space output here \item\points@{15@} extra space output between the number and the word `extra' \end@{enumerate@} @end example The solution is to change to @code{\newcommand@{\points@}[1]@{\makebox[0pt]@{\makebox[10em][l]@{#1~pts@}@}\ignorespaces@}}. 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} will reproduce that. @example \makeatletter \newcommand@{\honorific@}[1]@{\def\@@honorific@{#1@}@} % remember title \newcommand@{\fullname@}[1]@{\@@honorific~#1@} % recall title; put before name \makeatother \begin@{tabular@}@{|l|@} \honorific@{Mr/Ms@} \fullname@{Jones@} \\ % no extra space here \honorific@{ Mr/Ms@} \fullname@{Jones@} % extra space before title \end@{tabular@} @end example To fix this, change to @code{\newcommand@{\fullname@}[1]@{\ignorespaces\@@honorific~#1@}}. The @code{\ignorespaces} is also often used in a @code{\newenvironment} at the end of the @var{begin} clause, that is, as part of the second argument, as in @code{\begin@{newenvironment@}@{@var{env name}@}@{... \ignorespaces@}@{...@}}. To strip spaces off the end of an environment use @code{\ignorespacesafterend}. An example is that this will show a much larger vertical space between the first and second environments than between the second and third. @example \newenvironment@{eq@}@{\begin@{equation@}@}@{\end@{equation@}@} \begin@{eq@} e=mc^2 \end@{eq@} \begin@{equation@} F=ma \end@{equation@} \begin@{equation@} E=IR \end@{equation@} @end example Putting a comment character@tie{}@code{%} immediately after the @code{\end@{eq@}} will make the vertical space disappear, but that is inconvenient. The solution is to change to @code{\newenvironment@{eq@}@{\begin@{equation@}@}@{\end@{equation@}\ignorespacesafterend@}}. @node Counters @chapter Counters @cindex counters, a list of @cindex variables, a list of 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's name has no backslash@tie{}@code{\}. Thus, associated with the @code{\chapter} command is the @code{chapter} counter that keeps track of the chapter number. Below is a list of the counters used in @LaTeX{}'s standard document classes to control numbering. @example part paragraph figure enumi chapter subparagraph table enumii section page footnote enumiii subsection equation mpfootnote enumiv subsubsection @end example The @code{mpfootnote} counter is used by the @code{\footnote} command inside of a minipage (@pxref{minipage}). The counters @code{enumi} through @code{enumiv} are used in the @code{enumerate} environment, for up to four levels of nesting (@pxref{enumerate}). New counters are created with @code{\newcounter}. @xref{\newcounter}. @menu * \alph \Alph \arabic \roman \Roman \fnsymbol:: Print value of a counter. * \usecounter:: Use a specified counter in a list environment. * \value:: Use the value of a counter in an expression. * \setcounter:: Set the value of a counter. * \addtocounter:: Add a quantity to a counter. * \refstepcounter:: Add to a counter. * \stepcounter:: Add to a counter, resetting subsidiary counters. * \day \month \year:: Numeric date values. @end menu @node \alph \Alph \arabic \roman \Roman \fnsymbol @section @code{\alph \Alph \arabic \roman \Roman \fnsymbol}: Printing counters @cindex counters, printing Print the value of a counter, in a specified style. For instance, if the counter @var{counter} has the value 1 then a @code{\alph@{@var{counter}@}} in your source will result in a lower case letter@tie{}a appearing in the output. All of these commands take a single counter as an argument, for instance, @code{\alph@{enumi@}}. Note that the counter name does not start with a backslash. @ftable @code @item \alph@{@var{counter}@} Print the value of @var{counter} in lowercase letters: `a', `b', @enddots{} @item \Alph@{@var{counter}@} Print in uppercase letters: `A', `B', @enddots{} @item \arabic@{@var{counter}@} Print in Arabic numbers: `1', `2', @enddots{} @item \roman@{@var{counter}@} Print in lowercase roman numerals: `i', `ii', @enddots{} @item \Roman@{@var{counter}@} Print in uppercase roman numerals: `I', `II', @enddots{} @item \fnsymbol@{@var{counter}@} Prints the value of @var{counter} in a specific sequence of nine symbols (conventionally used for labeling footnotes). The value of @var{counter} must be between@tie{}1 and@tie{}9, inclusive. Here are the symbols: @multitable @columnfractions .33 .33 .33 @headitem Name@tab Command@tab@iftexthenelse{Symbol,Equivalent Unicode symbol and/or numeric code point} @item asterisk@tab@code{\ast}@tab@iftexthenelse{@math{@ast},*} @item dagger@tab@code{\dagger}@tab@BES{2020,\dagger} @item ddagger@tab@code{\ddagger}@tab@BES{2021,\ddagger} @item section-sign@tab@code{\S}@tab@BES{00A7,\S} @item paragraph-sign@tab@code{\P}@tab@BES{00B6,\P} @item double-vert@tab@code{\parallel}@tab@BES{2016,\parallel} @item double-asterisk@tab@code{\ast\ast}@tab@iftexthenelse{@math{@ast@ast},**} @item double-dagger@tab@code{\dagger\dagger}@tab@BES{2020,\dagger}@BES{2020,\dagger} @item double-ddagger@tab@code{\ddagger\ddagger}@tab@BES{2021,\ddagger}@BES{2021,\ddagger} @end multitable @end ftable @node \usecounter @section @code{\usecounter@{@var{counter}@}} @findex \usecounter @cindex list items, specifying counter @cindex numbered items, specifying counter Synopsis: @example \usecounter@{@var{counter}@} @end example In the @code{list} environment, when used in the second argument, this command sets up @var{counter} to number the list items. It initializes @var{counter} to zero, and arranges that when @code{\item} is called without its optional argument then @var{counter} is incremented by @code{\refstepcounter}, making its value be the current @code{ref} value. This command is fragile (@pxref{\protect}). Put in the preamble, this makes a new list environment enumerated with @var{testcounter}: @example \newcounter@{testcounter@} \newenvironment@{test@}@{% \begin@{list@}@{@}@{% \usecounter@{testcounter@} @} @}@{% \end@{list@} @} @end example @node \value @section @code{\value@{@var{counter}@}} @findex \value @cindex counters, getting value of Synopsis: @example \value@{@var{counter}@} @end example This command expands to the value of @var{counter}. It is often used in @code{\setcounter} or @code{\addtocounter}, but @code{\value} can be used anywhere that @LaTeX{} expects a number. It must not be preceded by @code{\protect} (@pxref{\protect}). The @code{\value} command is not used for typesetting the value of the counter. @xref{\alph \Alph \arabic \roman \Roman \fnsymbol}. This example outputs @samp{Test counter is@tie{}6. Other counter is@tie{}5.}. @example \newcounter@{test@} \setcounter@{test@}@{5@} \newcounter@{other@} \setcounter@{other@}@{\value@{test@}@} \addtocounter@{test@}@{1@} Test counter is \arabic@{test@}. Other counter is \arabic@{other@}. @end example This example inserts @code{\hspace@{4\parindent@}}. @example \setcounter@{myctr@}@{3@} \addtocounter@{myctr@}@{1@} \hspace@{\value@{myctr@}\parindent@} @end example @node \setcounter @section @code{\setcounter@{@var{counter}@}@{@var{value}@}} @findex \setcounter @cindex counters, setting @cindex setting counters Synopsis: @example \setcounter@{@var{counter}@}@{@var{value}@} @end example The @code{\setcounter} command globally sets the value of @var{counter} to the @var{value} argument. Note that the counter name does not start with a backslash. In this example the section value appears as @samp{V}. @example \setcounter@{section@}@{5@} Here it is in Roman: \Roman@{section@}. @end example @node \addtocounter @section @code{\addtocounter@{@var{counter}@}@{@var{value}@}} @findex \addtocounter The @code{\addtocounter} command globally increments @var{counter} by the amount specified by the @var{value} argument, which may be negative. In this example the section value appears as @samp{VII}. @example \setcounter@{section@}@{5@} \addtocounter@{section@}@{2@} Here it is in Roman: \Roman@{section@}. @end example @node \refstepcounter @section @code{\refstepcounter@{@var{counter}@}} @findex \refstepcounter The @code{\refstepcounter} command works in the same way as @code{\stepcounter} (@pxref{\stepcounter}): it globally increments the value of @var{counter} by one and resets the value of any counter numbered within it. (For the definition of ``counters numbered within'', @pxref{\newcounter}.) In addition, this command also defines the current @code{\ref} value to be the result of @code{\thecounter}. While the counter value is set globally, the @code{\ref} value is set locally, i.e., inside the current group. @node \stepcounter @section @code{\stepcounter@{@var{counter}@}} @findex \stepcounter The @code{\stepcounter} command globally adds one to @var{counter} and resets all counters numbered within it. (For the definition of ``counters numbered within'', @pxref{\newcounter}.) @node \day \month \year @section @code{\day \month \year}: Predefined counters @findex \day @findex \month @findex \year @LaTeX{} defines counters for the day of the month (@code{\day}, 1--31), month of the year (@code{\month}, 1--12), and year (@code{\year}, 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. The related command @code{\today} produces a string representing the current day (@pxref{\today}). @node Lengths @chapter Lengths @cindex lengths, defining and using A @dfn{length} is a measure of distance. Many @LaTeX{} commands take a length as an argument. Lengths come in two types. A @dfn{rigid length} (what Plain @TeX{} calls a @dfn{dimen}) such as @code{10pt} cannot contain a @code{plus} or @code{minus} component. A @dfn{rubber length} (what Plain @TeX{} calls a @dfn{skip}) can contain those, as with @code{1cm plus0.05cm minus0.01cm}. These give the ability to stretch or shrink; the length in the prior sentence could appear in the output as long as 1.05@tie{}cm or as short as 0.99@tie{}cm, depending on what @TeX{}'s typesetting algorithm finds optimum. The @code{plus} or @code{minus} component of a rubber length can contain a @dfn{fill} component, as in @code{1in plus2fill}. 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@tie{}inch. @TeX{} actually provides three infinite glue components @code{fil}, @code{fill}, and @code{filll}, such that the later ones overcome the earlier ones, but only the middle value is ordinarily used. @xref{\hfill}, @xref{\vfill}. Multiplying an entire rubber length by a number turns it into a rigid length, so that after @code{\setlength@{\ylength@}@{1in plus 0.2in@}} and @code{\setlength@{\zlength@}@{3\ylength@}} then the value of @code{\zlength} is @code{3in}. @menu * Units of length:: The units that @LaTeX{} knows. * \setlength:: Set the value of a length. * \addtolength:: Add a quantity to a length. * \settodepth:: Set a length to the depth of something. * \settoheight:: Set a length to the height of something. * \settowidth:: Set a length to the width of something. * Predefined lengths:: Lengths that are, like, predefined. @end menu @node Units of length @section Units of length @cindex units, of length @TeX{} and @LaTeX{} know about these units both inside and outside of math mode. @table @code @item pt @findex pt @cindex Point Point 1/72.27 inch. The conversion to metric units, to two decimal places, is 1@dmn{point} = 2.85@dmn{mm} = 28.45@dmn{cm}. @item pc @cindex pica @findex pc Pica, 12 pt @item in @findex in @findex inch Inch, 72.27 pt @item bp @findex bp @cindex Big point Big point, 1/72 inch. This length is the definition of a point in PostScript and many desktop publishing systems. @item cm @cindex Centimeter @findex cm Centimeter @item mm @cindex Millimeter @findex mm Millimeter @item dd @cindex Didot point @findex dd Didot point, 1.07 pt @item cc @cindex Cicero @findex cc Cicero, 12 dd @item sp @cindex Scaled point @findex sp Scaled point, 1/65536 pt @end table @cindex ex @cindex x-height @findex ex @cindex m-width @cindex em @findex em 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}, traditionally the height of the lower case letter x, is often used for vertical lengths. Similarly @dfn{em}, traditionally the width of the capital letter M, is often used for horizontal lengths (there is also @code{\enspace}, which is @code{0.5em}). 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@{\itemsep@}@{1ex plus 0.05ex minus 0.01ex@}} is more likely to still be reasonable if the font is changed than a definition given in points. @cindex mu, math unit @findex mu In math mode, many definitions are expressed in terms of the math unit @dfn{mu} given by 1 em = 18 mu, where the em is taken from the current math symbols family. @xref{Spacing in math mode}. @node \setlength @section @code{\setlength} @findex \setlength @cindex lengths, setting Synopsis: @example \setlength@{@var{\len}@}@{@var{amount}@} @end example The @code{\setlength} sets the value of @dfn{length command} @cindex length command @code{\@var{len}} to the @var{value} argument which can be expressed in any units that @LaTeX{} understands, i.e., inches (@code{in}), millimeters (@code{mm}), points (@code{pt}), big points (@code{bp}), etc. @node \addtolength @section @code{\addtolength} @findex \addtolength @cindex lengths, adding to Synopsis: @example \addtolength@{@var{\len}@}@{@var{amount}@} @end example The @code{\addtolength} command increments a length command @code{\@var{len}} by the amount specified in the @var{amount} argument, which may be negative. @node \settodepth @section @code{\settodepth} @findex \settodepth Synopsis: @example \settodepth@{\@var{len}@}@{@var{text}@} @end example The @code{\settodepth} command sets the value of a length command @code{\@var{len}} equal to the depth of the @var{text} argument. @node \settoheight @section @code{\settoheight} @findex \settoheight Synopsis: @example \settoheight@{\@var{len}@}@{text@} @end example The @code{\settoheight} command sets the value of a length command @code{\@var{len}} equal to the height of the @code{text} argument. @node \settowidth @section @code{\settowidth@{\@var{len}@}@{@var{text}@}} @findex \settowidth Synopsis: @example \settowidth@{\@var{len}@}@{@var{text}@} @end example The @code{\settowidth} command sets the value of the command @var{\len} to the width of the @var{text} argument. @node Predefined lengths @section Predefined lengths @cindex lengths, predefined @cindex predefined lengths @code{\width} @findex \width @code{\height} @findex \height @code{\depth} @findex \depth @code{\totalheight} @findex \totalheight These length parameters can be used in the arguments of the box-making commands (@pxref{Boxes}). They specify the natural width, etc., of the text in the box. @code{\totalheight} equals @math{@code{@backslashchar{}height} + @code{@backslashchar{}depth}}. To make a box with the text stretched to double the natural size, e.g., say @example \makebox[2\width]@{Get a stretcher@} @end example @node Making paragraphs @chapter Making paragraphs @cindex making paragraphs @cindex paragraphs A paragraph is ended by one or more completely blank lines---lines not containing even a @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. @menu * \indent:: Indent this paragraph. * \noindent:: Do not indent this paragraph. * \parskip:: Space added before paragraphs. * Marginal notes:: Putting remarks in the margin. @end menu @node \indent @section @code{\indent} @findex \indent @findex \parindent @cindex indent, forcing @code{\indent} produces a horizontal space whose width equals to the @code{\parindent} length, the normal paragraph indentation. It is used to add paragraph indentation where it would otherwise be suppressed. The default value for @code{\parindent} is @code{1em} in two-column mode, otherwise @code{15pt} for @code{10pt} documents, @code{17pt} for @code{11pt}, and @code{1.5em} for @code{12pt}. @node \noindent @section @code{\noindent} @findex \noindent @cindex indent, suppressing When used at the beginning of the paragraph, this command suppresses any paragraph indentation, as in this example. @example ... end of the prior paragraph. \noindent This paragraph is not indented. @end example It has no effect when used in the middle of a paragraph. To eliminate paragraph indentation in an entire document, put @code{\setlength@{\parindent@}@{0pt@}} in the preamble. @node \parskip @section @code{\parskip} @findex \parskip @cindex vertical space before paragraphs @code{\parskip} is a rubber length defining extra vertical space added before each paragraph. The default is @code{0pt plus1pt}. @node Marginal notes @section Marginal notes @cindex marginal notes @cindex notes in the margin @cindex remarks in the margin @findex \marginpar Synopsis: @example \marginpar[@var{left}]@{@var{right}@} @end example The @code{\marginpar} 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} occurs. When you only specify the mandatory argument @var{right}, the text will be placed @itemize @bullet @item in the right margin for one-sided layout (option @code{oneside}, see @ref{Document class options}); @item in the outside margin for two-sided layout (option @code{twoside}, see @ref{Document class options}); @item in the nearest margin for two-column layout (option @code{twocolumn}, see @ref{Document class options}). @end itemize @findex \reversemarginpar @findex \normalmarginpar The command @code{\reversemarginpar} places subsequent marginal notes in the opposite (inside) margin. @code{\normalmarginpar} places them in the default position. When you specify both arguments, @var{left} is used for the left margin, and @var{right} is used for the right margin. The first word will normally not be hyphenated; you can enable hyphenation there by beginning the node with @code{\hspace@{0pt@}}. These parameters affect the formatting of the note: @ftable @code @item \marginparpush Minimum vertical space between notes; default @samp{7pt} for @samp{12pt} documents, @samp{5pt} else. @item \marginparsep Horizontal space between the main text and the note; default @samp{11pt} for @samp{10pt} documents, @samp{10pt} else. @item \marginparwidth Width of the note itself; default for a one-sided @samp{10pt} document is @samp{90pt}, @samp{83pt} for @samp{11pt}, and @samp{68pt} for @samp{12pt}; @samp{17pt} more in each case for a two-sided document. In two column mode, the default is @samp{48pt}. @end ftable 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) @node Math formulas @chapter Math formulas @cindex math formulas @cindex formulas, math @cindex math mode, entering @EnvIndex{math} @EnvIndex{displaymath} @EnvIndex{equation} There are three environments that put @LaTeX{} in math mode: @table @code @item math For formulas that appear right in the text. @item displaymath For formulas that appear on their own line. @item equation The same as the displaymath environment except that it adds an equation number in the right margin. @end table @findex \( @findex \) @findex \[ @findex \] The @code{math} environment can be used in both paragraph and LR mode, but the @code{displaymath} and @code{equation} environments can be used only in paragraph mode. The @code{math} and @code{displaymath} environments are used so often that they have the following short forms: @example \(...\) @r{instead of} \begin@{math@}...\end@{math@} \[...\] @r{instead of} \begin@{displaymath@}...\end@{displaymath@} @end example @findex $ In fact, the @code{math} environment is so common that it has an even shorter form: @example $ ... $ @r{instead of} \(...