@c This is part of the Eplain manual. Public domain. @node User definitions @chapter User definitions This chapter describes definitions that are meant to be used directly in a document. When appropriate, ways to change the default formatting are described in subsections. @menu * Diagnostics:: Tracing information. * Rules:: Changing the default rule dimensions. * Citations:: Using BibTeX and Eplain to make bibliographies. * Displays:: Changing the formatting of math displays. * Time of day:: Producing the time of day. * Lists:: Producing numbered and unordered lists. * Verbatim listing:: Producing text just as it appears. * Contents:: Making a table of contents. * Cross-references:: Symbolic references to equations, figures, etc. * Page references:: Symbolic references to page numbers. * Equation references:: Symbolic references to equation numbers. * Indexing:: Creating and typesetting indexes. * Justification:: Ragged left, ragged right, centered. * Tables:: Producing ordered tables. * Margins:: Changing the margins directly. * Multiple columns:: Getting output in two columns. * Footnotes:: Autonumbered footnotes; changing formatting. * Fractions:: A better way to produce fractions in text. * Paths:: Allowing line breaks in pathnames. * Logos:: Various logos. * Boxes:: Producing filled or open rectangles. * Checking for PDF output:: Checking for pdfTeX in PDF mode. * Loading LaTeX packages:: Support for LaTeX packages under plain TeX. @end menu @node Diagnostics @section Diagnostics @cindex diagnostics @cindex tracing Plain @TeX{} provides the @code{\tracingall} command, to turn on the maximum amount of tracing possible in @TeX{}. The (usually voluminous) output from @code{\tracingall} goes both on the terminal and into the transcript file. @findex tracingall It is sometimes easier to have the output go only to the transcript file, so you can peruse it at your leisure and not obscure other output to the terminal. So, Eplain provides the command @code{\loggingall}. @findex loggingall (For some reason, this command is available in Metafont, but not in @TeX{}.) It is also sometimes useful to see the complete contents of boxes. @code{\tracingboxes} does this. (It doesn't affect whether or not the contents @findex tracingboxes are shown on the terminal.) You can turn off all tracing with @code{\tracingoff}. @findex tracingoff You can also turn logging on and off globally, so you don't have to worry about whether or not you're inside a group at the time of command. These variants are named @code{\gloggingall} @findex gloggingall and @code{\gtracingall}. @findex gtracingall Finally, if you write your own help messages (see @code{\newhelp} @cindex help messages @cindex error messages in @cite{The @TeX{}book}), you want a convenient way to break lines in them. This is what @TeX{}'s @code{\newlinechar} parameter is for; @cindex newlinechar however, plain @TeX{} doesn't set @code{\newlinechar}. Therefore, Eplain defines it to be the character @code{^^J}. For example, one of Eplain's own error messages is defined as follows: @example \newhelp\envhelp@{Perhaps you forgot to end the previous^^J% environment? I'm finishing off the current group,^^J% hoping that will fix it.@}% @end example @node Rules @section Rules The default dimensions of rules are defined in chapter@tie{}21 of the @cite{The @TeX{}book}. To sum up what is given there, the ``thickness'' of rules is @cindex rule thickness 0.4pt by default. Eplain defines three parameters that let you change this dimension: @code{\hruledefaultheight}, @code{\hruledefaultdepth}, @findex hruledefaultheight @findex hruledefaultdepth and @code{\vruledefaultwidth}. By default, they are defined as @findex vruledefaultwidth @cite{The @TeX{}book} describes. But it would be wrong to redefine @code{\hrule} and @code{\vrule}. For one thing, some macros in plain @TeX{} depend on the default dimensions being used; for another, rules are used quite heavily, and the performance impact of making it a macro can be noticeable. Therefore, to take advantage of the default rule parameters, you must use @code{\ehrule} @findex ehrule and @code{\evrule}. @findex evrule @node Citations @section Citations @cindex citations @cindex bibliographies Bibliographies are part of almost every technical document. To handle them easily, you need two things: a program to do the tedious formatting, and a way to cite references by labels, rather than by numbers. The Bib@TeX{} program, written by Oren Patashnik, takes care @cindex Bib@TeX{} @cindex Patashnik, Oren of the first item; the citation commands in @LaTeX{}, written to be used @cindex @LaTeX{} with Bib@TeX{}, take care of the second. Therefore, Eplain adopts the use of Bib@TeX{}, and virtually the same interface as @LaTeX{}. The general idea is that you put citation commands in the text of your document, and commands saying where the bibliography data is. When you run @TeX{}, these commands produce output on the file with the same root name as your document (by default) and the extension @file{.aux}. @pindex .aux @r{file} @findex jobname Bib@TeX{} reads this file. You should put the bibliography data in a file or files with the extension @file{.bib}. Bib@TeX{} writes out a file with the same root @pindex .bib @r{file} name as your document and extension @file{.bbl}. Eplain reads this file @pindex .bbl @r{file} the next time you run your document through @TeX{}. (It takes multiple passes to get everything straight, because usually after seeing your bibliography typeset, you want to make changes in the @file{.bib} file, which means you have to run Bib@TeX{} again, which means you have to run @TeX{} again@dots{}) An annotated example of the whole process is given below. If your document has more than one bibliography---for example, if it is a collection of papers---you can tell Eplain to use a different root name for the @file{.bbl} file by defining the control sequence @code{\bblfilebasename}. @findex bblfilebasename The default definition is simply @code{\jobname}. See the document @cite{Bib@TeX{}ing} (whose text is in the file @file{btxdoc.tex}, which should be in the Eplain distribution you got) for information on how to write your @t{.bib} files. Both the Bib@TeX{} and the Eplain distributions contain several examples, also. The @code{\cite} @findex cite command produces a citation in the text of your document. The exact printed form the citation will take is under your control; @pxref{Formatting citations}. @code{\cite} takes one required argument, a comma-separated list of cross-reference labels (@pxref{Cross-references}, for exactly what characters are allowed in such labels). Warning: spaces in this list are taken as part of the following label name, which is probably not what you expect. @cindex citations, undefined The @code{\cite} command also produces a command in the @t{.aux} file that tells Bib@TeX{} to retrieve the given reference(s) from the @t{.bib} file. @code{\cite} also takes one optional argument, which you specify within square brackets, as in @LaTeX{}. This text is simply typeset after the citations. (See the example below.) Eplain can create hypertext links for citations pointing to the relevant bibliography entries; @pxref{Citation hyperlinks}. Another command, @code{\nocite}, @findex nocite puts the given reference(s) into the bibliography, but produces nothing in the text. The @code{\bibliography} @findex bibliography command is next. It serves two purposes: producing the typeset bibliography, and telling Bib@TeX{} the root names of the @t{.bib} files. Therefore, the argument to @code{\bibliography} is a comma separated list of the @t{.bib} files (without the @samp{.bib}). Again, spaces in this list are significant. You tell Bib@TeX{} the particular style in which you want your bibliography typeset with one more command: @code{\bibliographystyle}. @findex bibliographystyle The argument to this is a single filename @var{style}, which tells Bib@TeX{} to look for a file @var{style}@t{.bst}. @pindex .bst @r{files} See the document @cite{Designing Bib@TeX{} styles} (whose text is in the @file{btxhak.tex}) for information on how to write your own styles. Eplain automatically reads the citations from the @t{.aux} file when your job starts. If you don't want to see the messages about undefined citations, you can say @code{\xrefwarningfalse} before making any citations. @findex xrefwarningfalse Eplain automatically does this if the @t{.aux} file does not exist. You can restore the default by saying @code{\xrefwarningtrue}. Here is a @TeX{} input file that illustrates the various commands. @example \input eplain % Reads the .aux file. Two citations to Knuthian works: \cite[note]@{surreal,concrete-math@}. \beginsection@{References.@}\par % Title for the bibliography. \bibliography@{knuth@} % Use knuth.bib for the labels. \bibliographystyle@{plain@} % Number the references. \end % End of the document. @end example @cindex Knuth, Donald Ervin @cindex Graham, Ronald L. @cindex numbered references @cindex references, numbered If we suppose that this file was named @file{citex.tex} and that the bibliography data is in @file{knuth.bib} (as the @code{\bibliography} command says), the following commands do what's required. (@samp{$ } represents the shell prompt.) @example $ tex citex (produces undefined citation messages) $ bibtex citex (read knuth.bib and citex.aux, write citex.bbl) $ tex citex (read citex.bbl, still have undefined citations) $ tex citex (one more time, to resolve the references) @end example @pindex texi2dvi @noindent (The @command{texi2dvi} program can help you automate this process, @pxref{Invoking Eplain}.) The output looks something like (because we used the @t{plain} bibliography style): @quotation Two citations to Knuthian works: [2,1 note]. @b{References} @tex @frenchspacing @end tex [1] Ronald L. Graham, Donald E. Knuth, and Oren Patashnik. @i{Concrete Mathematics}. Addison-Wesley, Reading, Massachusetts, 1989. [2] Donald E. Knuth. @i{Surreal Numbers}. Addison-Wesley, Reading, Massachusetts, 1974. @end quotation See the Bib@TeX{} documentation