\) @end example @findex \boldmath @findex \unboldmath The @code{\boldmath} command changes math letters and symbols to be in a bold font. It is used @emph{outside} of math mode. Conversely, the @code{\unboldmath} command changes math glyphs to be in a normal font; it too is used @emph{outside} of math mode. @c xx own section? Math fonts? @findex \displaystyle The @code{\displaystyle} declaration forces the size and style of the formula to be that of @code{displaymath}, e.g., with limits above and below summations. For example: @example $\displaystyle \sum_@{n=0@}^\infty x_n $ @end example @c xx see also \cal, \mathcal @menu * Subscripts & superscripts:: Also known as exponent or index. * Math symbols:: Various mathematical squiggles. * Math functions:: Math function names like sin and exp. * Math accents:: Accents in math. * Spacing in math mode:: Thick, medium, thin and negative spaces. * Math miscellany:: Stuff that doesn't fit anywhere else. @end menu @node Subscripts & superscripts @section Subscripts & superscripts @cindex superscript @cindex subscript @cindex exponent @findex _ @findex ^ In math mode, use the caret character@tie{}@code{^} to make the @var{exp} appear as a superscript: @code{^@{@var{exp}@}}. Similarly, in math mode, underscore@tie{}@code{_@{@var{exp}@}} makes a subscript out of @var{exp}. In this example the @code{0} and @code{1} appear as subscripts while the @code{2} is a superscript. @example \( (x_0+x_1)^2 \) @end example To have more than one character in @var{exp} use curly braces as in @code{e^@{-2x@}}. @LaTeX{} handles superscripts on superscripts, and all of that stuff, in the natural way, so expressions such as @code{e^@{x^2@}} and @code{x_@{a_0@}} will look right. It also does the right thing when something has both a subscript and a superscript. In this example the @code{0} appears at the bottom of the integral sign while the @code{10} appears at the top. @example \int_0^@{10@} x^2 \,dx @end example You can put a superscript or subscript before a symbol with a construct such as @code{@{@}_t K^2} in math mode (the initial @code{@{@}} prevents the prefixed subscript from being attached to any prior symbols in the expression). Outside of math mode, a construct like @code{A test$_\textnormal@{subscript@}$} 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}. @c xx display mode @node Math symbols @section Math symbols @cindex math symbols @cindex symbols, math @cindex greek letters @LaTeX{} provides almost any mathematical symbol you're likely to need. For example, if you include @code{$\pi$} in your source, you will get the pi symbol @BES{03C0,\pi}. 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. To redefine a command so that it can be used whatever the current mode, see @ref{\ensuremath}. @c xx Add Negation: @code{} for negations of relevant symbols @c Useful: http://www.w3.org/TR/WD-math-970515/section6.html @ftable @code @item \| @BES{2225,\|} Parallel (relation). Synonym:@tie{}@code{\parallel}. @item \aleph @BES{2135,\aleph} Aleph, transfinite cardinal (ordinary). @item \alpha @BES{03B1,\alpha} Lower case Greek letter alpha (ordinary). @item \amalg @BES{2A3F,\amalg} Disjoint union (binary) @item \angle @BES{2220,\angle} Geometric angle (ordinary). Similar: less-than sign@tie{}@code{<} and angle bracket@tie{}@code{\langle}. @item \approx @BES{2248,\approx} Almost equal to (relation). @item \ast @BES{2217,\ast} Asterisk operator, convolution, six-pointed (binary). Synonym:@tie{}@code{*}, which is often a superscript or subscript, as in the Kleene star. Similar:@tie{}@code{\star}, which is five-pointed, and is sometimes used as a general binary operation, and sometimes reserved for cross-correlation. @item \asymp @BES{224D,\asymp} Asymptotically equivalent (relation). @item \backslash \ Backslash (ordinary). Similar: set minus@tie{}@code{\setminus}, and @code{\textbackslash} for backslash outside of math mode. @item \beta @BES{03B2,\beta} Lower case Greek letter beta (ordinary). @item \bigcap @BES{22C2,\bigcap} Variable-sized, or n-ary, intersection (operator). Similar: binary intersection@tie{}@code{\cap}. @item \bigcirc @BES{26AA,\bigcirc} Circle, larger (binary). Similar: function composition@tie{}@code{\circ}. @c bb Best unicode symbol for this? @item \bigcup @BES{22C3,\bigcup} Variable-sized, or n-ary, union (operator). Similar: binary union@tie{}@code{\cup}. @item \bigodot @BES{2A00,\bigodot} Variable-sized, or n-ary, circled dot operator (operator). @item \bigoplus @BES{2A01,\bigoplus} Variable-sized, or n-ary, circled plus operator (operator). @item \bigotimes @BES{2A02,\bigotimes} Variable-sized, or n-ary, circled times operator (operator). @item \bigtriangledown @BES{25BD,\bigtriangledown} Variable-sized, or n-ary, open triangle pointing down (operator). @item \bigtriangleup @BES{25B3,\bigtriangleup} Variable-sized, or n-ary, open triangle pointing up (operator). @item \bigsqcup @BES{2A06,\bigsqcup} Variable-sized, or n-ary, square union (operator). @item \biguplus @BES{2A04,\biguplus} Variable-sized, or n-ary, union operator with a plus (operator). (Note that the name has only one p.) @item \bigvee @BES{22C1,\bigvee} Variable-sized, or n-ary, logical-and (operator). @item \bigwedge @BES{22C0,\bigwedge} Variable-sized, or n-ary, logical-or (operator). @item \bot @BESU{22A5,bot} Up tack, bottom, least element of a partially ordered set, or a contradiction (ordinary). See also@tie{}@code{\top}. @item \bowtie @BES{22C8,\bowtie} Natural join of two relations (relation). @item \Box @BESU{25A1,Box} Modal operator for necessity; square open box (ordinary). @value{NeedsAMSSymb} @c bb Best Unicode equivalent? @item \bullet @cindex bullet symbol @BES{2022,\bullet} Bullet (binary). Similar: multiplication dot@tie{}@code{\cdot}. @item \cap @BES{2229,\cap} Intersection of two sets (binary). Similar: variable-sized operator@tie{}@code{\bigcap}. @item \cdot @BES{22C5,\cdot} Multiplication (binary). Similar: Bullet dot@tie{}@code{\bullet}. @item \chi @BES{03C7,\chi} Lower case Greek chi (ordinary). @item \circ @BES{2218,\circ} Function composition, ring operator (binary). Similar: variable-sized operator@tie{}@code{\bigcirc}. @item \clubsuit @BES{2663,\clubsuit} Club card suit (ordinary). @item \complement @BESU{2201,complement} Set complement, used as a superscript as in @code{$S^\complement$} (ordinary). @value{NeedsAMSSymb} Also used: @code{$S^@{\mathsf@{c@}@}$} or@tie{}@code{$\bar@{S@}$}. @item \cong @BES{2245,\cong} Congruent (relation). @item \coprod @BES{2210,\coprod} Coproduct (operator). @item \cup @BES{222A,\cup} Union of two sets (binary). Similar: variable-sized operator@tie{}@code{\bigcup}. @item \dagger @BES{2020,\dagger} Dagger relation (binary). @item \dashv @BES{22A3,\dashv} Dash with vertical, reversed turnstile (relation). Similar: turnstile@tie{}@code{\vdash}. @item \ddagger @BES{2021,\ddagger} Double dagger relation (binary). @item \Delta @BES{0394,\Delta} Greek upper case delta, used for increment (ordinary). @item \delta @BES{03B4,\delta} Greek lower case delta (ordinary). @item \Diamond @BESU{25C7,Diamond} Large diamond operator (ordinary). @value{NeedsAMSSymb} @c bb Best Unicode equivalent? @item \diamond @BES{22C4,\diamond} Diamond operator, or diamond bullet (binary). Similar: large diamond@tie{}@code{\Diamond}, circle bullet@tie{}@code{\bullet}. @item \diamondsuit @BES{2662,\diamondsuit} Diamond card suit (ordinary). @item \div @BES{00F7,\div} Division sign (binary). @item \doteq @BES{2250,\doteq} Approaches the limit (relation). Similar: geometrically equal to@tie{}@code{\Doteq}. @item \downarrow @BES{2193,\downarrow} Down arrow, converges (relation). Similar: double line down arrow@tie{}@code{\Downarrow}. @item \Downarrow @BES{21D3,\Downarrow} Double line down arrow (relation). Similar: single line down arrow@tie{}@code{\downarrow}. @item \ell @BES{2113,\ell} Lowercase cursive letter l (ordinary). @item \emptyset @BES{2205,\emptyset} Empty set symbol (ordinary). The variant form is @code{\varnothing}. @c bb Why Unicode has \revemptyset but no \emptyset? @item \epsilon @BES{03F5,\epsilon} Lower case lunate epsilon (ordinary). Similar to Greek text letter. More widely used in mathematics is the script small letter epsilon @code{\varepsilon}@tie{}@BES{03B5,\varepsilon}. Related: the set membership relation @code{\in}@tie{}@BES{2208,\in}. @c src: David Carlisle http://tex.stackexchange.com/a/98018/339 and @c Unicode referenced there asserts varepsilon is much more widely used. @item \equiv @BES{2261,\equiv} Equivalence (relation). @item \eta @BES{03B7,\eta} Lower case Greek letter (ordinary). @item \exists @BES{2203,\exists} Existential quantifier (ordinary). @item \flat @BES{266D,\flat} Musical flat (ordinary). @item \forall @BES{2200,\forall} Universal quantifier (ordinary). @item \frown @BES{2322,\frown} Downward curving arc (ordinary). @item \Gamma @BES{0393,\Gamma} Upper case Greek letter (ordinary). @item \gamma @BES{03B3,\gamma} Lower case Greek letter (ordinary). @item \ge @BES{2265,\ge} Greater than or equal to (relation). This is a synonym for@tie{}@code{\geq}. @item \geq @BES{2265,\geq} Greater than or equal to (relation). This is a synonym for@tie{}@code{\ge}. @item \gets @BES{2190,\gets} Is assigned the value (relation). Synonym:@tie{}@code{\leftarrow}. @item \gg @BES{226B,\gg} Much greater than (relation). Similar: much less than@tie{}@code{\ll}. @item \hbar @BES{210F,\hbar} Planck constant over two pi (ordinary). @item \heartsuit @BES{2661,\heartsuit} Heart card suit (ordinary). @item \hookleftarrow @BES{21A9,\hookleftarrow} Hooked left arrow (relation). @item \hookrightarrow @BES{21AA,\hookrightarrow} Hooked right arrow (relation). @item \iff @BES{27F7,\iff} If and only if (relation). It is @code{\Longleftrightarrow} with a @code{\thickmuskip} on either side. @item \Im @BES{2111,\Im} Imaginary part (ordinary). See: real part@tie{}@code{\Re}. @item \in @BES{2208,\in} Set element (relation). See also: lower case lunate epsilon@tie{}@code{\epsilon}@BES{03F5,\epsilon} and small letter script epsilon@tie{}@code{\varepsilon}. @item \infty @BES{221E,\infty} Infinity (ordinary). @item \int @BES{222B,\int} Integral (operator). @item \iota @BES{03B9,\iota} Lower case Greek letter (ordinary). @item \Join @BESU{2A1D,Join} Condensed bowtie symbol (relation). Not available in Plain @TeX{}. @item \kappa @BES{03BA,\kappa} Lower case Greek letter (ordinary). @item \Lambda @BES{039B,\Lambda} Upper case Greek letter (ordinary). @item \lambda @BES{03BB,\lambda} Lower case Greek letter (ordinary). @item \land @BES{2227,\land} Logical and (binary). This is a synonym for @code{\wedge}. See also logical or@tie{}@code{\lor}. @item \langle @BES{27E8,\langle} Left angle, or sequence, bracket (opening). Similar: less-than@tie{}@code{<}. Matches@tie{}@code{\rangle}. @item \lbrace @BES{007B,\lbrace} Left curly brace (opening). Synonym:@tie{}@code{\@{}. Matches@tie{}@code{\rbrace}. @item \lbrack @BES{005B,\lbrack} Left square bracket (opening). Synonym:@tie{}@code{[}. Matches@tie{}@code{\rbrack}. @item \lceil @BES{2308,\lceil} Left ceiling bracket, like a square bracket but with the bottom shaved off (opening). Matches@tie{}@code{\rceil}. @item \le @BES{2264,\le} Less than or equal to (relation). This is a synonym for@tie{}@code{\leq}. @item \leadsto @BESU{21DD,leadsto} Squiggly right arrow (relation). @value{NeedsAMSSymb} To get this symbol outside of math mode you can put @code{\newcommand*@{\Leadsto@}@{\ensuremath@{\leadsto@}@}} in the preamble and then use @code{\Leadsto} instead. @c bb Best Unicode equivalent? @item \Leftarrow @BES{21D0,\Leftarrow} Is implied by, double-line left arrow (relation). Similar: single-line left arrow@tie{}@code{\leftarrow}. @item \leftarrow @BES{2190,\leftarrow} Single-line left arrow (relation). Synonym:@tie{}@code{\gets}. Similar: double-line left arrow@tie{}@code{\Leftarrow}. @item \leftharpoondown @BES{21BD,\leftharpoondown} Single-line left harpoon, barb under bar (relation). @item \leftharpoonup @BES{21BC,\leftharpoonup} Single-line left harpoon, barb over bar (relation). @item \Leftrightarrow @BES{21D4,\Leftrightarrow} Bi-implication; double-line double-headed arrow (relation). Similar: single-line double headed arrow@tie{}@code{\leftrightarrow}. @item \leftrightarrow @BES{2194,\leftrightarrow} Single-line double-headed arrow (relation). Similar: double-line double headed arrow@tie{}@code{\Leftrightarrow}. @item \leq @BES{2264,\leq} Less than or equal to (relation). This is a synonym for@tie{}@code{\le}. @item \lfloor @BES{230A,\lfloor} Left floor bracket (opening). Matches:@tie{}@code{\floor}. @item \lhd @BESU{25C1,lhd} Arrowhead, that is, triangle, pointing left (binary). @value{NeedsAMSSymb} For the normal subgroup symbol you should load @file{amssymb} and use@tie{}@code{\vartriangleleft} (which is a relation and so gives better spacing). @item \ll @BES{226A,\ll} Much less than (relation). Similar: much greater than@tie{}@code{\gg}. @item \lnot @BES{00AC,\lnot} Logical negation (ordinary). Synonym:@tie{}@code{\neg}. @item \longleftarrow @BES{27F5,\longleftarrow} Long single-line left arrow (relation). Similar: long double-line left arrow@tie{}@code{\Longleftarrow}. @item \longleftrightarrow @BES{27F7,\longleftrightarrow} Long single-line double-headed arrow (relation). Similar: long double-line double-headed arrow@tie{}@code{\Longleftrightarrow}. @item \longmapsto @BES{27FC,\longmapsto} Long single-line left arrow starting with vertical bar (relation). Similar: shorter version@tie{}@code{\mapsto}. @item \longrightarrow @BES{27F6,\longrightarrow} Long single-line right arrow (relation). Similar: long double-line right arrow@tie{}@code{\Longrightarrow}. @item \lor @BES{2228,\lor} Logical or (binary). Synonym: wedge@tie{}@code{\wedge}. @item \mapsto @BES{21A6,\mapsto} Single-line left arrow starting with vertical bar (relation). Similar: longer version@tie{}@code{\longmapsto}. @item \mho @BESU{2127,mho} Conductance, half-circle rotated capital omega (ordinary). @value{NeedsAMSSymb} @item \mid @BES{2223,\mid} Single-line vertical bar (relation). A typical use of @code{\mid} is for a set @code{\@{\, x \mid x\geq 5 \,\@}}. Similar: @code{\vert} and@tie{}@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@tie{}@code{\vert} and for norm see the entry for@tie{}@code{\Vert}. @item \models @BES{22A8,\models} Entails, or satisfies; double turnstile, short double dash (relation). Similar: long double dash@tie{}@code{\vDash}. @item \mp @BES{2213,\mp} Minus or plus (relation). @item \mu @BES{03BC,\mu} Lower case Greek letter (ordinary). @item \nabla @BES{2207,\nabla} Hamilton's del, or differential, operator (ordinary). @item \natural @BES{266E,\natural} Musical natural notation (ordinary). @item \ne @BES{2260,\ne} Not equal (relation). Synonym:@tie{}@code{\neq}. @item \nearrow @BES{2197,\nearrow} North-east arrow (relation). @item \neg @BES{00AC,\neg} Logical negation (ordinary). Synonym:@tie{}@code{\lnot}. Sometimes instead used for negation:@tie{}@code{\sim}. @item \neq @BES{2260,\neq} Not equal (relation). Synonym:@tie{}@code{\ne}. @item \ni @BES{220B,\ni} Reflected membership epsilon; has the member (relation). Synonym:@tie{}@code{\owns}. Similar: is a member of@tie{}@code{\in}. @item \not @BES{0020,\not}@BES{00A0,}@BES{0338,} Long solidus, or slash, used to overstrike a following operator (relation). @c Need blank space for it to overstrike Many negated operators that don't require @code{\not} are available, particularly with the @file{amssymb} package. For example, @code{\notin} is probably typographically preferable to @code{\not\in}. @item \notin @BES{2209,\notin} Not an element of (relation). Similar: not subset of@tie{}@code{\nsubseteq}. @item \nu @BES{03BD,\nu} Lower case Greek letter (ordinary). @item \nwarrow @BES{2196,\nwarrow} North-west arrow (relation). @item \odot @BES{2299,\odot} Dot inside a circle (binary). Similar: variable-sized operator@tie{}@code{\bigodot}. @item \oint @BES{222E,\oint} Contour integral, integral with circle in the middle (operator). @item \Omega @BES{03A9,\Omega} Upper case Greek letter (ordinary). @item \omega @BES{03C9,\omega} Lower case Greek letter (ordinary). @item \ominus @BES{2296,\ominus} Minus sign, or dash, inside a circle (binary). @item \oplus @BES{2295,\oplus} Plus sign inside a circle (binary). Similar: variable-sized operator@tie{}@code{\bigoplus}. @item \oslash @BES{2298,\oslash} Solidus, or slash, inside a circle (binary). @item \otimes @BES{2297,\otimes} Times sign, or cross, inside a circle (binary). Similar: variable-sized operator@tie{}@code{\bigotimes}. @item \owns @BES{220B,\owns} Reflected membership epsilon; has the member (relation). Synonym:@tie{}@code{\ni}. Similar: is a member of@tie{}@code{\in}. @item \parallel @BES{2225,\parallel} Parallel (relation). Synonym:@tie{}@code{\|}. @item \partial @BES{2202,\partial} Partial differential (ordinary). @item \perp @BES{27C2,\perp} Perpendicular (relation). Similar:@tie{}@code{\bot} uses the same glyph but the spacing is different because it is in the class ordinary. @item \phi @BES{03D5,\phi} Lower case Greek letter (ordinary). The variant form is @code{\varphi}@tie{}@BES{03C6,\varphi}. @item \Pi @BES{03A0,\Pi} Upper case Greek letter (ordinary). @item \pi @BES{03C0,\pi} Lower case Greek letter (ordinary). The variant form is @code{\varpi}@tie{}@BES{03D6,\varpi}. @item \pm @BES{00B1,\pm} Plus or minus (binary). @item \prec @BES{227A,\prec} Precedes (relation). Similar: less than@tie{}@code{<}. @item \preceq @BES{2AAF,\preceq} Precedes or equals (relation). Similar: less than or equals@tie{}@code{\leq}. @item \prime @BES{2032,\prime} Prime, or minute in a time expression (ordinary). Typically used as a superscript: @code{$f^\prime$}; @code{$f^\prime$} and @code{$f'$} produce the same result. An advantage of the second is that @code{$f'''$} produces the desired symbol, that is, the same result as @code{$f^@{\prime\prime\prime@}$}, but uses rather less typing. You can only use @code{\prime} in math mode. Using the right single quote@tie{}@code{'} in text mode produces a different character (apostrophe). @item \prod @BES{220F,\prod} Product (operator). @item \propto @BES{221D,\propto} Is proportional to (relation) @item \Psi @BES{03A8,\Psi} Upper case Greek letter (ordinary). @item \psi @BES{03C8,\psi} Lower case Greek letter (ordinary). @item \rangle @BES{27E9,\rangle} Right angle, or sequence, bracket (closing). Similar: greater than@tie{}@code{>}. Matches:@code{\langle}. @item \rbrace @BES{007D,\rbrace} Right curly brace (closing). Synonym:@tie{}@code{\@}}. Matches@tie{}@code{\lbrace}. @item \rbrack @BES{005D,\rbrack} Right square bracket (closing). Synonym:@tie{}@code{]}. Matches@tie{}@code{\lbrack}. @item \rceil @BES{2309,\rceil} Right ceiling bracket (closing). Matches@tie{}@code{\lceil}. @item \Re @BES{211C,\Re} Real part, real numbers, cursive capital R (ordinary). Related: double-line, or blackboard bold, R@tie{}@code{\mathbb@{R@}}; to access this, load the @file{amsfonts} package. @item \restriction @BESU{21BE,restriction} Restriction of a function (relation). Synonym:@tie{}@code{\upharpoonright}. @value{NeedsAMSSymb} @item \revemptyset @BESU{29B0,revemptyset} Reversed empty set symbol (ordinary). Related: @code{\varnothing}. @value{NeedsSTIX} @item \rfloor @BES{230B,\rfloor} Right floor bracket, a right square bracket with the top cut off (closing). Matches@tie{}@code{\lfloor}. @item \rhd @BESU{25C1,rhd} Arrowhead, that is, triangle, pointing right (binary). @value{NeedsAMSSymb} For the normal subgroup symbol you should instead load @file{amssymb} and use@tie{}@code{\vartriangleright} (which is a relation and so gives better spacing). @item \rho @BES{03C1,\rho} Lower case Greek letter (ordinary). The variant form is @code{\varrho}@tie{}@BES{03F1,\varrho}. @item \Rightarrow @BES{21D2,\Rightarrow} Implies, right-pointing double line arrow (relation). Similar: right single-line arrow@tie{}@code{\rightarrow}. @item \rightarrow @BES{2192,\rightarrow} Right-pointing single line arrow (relation). Synonym:@tie{}@code{\to}. Similar: right double line arrow@tie{}@code{\Rightarrow}. @item \rightharpoondown @BES{21C1,\rightharpoondown} Right-pointing harpoon with barb below the line (relation). @item \rightharpoonup @BES{21C0,\rightharpoonup} Right-pointing harpoon with barb above the line (relation). @item \rightleftharpoons @BES{21CC,\rightleftharpoons} Right harpoon up above left harpoon down (relation). @item \searrow @BES{2198,\searrow} Arrow pointing southeast (relation). @item \setminus @BES{29F5,\setminus} Set difference, reverse solidus or slash, like \ (binary). Similar: backslash@tie{}@code{\backslash} and also @code{\textbackslash} outside of math mode. @item \sharp @BES{266F,\sharp} Musical sharp (ordinary). @item \Sigma @BES{03A3,\Sigma} Upper case Greek letter (ordinary). @item \sigma @BES{03C3,\sigma} Lower case Greek letter (ordinary). The variant form is @code{\varsigma}@tie{}@BES{03C2,\varsigma}. @item \sim @BES{223C,\sim} Similar, in a relation (relation). @item \simeq @BES{2243,\simeq} Similar or equal to, in a relation (relation). @item \smallint @BES{222B,\smallint} Integral sign that does not change to a larger size in a display (operator). @item \smile @BES{2323,\smile} Upward curving arc, smile (ordinary). @item \spadesuit @BES{2660,\spadesuit} Spade card suit (ordinary). @item \sqcap @BES{2293,\sqcap} Square intersection symbol (binary). Similar: intersection@tie{}@code{cap}. @item \sqcup @BES{2294,\sqcup} Square union symbol (binary). Similar: union@tie{}@code{cup}. Related: variable-sized operator@tie{}@code{\bigsqcup}. @item \sqsubset @BESU{228F,sqsubset} Square subset symbol (relation). Similar: subset@tie{}@code{\subset}. @value{NeedsAMSSymb} @item \sqsubseteq @BES{2291,\sqsubseteq} Square subset or equal symbol (binary). Similar: subset or equal to@tie{}@code{\subseteq}. @item \sqsupset @BESU{2290,sqsupset} Square superset symbol (relation). Similar: superset@tie{}@code{\supset}. @value{NeedsAMSSymb} @item \sqsupseteq @BES{2292,\sqsupseteq} Square superset or equal symbol (binary). Similar: superset or equal@tie{}@code{\supseteq}. @item \star @BES{22C6,\star} Five-pointed star, sometimes used as a general binary operation but sometimes reserved for cross-correlation (binary). Similar: the synonyms asterisk@tie{}@code{*} and @code{\ast}, which are six-pointed, and more often appear as a superscript or subscript, as with the Kleene star. @item \subset @BES{2282,\subset} Subset (occasionally, is implied by) (relation). @item \subseteq @BES{2286,\subseteq} Subset or equal to (relation). @item \succ @BES{227B,\succ} Comes after, succeeds (relation). Similar: is less than@tie{}@code{>}. @item \succeq @BES{2AB0,\succeq} Succeeds or is equal to (relation). Similar: less than or equal to@tie{}@code{\leq}. @item \sum @BES{2211,\sum} Summation (operator). Similar: Greek capital sigma@tie{}@code{\Sigma}. @item \supset @BES{2283,\supset} Superset (relation). @item \supseteq @BES{2287,\supseteq} Superset or equal to (relation). @item \surd @BES{221A,\surd} Radical symbol (ordinary). The @LaTeX{} command @code{\sqrt@{...@}} typesets the square root of the argument, with a bar that extends to cover the argument. @item \swarrow @BES{2199,\swarrow} Southwest-pointing arrow (relation). @item \tau @BES{03C4,\tau} Lower case Greek letter (ordinary). @item \theta @BES{03B8,\theta} Lower case Greek letter (ordinary). The variant form is @code{\vartheta}@tie{}@BES{03D1,\vartheta}. @item \times @BES{00D7,\times} Primary school multiplication sign (binary). See also@tie{}@code{\cdot}. @item \to @BES{2192,\to} Right-pointing single line arrow (relation). Synonym:@tie{}@code{\rightarrow}. @item \top @BESU{22A4,top} Top, greatest element of a partially ordered set (ordinary). See also@tie{}@code{\bot}. @item \triangle @BES{25B3,\triangle} Triangle (ordinary). @item \triangleleft @BES{25C1,\triangleleft} Not-filled triangle pointing left (binary). Similar:@tie{}@code{\lhd}. For the normal subgroup symbol you should load @file{amssymb} and use@tie{}@code{\vartriangleleft} (which is a relation and so gives better spacing). @item \triangleright @BES{25B7,\triangleright} Not-filled triangle pointing right (binary). For the normal subgroup symbol you should instead load @file{amssymb} and use@tie{}@code{\vartriangleright} (which is a relation and so gives better spacing). @item \unlhd @BESU{22B4,unlhd} Left-pointing not-filled underlined arrowhead, that is, triangle, with a line under (binary). @value{NeedsAMSSymb} For the normal subgroup symbol load @file{amssymb} and use@tie{}@code{\vartrianglelefteq} (which is a relation and so gives better spacing). @item \unrhd @BESU{22B5,unrhd} Right-pointing not-filled underlined arrowhead, that is, triangle, with a line under (binary). @value{NeedsAMSSymb} For the normal subgroup symbol load @file{amssymb} and use@tie{}@code{\vartrianglerighteq} (which is a relation and so gives better spacing). @item \Uparrow @BES{21D1,\Uparrow} Double-line upward-pointing arrow (relation). Similar: single-line up-pointing arrow@tie{}@code{\uparrow}. @item \uparrow @BES{2191,\uparrow} Single-line upward-pointing arrow, diverges (relation). Similar: double-line up-pointing arrow@tie{}@code{\Uparrow}. @item \Updownarrow @BES{21D5,\Updownarrow} Double-line upward-and-downward-pointing arrow (relation). Similar: single-line upward-and-downward-pointing arrow@tie{}@code{\updownarrow}. @item \updownarrow @BES{2195,\updownarrow} Single-line upward-and-downward-pointing arrow (relation). Similar: double-line upward-and-downward-pointing arrow@tie{}@code{\Updownarrow}. @item \upharpoonright @BESU{21BE,upharpoonright} Up harpoon, with barb on right side (relation). Synonym:@tie{}@code{@backslashchar{}restriction}. @value{NeedsAMSSymb} @item \uplus @BES{228E,\uplus} Multiset union, a union symbol with a plus symbol in the middle (binary). Similar: union@tie{}@code{\cup}. Related: variable-sized operator@tie{}@code{\biguplus}. @item \Upsilon @BES{03A5,\Upsilon} Upper case Greek letter (ordinary). @item \upsilon @BES{03C5,\upsilon} Lower case Greek letter (ordinary). @item \varepsilon @BES{03B5,\varepsilon} Small letter script epsilon (ordinary). This is more widely used in mathematics than the non-variant lunate epsilon form @code{\epsilon}@tie{}@BES{03F5,\epsilon}. Related: set membership@tie{}@code{\in}. @item \vanothing @BESU{2205,varnothing} Empty set symbol. Similar: @code{\emptyset}. Related: @code{\revemptyset}. @value{NeedsAMSSymb} @item \varphi @BES{03C6,\varphi} Variant on the lower case Greek letter (ordinary). The non-variant form is @code{\phi}@tie{}@BES{03D5,\phi}. @item \varpi @BES{03D6,\varpi} Variant on the lower case Greek letter (ordinary). The non-variant form is @code{\pi}@tie{}@BES{03C0,\pi}. @item \varrho @BES{03F1,\varrho} Variant on the lower case Greek letter (ordinary). The non-variant form is @code{\rho}@tie{}@BES{03C1,\rho}. @item \varsigma @BES{03C2,\varsigma} Variant on the lower case Greek letter (ordinary). The non-variant form is @code{\sigma}@tie{}@BES{03C3,\sigma}. @item \vartheta @BES{03D1,\vartheta} Variant on the lower case Greek letter (ordinary). The non-variant form is @code{\theta}@tie{}@BES{03B8,\theta}. @item \vdash @BES{22A2,\vdash} Provable; turnstile, vertical and a dash (relation). Similar: turnstile rotated a half-circle@tie{}@code{\dashv}. @item \vee @BES{2228,\vee} Logical or; a downwards v shape (binary). Related: logical and@tie{}@code{\wedge}. Similar: variable-sized operator@tie{}@code{\bigvee}. @item \Vert @BES{2016,\Vert} Vertical double bar (ordinary). Similar: vertical single bar@tie{}@code{\vert}. For a norm symbol, you can use the @file{mathtools} package and add @code{\DeclarePairedDelimiter\norm@{\lVert@}@{\rVert@}} 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{$\norm*@{M^\perp@}$} then the height of the vertical bars will match the height of the argument, whereas with @code{\norm@{M^\perp@}} the bars do not grow with the height of the argument but instead are the default height, and @code{\norm[@var{size command}]@{M^\perp@}} also gives bars that do not grow but are set to the size given in the @var{size command}, e.g., @code{\Bigg}. @item \vert @BES{007C,\vert} Single line vertical bar (ordinary). Similar: double-line vertical bar@tie{}@code{\Vert}. For such that, as in the definition of a set, use@tie{}@code{\mid} because it is a relation. For absolute value you can use the @file{mathtools} package and add @code{\DeclarePairedDelimiter\abs@{\lvert@}@{\rvert@}} 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{$\abs*@{\frac@{22@}@{7@}@}$} then the height of the vertical bars will match the height of the argument, whereas with @code{\abs@{\frac@{22@}@{7@}@}} the bars do not grow with the height of the argument but instead are the default height, and @code{\abs[@var{size command}]@{\frac@{22@}@{7@}@}} also gives bars that do not grow but are set to the size given in the @var{size command}, e.g., @code{\Bigg}. @item \wedge @BES{2227,\wedge} Logical and (binary). Synonym:@tie{}@code{\land}. See also logical or @code{\vee}. Similar: variable-sized operator@tie{}@code{\bigwedge}. @item \wp @BES{2118,\wp} Weierstrass p (ordinary). @item \wr @BES{2240,\wr} Wreath product (binary). @item \Xi @BES{039E,\Xi} Upper case Greek letter (ordinary). @item \xi @BES{03BE,\xi} Lower case Greek letter (ordinary). @item \zeta @BES{03B6,\zeta} Lower case Greek letter (ordinary). @end ftable @node Math functions @section Math functions @cindex math functions @cindex functions, math These commands produce roman function names in math mode with proper spacing. @ftable @code @item \arccos @math{\arccos} @item \arcsin @math{\arcsin} @item \arctan @math{\arctan} @item \arg @math{\arg} @item \bmod Binary modulo operator (@math{x \bmod y}) @item \cos @math{\cos} @item \cosh @math{\cosh} @item \cot @math{\cot} @item \coth @math{\coth} @item \csc @math{\csc} @item \deg @math{\deg} @item \det @math{\det} @item \dim @math{\dim} @item \exp @math{\exp} @item \gcd @math{\gcd} @item \hom @math{\hom} @item \inf @math{\inf} @item \ker @math{\ker} @item \lg @math{\lg} @item \lim @math{\lim} @item \liminf @math{\liminf} @item \limsup @math{\limsup} @item \ln @math{\ln} @item \log @math{\log} @item \max @math{\max} @item \min @math{\min} @item \pmod parenthesized modulus, as in (@math{\pmod 2^n - 1}) @item \Pr @math{\Pr} @item \sec @math{\sec} @item \sin @math{\sin} @item \sinh @math{\sinh} @item \sup @iftex @math{\mathop {\rm sup}} @end iftex @ifnottex @math{\sup} @end ifnottex @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. @item \tan @math{\tan} @item \tanh @math{\tanh} @end ftable @node Math accents @section Math accents @cindex math accents @cindex accents, mathematical @LaTeX{} provides a variety of commands for producing accented letters in math. These are different from accents in normal text (@pxref{Accents}). @ftable @code @item \acute @cindex acute accent, math Math acute accent: @math{\acute{x}}. @item \bar @cindex bar-over accent, math @cindex macron accent, math Math bar-over accent: @math{\bar{x}}. @item \breve @cindex breve accent, math Math breve accent: @math{\breve{x}}. @item \check @cindex check accent, math @cindex h@'a@v{c}ek accent, math Math h@'a@v{c}ek (check) accent: @math{\check{x}}. @item \ddot @cindex double dot accent, math Math dieresis accent: @math{\ddot{x}}. @item \dot @cindex overdot accent, math @cindex dot over accent, math Math dot accent: @math{\dot{x}}. @item \grave @cindex grave accent, math Math grave accent: @math{\grave{x}}. @item \hat @cindex hat accent, math @cindex circumflex accent, math Math hat (circumflex) accent: @math{\hat{x}}. @item \imath @cindex dotless i, math Math dotless i. @item \jmath @cindex dotless j, math Math dotless j. @item \mathring @cindex ring accent, math Math ring accent: @ringaccent{x}. @c don't bother implementing in texinfo @item \tilde @cindex tilde accent, math Math tilde accent: @math{\tilde{x}}. @item \vec @cindex vector symbol, math Math vector symbol: @math{\vec{x}}. @item \widehat @cindex wide hat accent, math Math wide hat accent: @math{\widehat{x+y}}. @item \widetilde @cindex wide tilde accent, math Math wide tilde accent: @math{\widetilde{x+y}}. @end ftable @node Spacing in math mode @section Spacing in math mode @cindex spacing within math mode @cindex math mode, spacing In a @code{math} 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. Many math mode spacing definitions are expressed in terms of the math unit @dfn{mu} given by 1 em = 18 mu, where the em is taken from the current math symbols family (@pxref{Units of length}). @LaTeX{} provides the following commands for use in math mode: @table @code @item \; @findex \; @findex \thickspace Normally @code{5.0mu plus 5.0mu}. The longer name is @code{\thickspace}. Math mode only. @item \: @itemx \> @findex \: @findex \> @findex \medspace Normally @code{4.0mu plus 2.0mu minus 4.0mu}. The longer name is @code{\medspace}. Math mode only. @item \, @findex \, @findex \thinspace Normally @code{3mu}. The longer name is @code{\thinspace}. This can be used in both math mode and text mode. @xref{\thinspace}. @item \! @findex \! A negative thin space. Normally @code{-3mu}. Math mode only. @item \quad @cindex quad @findex \quad This is 18@dmn{mu}, that is, 1@dmn{em}. This is often used for space surrounding equations or expressions, for instance for the space between two equations inside a @code{displaymath} environment. It is available in both text and math mode. @item \qquad @findex \qquad A length of 2 quads, that is, 36@dmn{mu} = 2@dmn{em}. It is available in both text and math mode. @end table In this example a thinspace separates the function from the infinitesimal. @example \int_0^1 f(x)\,dx @end example @node Math miscellany @section Math miscellany @cindex math miscellany @ftable @code @item \* @cindex discretionary multiplication @cindex multiplication symbol, discretionary line break A @dfn{discretionary} 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 @BES{00D7,\times} symbol is printed immediately before the break. So @example \documentclass@{article@} \begin@{document@} 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@{document@} @end example will make that sort of output@c @ifnottex @w{ }(the ellipsis @samp{[@dots{}]} is here to show the line break at the same place as in a @TeX{} output)@c @end ifnottex : @indentedblock Now @math{A_3 = 0}, @iftex hence the product of all terms @end iftex @ifnottex [@dots{}] @end ifnottex @math{A_1} through @math{A_4}, that is @math{A_1 A_2 \times}@*@math{A_3 A_4}, is equal to zero. @end indentedblock @item \cdots A horizontal ellipsis with the dots raised to the center of the line. @tex As in: `$\cdots$'. @end tex @item \ddots A diagonal ellipsis: @math{\ddots}. @item \frac@{@var{num}@}@{@var{den}@} @findex \frac Produces the fraction @var{num} divided by @var{den}. @ifset HAS-MATH eg. @math{{1}\over{4}} @end ifset @item \left @var{delim1} ... \right @var{delim2} @findex \right @cindex null delimiter The two delimiters need not match; @samp{.} acts as a @dfn{null delimiter}, producing no output. The delimiters are sized according to the math in between. Example: @code{\left( \sum_@{i=1@}^@{10@} a_i \right]}. @item \mathdollar Dollar sign in math mode: $. @item \mathellipsis Ellipsis (spaced for text) in math mode: @dots{}. @item \mathparagraph Paragraph sign (pilcrow) in math mode: @BES{00B6,\P}. @item \mathsection Section sign in math mode. @item \mathsterling Sterling sign in math mode: @pounds{}. @item \mathunderscore Underscore in math mode: _. @item \overbrace@{@var{math}@} Generates a brace over @var{math}. For example, @code{\overbrace@{x+\cdots+x@}^@{k \;\textrm@{times@}@}}. @ifset HAS-MATH The result looks like: @math{\overbrace{x+\cdots+x}^{k \rm\;times}} @end ifset @item \overline@{@var{text}@} Generates a horizontal line over @var{tex}. For example, @code{\overline@{x+y@}}. @ifset HAS-MATH The result looks like: @math{\overline{x+y}}. @end ifset @item \sqrt[@var{root}]@{@var{arg}@} Produces the representation of the square root of @var{arg}. The optional argument @var{root} determines what root to produce. For example, the cube root of @code{x+y} would be typed as @code{\sqrt[3]@{x+y@}}. @ifset HAS-MATH The result looks like this: @math{\root 3 \of {x+y}}. @end ifset @item \stackrel@{@var{text}@}@{@var{relation}@} Puts @var{text} above @var{relation}. For example, @code{\stackrel@{f@}@{\longrightarrow@}}. @ifset HAS-MATH The result looks like this: @math{\buildrel f \over \longrightarrow}. @end ifset @item \underbrace@{@var{math}@} Generates @var{math} with a brace underneath. For example, @code{\underbrace@{x+y+z@}_@{>\,0@}} @ifset HAS-MATH The result looks like this: @math{\underbrace{x+y+z}_{>\,0}}. @end ifset @item \underline@{@var{text}@} Causes @var{text}, which may be either math mode or not, to be underlined. The line is always below the text, taking account of descenders. @ifset HAS-MATH The result looks like this: @math{\underline{xyz}} @end ifset @item \vdots Produces a vertical ellipsis. @ifset HAS-MATH The result looks like this: @math{\vdots}. @end ifset @end ftable @node Modes @chapter Modes @cindex modes @cindex paragraph mode @cindex math mode @cindex left-to-right mode @cindex LR mode When @LaTeX{} is processing your input text, it is always in one of three modes: @itemize @bullet @item Paragraph mode @item Math mode @item Left-to-right mode, called LR mode for short @end itemize Mode changes occur only when entering or leaving an environment, or when @LaTeX{} is processing the argument of certain text-producing commands. @dfn{Paragraph mode} is the most common; it'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. @LaTeX{} is in @dfn{math mode} when it's generating a mathematical formula, either displayed math or within a line. @findex \mbox@r{, and LR mode} In @dfn{LR mode}, 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}, @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} command. You can get it to enter a different mode inside the box---for example, you can make it enter math mode to put a formula in the box. 