for information on how to write the bibliography databases, and the bibliography styles that are available. (If you want your references printed with names, as in [Knu74], instead of numbered, the bibliography style is @code{alpha}.) @cindex alphanumeric references @cindex references, alphanumeric @menu * Formatting citations:: Changing the way citations are printed. * Formatting bibliographies:: Changing the way bibliographies are printed. @end menu @node Formatting citations @subsection Formatting citations @cindex citations, formatting You may wish to change Eplain's formatting of citations; i.e., the result of your @code{\cite} commands. By default, the citation labels are printed one after another, separated by commas and enclosed in brackets, using the main text font. Some formats require other styles, such as superscripted labels. You can accomodate such formats by redefining the following macros. @table @code @itemx \printcitestart @item \printcitefinish @findex printcitestart @findex printcitefinish Eplain expands these macros at the begining and end of the list of citations for each @code{\cite} command. By default, they produce a @samp{[} and @samp{]}, respectively. @item \printbetweencitations @findex printbetweencitations If a @code{\cite} command has multiple citations, as in @code{\cite@{acp,texbook@}}, Eplain expands this macro in between each pair of citations. By default, it produces a comma followed by a space. @item \printcitenote @findex printcitenote This macro takes one argument, which is the optional note to the @code{\cite} command. If the @code{\cite} command had no note, this macro isn't used. Otherwise, it should print the note. By default, the note is preceded with a comma and a space. @end table Here is an example, showing you could produce citations as superscripted labels, with the optional notes in parentheses. @example \def\printcitestart@{\unskip $^\bgroup@} \def\printbetweencitations@{,@} \def\printcitefinish@{\egroup$@} \def\printcitenote#1@{\hbox@{\sevenrm\space (#1)@}@} @end example @node Formatting bibliographies @subsection Formatting bibliographies @cindex bibliography, formatting the You may wish to change Eplain's formatting of the bibliography, especially with respect to the fonts that are used. Therefore, Eplain provides the following control sequences: @table @code @item \biblabelwidth @findex biblabelwidth This control sequence represents a @code{\dimen} register, and its value is the width of the widest label in the bibliography. Although it is unlikely you will ever want to redefine it, you might want to use it if you redefine @code{\biblabelprint}, below. @item \biblabelprint @findex biblabelprint This macro takes one argument, the label to print. By default, the label is put in a box of width @code{\biblabelwidth}, and is followed by an enspace. When you want to change the spacing around the labels, this is the right macro to redefine. @item \biblabelcontents @findex biblabelcontents This macro also takes one argument, the label to print. By default, the label is printed using the font @code{\bblrm} (below), and enclosed in brackets. When you want to change the appearance of the label, but not the spacing around it, this is the right macro to redefine. @item \bblrm @findex bblrm @cindex bibliography fonts The default font used for printing the bibliography. @item \bblem @findex bblem The font used for printing the titles and other ``emphasized'' material. @item \bblsc @findex bblsc In some styles, authors' names are printed in a caps-and-small-caps font. In those cases, this font is used. @item \bblnewblock @findex bblnewblock This is invoked between each of the parts of a bibliography entry. The default is to leave some extra space between the parts; you could redefine it to start each part on a new line (for example). A part is simply a main element of the entry; for example, the author is a part. (It was @LaTeX{} that introduced the (misleading, as far as I am concerned) term `block' for this.) @item \biblabelextraspace @findex biblabelextraspace Bibliography entries are typeset with a hanging indentation of @code{\biblabelwidth} plus this. The default is @code{.5em}, where the em width is taken from the @code{\bblrm} font. If you want to change this, you should do it inside @code{\bblhook}. @item \bblhook @findex bblhook @cindex bibliography items, extra space between This is expanded before reading the @t{.bbl} file. By default, it does nothing. You could, for example, define it to set the bibliography fonts, or produce the heading for the references. Two spacing parameters must be changed inside @code{\bblhook}: @code{\parskip}, which produces extra space between the items; and @code{\biblabelextraspace}, which is described above. (By the way, @code{\hookappend} won't work with @code{\bblhook}, despite the names. Just use @code{\def}.) @end table If you are really desperate, you can also hand-edit the @t{.bbl} file that Bib@TeX{} produces to do anything you wish. @node Displays @section Displays @cindex displays, left-justifying @cindex mathematics displays, formatting @cindex left-justification of displays By default, @TeX{} centers displayed material. (Displayed material is just whatever you put between @code{$$}'s---it's not necessarily mathematics.) Many layouts would be better served if the displayed material was left-justified. Therefore, Eplain provides the command @code{\leftdisplays}, @findex leftdisplays which indents displayed material by @code{\parindent} plus @code{\leftskip}, plus @code{\leftdisplayindent}. @findex leftdisplayindent You can go back to centering displays with @code{\centereddisplays}. @findex centereddisplays (It is usually poor typography to have both centered and left-justified displays in a single publication, though.) @code{\leftdisplays} also changes the plain @TeX{} commands that deal with alignments inside math displays, @code{\displaylines}, @findex displaylines @code{\eqalignno}, @findex eqalignno and @code{\leqalignno}, @findex leqalignno to produce left-justified text. You can still override this formatting by inserting @code{\hfill} glue, as explained in @cite{The @TeX{}book}. @menu * Formatting displays:: General formatting of displays. @end menu @node Formatting displays @subsection Formatting displays If you want some other kind of formatting, you can write a definition of your own, analogous to @code{\leftdisplays}. You need only make sure that @code{\leftdisplaysetup} @findex leftdisplaysetup is called at the beginning of every display (presumably by invoking it in @TeX{}'s @code{\everydisplay} parameter), and to define @code{\generaldisplay}. @findex generaldisplay @code{\leftdisplays} expands the old value of @code{\everydisplay} before calling @code{\leftdisplaysetup}, so that any changes you have made to it won't be lost. That old token list as available as the value of the token register @code{\previouseverydisplay}. @findex previouseverydisplay @node Time of day @section Time of day @cindex time of day @cindex date @TeX{} provides the day, month, and year as numeric quantities (unless your @TeX{} implementation is woefully deficient). Eplain provides some control sequences to make them a little more friendly to humans. @code{\monthname} @findex monthname produces the name of the current month, abbreviated to three letters. @code{\fullmonthname} @findex fullmonthname produces the name of the current month, unabbreviated (in English). @code{\timestring} @findex timestring produces the current time, as in `1:14 p.m.' @code{\timestamp} @findex timestamp produces the current date and time, as in `23 Apr 64 1:14 p.m.'. (Except the spacing is slightly different.) @code{\today} @findex today produces the current date, as in `23 April 1964'. @node Lists @section Lists @cindex lists @cindex numbered lists @cindex ordered list @cindex unordered lists Many documents require lists of items, either numbered or simply enumerated. Plain @TeX{} defines one macro to help with creating lists, @code{\item}, but that is insufficient in many cases. Therefore, Eplain provides two pairs of commands: @table @code @itemx \numberedlist @dots{} \endnumberedlist @item \orderedlist @dots{} \endorderedlist @findex numberedlist @findex endnumberedlist @findex orderedlist @findex endorderedlist These commands (they are synonyms) produce a list with the items numbered sequentially, starting from one. A nested @code{\numberedlist} labels the items with lowercase letters, starting with `a'. Another nested @code{\numberedlist} labels the items with roman numerals. Yet more deeply nested numbered lists label items with @samp{*}. @item \unorderedlist @dots{} \endunorderedlist @findex unorderedlist @findex endunorderedlist This produces a list with the items labelled with small black boxes (``square bullets''). A nested @code{\unorderedlist} labels items with em-dashes. Doubly (and deeper) nested unordered lists label items with `*'s. @end table The two kinds of lists can be nested within each other, as well. In both kinds of lists, you begin an item with @code{\li}. @findex li An item may continue for several paragraphs. Each item starts a paragraph. You can give @code{\li} an optional argument, a cross-reference label. It's defined to be the ``marker'' for the current item. This is useful if the list items are numbered. You can produce the value of the label with @code{\xrefn}. @xref{Cross-references}. Eplain can create hypertext links for the markers produced by @code{\xrefn} pointing to the relevant list item; @pxref{List hyperlinks}. You can also say @code{\listcompact} @findex listcompact right after @code{\numberedlist} or @code{\unorderedlist}. The items in the list will then not have any extra space between them (@pxref{Formatting lists}). You might want to do this if the items in this particular list are short. Here is an example: @example \numberedlist\listcompact \li The first item. \li The second item. The second paragraph of the second item. \endnumberedlist @end example @menu * Formatting lists:: Changing how the lists look. @end menu @node Formatting lists @subsection Formatting lists @cindex lists, formatting Several registers define the spacing associated with lists. It is likely that their default values won't suit your particular layout. @table @code @item \abovelistskipamount, \belowlistskipamount @findex abovelistskipamount @findex belowlistskipamount The vertical glue inserted before and after every list, respectively. @item \interitemskipamount @findex interitemskipamount The vertical glue inserted before each item except the first. @code{\listcompact} resets this to zero, as mentioned above. @item \listleftindent, \listrightindent @findex listleftindent @findex listrightindent @code{\listrightindent} is the amount of space by which the list is indented on the right; i.e., it is added to @code{\rightskip}. @code{\listleftindent} is the amount of space, @emph{relative to} @code{\parindent}, by which the list is indented on the left. Why treat the two parameters differently? Because (a)@tie{}it is more useful to make the list indentation depend on the paragraph indentation; (b)@tie{}footnotes aren't formatted right if @code{\parindent} is reset to zero. @end table The three vertical glues are inserted by macros, and preceded by penalties: @code{\abovelistskip} @findex abovelistskip does @code{\vpenalty\abovelistpenalty} @findex abovelistpenalty and then @code{\vskip\abovelistskip}. @code{\belowlistskip} @findex belowlistskip and @code{\interitemskip} @findex interitemskip are analogous. In addition, the macro @code{\listmarkerspace} @findex listmarkerspace is called to separate the item label from the item text. This is set to @code{\enspace} by default. If you want to change the labels on the items, you can redefine these macros: @code{\numberedmarker} @findex numberedmarker or @code{\unorderedmarker}. @findex unorderedmarker The following registers might be useful if you do: @table @code @item \numberedlistdepth, \unorderedlistdepth @findex numberedlistdepth @findex unorderedlistdepth These keep track of the depth of nesting of the two kinds of lists. @item \itemnumber, \itemletter @findex itemnumber @findex itemletter These keep track of the number of items that have been seen in the current numbered list. They are both integer registers. The difference is that @code{\itemnumber} starts at one, and @code{\itemletter} starts at 97, i.e., lowercase `a'. @end table You can also redefine the control sequences that are used internally, if you want to do something radically different: @code{\beginlist} @findex beginlist is invoked to begin both kinds of lists; @code{\printitem} @findex printitem is invoked to print the label (and space following the label) for each item; and @code{\endlist} @findex endlist is invoked to end both kinds of lists. @cindex item labels, changing @cindex labels on items, changing @node Verbatim listing @section Verbatim listing @cindex verbatim listing @cindex listing files @cindex files, verbatim listing of It is sometimes useful to include a file verbatim in your document; for example, part of a computer program. The @code{\listing} @findex listing command is given one argument, a filename, and produces the contents of that file in your document. @code{\listing} expands @code{\listingfont} to set the current font. The default value of @code{\listingfont} @findex listingfont is @code{\tt}. You can take arbitrary actions before reading the file by defining the macro @code{\setuplistinghook}. @findex setuplistinghook This is expanded just before the file is input. If you want to have line numbers on the output, you can say @code{\let\setuplistinghook = \linenumberedlisting}. @findex linenumberedlisting The line numbers are stored in the count register @code{\lineno} while the file is being read. You can redefine the macro @code{\printlistinglineno} to change how they are printed. You can produce in-line verbatim text in your document with @code{\verbatim}. @findex verbatim End the text with @code{|endverbatim}. If you need a @samp{|} in the text, double it. If the first character of the verbatim text is a space, use @code{| }. (@code{| } will work elsewhere in the argument, too, but isn't necessary.) For example: @example \verbatim| ||\#%&!|endverbatim @end example @noindent produces @code{ |\#%&!}. Line breaks and spaces in the verbatim text are preserved. @findex verbatimescapechar @cindex escape character, changing verbatim You can change the verbatim escape character from the default @samp{|} with @code{\verbatimescapechar @var{char}}; for example, this changes it to @samp{@@}. @example \verbatimescapechar \@@ @end example @noindent The backslash is not necessary in some cases, but is in others, depending on the catcode of the character. The argument to @code{\verbatimescapechar} is used as @code{\catcode `@var{char}}, so the exact rules follow that for @code{\catcode}. Because @code{\verbatim} must change the category code of special characters, calling inside a macro definition of your own does not work properly. For example: @example \def\mymacro@{\verbatim &#%|endverbatim@}% Doesn't work! @end example To accomplish this, you must change the category codes yourself before making the macro definition. Perhaps @code{\uncatcodespecials} will help you (@pxref{Category codes}). @node Contents @section Contents @cindex table of contents @cindex contents Producing a table of contents that is both useful and aesthetic is one of the most difficult design problems in any work. Naturally, Eplain does not pretend to solve the design problem. Collecting the raw data for a table of contents, however, is much the same across documents. Eplain uses an auxiliary file with extension @file{.toc} @pindex .toc @r{file} (and the same root name as your document) to save the information. To write an entry for the table of contents, you say @code{\writetocentry@{@var{part}@}@{@var{text}@}}, @findex writetocentry where @var{part} is the type of part this entry is, e.g., @samp{chapter}, and @var{text} is the text of the title. @code{\writetocentry} puts an entry into the @t{.toc} file that looks @findex toc@dots{}entry like @code{\toc@var{part}entry@{@var{text}@}@{@var{page number}@}}. The @var{text} is written unexpanded. @findex writenumberedtocentry A related command, @code{\writenumberedtocentry}, takes one additional argument, the first token of which is expanded at the point of the @code{\writenumberedtocentry}, but the rest of the argument is not expanded. The usual application is when the parts of the document are numbered. On the other hand, the one-level expansion allows you to use the argument for other things as well (author's names in a proceedings, say), and not have accents or other control sequences expanded. The downside is that if you @emph{want} full expansion of the third argument, you don't get it---you must expand it yourself, before you call @code{\writenumberedtocentry}. For example: @example \writenumberedtocentry@{chapter@}@{A $\sin$ wave@}@{\the\chapno@} \writetocentry@{section@}@{A section title@} @end example @noindent Supposing @code{\the\chapno} expanded to @samp{3} and that the @code{\write}'s occurred on pages eight and nine, respectively, the above writes the following to the @t{.toc} file: @example \tocchapterentry@{A $\sin$ wave@}@{3@}@{8@} \tocsectionentry@{A section title@}@{9@} @end example @findex readtocfile You read the @t{.toc} file with the command @code{\readtocfile}. Naturally, whatever @code{\toc@dots{} entry} commands that were written to the file must be defined when @code{\readtocfile} is invoked. Eplain has minimal definitions for @code{\tocchapterentry}, @code{\tocsectionentry}, and @code{\tocsubsectionentry}, just to prevent undefined control sequence errors in common cases. They aren't suitable for anything but preliminary proofs. Each of @code{\writetocentry} and @code{\writenumberedtocentry} opens the @t{.toc} file for writing, thereby deleting the information from the previous run. You should therefore arrange that @code{\readtocfile} be called @emph{before} the first call to a @code{\writetoc@dots{}} macro. @code{\readtocfile} does not itself delete the information from the @t{.toc} file, so that you can call it several times, e.g., to create both a short @cindex table of contents, short and normal table of contents. (To produce this in particular, define @code{\tocsectionentry} to produce nothing while you are reading @t{.toc} file for a short table of contents (@pxref{Macro arguments}).) On the other hand, if you don't want to rewrite the @t{.toc} file at all, perhaps because you are only running @TeX{} on part of your manuscript, you can set @code{\rewritetocfilefalse}. @findex ifrewritetocfile @findex rewritetocfile @r{(conditional)} By default, the @file{.toc} file has the root @code{\jobname}. If your document has more than one contents---for example, if it is a collection of papers, some of which have their own contents---you can tell Eplain to use a different root name by defining the control sequence @code{\tocfilebasename}. @findex tocfilebasename @cindex list of figures @cindex list of tables @findex definecontentsfile In addition to the usual table of contents, you may want to have a list of figures, list of tables, or other such contents-like list. You can do this with @code{\definecontentsfile@{@var{abbrev}@}}. All of the above commands are actually a special case that Eplain predefines with @example \definecontentsfile@{toc@} @end example @noindent The @var{abbrev} is used both for the file extension and in the control sequence names. @node Cross-references @section Cross-references @cindex cross-references It is often useful to refer the reader to other parts of your document; but putting literal page, section, equation, or whatever numbers in the text is certainly a bad thing. Eplain therefore provides commands for symbolic cross-references. It uses an auxiliary file with extension @t{.aux} @pindex .aux @r{file} (and the same root name as your document) to keep track of the information. Therefore, it takes two passes to get the cross-references right---one to write