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}. When @LaTeX{} is in paragraph mode while making a box, it is said to be in ``inner paragraph mode'' (no page breaks). Its normal paragraph mode, which it starts out in, is called ``outer paragraph mode''. @menu * \ensuremath:: Ensure that math mode is active @end menu @node \ensuremath @section @code{\ensuremath} Synopsis: @example \ensuremath@{@var{formula}@} @end example The @code{\ensuremath} command ensures that @var{formula} is typeset in math mode whatever the current mode in which the command is used. For instance: @example \documentclass@{report@} \newcommand@{\ab@}@{\ensuremath@{(\delta, \varepsilon)@}@} \begin@{document@} Now, the \ab\ pair is equal to \(\ab = (\frac@{1@}@{\pi@}, 0)\), ... \end@{document@} @end example 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}: @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 \documentclass@{report@} \usepackage@{amssymb@} \newcommand@{\originalMeaningOfLeadsTo@}@{@} \let\originalMeaningOfLeadsTo\leadsto \renewcommand\leadsto@{\ensuremath@{\originalMeaningOfLeadsTo@}@} \begin@{document@} All roads \leadsto\ Rome. \end@{document@} @end example @node Page styles @chapter Page styles @cindex styles, page @cindex page styles The @code{\documentclass} command determines the size and position of the page's head and foot. The page style determines what goes in them. @menu * \maketitle:: Generate a title page. * \pagenumbering:: Set the style used for page numbers. * \pagestyle:: Change the headings/footings style. * \thispagestyle:: Change the headings/footings style for this page. @end menu @node \maketitle @section @code{\maketitle} @cindex titles, making @findex \maketitle The @code{\maketitle} command generates a title on a separate title page---except in the @code{article} 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: @ftable @code @item \author@{@var{name} \and @var{name2}@} @cindex author, for titlepage @findex \\ @r{for @code{\author}} @findex \and @r{for @code{\author}} The @code{\author} command declares the document author(s), where the argument is a list of authors separated by @code{\and} commands. Use @code{\\} to separate lines within a single author's entry---for example, to give the author's institution or address. @item \date@{@var{text}@} @cindex date, for titlepage The @code{\date} command declares @var{text} to be the document's date. With no @code{\date} command, the current date (@pxref{\today}) is used. @item \thanks@{@var{text}@} @cindex thanks, for titlepage @cindex credit footnote The @code{\thanks} command produces a @code{\footnote} to the title, usually used for credit acknowledgements. @item \title@{@var{text}@} @cindex title, for titlepage @findex \\ @r{for @code{\title}} The @code{\title} command declares @var{text} to be the title of the document. Use @code{\\} to force a line break, as usual. @end ftable @node \pagenumbering @section @code{\pagenumbering} @findex \pagenumbering @cindex page numbering style Synopsis: @example \pagenumbering@{@var{style}@} @end example Specifies the style of page numbers, according to @var{style}; also resets the page number to 1. The @var{style} argument is one of the following: @table @code @item arabic arabic numerals @item roman lowercase Roman numerals @item Roman uppercase Roman numerals @item alph lowercase letters @item Alph uppercase letters @end table @node \pagestyle @section @code{\pagestyle} @findex \pagestyle @cindex header style @cindex footer style @cindex running header and footer style Synopsis: @example \pagestyle@{@var{style}@} @end example The @code{\pagestyle} command specifies how the headers and footers are typeset from the current page onwards. Values for @var{style}: @table @code @item plain Just a plain page number. @item empty Empty headers and footers, e.g., no page numbers. @item headings Put running headers on each page. The document style specifies what goes in the headers. @item myheadings Custom headers, specified via the @code{\markboth} or the @code{\markright} commands. @end table Here are the descriptions of @code{\markboth} and @code{\markright}: @ftable @code @item \markboth@{@var{left}@}@{@var{right}@} Sets both the left and the right heading. A ``left-hand heading'' (@var{left}) is generated by the last @code{\markboth} command before the end of the page, while a ``right-hand heading'' (@var{right}) is generated by the first @code{\markboth} or @code{\markright} that comes on the page if there is one, otherwise by the last one before the page. @item \markright@{@var{right}@} Sets the right heading, leaving the left heading unchanged. @end ftable @node \thispagestyle @section @code{\thispagestyle@{@var{style}@}} @findex \thispagestyle The @code{\thispagestyle} command works in the same manner as the @code{\pagestyle} command (see previous section) except that it changes to @var{style} for the current page only. @node Spaces @chapter Spaces @cindex spaces @cindex white space @LaTeX{} has many ways to produce white (or filled) space. @menu Horizontal space * \hspace:: Fixed horizontal space. * \hfill:: Stretchable horizontal space. * \spacefactor:: Stretchability of following space * \(SPACE) after control sequence:: Space (gobbling) after a control sequence. * \thinspace:: One-sixth of an em. * \/:: Insert italic correction. * \hrulefill \dotfill:: Stretchable horizontal rule or dots. Vertical space * \addvspace:: Add arbitrary vertical space if needed. * \bigskip \medskip \smallskip:: Fixed vertical spaces. * \vfill:: Infinitely stretchable vertical space. * \vspace:: Add arbitrary vertical space. @end menu @node \hspace @section @code{\hspace} @findex \hspace Synopsis: @example \hspace@{@var{length}@} \hspace*@{@var{length}@} @end example Add the horizontal space given by @var{length}. The @var{length} is a rubber length, that is, it may contain a @code{plus} or @code{minus} component, in any unit that @LaTeX{} understands (@pxref{Lengths}). This command can add both positive and negative space; adding negative space is like backspacing. 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's starred version @code{\hspace*@{...@}} puts a non-discardable invisible item in front of the space, so the space appears in the output. This example make a one-line paragraph that puts @samp{Name:} an inch from the right margin. @example \noindent\makebox[\linewidth]@{\hspace@{\fill@}Name:\hspace@{1in@}@} @end example @node \hfill @section @code{\hfill} @findex \hfill @cindex stretch, infinite horizontal @cindex infinite horizontal stretch Produce a rubber length which has no natural space but can stretch horizontally as far as needed (@pxref{Lengths}). @findex \fill The command @code{\hfill} is equivalent to @code{\hspace@{\fill@}}. For space that does not disappear at line breaks use @code{\hspace*@{\fill@}} instead (@pxref{\hspace}). @node \spacefactor @section @code{\spacefactor} Synopsis: @example \spacefactor=@var{integer} @end example @findex \spacefactor 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} command (from Plain@tie{}@TeX{}) allows you to change the @LaTeX{}'s default behavior. After @LaTeX{} places each character, or rule or other box, it sets a parameter called the @dfn{space factor}. 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}.) A larger space factor means that the glue gap can stretch more and shrink less. 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. If the space factor@tie{}@var{f} is 1000 then the glue gap will be the font's normal space value (for Computer Modern Roman 10 point this is 3.3333@tie{}points). Otherwise, if the space factor @var{f} is greater than 2000 then @TeX{} adds the font's extra space value (for Computer Modern Roman 10 point this is 1.11111@tie{}points), and then the font's normal stretch value is multiplied by @math{f /1000} and the normal shrink value is multiplied by @math{1000/f} (for Computer Modern Roman 10 point these are 1.66666 and 1.11111@tie{}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. 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{\(SPACE) and \@@}. @menu * \(SPACE) and \@@:: Space after a period. * \frenchspacing:: Equal interword and inter-sentence space. * \normalsfcodes:: Restore space factor settings to the default. @end menu @node \(SPACE) and \@@ @subsection @code{\(SPACE)} and @code{\@@} @findex \(SPACE) @findex \TAB @findex \NEWLINE @findex \@@ @anchor{\AT}@c old name Here, @code{\(SPACE)} 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. 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{\spacefactor}. 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. 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{\ }) or a tie (@code{~}) or a @code{\@@}. Examples are @code{Nat.\ Acad.\ Science}, and @code{Mr.~Bean}, and @code{(manure, etc.\@@) for sale} (note that in the last the @code{\@@} comes before the closing parenthesis). In the opposite situation, if you have a capital letter followed by a period that does end the sentence, then put @code{\@@} before the period. For example, @code{book by the MAA\@@.} will have correct inter-sentence spacing after the period. For another use of @code{\(SPACE)}, @pxref{\(SPACE) after control sequence}. @node \frenchspacing @subsection @code{\frenchspacing} @findex \frenchspacing @findex \nonfrenchspacing @cindex spacing, inter-sentence This declaration (from Plain @TeX{}) causes @LaTeX{} to treat inter-sentence spacing in the same way as interword spacing. 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. Revert to the default behavior by declaring @code{\nonfrenchspacing}. @node \normalsfcodes @subsection @code{\normalsfcodes} @findex \normalsfcodes @cindex spacing, inter-sentence Reset the @LaTeX{} space factor values to the default. @node \(SPACE) after control sequence @section @code{\ } after control sequence The @code{\ } command is often used after control sequences to keep them from gobbling the space that follows, as in @samp{\TeX\ is nice}. And, under normal circumstances, @code{\}@key{tab} and @code{\}@key{newline} are equivalent to @code{\ }. For another use of @code{\ }, see also @ref{\(SPACE) and \@@}. Some people prefer to use @code{@{@}} for the same purpose, as in @code{\TeX@{@} is nice}. This has the advantage that you can always write it the same way, namely @code{\TeX@{@}}, whether it is followed by a space or by a punctuation mark. Compare: @example \TeX\ is a nice system. \TeX, a nice system.@* \TeX@{@} is a nice system. \TeX@{@}, a nice system. @end example @PkgIndex{xspace} Some individual commands, notably those defined with the @code{xspace}, package do not follow the standard behavior. @node \thinspace @section @code{\thinspace}: Insert 1/6@dmn{em} @findex \thinspace @code{\thinspace} 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 '@dmn{}''.@c Abuse @dmn, which is a thin space in Texinfo. @node \/ @section @code{\/}: Insert italic correction @findex \/ @cindex italic correction The @code{\/} command produces an @dfn{italic correction}. 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} character typically has a large italic correction value. If the following character is a period or comma, it'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 {\it f\/: f\/;} @end tex @ifnottex @i{f: f;} (in the @TeX{} output, the `f's are nicely separated) @end ifnottex with @i{f: f;}. When changing fonts with commands such as @code{\textit@{italic text@}} or @code{@{\itshape italic text@}}, @LaTeX{} will automatically insert an italic correction if appropriate (@pxref{Font styles}). Despite the name, roman characters can also have an italic correction. Compare @tex pdf\/\TeX{} @end tex @ifnottex pdf@TeX{} (in the @TeX{} output, there is a small space after the `f') @end ifnottex with pdf@TeX{}. There is no concept of italic correction in math mode; spacing is done in a different way. @node \hrulefill \dotfill @section @code{\hrulefill \dotfill} @findex \hrulefill @findex \dotfill Produce an infinite rubber length (@pxref{Lengths}) filled with a horizontal rule (that is, a line) or with dots, instead of just white space. 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. @example \noindent Jack Aubrey\dotfill Melbury Lodge @end example To make the rule or dots go to the line's end use @code{\null} at the start or end. To change the rule's thickness, copy the definition and adjust it, as with @code{\renewcommand@{\hrulefill@}@{\leavevmode\leaders\hrule height 1pt\hfill\kern\z@@@}}, which changes the default thickness of 0.4@dmn{pt} to 1@dmn{pt}. Similarly, adjust the dot spacing as with @code{\renewcommand@{\dotfill@}@{\leavevmode\cleaders\hb@@xt@@ 1.00em@{\hss .\hss @}\hfill\kern\z@@@}}, which changes the default length of 0.33@dmn{em} to 1.00@dmn{em}. @node \addvspace @section @code{\addvspace} @findex \addvspace @cindex vertical space @cindex space, inserting vertical @code{\addvspace@{@var{length}@}} Add a vertical space of height @var{length}, which is a rubber length (@pxref{Lengths}). However, if vertical space has already been added to the same point in the output by a previous @code{\addvspace} 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}. 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@{...@}} so that two consecutive Theorem's are separated by one vertical space, not two. This command is fragile (@pxref{\protect}). The error @samp{Something's wrong--perhaps a missing \item} 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} command. @node \bigskip \medskip \smallskip @section @code{\bigskip \medskip \smallskip} These commands produce a given amount of space, specified by the document class. @ftable @code @item \bigskip @findex \bigskipamount The same as @code{\vspace@{\bigskipamount@}}, ordinarily about one line space, with stretch and shrink (the default for the @code{book} and @code{article} classes is @code{12pt plus 4pt minus 4pt}). @item \medskip @findex \medskipamount The same as @code{\vspace@{\medskipamount@}}, ordinarily about half of a line space, with stretch and shrink (the default for the @code{book} and @code{article} classes is @code{6pt plus 2pt minus 2pt}). @item \smallskip @findex \smallskipamount The same as @code{\vspace@{\smallskipamount@}}, ordinarily about a quarter of a line space, with stretch and shrink (the default for the @code{book} and @code{article} classes is @code{3pt plus 1pt minus 1pt}). @end ftable @node \vfill @section @code{\vfill} @findex \vfill @cindex stretch, infinite vertical @cindex infinite vertical stretch End the current paragraph and insert a vertical rubber length (@pxref{Lengths}) that is infinite, so it can stretch or shrink as far as needed. It is often used in the same way as @code{\vspace@{\fill@}}, except that @code{\vfill} ends the current paragraph, whereas @code{\vspace@{\fill@}} 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@tie{}@ref{\vspace}. In this example the page is filled, so the top and bottom lines contain the text @samp{Lost Dog!} and the third @samp{Lost Dog!} is exactly halfway between them. @example \begin@{document@} Lost Dog! \vfill Lost Dog! \vfill Lost Dog! \end@{document@} @end example @node \vspace @section @code{\vspace@{@var{length}@}} @findex \vspace @cindex vertical space @cindex space, vertical Synopsis, one of these two: @example \vspace@{@var{length}@} \vspace*@{@var{length}@} @end example Add the vertical space @var{length}. This can be negative or positive, and is a rubber length (@pxref{Lengths}). @LaTeX{} removes the vertical space from @code{\vspace} at a page break, that is, at the top or bottom of a page. The starred version @code{\vspace*@{...@}} causes the space to stay. If @code{\vspace} is used in the middle of a paragraph (i.e., in horizontal mode), the space is inserted @emph{after} the line with the @code{\vspace} command. A new paragraph is not started. In this example the two questions will be evenly spaced vertically on the page, with at least one inch of space below each. @example \begin@{document@} 1) Who put the bomp in the bomp bah bomp bah bomp? \vspace@{1in plus 1fill@} 2) Who put the ram in the rama lama ding dong? \vspace@{1in plus 1fill@} \end@{document@} @end example @node Boxes @chapter Boxes @cindex boxes All the predefined length parameters (@pxref{Predefined lengths}) can be used in the arguments of the box-making commands. @menu * \mbox:: Horizontal boxes. * \fbox and \framebox:: Put a frame around a box. * lrbox:: An environment like @code{\sbox}. * \makebox:: Box, adjustable position. * \parbox:: Box with text in paragraph mode. * \raisebox:: Raise or lower text. * \savebox:: Like @code{\makebox}, but save the text for later use. * \sbox:: Like @code{\mbox}, but save the text for later use. * \usebox:: Print saved text. @end menu @node \mbox @section @code{\mbox@{@var{text@}}} @findex \mbox @cindex hyphenation, preventing The @code{\mbox} command creates a box just wide enough to hold the text created by its argument. The @var{text} is not broken into lines, so it can be used to prevent hyphenation. @node \fbox and \framebox @section @code{\fbox} and @code{\framebox} @findex \fbox @findex \framebox Synopses: @example \fbox@{@var{text}@} \framebox[@var{width}][@var{position}]@{@var{text}@} @end example The @code{\fbox} and @code{\framebox} commands are like @code{\mbox}, except that they put a frame around the outside of the box being created. In addition, the @code{\framebox} command allows for explicit specification of the box width with the optional @var{width} argument (a dimension), and positioning with the optional @var{position} argument. @c xxref @findex \fboxrule @findex \fboxsep Both commands produce a rule of thickness @code{\fboxrule} (default @code{0.4pt}), and leave a space of @code{\fboxsep} (default @code{3pt}) between the rule and the contents of the box. @xref{\framebox (picture)}, for the @code{\framebox} command in the @code{picture} environment. @node lrbox @section @code{lrbox} @findex lrbox Synopsis: @example \begin@{lrbox@}@{\@var{cmd}@} @var{text } \end@{lrbox@} @end example This is the environment form of @ref{\sbox,@code{\sbox}}. The @var{text} inside the environment is saved in the box @code{\@var{cmd}}, which must have been declared with @code{\newsavebox}. @node \makebox @section @code{\makebox} @findex \makebox Synopsis: @example \makebox[@var{width}][@var{position}]@{@var{text}@} @end example The @code{\makebox} command creates a box just wide enough to contain the @var{text} specified. The width of the box can be overridden by the optional @var{width} argument. The position of the text within the box is determined by the optional @var{position} argument, which may take the following values: @table @code @item c Centered (default). @item l Flush left. @item r Flush right. @item s Stretch (justify) across entire @var{width}; @var{text} must contain stretchable space for this to work. @end table @code{\makebox} is also used within the @code{picture} environment @pxref{\makebox (picture)}. @node \parbox @section @code{\parbox} @findex \parbox Synopsis: @example \parbox[@var{position}][@var{height}][@var{inner-pos}]@{@var{width}@}@{@var{text}@} @end example @cindex paragraph mode The @code{\parbox} command produces a box whose contents are created in @dfn{paragraph mode}. It should be used to make a box small pieces of text, with nothing fancy inside. In particular, you shouldn't use any paragraph-making environments inside a @code{\parbox} argument. For larger pieces of text, including ones containing a paragraph-making environment, you should use a @code{minipage} environment (@pxref{minipage}). @code{\parbox} has two mandatory arguments: @table @var @item width the width of the parbox; @item text the text that goes inside the parbox. @end table 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} argument is present and equal either to @samp{t} or @samp{b}, 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} for @var{position} to get the default behaviour. The optional @var{height} argument overrides the natural height of the box. The @var{inner-pos} argument controls the placement of the text inside the box, as follows; if it is not specified, @var{position} is used. @table @code @item t text is placed at the top of the box. @item c text is centered in the box. @item b text is placed at the bottom of the box. @item s stretch vertically; the text must contain vertically stretchable space for this to work. @end table @node \raisebox @section @code{\raisebox} @findex \raisebox Synopsis: @example \raisebox@{@var{distance}@}[@var{height}][@var{depth}]@{@var{text}@} @end example The @code{\raisebox} command raises or lowers @var{text}. The first mandatory argument specifies how high @var{text} is to be raised (or lowered if it is a negative amount). @var{text} itself is processed in LR mode. The optional arguments @var{height} and @var{depth} are dimensions. If they are specified, @LaTeX{} treats @var{text} as extending a certain distance above the baseline (@var{height}) or below (@var{depth}), ignoring its natural height and depth. @node \savebox @section @code{\savebox} @findex \savebox Synopsis: @example \savebox@{@var{\boxcmd}@}[@var{width}][@var{pos}]@{@var{text}@} @end example This command typeset @var{text} in a box just as with @code{\makebox} (@pxref{\makebox}), except that instead of printing the resulting box, it saves it in the box labeled @var{\boxcmd}, which must have been declared with @code{\newsavebox} (@pxref{\newsavebox}). @node \sbox @section @code{\sbox@{@var{\boxcmd}@}@{@var{text}@}} @findex \sbox Synopsis: @example \sbox@{@var{\boxcmd}@}@{@var{text}@} @end example @code{\sbox} types @var{text} in a box just as with @code{\mbox} (@pxref{\mbox}) except that instead of the resulting box being included in the normal output, it is saved in the box labeled @var{\boxcmd}. @var{\boxcmd} must have been previously declared with @code{\newsavebox} (@pxref{\newsavebox}). @node \usebox @section @code{\usebox@{@var{\boxcmd}@}} @findex \usebox Synopsis: @example \usebox@{@var{\boxcmd}@} @end example @code{\usebox} produces the box most recently saved in the bin @var{\boxcmd} by a @code{\savebox} command (@pxref{\savebox}). @node Color @chapter Color @cindex color 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. Color support comes as an additional package. So all the commands below will only work if your document preamble contains @code{\usepackage@{color@}}, that brings in the standard package. Many other packages also supplement @LaTeX{}'s color abilities. Particularly worth mentioning is @file{xcolor}, which is widely used and significantly extends the capabilities described here, including adding @samp{HTML} and @samp{Hsb} color models. @menu * Color package options:: Options when you load the standard package. * Color models:: How colors are represented. * Commands for color:: The available commands. @end menu @node Color package options @section Color package options @cindex color package options @cindex options, color package Synopsis (must be in the document preamble): @example \usepackage[@var{comma-separated option list}]@{color@} @end example When you load the @file{color} package there are two kinds of available options. The first specifies the @dfn{printer driver}. @LaTeX{} doesn'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'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{dvips}, @file{dvisvgm}, @file{luatex}, @file{pdftex}, @file{xetex}. The two @file{xdvi} and @file{oztex} are essentially aliases for @file{dvips} (and @file{xdvi} is monochrome). Ones that should not be used for new systems are: @file{dvipdf}, @file{dvipdfm}, @file{dviwin}, @file{dvipsone}, @file{emtex}, @file{pctexps}, @file{pctexwin}, @file{pctexhp}, @file{pctex32}, @file{truetex}, @file{tcidvi}, @file{vtex} (and @file{dviwindo} is an alias for @file{dvipsone}). The second kind of options, beyond the drivers, are below. @table @code @item monochrome Disable the color commands, so that they do not generate errors but do not generate color either. @item dvipsnames 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} driver, giving the option name. @item nodvipsnames Do not load that list of color names, saving @LaTeX{} a tiny amount of memory space. @end table @node Color models @section Color models @cindex color models A @dfn{color model} is a way of representing colors. @LaTeX{}'s capabilities depend on the printer driver. However, the @file{pdftex}, @file{xetex}, and @file{luatex} 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. 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. @table @code @item cmyk 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. @item gray A single real number between 0 and 1, inclusive. The colors are shades of grey. The number 0 produces black while 1 gives white. @item rgb 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. @item RGB (@file{pdftex}, @file{xetex}, @file{luatex} drivers) A comma-separated list with three integers between 0 and 255, inclusive. This model is a convenience for using @code{rgb} 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} model by dividing by 255. @item named Colors are accessed by name, such as @samp{PrussianBlue}. The list of names depends on the driver, but all support the names @samp{black}, @samp{blue}, @samp{cyan}, @samp{green}, @samp{magenta}, @samp{red}, @samp{white}, and @samp{yellow} (See the @code{dvipsnames} option in @ref{Color package options}). @end table @node Commands for color @section Commands for color @cindex color package commands These are the commands available with the @file{color} package. @menu * Define colors:: Give a color a name. * Colored text:: Text or rules in color. * Colored boxes:: A box of color, to write over. * Colored pages:: A whole page colored. @end menu @node Define colors @subsection Define colors @cindex color @cindex define color @cindex color, define Synopsis: @example \definecolor@{@var{name}@}@{@var{model}@}@{@var{specification}@} @end example Give the name @var{name} to the color. For example, after @code{\definecolor@{silver@}@{rgb@}@{0.75,0.75,0.74@}} you can use that color name with @code{Hi ho, \textcolor@{silver@}@{Silver@}!}. This example gives the color a more abstract name, so it could change and not be misleading. @example \definecolor@{logocolor@}@{RGB@}@{145,92,131@} % RGB needs pdflatex \newcommand@{\logo@}@{\textcolor@{logocolor@}@{Bob's Big Bagels@}@} @end example Often a document's colors are defined in the preamble, or in the class or style, rather than in the document body. @node Colored text @subsection Colored text @cindex color @cindex colored text Synopses: @example \textcolor@{@var{name}@}@{...@} \textcolor[@var{color model}]@{@var{color specification}@}@{...@} @end example or @example \color@{@var{name}@} \color[@var{color model}]@{@var{specification}@} @end example The affected text gets the color. This line @example \textcolor@{magenta@}@{My name is Ozymandias, king of kings:@} Look on my works, ye Mighty, and despair! @end example causes the first half to be in magenta while the rest is in black. You can use a color declared with @code{\definecolor} in exactly the same way that we just used the builtin color @samp{magenta}. @example \definecolor@{MidlifeCrisisRed@}@{rgb@}@{1.0,0.11,0.0@} I'm thinking about getting a \textcolor@{MidlifeCrisisRed@}@{sports car@}. @end example The two @code{\textcolor} and @code{\color} 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 @{\color@{green@} green@} cheese}, 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} environment, including the vertical and horizontal lines. @example \begin@{center@} \color@{blue@} \begin@{tabular@}@{l|r@} UL &UR \\ \hline LL &LR \end@{tabular@} \end@{center@} @end example You can use color in equations. A document might have @code{\definecolor@{highlightcolor@}@{RGB@}@{225,15,0@}} in the preamble, and then contain this equation. @example \begin@{equation@} \int_a^b \textcolor@{highlightcolor@}@{f'(x)@}\,dx=f(b)-f(a) \end@{equation@} @end example 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. @example Colors of \textcolor[rgb]@{0.33,0.14,0.47@}@{Purple@} and @{\color[rgb]@{0.72,0.60,0.37@} Gold@} for the team @end example The format of @var{color specification } depends on the color model (@pxref{Color models}). For instance, while @code{rgb} takes three numbers, @code{gray} takes only one. @example The selection was \textcolor[gray]@{0.5@}@{grayed out@}. @end example Colors inside colors do not combine. Thus @example \textcolor@{green@}@{kind of \textcolor@{blue@}@{blue@}@} @end example has a final word that is blue, not a combination of blue and green. @c xx address coloring a line of a table? @node Colored boxes @subsection Colored boxes @cindex color @cindex colored boxes @cindex box, colored Synopses: @example \colorbox@{@var{name}@}@{...@} \colorbox[@var{model name}]@{@var{box background color specification}@}@{...@} @end example or @example \fcolorbox@{@var{frame color}@}@{@var{box background color}@}@{...@} \fcolorbox[@var{model name}]@{@var{frame color specification}@}@{@var{box background color specification}@}@{...@} @end example Make a box with the stated background color. The @code{\fcolorbox} command puts a frame around the box. For instance this @example Name:~\colorbox@{cyan@}@{\makebox[5cm][l]@{\strut@}@} @end example makes a cyan-colored box that is five centimeters long and gets its depth and height from the @code{\strut} (so the depth is @code{-.3\baselineskip} and the height is @code{\baselineskip}). This puts white text on a blue background. @example \colorbox@{blue@}@{\textcolor@{white@}@{Welcome to the machine.@}@} @end example The @code{\fcolorbox} commands use the same parameters as @code{\fbox} (@pxref{\fbox and \framebox}), @code{\fboxrule} and @code{\fboxsep}, to set the thickness of the rule and the boundary between the box interior and the surrounding rule. @LaTeX{}'s defaults are @code{0.4pt} and @code{3pt}, respectively. 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. @example @{\setlength@{\fboxrule@}@{0.8pt@} \fcolorbox@{black@}@{red@}@{Under no circumstances turn this knob.@}@} @end example @node Colored pages @subsection Colored pages @cindex color @cindex colored page @cindex page, colored @cindex background, colored Synopses: @example \pagecolor@{@var{name}@} \pagecolor[@var{color model}]@{@var{color specification}@} \nopagecolor @end example 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{Colored text}. The third returns the background to normal, which is a transparent background. (If that is not supported use @code{\pagecolor@{white@}}, although that will make a white background rather than the default transparent background.) @example ... \pagecolor@{cyan@} ... \nopagecolor @end example @node Graphics @chapter Graphics @cindex graphics @cindex graphics package 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. @example \include@{graphicx@} % goes in the preamble ... \includegraphics[width=0.5\linewidth]@{plot.pdf@} @end example To use the commands described here your document preamble must contain either @code{\usepackage@{graphicx@}} or @code{\usepackage@{graphics@}}. Most of the time, @file{graphicx} is the better choice. 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}. 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. 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} environment (@pxref{picture}) 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. @menu * Graphics package options:: Options when you load the package. * Graphics package configuration:: Where to look for files, which file types. * Commands for graphics:: The available commands. @end menu @node Graphics package options @section Graphics package options @cindex graphics package options @cindex options, graphics package Synopsis (must be in the document preamble): @example \usepackage[@var{comma-separated option list}]@{graphics@} @end example or @example \usepackage[@var{comma-separated option list}]@{graphicx@} @end example The @code{graphicx} package has a format for optional arguments to the @code{\includegraphics} 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} or @file{graphicx} package with @code{\usepackage} there are two kinds of available options. The first is that @LaTeX{} does not contain information about different output systems but instead depends on information stored in a @dfn{printer driver} file. Normally you should not specify the driver option in the document, and instead rely on your system's default. One advantage of this is that it makes the document portable across systems. For completeness here is a list of the drivers. The currently relevant ones are: @file{dvipdfmx}, @file{dvips}, @file{dvisvgm}, @file{luatex}, @file{pdftex}, @file{xetex}. The two @file{xdvi} and @file{oztex} are essentially aliases for @file{dvips} (and @file{xdvi} is monochrome). Ones that should not be used for new systems are: @file{dvipdf}, @file{dvipdfm}, @file{dviwin}, @file{dvipsone}, @file{emtex}, @file{pctexps}, @file{pctexwin}, @file{pctexhp}, @file{pctex32}, @file{truetex}, @file{tcidvi}, @file{vtex} (and @file{dviwindo} is an alias for @file{dvipsone}). These are stored in files with a @file{.def} extension, such as @file{pdftex.def}. The second kind of options are below. @table @code @item demo Instead of an image file, @LaTeX{} puts in a 150@tie{}pt by 100@tie{}pt rectangle (unless another size is specified in the @code{\includegraphics} command). @item draft 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. @item final (Default) Override any previous @code{draft} option, so that the document shows the contents of the graphic files. @item hiderotate 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? @item hidescale 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? @item hiresbb In a PS or EPS file the graphic size may be specified in two ways. The @code{%%BoundingBox} 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} lines. This option has @LaTeX{} to read the size from the latter. @end table @node Graphics package configuration @section Graphics package configuration @cindex graphics @cindex graphics package @cindex configuration, graphics package @cindex EPS files @cindex JPEG files @cindex JPG files @cindex PDF graphic files @cindex PNG files These commands configure the way @LaTeX{} searches the file system for the graphic. 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}, or the @LaTeX{} source, or your @TeX{} distribution's documentation. @menu * \graphicspath:: Directories to search. * \DeclareGraphicsExtensions:: File types, such as JPG or EPS. * \DeclareGraphicsRule:: How to handle file types. @end menu @node \graphicspath @subsection @code{\graphicspath} @findex \graphicspath Synopsis: @example \graphicspath@{@var{list of dir names inside curly brackets}@} @end example Declare a list of directories to search for graphics files. This allows you to later say something like @code{\includegraphics@{lion.png@}} instead of having to give its path. @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}, and then @file{../pix}. @example \usepackage@{graphicx@} % or graphics; put in preamble ... \graphicspath@{ @{pix/@} @{../pix/@} @} @end example The @code{\graphicspath} declaration is optional. If you don't include it then @LaTeX{}'s default is to search all of the places that it usually looks for a file (it uses @LaTeX{}'s @code{\input@@path}). In particular, in this case one of the places it looks is the current directory. Enclose each directory name in curly braces; for example, above it says @samp{@code{@{pix@}}}. Do this even if there is only one directory. Each directory name must end in a forward slash, @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{@{"my docs/"@}}. Getting one of these rules wrong will cause @LaTeX{} to report @code{Error: File `@var{filename}' not found}. Basically, the algorithm is that with this example, after looking in the current directory, @example \graphicspath@{ @{pix/@} @{../pix/@} @} ... \usepackage@{lion.png@} @end example for each of the listed directories, @LaTeX{} concatenates it with the file name and searches for the result, checking for @file{pix/lion.png} and then @file{../pix/lion.png}. This algorithm means that the @code{\graphicspath} command does not recursively search subdirectories: if you issue @code{\graphicspath@{@{a/@}@}} and the graphic is in @file{a/b/lion.png} then @LaTeX{} will not find it. It also means that you can use absolute paths such as @code{\graphicspath@{@{/home/jim/logos/@}@}} or @code{\graphicspath@{@{C:/Users/Albert/Pictures/@}@}}. 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}; see the documentation of your system.) You can use @code{\graphicspath} in the preamble or in the document body. You can use it more than once. For debugging, show its value with @code{\makeatletter\typeout@{\Ginput@@path@}\makeatother}. 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} and it contains @code{\include@{chapters/chap1@}}. If in @file{chap1.tex} you put @code{\graphicspath@{@{plots/@}@}} then @LaTeX{} will not search for graphics in @file{book/chapters/plots}, but instead in @file{book/plots}. @node \DeclareGraphicsExtensions @subsection @code{\DeclareGraphicsExtensions} @findex \DeclareGraphicsExtensions Synopses: @example \DeclareGraphicsExtensions@{@var{comma-separated list of file extensions}@} @end example 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@{functionplot@}}. In this example, @LaTeX{} will find files in the PNG format before PDF files. @example \DeclareGraphicsExtensions@{.png,PNG,.pdf,.PDF@} ... \includegraphics@{lion@} % will find @file{lion.png} before @file{lion.pdf} @end example Because the file name @file{lion} does not have a period, @LaTeX{} uses the extension list. For each directory in the graphics path (@pxref{\graphicspath}), @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}' not found}. Note that you must include the periods at the start of the extensions. 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. You are not required to include @code{\DeclareGraphicsExtensions} in your document; the printer driver has a sensible default. For example, the most recent @file{pdftex.def} has the extension list @samp{@code{.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPEG,.JBIG2,.JB2}}. 