them out, and one to read them in. Eplain automatically reads the @t{.aux} file at the first reference; after reading it, Eplain reopens it for writing. You can control whether or not Eplain warns you about undefined labels. @xref{Citations}. @cindex labels, characters valid in Labels in Eplain's cross-reference commands can use characters of category code eleven (letter), twelve (other), ten (space), three (math shift), four (alignment tab), seven (superscript), or eight (subscript). For example, @samp{(a1 $&^_} is a valid label (assuming the category codes of plain @TeX{}), but @samp{%#\@{} has no valid characters. You can also do symbolic cross-references for bibliographic citations and list items. @xref{Citations}, and @ref{Lists}. Eplain can create hypertext links for the cross-references; @pxref{Cross-reference hyperlinks}. @menu * Defining generic references:: * Using generic references:: @end menu @node Defining generic references @subsection Defining generic references @cindex defining general references @cindex references, defining general @cindex cross-references, defining general @findex definexref Eplain provides the command @code{\definexref} for general cross-references. It takes three arguments: the name of the label (see section above for valid label names), the value of the label (which can be anything), and the ``class'' of the reference---whether it's a section, or theorem, or what. For example: @example \definexref@{sec-intro@}@{3.1@}@{section@} @end example @noindent Of course, the label value is usually generated by another macro using @TeX{} count registers or some such. @code{\definexref} doesn't actually define @var{label}; instead, it writes out the definition to the @t{.aux} file, where Eplain will read it on the next @TeX{} run. The @var{class} argument is used by the @code{\ref} and @code{\refs} commands. See the next section. @node Using generic references @subsection Using generic references @cindex defining general references @cindex references, defining general @cindex cross-references, defining general To retrieve the value of the label defined via @code{\definexref} (see the previous section), Eplain provides the following macros: @table @code @findex refn @itemx \refn@{@var{label}@} @findex xrefn @item \xrefn@{@var{label}@} @code{\refn} and @code{\xrefn} (they are synonyms) produce the bare definition of @var{label}. If @var{label} isn't defined, issue a warning, and produce @var{label} itself instead, in typewriter. (The warning isn't given if @code{\xrefwarningfalse}.) @findex xrefwarning @r{conditional} @findex ref @item \ref@{@var{label}@} Given the class @var{c} for @var{label} (see the description of @code{\definexref} in the previous section), expand the control sequence @code{\@var{c} word} (if it's defined) followed by a tie. Then call @code{\refn} on @var{label}. (Example below.) @findex refs @item \refs@{@var{label}@} Like @code{\ref}, but append the letter @samp{s} to the @code{\@dots{}word}. @end table The purpose of the @code{\@dots{}word} macro is to produce the word `Section' or `Figure' or whatever that usually precedes the actual reference number. Here is an example: @example \def\sectionword@{Section@} \definexref@{sec-intro@}@{3.1@}@{section@} \definexref@{sec-next@}@{3.2@}@{section@} See \refs@{sec-intro@} and \refn@{sec-next@} @dots{} @end example @noindent This produces `See Sections 3.1 and 3.2 @dots{}' @node Page references @section Page references Eplain provides two commands for handling references to page numbers, one for definition and one for use. @table @code @item \xrdef@{@var{label}@} @findex xrdef Define @var{label} to be the current page number. This produces no printed output, and ignores following spaces. @item \xref@{@var{label}@} @findex xref Produce the text `p.@tie{}@var{pageno}', which is the usual form for cross-references. The @var{pageno} is actually @var{label}'s definition; if @var{label} isn't defined, the text of the label itself is printed. The `p.@tie{}' prefix is defined by @code{\xrefpageword}. @findex xrefpageword Its default definition is @code{p.\thinspace}. @end table Eplain can create hypertext links for the page references; @pxref{Page reference hyperlinks}. @node Equation references @section Equation references @cindex equations, references to @cindex equations, numbering Instead of referring to pages, it's most useful if equation labels refer to equation numbers. Therefore, Eplain reserves a @code{\count} register, @code{\eqnumber}, @findex eqnumber for the current equation number, and increments it at each numbered equation. Here are the commands to define equation labels and then refer to them: @table @code @item \eqdef@{@var{label}@} @findex eqdef This defines @var{label} to be the current value of @code{\eqnumber}, and, if the current context is not inner, then produces a @code{\eqno} command. (The condition makes it possible to use @code{\eqdef} in an @code{\eqalignno} construction, for example.) The text of the equation number is produced using @code{\eqprint}. @xref{Formatting