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@{\Gin@@extensions@}\makeatother}. @node \DeclareGraphicsRule @subsection @code{\DeclareGraphicsRule} @findex \DeclareGraphicsRule Synopsis: @example \DeclareGraphicsRule@{@var{extension}@}@{@var{type}@}@{@var{size-file extension}@}@{@var{command}@} @end example Declare how to handle graphic files whose names end in @var{extension}. This example declares that all files with names have the form @file{filename-without-dot.mps} will be treated as output from MetaPost, meaning that the printer driver will use its MetaPost-handling code to input the file. @example \DeclareGraphicsRule@{.mps@}@{mps@}@{.mps@}@{@} @end example This @example \DeclareGraphicsRule@{*@}@{mps@}@{*@}@{@} @end example 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{filename.2}, etc. This describes the four arguments. @table @var @item extension 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{*}, to denote the default behaviour for all undeclared extensions. @item type 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{.eps}, or @file{.ps.gz} may all be classed as type @code{eps}. 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} recognizes are: @code{jpg}, @code{jbig2}, @code{mps}, @code{pdf}, @code{png}, @code{tif}. @item size-file extension 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} but it may be different. As an example, consider a PostScript graphic. To make it smaller, it might be compressed into a @file{.ps.gz} 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} is empty then you must specify size information in the arguments of @code{\includegraphics}. If the driver file has a procedure for reading size files for @code{type} then that will be used, otherwise it will use the procedure for reading @file{.eps} files. (Thus you may specify the size of bitmap files in a file with a PostScript style @code{%%BoundingBox} line if no other format is available.) @item command 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@{.eps.gz@}@{eps@}@{.eps.bb@}@{`gunzip -c #1@}} specifies that any file with the extension @file{.eps.gz} should be treated as an @code{eps} file, with the the BoundingBox information stored in the file with extension @file{.eps.bb}, and that the command @code{gunzip -c} will run on your platform to decompresses the file. 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. @end table @node Commands for graphics @section Commands for graphics @cindex graphics package commands @cindex commands, graphics package These are the commands available with the @file{graphics} and @file{graphicx} packages. @menu * \includegraphics:: Using a graphic in your document. * \rotatebox:: Rotating boxes, including graphics. * \scalebox:: Scaling boxes, including graphics. * \resizebox:: Scaling boxes, including graphics, to a set size. @end menu @node \includegraphics @subsection @code{\includegraphics} @cindex graphics @cindex graphics package @cindex including graphics @cindex importing graphics @cindex EPS files @cindex JPEG files @cindex JPG files @cindex PDF graphic files @cindex PNG files @findex \includegraphics Synopses for @file{graphics} package: @example \includegraphics@{@var{filename}@} \includegraphics[@var{urx},@var{ury}]@{@var{filename}@} \includegraphics[@var{llx},@var{lly}][@var{urx},@var{ury}]@{@var{filename}@} \includegraphics*@{@var{filename}@} \includegraphics*[@var{urx},@var{ury}]@{@var{filename}@} \includegraphics*[@var{llx},@var{lly}][@var{urx},@var{ury}]@{@var{filename}@} @end example Synopses for @file{graphicx} package: @example \includegraphics@{@var{filename}@} \includegraphics[@var{key-value list}]@{@var{filename}@} \includegraphics*@{@var{filename}@} \includegraphics*[@var{key-value list}]@{@var{filename}@} @end example Include a graphics file. The starred form @code{\includegraphics*} 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. This @example \usepackage@{graphicx@} % in preamble ... \begin@{center@} \includegraphics@{plot.pdf@} \end@{center@} @end example will incorporate into the document the graphic in @file{plot.pdf}, centered and at its nominal size. You can also give a path to the file, as with @code{\includegraphics@{graphics/plot.pdf@}}. To specify a list of locations to search for the file, @pxref{\graphicspath}. If your filename includes spaces then put it in double quotes, as with @code{\includegraphics@{"sister picture.jpg"@}}. The @code{\includegraphics@{@var{filename}@}} command decides on the type of graphic by splitting @var{filename} on the first dot. You can use @var{filename} with no dot, as in @code{\includegraphics@{turing@}} and then @LaTeX{} tries a sequence of extensions such as @code{.png} and @code{.pdf} until it finds a file with that extension (@pxref{\DeclareGraphicsExtensions}). If your file name contains dots before the extension then you can hide them with curly braces, as in @code{\includegraphics@{@{plot.2018.03.12.a@}.pdf@}}. Or, if you use the @file{graphicx} package then you can use the options @code{type} and @code{ext}; see below. This and other filename issues are also handled with the package @file{grffile}. 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{figure}). @example \begin@{figure@} \centering \includegraphics[width=3cm]@{lungxray.jpg@} \caption@{The evidence is overwhelming: don't smoke.@} \label@{fig:xray@} \end@{figure@} @end example 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. @example \usepackage@{caption@} % in preamble ... \begin@{center@} \includegraphics@{pix/nix.png@} \captionof@{figure@}@{The spirit of the night@} \label@{pix:nix@} % if you want a caption \end@{center@} @end example This example puts a box with a graphic side by side with one having text, with the two vertically centered. @example \newcommand*@{\vcenteredhbox@}[1]@{\begingroup \setbox0=\hbox@{#1@}\parbox@{\wd0@}@{\box0@}\endgroup@} ... \begin@{center@} \vcenteredhbox@{\includegraphics[width=0.4\textwidth]@{plot@}@} \hspace@{1em@} \vcenteredhbox@{\begin@{minipage@}@{0.4\textwidth@} \begin@{displaymath@} f(x)=x\cdot \sin (1/x) \end@{displaymath@} \end@{minipage@}@} \end@{center@} @end example If you use the @file{graphics} package then the only options involve the size of the graphic (but see @ref{\rotatebox} and @ref{\scalebox}). When one optional argument is present then it is @code{[@var{urx},@var{ury}]} and it gives the coordinates of the top right corner of the image, as a pair of @TeX{} dimensions (@pxref{Units of length}). If the units are omitted they default to @code{bp}. 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{lly}]}, specifying the coordinates of the image's lower left. Thus, @code{\includegraphics[1in,0.618in]@{...@}} calls for the graphic to be placed so it is 1@tie{}inch wide and 0.618@tie{}inches tall and so its origin is at (0,0). The @file{graphicx} package gives you many more options. Specify them in a key-value form, as here. @example \begin@{center@} \includegraphics[width=1in,angle=90]@{lion@} \hspace@{2em@} \includegraphics[angle=90,width=1in]@{lion@} \end@{center@} @end example 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. There are many options. The primary ones are listed first. 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'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. @table @code @item width The graphic will be shown so its bounding box is this width. An example is @code{\includegraphics[width=1in]@{plot@}}. You can use the standard @TeX{} dimensions (@pxref{Units of length}) and also convenient is @code{\linewidth}, or in a two-column document, @code{\columnwidth} (@pxref{Page layout parameters}). An example is that by using the @file{calc} package you can make the graphic be 1@tie{}cm narrow than the width of the text with @code{\includegraphics[width=\linewidth-1.0cm]@{hefferon.jpg@}}. @item height The graphic will be shown so its bounding box is this height. You can use the standard @TeX{} dimensions (@pxref{Units of length}), and also convenient are @code{\pageheight} and @code{\textheight} (@pxref{Page layout parameters}). For instance, @code{\includegraphics[height=0.25\textheight]@{godel@}} will make the graphic be a quarter of the height of the text area. @item totalheight 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. @item keepaspectratio If set to @code{true}, or just specified as with @code{\includegraphics[...,keepaspectratio,...]@{...@}} and you give as options both @code{width} and @code{height} (or @code{totalheight}), 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} nor taller than @code{height} (or @code{totalheight}). @item scale Factor by which to scale the graphic. Specifying @code{\includegraphics[scale=2.0]@{...@}} makes the graphic twice its nominal size. This number may be any value; a number between 1 and@tie{}0 will shrink the graphic and a negative number will reflect it. @item angle Rotate the picture. The angle is taken in degrees and counterclockwise. The graphic is rotated about its @code{origin}; see that option. For a complete description of how rotated material is typeset, @pxref{\rotatebox}. @item origin The point of the graphic about which the rotation happens. Possible values are any string containing one or two of: @code{l} for left, @code{r} for right, @code{b} for bottom, @code{c} for center, @code{t} for top, and @code{B} for baseline. Thus, @code{\includegraphics[angle=180,origin=c]@{moon@}} will turn the picture upside down from the center, while @code{\includegraphics[angle=180,origin=lB]@{LeBateau@}} will turn its picture upside down about its left baseline. (The character @code{c} gives the horizontal center in @code{bc} or @code{tc}, but gives the vertical center in @code{lc} or @code{rc}.) The default is @code{lB}. To rotate about an arbitrary point, @pxref{\rotatebox}. @end table These are lesser-used options. @table @code @item viewport 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]@{...@}}. The dimensions default to big points,@tie{}@code{bp}. They are taken relative to the origin specified by the bounding box. See also the @code{trim} option. @item trim 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, ...]@{...@}}. These give the amounts of the graphic not to show, that is, @LaTeX{} will crop the picture by 0@tie{}inches on the left, 0.1@tie{}inches on the bottom, 0.2@tie{}inches on the right, and 0.3@tie{}inches on the top. See also the @code{viewport} option. @item clip If set to @code{true}, or just specified as with @code{\includegraphics[...,clip,...]@{...@}}, 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*[...]@{...@}}. @item page Give the page number of a multi-page PDF file. The default is @code{page=1}. @item pagebox Specifies which bounding box to use for PDF files from among @code{mediabox}, @code{cropbox}, @code{bleedbox}, @code{trimbox}, or @code{artbox}. 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'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. @item interpolate Enable or disable interpolation of raster images by the viewer. Can be set with @code{interpolate=true} or just specified as with @code{\includegraphics[...,interpolate,...]@{...@}}. @item quiet Do not write information to the log. You can set it with @code{quiet=true} or just specified it with @code{\includegraphics[...,quite,...]@{...@}}, @item draft If you set it with @code{draft=true} or just specified it with @code{\includegraphics[...,draft,...]@{...@}}, 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. @end table These options address the bounding box for Encapsulated PostScript graphic files, which have a size specified with a line @code{%%BoundingBox} that appears in the file. It has four values, giving the lower @math{x} coordinate, lower @math{y} coordinate, upper @math{x} coordinate, and upper @math{y} coordinate. The units are PostScript points, equivalent to @TeX{}'s big points, 1/72@tie{}inch. For example, if an @file{.eps} file has the line @code{%%BoundingBox 10 20 40 80} then its natural size is 30/72@tie{}inch wide by 60/72@tie{}inch tall. @table @code @item bb 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]@{...@}}. Usually @code{\includegraphics} 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. @item bbllx, bblly, bburx, bbury Set the bounding box. These four are obsolete, but are retained for compatibility with old packages. @item natwidth, natheight An alternative for @code{bb}. Setting @code{\includegraphics[...,natwidth=1in,natheight=0.618in,...]@{...@}} is the same as setting @code{bb=0 0 1in 0.618in}. @item hiresbb If set to @code{true}, or just specified as with @code{\includegraphics[...,hiresbb,...]@{...@}}, then @LaTeX{} will look for @code{%%HiResBoundingBox} lines instead of @code{%%BoundingBox} lines. (The @code{BoundingBox} lines use only natural numbers while the @code{HiResBoundingBox} lines use decimals; both use units equivalent to @TeX{}'s big points, 1/72@tie{}inch.) To override a prior setting of @code{true}, you can set it to @code{false}. @end table These following options allow a user to override @LaTeX{}'s method of choosing the graphic type based on the filename extension. An example is that @code{\includegraphics[type=png,ext=.xxx,read=.xxx]@{lion@}} will read the file @file{lion.xxx} as though it were @file{lion.png}. For more on these, @pxref{\DeclareGraphicsRule}. @table @code @item type Specify the graphics type. @item ext Specify the graphics extension. Only use this in conjunction with the option @code{type}. @item read Specify the file extension of the read file. Only use this in conjunction with the option @code{type}. @item command Specify a command to be applied to this file. Only use this in conjunction with the option @code{type}. @c write18 and restricted execution. @end table @node \rotatebox @subsection @code{\rotatebox} @cindex rotation @cindex rotating graphics @cindex rotating text @findex \rotatebox Synopsis for @file{graphics} package: @example \rotatebox@{@var{angle}@}@{@var{material}@} @end example Synopses for @file{graphicx} package: @example \rotatebox@{@var{angle}@}@{@var{material}@} \rotatebox[@var{key-value list}]@{@var{angle}@}@{@var{material}@} @end example Put @var{material} in a box and rotate it @var{angle} degrees counterclockwise. This example rotates the table column heads forty five degrees. @example \begin@{tabular@}@{ll@} \rotatebox@{45@}@{Character@} &\rotatebox@{45@}@{NATO phonetic@} \\ A &AL-FAH \\ B &BRAH-VOH \end@{tabular@} @end example The @var{material} can be anything that goes in a box, including a graphic. @example \rotatebox[origin=c]@{45@}@{\includegraphics[width=1in]@{lion@}@} @end example To place the rotated material, the first step is that @LaTeX{} sets @var{material} 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. If you use the @file{graphics} package then the rotation is about the reference point of the box. If you use the @file{graphicx} package then then these are the options that can go in the @var{key-value list}, but note that you can get the same effect without needing this package, except for the @code{x} and @code{y} options (@pxref{\includegraphics}). @table @code @item origin The point of the @var{material}'s box about which the rotation happens. Possible values are any string containing one or two of: @code{l} for left, @code{r} for right, @code{b} for bottom, @code{c} for center, @code{t} for top, and @code{B} for baseline. Thus, @code{\includegraphics[angle=180,origin=c]@{moon@}} will turn the picture upside down from the center, while @code{\includegraphics[angle=180,origin=lB]@{LeBateau@}} will turn its picture upside down about its left baseline. (The character @code{c} gives the horizontal center in @code{bc} or @code{tc} but gives the vertical center in @code{lc} or @code{rc}.) The default is @code{lB}. @item x, y Specify an arbitrary point of rotation with @code{\rotatebox[x=@var{@TeX{} dimension},y=@var{@TeX{} dimension}]@{...@}} (@pxref{Units of length}). These give the offset from the box's reference point. @item units This key allows you to change the default of degrees counterclockwise. Setting @code{units=-360} changes the direction to degrees clockwise and setting @code{units=6.283185} changes to radians counterclockwise. @end table @node \scalebox @subsection @code{\scalebox} @cindex graphics, scaling @cindex graphics, resizing @cindex scaling @cindex resizing @cindex text, scaling @cindex text, resizing @findex \scalebox @findex \reflectbox Synopses: @example \scalebox@{@var{horizontal factor}@}@{@var{material}@} \scalebox@{@var{horizontal factor}@}[@var{vertical factor}]@{@var{material}@} \reflectbox@{@var{material}@} @end example Scale the @var{material}. This example halves the size, both horizontally and vertically, of the first text and doubles the size of the second. @example \scalebox@{0.5@}@{DRINK ME@} and \scalebox@{2.0@}@{Eat Me@} @end example If you do not specify the optional @var{vertical factor} then it defaults to the same value as the @var{horizontal factor}. You can use this command to resize a graphic, as with @code{\scalebox@{0.5@}@{\includegraphics@{lion@}@}}. If you use the @file{graphicx} package then you can accomplish the same thing with optional arguments to @code{\includegraphics} (@pxref{\includegraphics}). The @code{\reflectbox} command abbreviates @code{\scalebox@{-1@}[1]@{@var{material}@}}. Thus, @code{Able was I\reflectbox@{Able was I@}} will show the phrase @samp{Able was I} immediately followed by its mirror reflection. @node \resizebox @subsection @code{\resizebox} @cindex graphics, scaling @cindex graphics, resizing @cindex scaling @cindex resizing @cindex text, scaling @cindex text, resizing @findex \resizebox Synopses: @example \resizebox@{@var{horizontal length}@}@{@var{vertical length}@}@{@var{material}@} \resizebox*@{@var{horizontal length}@}@{@var{vertical length}@}@{@var{material}@} @end example Given a size, such as @code{3cm}, transform @var{material} to make it that size. If either @var{horizontal length} or @var{vertical length} is an exclamation point@tie{}@code{!} then the other argument is used to determine a scale factor for both directions. This example makes the graphic be a half inch wide and scales it vertically by the same factor to keep it from being distorted. @example \resizebox@{0.5in@}@{!@}@{\includegraphics@{lion@}@} @end example The unstarred form @code{\resizebox} takes @var{vertical length} to be the box's height while the starred form @code{\resizebox*} takes it to be height+depth. For instance, make the text have a height+depth of a quarter inch with @code{\resizebox*@{!@}@{0.25in@}@{\parbox@{1in@}@{This box has both height and depth.