equation references}. @cindex empty equation labels @cindex labels, empty equation @cindex equations, giving numbers to all If @var{label} is empty, you still get an equation number (although naturally you can't reliably refer to it). This is useful if you want to put numbers on all equations in your document, and you don't want to think up unique labels. @cindex empty equation labels, referring to @cindex labels, empty equation, referring to To refer to the last equation with the empty label, you just use the empty label in one of the equation reference macros (see below). This can be handy when you want to refer to an equation shortly after its definition, say, in the sentence following the displayed equation, and do not intend to refer to the equation later. But use this trick with extreme caution: if later you change the text and insert another empty definition between the original definition and the reference, the reference will start to refer to the new empty-labeled equation. @item \eqdefn@{@var{label}@} @findex eqdefn This is like @code{\eqdef}, except it always omits the @code{\eqno} command. It can therefore be used in places where @code{\eqdef} can't; for example, in a non-displayed equation. The text of the equation number is not produced, so you can also use it in the (admittedly unusual) circumstance when you want to define an equation label but not print that label. @item \eqref@{@var{label}@} @findex eqref This produces a formatted reference to @var{label}. If @var{label} is undefined (perhaps because it is a forward reference), it just produces the text of the label itself. Otherwise, it calls @code{\eqprint}. @item \eqrefn@{@var{label}@} @findex eqrefn This produces the cross-reference text for @var{label}. That is, it is like @code{\eqref}, except it doesn't call @code{\eqprint}. @end table @cindex equation labels, characters valid in Equation labels can contain the same characters that are valid in general cross-references. Eplain can create hypertext links for the equation references; @pxref{Equation reference hyperlinks}. @menu * Formatting equation references:: * Subequation references:: @end menu @node Formatting equation references @subsection Formatting equation references @cindex equation numbers, formatting of Both defining an equation label and referring to it should usually produce output. This output is produced with the @code{\eqprint} macro, which takes one argument, the equation number being defined or referred to. By default, this just produces @samp{(@var{number})}, where @var{number} is the equation number. To produce the equation number in a different font, or with different surrounding symbols, or whatever, you can redefine @code{\eqprint}. @findex eqprint For example, the following definition would print all equation numbers in italics. (The extra braces define a group, to keep the font change from affecting surrounding text.) @example \def\eqprint#1@{@{\it (#1)@}@} @end example In addition to changing the formatting of equation numbers, you might to add more structure to the equation number; for example, you might want to include the chapter number, to get equation numbers like `(1.2)'. To achieve this, you redefine @code{\eqconstruct}. @findex eqconstruct For example: @example \def\eqconstruct#1@{\the\chapternumber.#1@} @end example @noindent (If you are keeping the chapter number in a count register named @code{\chapternumber}, naturally.) The reason for having both @code{\eqconstruct} and @code{\eqprint} may not be immediately apparent. The difference is that @code{\eqconstruct} affects the text that cross-reference label is defined to be, while @code{\eqprint} affects only what is typeset on the page. The example just below might help. Usually, you want equation labels to refer to equation numbers. But sometimes you might want a more complicated text. For example, you might have an equation `(1)', and then have a variation several pages later which you want to refer to as `(1*)'. Therefore, Eplain allows you to give an optional argument (i.e., arbitrary text in square brackets) before the cross-reference label to \eqdef. Then, when you refer to the equation, that text is produced. Here's how to get the example just mentioned: @example $$@dots{}\eqdef@{a-eq@}$$ @dots{} $$@dots{}\eqdef[\eqrefn@{a-eq@}*]@{a-eq-var@}$$ In \eqref@{a-eq-var@}, we expand on \eqref@{a-eq@}, @dots{} @end example We use @code{\eqrefn} in the cross-reference text, not @code{\eqref}, so that @code{\eqprint} is called only once. @node Subequation references @subsection Subequation references @cindex equations, groups of @cindex subequations, referring to Eplain also provides for one level of substructure for equations. That is, you might want to define a related group of equations with numbers like `2.1' and `2.2', and then be able to refer to the group as a whole: ``@dots{} in the system of equations (2)@dots{}''. The commands to do this are @code{\eqsubdef} and @findex eqsubdef @code{\eqsubdefn}. @findex eqsubdefn They take one @var{