@}@}}. You can use @code{\depth}, @code{\height}, @code{\totalheight}, and @code{\width} to refer to the original size of the box. Thus, make the text two inches wide but keep the original height with @code{\resizebox@{2in@}@{\height@}@{Two inches@}}. @node Special insertions @chapter Special insertions @cindex special insertions @cindex insertions of special characters @LaTeX{} provides commands for inserting characters that have a special meaning do not correspond to simple characters you can type. @menu * Reserved characters:: Inserting @samp{# $ % & @{ @} _ ~ ^ \} * Upper and lower case:: Make text upper or lower case. * Symbols by font position:: Inserting font symbols by number. * Text symbols:: Inserting other non-letter symbols in text. * Accents:: Inserting accents. * Additional Latin letters:: Inserting other non-English characters. * \rule:: Inserting lines and rectangles. * \today:: Inserting today's date. @end menu @node Reserved characters @section Reserved characters @cindex reserved characters @cindex characters, reserved @cindex special characters @cindex characters, special @LaTeX{} sets aside the following characters for special purposes (for example, the percent sign@tie{}@code{%} is for comments) so they are called @dfn{reserved characters} or @dfn{special characters}. @example # $ % & @{ @} _ ~ ^ \ @end example @findex \# @findex \$ @findex \% @findex \& @findex \_ @findex \@{ @findex \@} 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@tie{}@code{\} in front of the character. Thus, @code{\$1.23} will produce@tie{}@code{$1.23} in your output. @findex \~ @findex \^ @findex \textbackslash As to the last three characters, to get a tilde in the text body font use @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{\^@{@}}. A text body font backslash results from @code{\textbackslash@{@}}. To produce the reserved characters in a typewriter font use @code{\verb!!}, as below. @example \begin@{center@} \# \$ \% \& \@{ \@} \_ \~@{@} \^@{@} \textbackslash \\ \verb!# $ % & @{ @} _ ~ ^ \! \end@{center@} @end example In that example the double backslash@tie{}@code{\\} is only there to split the lines. @node Upper and lower case @section Upper and lower case @cindex Upper case @cindex Lower case @cindex characters, case Synopsis: @example \uppercase@{@var{text}@} \lowercase@{@var{text}@} \MakeUppercase@{@var{text}@} \MakeLowercase@{@var{text}@} @end example Change the case of characters. The @TeX{} primitives commands @code{\uppercase} and @code{\lowercase} only work for American characters. The @LaTeX{} commands @code{\MakeUppercase} and @code{\MakeLowercase} commands also change characters accessed by commands such as @code{\ae} or @code{\aa}. The commands @code{\MakeUppercase} and @code{\MakeLowercase} are robust but they have moving arguments (@pxref{\protect}). These commands do not change the case of letters used in the name of a command within @var{text}. But they do change the case of every other Latin letter inside the argument @var{text}. Thus, @code{\MakeUppercase@{Let $y=f(x)$}@} produces @samp{LET Y=F(X)}. Another example is that the name of an environment will be changed, so that @code{\MakeUppercase@{\begin@{tabular@} ... \end@{tabular@}@}} will produce an error because the first half is changed to @code{\begin@{TABULAR@}}. @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. To change the case of text that results from a macro inside @var{text} you need to do expansion. Here the @code{\Schoolname} produces @samp{COLLEGE OF MATHEMATICS}. @example \newcommand@{\schoolname@}@{College of Mathematics@} \newcommand@{\Schoolname@}@{\expandafter\MakeUppercase @w{ }\expandafter@{\schoolname@}@} @end example @PkgIndex{textcase} The @file{textcase} package brings some of the missing feature of the standard @LaTeX{} commands @code{\MakeUppercase} and @code{\MakeLowerCase}. @PkgIndex{mfirstuc} To uppercase only the first letter of words, you can use the package @file{mfirstuc}. @node Symbols by font position @section Symbols by font position @findex \symbol @cindex accessing any character of a font @cindex font symbols, by number You can access any character of the current font using its number with the @code{\symbol} command. For example, the visible space character used in the @code{\verb*} command has the code decimal 32, so it can be typed as @code{\symbol@{32@}}. You can also specify numbers in octal (base 8) by using a @code{'} prefix, or hexadecimal (base 16) with a @code{"} prefix, so the previous example could also be written as @code{\symbol@{'40@}} or @code{\symbol@{"20@}}. @node Text symbols @section Text symbols @cindex text symbols @cindex symbols, text @findex textcomp @r{package} @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} package. @ftable @code @item \copyright @itemx \textcopyright @cindex copyright symbol The copyright symbol, @copyright{}. @item \dag @cindex dagger, in text The dagger symbol (in text). @item \ddag @cindex double dagger, in text The double dagger symbol (in text). @item \LaTeX @cindex @LaTeX{} logo @cindex logo, @LaTeX{} The @LaTeX{} logo. @item \LaTeXe @cindex @LaTeX{}2e logo @cindex logo, @LaTeX{}2e The @LaTeX{}2e logo. @item \guillemotleft @r{(@guillemotleft{})} @itemx \guillemotright @r{(@guillemotright{})} @itemx \guilsinglleft @r{(@guilsinglleft{})} @itemx \guilsinglright @r{(@guilsinglright{})} @cindex double guillemets @cindex single guillemets @cindex left angle quotation marks @cindex right angle quotation marks @cindex double angle quotation marks @cindex single angle quotation marks @cindex French quotation marks @cindex quotation marks, French Double and single angle quotation marks, commonly used in French: @guillemotleft{}, @guillemotright{}, @guilsinglleft{}, @guilsinglright{}. @item \ldots @itemx \dots @itemx \textellipsis @cindex ellipsis An ellipsis (three dots at the baseline): `@dots{}'. @code{\ldots} and @code{\dots} also work in math mode. @item \lq @cindex left quote @cindex opening quote Left (opening) quote: `. @item \P @itemx \textparagraph @cindex paragraph symbol @cindex pilcrow Paragraph sign (pilcrow): @BES{00B6,\P}. @item \pounds @itemx \textsterling @cindex pounds symbol @cindex sterling symbol English pounds sterling: @pounds{}. @item \quotedblbase @r{(@quotedblbase{})} @itemx \quotesinglbase @r{(@quotesinglbase{})} @cindex double low-9 quotation mark @cindex single low-9 quotation mark @cindex low-9 quotation marks, single and double Double and single quotation marks on the baseline: @quotedblbase{} and @quotesinglbase{}. @item \rq @cindex right quote @cindex closing quote Right (closing) quote: '. @item \S \itemx \textsection @cindex section symbol Section sign: @BES{00A7,\S}. @item \TeX @cindex @TeX{} logo @cindex logo, @TeX{} The @TeX{} logo. @item \textasciicircum @cindex circumflex, ASCII, in text @cindex ASCII circumflex, in text ASCII circumflex: ^. @item \textasciitilde @cindex tilde, ASCII, in text @cindex ASCII tilde, in text ASCII tilde: ~. @item \textasteriskcentered @cindex asterisk, centered, in text @cindex centered asterisk, in text Centered asterisk: *. @item \textbackslash @cindex backslash, in text Backslash: \. @item \textbar @cindex vertical bar, in text @cindex bar, vertical, in text Vertical bar: |. @item \textbardbl @cindex vertical bar, double, in text @cindex bar, double vertical, in text @cindex double vertical bar, in text Double vertical bar. @item \textbigcircle @cindex big circle symbols, in text @cindex circle symbol, big, in text Big circle symbol. @item \textbraceleft @cindex left brace, in text @cindex brace, left, in text Left brace: @{. @item \textbraceright @cindex right brace, in text @cindex brace, right, in text Right brace: @}. @item \textbullet @cindex bullet, in text Bullet: @bullet{}. @item \textcircled@{@var{letter}@} @cindex circled letter, in text @var{letter} in a circle, as in @registeredsymbol{}. @item \textcompwordmark @itemx \textcapitalcompwordmark @itemx \textascendercompwordmark @cindex composite word mark, in text @cindex cap height @cindex ascender height Composite word mark (invisible). The @code{\textcapital...} form has the cap height of the font, while the @code{\textascender...} form has the ascender height. @item \textdagger @cindex dagger, in text Dagger: @math{\dag}. @item \textdaggerdbl @cindex dagger, double, in text @cindex double dagger, in text Double dagger: @math{\ddag}. @item \textdollar @r{(or @code{\$})} @cindex dollar sign @cindex currency, dollar Dollar sign: $. @item \textemdash @r{(or @code{---})} @cindex em-dash Em-dash: --- (for punctuation). @item \textendash @r{(or @code{--})} @cindex e-dash En-dash: -- (for ranges). @item \texteuro @cindex euro symbol @cindex currency, euro The Euro symbol: @euro{}. @item \textexclamdown @r{(or @code{!`})} @cindex exclamation point, upside-down Upside down exclamation point: @exclamdown{}. @item \textgreater @cindex greater than symbol, in text Greater than: >. @item \textless @cindex less than symbol, in text Less than: <. @item \textleftarrow @cindex arrow, left, in text @cindex left arrow, in text Left arrow. @item \textordfeminine @itemx \textordmasculine @cindex feminine ordinal symbol @cindex masculine ordinal symbol @cindex ordinals, feminine and masculine @cindex Spanish ordinals, feminine and masculine Feminine and masculine ordinal symbols: @ordf{}, @ordm{}. @item \textperiodcentered @cindex period, centered, in text @cindex centered period, in text Centered period: @BES{00B7,\cdot}. @item \textquestiondown @r{(or @code{?`})} @cindex question mark, upside-down Upside down question mark: @questiondown{}. @item \textquotedblleft @r{(or @code{``})} @cindex left quote, double @cindex double left quote Double left quote: ``. @item \textquotedblright @r{(or @code{''})} @cindex right quote, double @cindex double right quote Double right quote: ''. @item \textquoteleft @r{(or @code{`})} @cindex left quote, single @cindex single left quote Single left quote: `. @item \textquoteright @r{(or @code{'})} @cindex right quote, single @cindex single right quote Single right quote: '. @item \textquotesingle @cindex quote, single straight @cindex straight single quote @cindex single quote, straight Straight single quote. (From TS1 encoding.) @item \textquotestraightbase @itemx \textquotestraightdblbase @cindex quote, straight base @cindex straight quote, base @cindex double quote, straight base @cindex straight double quote, base Single and double straight quotes on the baseline. @item \textregistered @cindex registered symbol Registered symbol: @registeredsymbol{}. @item \textrightarrow @cindex arrow, right, in text @cindex right arrow, in text Right arrow. @item \textthreequartersemdash @cindex three-quarters em-dash @cindex em-dash, three-quarters ``Three-quarters'' em-dash, between en-dash and em-dash. @item \texttrademark @cindex trademark symbol Trademark symbol: @BES{2122,^{\hbox{TM}}}. @item \texttwelveudash @cindex two-thirds em-dash @cindex em-dash, two-thirds ``Two-thirds'' em-dash, between en-dash and em-dash. @item \textunderscore @cindex underscore, in text Underscore: _. @item \textvisiblespace @cindex visible space symbol, in text Visible space symbol. @end ftable @node Accents @section Accents @cindex accents @cindex characters, accented @cindex letters, accented @PkgIndex{babel} @cindex multilingual support @LaTeX{} has wide support for many of the world's scripts and languages, through the @code{babel} 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. The @code{\capital...} commands produce alternative forms for use with capital letters. These are not available with OT1. @table @code @item \" @itemx \capitaldieresis @findex \" @r{(umlaut accent)} @findex \capitaldieresis @cindex umlaut accent @cindex dieresis accent Produces an umlaut (dieresis), as in @"{o}. @item \' @itemx \capitalacute @findex \' @r{(acute accent)} @findex \capitalacute @cindex acute accent Produces an acute accent, as in @'{o}. In the @code{tabbing} environment, pushes current column to the right of the previous column (@pxref{tabbing}). @item \. @findex \. @r{(dot-over accent)} @cindex dot accent @cindex dot-over accent Produces a dot accent over the following, as in @dotaccent{o}. @item \= @itemx \capitalmacron @findex \= @r{(macron accent)} @findex \capitalmacron @cindex macron accent @cindex overbar accent @cindex bar-over accent Produces a macron (overbar) accent over the following, as in @={o}. @item \^ @itemx \capitalcircumflex @findex \^ @r{(circumflex accent)} @findex \capitalcircumflex @cindex circumflex accent @cindex hat accent Produces a circumflex (hat) accent over the following, as in @^{o}. @item \` @itemx \capitalgrave @findex \` @r{(grave accent)} @findex \capitalgrave @cindex grave accent Produces a grave accent over the following, as in @`{o}. In the @code{tabbing} environment, move following text to the right margin (@pxref{tabbing}). @item \~ @itemx \capitaltilde @findex \~ @r{(tilde accent)} @findex \capitaltilde @cindex tilde accent Produces a tilde accent over the following, as in @~{n}. @item \b @findex \b @r{(bar-under accent)} @cindex bar-under accent Produces a bar accent under the following, as in @ubaraccent{o}. See also @code{\underbar} hereinafter. @item \c @itemx \capitalcedilla @findex \c @r{(cedilla accent)} @findex \capitalcedilla @cindex cedilla accent Produces a cedilla accent under the following, as in @,{c}. @item \d @itemx \capitaldotaccent @findex \d @r{(dot-under accent)} @findex \capitaldotaccent @cindex dot-under accent Produces a dot accent under the following, as in @udotaccent{o}. @item \H @itemx \capitalhungarumlaut @findex \H @r{(Hungarian umlaut accent)} @findex \capitalhungarumlaut @cindex hungarian umlaut accent Produces a long Hungarian umlaut accent over the following, as in @H{o}. @item \i @findex \i @r{(dotless i)} @cindex dotless i Produces a dotless i, as in `@dotless{i}'. @item \j @findex \j @r{(dotless j)} @cindex dotless j Produces a dotless j, as in `@dotless{j}'. @item \k @itemx \capitalogonek @findex \k @r{(ogonek)} @findex \capitalogonek @cindex ogonek Produces a letter with ogonek, as in `@ogonek{o}'. Not available in the OT1 encoding. @item \r @itemx \capitalring @findex \r @r{(ring accent)} @findex \capitalring @cindex ring accent Produces a ring accent, as in `@ringaccent{o}'. @item \t @itemx \capitaltie @itemx \newtie @itemx \capitalnewtie @findex \t @r{(tie-after accent)} @findex \capitaltie @findex \newtie @findex \capitalnewtie @cindex tie-after accent Produces a tie-after accent, as in `@tieaccent{oo}'. The @code{\newtie} form is centered in its box. @item \u @itemx \capitalbreve @findex \u @r{(breve accent)} @findex \capitalbreve @cindex breve accent Produces a breve accent, as in `@u{o}'. @item \underbar @findex \underbar @cindex underbar 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} in @ref{Math miscellany}. See also @code{\b} above. @item \v @itemx \capitalcaron @findex \v @r{(breve accent)} @findex \capitalcaron @cindex hacek accent @cindex check accent @cindex caron accent Produces a h@'a@v{c}ek (check, caron) accent, as in `@v{o}'. @end table @node Additional Latin letters @section Additional Latin letters @anchor{Non-English characters} @cindex Latin letters, additional @cindex letters, additional Latin @cindex extended Latin @cindex special characters @cindex non-English characters @cindex characters, non-English Here are the basic @LaTeX{} commands for inserting letters (beyond A--Z) extending the Latin alphabet, used primarily in languages other than English. @table @code @item \aa @itemx \AA @findex \aa (@aa{}) @findex \AA (@AA{}) @cindex aring @aa{} and @AA{}. @item \ae @itemx \AE @findex \ae (@ae{}) @findex \AE (@AE{}) @cindex ae ligature @ae{} and @AE{}. @item \dh @itemx \DH @findex \dh (@dh{}) @findex \DH (@DH{}) @cindex Icelandic eth @cindex eth, Icelandic letter Icelandic letter eth: @dh{} and @DH{}. Not available with @sc{OT1} encoding, you need the @file{fontenc} package to select an alternate font encoding, such as @sc{T1}. @item \dj @itemx \DJ @findex \dj @findex \DJ Crossed d and D, a.k.a.@: capital and small letter d with stroke. Not available with @sc{OT1} encoding, you need the @file{fontenc} package to select an alternate font encoding, such as @sc{T1}. @item \ij @itemx \IJ @findex \ij (ij) @findex \IJ (IJ) @cindex ij letter, Dutch ij and IJ (except somewhat closer together than appears here). @item \l @itemx \L @findex \l (@l{}) @findex \L (@L{}) @cindex polish l @l{} and @L{}. @item \ng @itemx \NG @findex \ng @findex \NG Lappish letter eng, also used in phonetics. @item \o @itemx \O @findex \o (@o{}) @findex \O (@O{}) @cindex oslash @o{} and @O{}. @item \oe @itemx \OE @findex \oe (@oe{}) @findex \OE (@OE{}) @cindex oe ligature @oe{} and @OE{}. @item \ss @itemx \SS @findex \ss (@ss{}) @findex \SS (SS) @cindex es-zet German letter @cindex sharp S letters @ss{} and SS. @item \th @itemx \TH @findex \th (@th{}) @findex \TH (@TH{}) @cindex Icelandic thorn @cindex thorn, Icelandic letter Icelandic letter thorn: @th{} and @TH{}. Not available with @sc{OT1} encoding, you need the @file{fontenc} package to select an alternate font encoding, such as @sc{T1}. @end table @node \rule @section @code{\rule} @findex \rule Synopsis: @example \rule[@var{raise}]@{@var{width}@}@{@var{thickness}@} @end example The @code{\rule} command produces @dfn{rules}, that is, lines or rectangles. The arguments are: @table @var @item raise How high to raise the rule (optional). @item width The length of the rule (mandatory). @item thickness The thickness of the rule (mandatory). @end table @node \today @section @code{\today} @findex \today @cindex date, today's The @code{\today} command produces today's date, in the format @samp{@var{month} @var{dd}, @var{yyyy}}; for example, @samp{July 4, 1976}. It uses the predefined counters @code{\day}, @code{\month}, and @code{\year} (@pxref{\day \month \year}) to do this. It is not updated as the program runs. Multilingual packages like @file{babel} or classes like @file{lettre}, among others, will localize @code{\today}. For example, the following will output @samp{4 juillet 1976}: @example \year=1976 \month=7 \day=4 \documentclass@{minimal@} \usepackage[french]@{babel@} \begin@{document@} \today \end@{document@} @end example @PkgIndex{datetime} The @code{datetime} package, among others, can produce a wide variety of other date formats. @node Splitting the input @chapter Splitting the input @cindex splitting the input file @cindex input file A large document requires a lot of input. Rather than putting the whole input in a single large file, it'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 root file @cindex file, root @dfn{root file}; it is the one whose name you type when you run @LaTeX{}. @xref{filecontents}, for an environment that allows bundling an external file to be created with the main document. @menu * \include:: Conditionally include a file. * \includeonly:: Determine which files are included. * \input:: Unconditionally include a file. @end menu @node \include @section @code{\include} @findex \include Synopsis: @example \include@{@var{file}@} @end example If no @code{\includeonly} command is present, the @code{\include} command executes @code{\clearpage} to start a new page (@pxref{\clearpage}), then reads @var{file}, then does another @code{\clearpage}. Given an @code{\includeonly} command, the @code{\include} actions are only run if @var{file} is listed as an argument to @code{\includeonly}. See @ref{\includeonly}. @cindex nested @code{\include}, not allowed The @code{\include} command may not appear in the preamble or in a file read by another @code{\include} command. @node \includeonly @section @code{\includeonly} @findex \includeonly Synopsis: @example \includeonly@{@var{file1},@var{file2},...@} @end example The @code{\includeonly} command controls which files will be read by subsequent @code{\include} commands. The list of filenames is comma-separated. Each element @var{file1}, @var{file2}, @dots{} must exactly match a filename specified in a @code{\include} command for the selection to be effective. This command can only appear in the preamble. @node \input @section @code{\input} @findex \input Synopsis: @example \input@{@var{file}@} @end example The @code{\input} command causes the specified @var{file} to be read and processed, as if its contents had been inserted in the current file at that point. If @var{file} does not end in @samp{.tex} (e.g., @samp{foo} or @samp{foo.bar}), it is first tried with that extension (@samp{foo.tex} or @samp{foo.bar.tex}). If that is not found, the original @var{file} is tried (@samp{foo} or @samp{foo.bar}). @node Front/back matter @chapter Front/back matter @menu * Tables of contents:: * Glossaries:: * Indexes:: @end menu @node Tables of contents @section Tables of contents @cindex table of contents, creating @findex \tableofcontents @findex .toc @r{file} A table of contents is produced with the @code{\tableofcontents} 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. The @code{\tableofcontents} 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} command after the @code{\tableofcontents} command. @findex \listoffigures @findex \listoftables @findex .lof @r{file} @findex .lot @r{file} The analogous commands @code{\listoffigures} and @code{\listoftables} produce a list of figures and a list of tables (from @file{.lof} and @file{.lot} files), respectively. Everything works exactly the same as for the table of contents. @findex \nofiles The command @code{\nofiles} overrides these commands, and @emph{prevents} any of these lists from being generated. @menu * \addcontentsline:: Add an entry to table of contents, etc. * \addtocontents:: Add text directly to table of contents file, etc. @end menu @node \addcontentsline @subsection @code{\addcontentsline} @findex \addcontentsline @cindex table of contents entry, manually adding Synopsis: @example \addcontentsline@{@var{ext}@}@{@var{unit}@}@{@var{text}@} @end example The @code{\addcontentsline} command adds an entry to the specified list or table where: @table @var @item ext The filename extension of the file on which information is to be written, typically one of: @code{toc} (table of contents), @code{lof} (list of figures), or @code{lot} (list of tables). @item unit The name of the sectional unit being added, typically one of the following, matching the value of the @var{ext} argument: @table @code @item toc The name of the sectional unit: @code{part}, @code{chapter}, @code{section}, @code{subsection}, @code{subsubsection}. @item lof For the list of figures: @code{figure}. @item lot For the list of tables: @code{table}. @end table @item text The text of the entry. @end table @findex \contentsline What is written to the @file{.@var{ext}} file is the command @code{\contentsline@{@var{unit}@}@{@var{text}@}@{@var{num}@}}, where @code{@var{num}} is the current value of counter @code{@var{unit}}. @c xx how hardwired are these values? other unit names? @node \addtocontents @subsection @code{\addtocontents} @findex \addtocontents@{@var{ext}@}@{@var{text}@} The @code{\addtocontents}@{@var{ext}@}@{@var{text}@} command adds text (or formatting commands) directly to the @file{.@var{ext}} file that generates the table of contents or lists of figures or tables. @table @var @item ext The extension of the file on which information is to be written, typically one of: @file{toc} (table of contents), @file{lof} (list of figures), or @file{lot} (list of tables). @item text The text to be written. @end table @node Glossaries @section Glossaries @cindex glossaries @findex \makeglossary The command @code{\makeglossary} enables creating glossaries. @findex \glossary @cindex @file{.glo} file The command @code{\glossary@{@var{text}@}} writes a glossary entry for @var{text} to an auxiliary file with the @file{.glo} extension. @findex \glossaryentry Specifically, what gets written is the command @code{\glossaryentry@{@var{text}@}@{@var{pageno}@}}, where @var{pageno} is the current @code{\thepage} value. @cindex glossary @r{package} The @code{glossary} package on CTAN provides support for fancier glossaries. @node Indexes @section Indexes @cindex indexes @findex \makeindex The command @code{\makeindex} enables creating indexes. Put this in the preamble. @findex \index @cindex @file{.idx} file The command @code{\index@{@var{text}@}} writes an index entry for @var{text} to an auxiliary file named with the @file{.idx} extension. @findex \indexentry Specifically, what gets written is the command @code{\indexentry@{@var{text}@}@{@var{pageno}@}}, where @var{pageno} is the current @code{\thepage} value. @cindex `see' and `see also' index entries @cindex index entries, `see' and `see also' To generate a index entry for `bar' that says `See foo', use a vertical bar: @code{\index@{bar|see@{foo@}@}}. Use @code{seealso} instead of @code{see} to make a `See also' entry. @findex \seename @findex \alsoname The text `See' is defined by the macro @code{\seename}, and `See also' by the macro @code{\alsoname}. These can be redefined for other languages. @cindex @command{makeindex} program @cindex @command{xindy} program @cindex @file{.ind} file The generated @file{.idx} file is then sorted with an external command, usually either @command{makeindex} (@url{http://mirror.ctan.org/indexing/makeindex}) or (the multi-lingual) @command{xindy} (@url{http://xindy.sourceforge.net}). This results in a @file{.ind} file, which can then be read to typeset the index. @findex \printindex @PkgIndex{makeidx} The index is usually generated with the @code{\printindex} command. This is defined in the @code{makeidx} package, so @code{\usepackage@{makeidx@}} needs to be in the preamble. @findex \indexspace The rubber length @code{\indexspace} is inserted before each new letter in the printed index; its default value is @samp{10pt plus5pt minus3pt}. @PkgIndex{showidx} The @code{showidx} 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. @PkgIndex{multind} The @code{multind} package supports multiple indexes. See also the @TeX{} FAQ entry on this topic, @url{http://www.tex.ac.uk/cgi-bin/texfaq2html?label=multind}. @node Letters @chapter Letters @cindex letters, writing @cindex writing letters Synopsis: @example \documentclass@{letter@} \address@{@var{sender address}@} \signature@{@var{sender name}@} \begin@{document@} \begin@{letter@}@{@var{recipient address}@} \opening@{@var{salutation}@} @var{letter body} \closing@{@var{closing text}@} \end@{letter@} ... more letters ... \end@{document@} @end example Produce one or more letters. Each letter is in a separate @code{letter} environment, whose argument @var{recipient address} often contains multiple lines separated with a double backslash@tie{}(@code{\\}). For example, you might have: @example \begin@{letter@}@{Mr. Joe Smith \\ 2345 Princess St. \\ Edinburgh, EH1 1AA@} ... \end@{letter@} @end example The start of the @code{letter} environment resets the page number to 1, and the footnote number to 1 also. The @var{sender address} and @var{sender name} 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} contains multiple lines separated by a double backslash@tie{}(@code{\\}). @LaTeX{} will put the @var{sender name} under the closing, after a vertical space for the traditional hand-written signature; it also can contain multiple lines. Each @code{letter} environment body begins with a required @code{\opening} command such as @code{\opening@{Dear Madam or Sir:@}}. The @var{letter body} text is ordinary @LaTeX{} so it can contain everything from enumerated lists to displayed math, except that commands such as @code{\chapter} that make no sense in a letter are turned off. Each @code{letter} environment body typically ends with a @code{\closing} command such as @code{\closing@{Yours,@}}. @findex \\ @r{for letters} Additional material may come after the @code{\closing}. You can say who is receiving a copy of the letter with a command like @code{\cc@{the Boss \\ the Boss's Boss@}}. There's a similar @code{\encl} command for a list of enclosures. And, you can add a postscript with @code{\ps}. @LaTeX{}'s default is to indent the signature and the @code{\closing} above it by a length of @code{\longindentation}. By default this is @code{0.5\textwidth}. To make them flush left, put @code{\setlength@{\longindentation@}@{0em@}} in your preamble. To set a fixed date use something like @code{\renewcommand@{\today@}@{2015-Oct-12@}}. If put in your preamble then it will apply to all the letters. This example shows only one @code{letter} environment. The three lines marked as optional are typically omitted. @example \documentclass@{letter@} \address@{Sender's street \\ Sender's town@} \signature@{Sender's name \\ Sender's title@} % optional: \location@{Mailbox 13@} % optional: \telephone@{(102) 555-0101@} \begin@{document@} \begin@{letter@}@{Recipient's name \\ Recipient's address@} \opening@{Sir:@} % optional: \thispagestyle@{firstpage@} I am not interested in entering a business arrangement with you. \closing@{Your most humble, etc.,@} \end@{letter@} \end@{document@} @end example These commands are used with the @code{letter} class. @menu * \address:: Sender's return address. * \cc:: Carbon copy list. * \closing:: Saying goodbye. * \encl:: List of enclosed material. * \location:: Sender's organizational location. * \makelabels:: Make address labels. * \name:: Sender's name, for the return address. * \opening:: Saying hello. * \ps:: Adding a postscript. * \signature:: Sender's signature. @c ?Not user-level? * \stopbreaks and \startbreaks:: Disallow and allow page breaks. * \telephone:: Sender's phone number. @end menu @node \address @section @code{\address} @findex \address Synopsis: @example \address@{@var{senders address}@} @end example Specifies the return address as it appears on the letter and on the envelope. Separate multiple lines in @var{senders address} with a double backslash@tie{}@code{\\}. 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} environment. This command is optional: without the @code{\address} declaration the letter is formatted with some blank space on top, for copying onto pre-printed letterhead paper. (@xref{Overview}, for details on your local implementation.) With the @code{\address} declaration, it is formatted as a personal letter. Here is an example. @example \address@{Stephen Maturin \\ The Grapes of the Savoy@} @end example @node \cc @section @code{\cc} @findex \cc @cindex cc list, in letters Synopsis: @example \cc@{@var{first name} \\ ... @} @end example 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}. Separate multiple lines with a double backslash@tie{}@code{\\}, as in: @example \cc@{President \\ Vice President@} @end example @node \closing @section @code{\closing} @findex \closing @cindex letters, ending @cindex closing letters Synopsis: @example \closing@{@var{text}@} @end example Usually at the end of a letter, above the handwritten signature, there is a @code{\closing} (although this command is optional). For example, @example \closing@{Regards,@} @end example @node \encl @section @code{\encl} @findex \encl @cindex enclosure list Synopsis: @example \encl@{@var{first enclosed object} \\ ... @} @end example Produce a list of things included with the letter. This command is optional; when it is used, it typically is put after @code{\closing}. Separate multiple lines with a double backslash@tie{}@code{\\}. @example \encl@{License \\ Passport @} @end example @node \location @section @code{\location} @findex \location Synopsis: @example \location@{@var{text}@} @end example The @var{text} appears centered at the bottom of the each page. It only appears if the page style is @code{firstpage}. @node \makelabels @section @code{\makelabels} @findex \makelabels Synopsis: @example \makelabels @end example 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. Customize the labels by redefining the commands @code{\startlabels}, @code{\mlabel}, and @code{\returnaddress} in the preamble. The command @code{\startlabels} sets the width, height, number of columns, etc., of the page onto which the labels are printed. The command @code{\mlabel@{@var{sender address}@}@{@var{recipient address}@}} produces the two labels (or one, if you choose to ignore the @var{sender address}). The @var{sender address} is the value returned by the macro @code{\returnaddress} while @var{recipient address} is the value passed in the argument to the @code{letter} environment. By default @code{\mlabel} ignores the first argument, the @var{sender address}. @c xxx TODO, align on latex2e-fr.texi, see https://mail.gna.org/public/latexrefman-discuss/2015-10/msg00000.html @node \name @section @code{\name} @findex \name Synopsis: @example \name@{@var{name}@} @end example Sender's name, used for printing on the envelope together with the return address. @node \opening @section @code{\opening} @findex \opening @cindex letters, starting Synopsis: @example \opening@{@var{text}@} @end example This command is required. It starts a letter, following the @code{\begin@{letter@}@{...@}}. The mandatory argument @var{text} is the text that starts your letter. For instance: @example \opening@{Dear John:@} @end example @node \ps @section @code{\ps} @findex \ps @cindex postscript, in letters Synopsis: @example \ps@{@var{text}@} @end example Add a postscript. This command is optional and usually is used after @code{\closing}. @example \ps@{P.S. After you have read this letter, burn it. Or eat it.@} @end example @node \signature @section @code{\signature} Synopsis: @example \signature@{@var{first line} \\ ... @} @end example @findex \signature The sender's name. This command is optional, although its inclusion is usual. 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@tie{}@code{\\}. For example: @example \signature@{J Fred Muggs \\ White House@} @end example @LaTeX{}'s default for the vertical space from the @code{\closing} text down to the @code{\signature} text is @code{6\medskipamount}, which is six times 0.7@dmn{em}. 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} environment and before the @code{\closing}. You can include a graphic in the signature, for instance with @code{\signature@{\vspace@{-6\medskipamount@}\includegraphics@{sig.png@}\\ My name@}} (this requires writing @code{\usepackage@{graphicx@}} in the preamble). @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 @node \telephone @section @code{\telephone} @findex \telephone Synopsis: @example \telephone@{@var{number}@} @end example The sender's telephone number. This is typically in the preamble, where it applies to all letters. This only appears if the @code{firstpage} pagestyle is selected. If so, it appears on the lower right of the page. @node Terminal input/output @chapter Terminal input/output @cindex input/output, to terminal @cindex terminal input/output @menu * \typein:: Read text from the terminal. * \typeout:: Write text to the terminal. @end menu @node \typein @section @code{\typein[@var{cmd}]@{@var{msg}@}} @findex \typein Synopsis: @example \typein[\@var{cmd}]@{@var{msg}@} @end example @code{\typein} prints @var{msg} 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}} argument is omitted, the typed input is processed as if it had been included in the input file in place of the @code{\typein} command. If the @code{\@var{cmd}} argument is present, it must be a command name. This command name is then defined or redefined to be the typed input. @node \typeout @section @code{\typeout@{@var{msg}@}} @findex \typeout Synopsis: @example \typeout@{@var{msg}@} @end example Prints @code{msg} on the terminal and in the @code{log} file. Commands in @code{msg} that are defined with @code{\newcommand} or @code{\renewcommand} (among others) are replaced by their definitions before being printed. @LaTeX{}'s usual rules for treating multiple spaces as a single space and ignoring spaces after a command name apply to @code{msg}. A @code{\space} command in @code{msg} causes a single space to be printed, independent of surrounding spaces. A @code{^^J} in @code{msg} prints a newline. @node Command line @chapter Command line @cindex command line @findex .tex, @r{default extension} The input file specification indicates the file to be formatted; @TeX{} uses @file{.tex} 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} without pausing after every error: @example latex '\nonstopmode\input foo.tex' @end example @findex --help @r{command-line option} With many, but not all, implementations, command-line options can also be specified in the usual Unix way, starting with @samp{-} or @samp{--}. For a list of those options, try @samp{latex --help}. @cindex @samp{*} prompt @cindex prompt, @samp{*} @findex \stop If @LaTeX{} stops in the middle of the document and gives you a @samp{*} prompt, it is waiting for input. You can type @code{\stop} (and return) and it will prematurely end the document. @xref{@TeX{} engines}, for other system commands invoking @LaTeX{}. @node Document templates @appendix Document templates @cindex document templates @cindex templates, document Although not reference material, perhaps these document templates will be useful. Additional template resources are listed at @url{http://tug.org/interest.html#latextemplates}. @menu * beamer template:: * book template:: * tugboat template:: @end menu @node beamer template @section @code{beamer} template @cindex @code{beamer} template and class @cindex template, @code{beamer} The @code{beamer} class creates presentation slides. It has a vast array of features, but here is a basic template: @verbatim \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} @end verbatim One web resource for this: @url{http://robjhyndman.com/hyndsight/beamer/}. @node book template @section @code{book} template @cindex template, @code{book} @verbatim \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} @end verbatim @node tugboat template @section @code{tugboat} template @cindex template, TUGboat @cindex TUGboat template @cindex @code{ltugboat} class @cite{TUGboat} is the journal of the @TeX{} Users Group, @url{http://tug.org/TUGboat}. @verbatim \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} -> {\small[er] fred} % please use! \cs{fred} -> \fred \meta{fred} -> \nth{n} -> 1st, 2nd, ... \sfrac{3/4} -> 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} @end verbatim @node Concept Index @unnumbered Concept Index @printindex cp @c The name of the `Command Index' node must NOT be altered for ltx-help.el. @node Command Index @unnumbered Command Index @printindex fn @bye \def\DeclareTextCommand{\foo}{T1} % then |\foo| is defined to be |\T1-cmd \foo \T1\foo|, % % where |\T1\foo| is \emph{one} control sequence, not two! \newcommand \def\ProvideTextCommand -- same with \providecommand \@onlypreamble\DeclareTextCommand \@onlypreamble\DeclareTextSymbol \gdef\TextSymbolUnavailable#1{% \@onlypreamble\def\DeclareTextCommandDefault#1{% \def\ProvideTextCommandDefault#1{% \def\DeclareTextAccent#1#2#3{% \def\DeclareTextCompositeCommand#1#2#3#4{% \@onlypreamble\def\DeclareTextComposite#1#2#3#4{% \def\UseTextAccent#1#2#3{% \def\UseTextSymbol#1#2{% \@onlypreamble\DeclareTextSymbolDefault@item \@onlypreamble\DeclareTextAccentDefault@item \def\UndeclareTextCommand#1#2{% @c Local Variables: @c ispell-dictionary: "english" @c coding: latin-1-unix @c End: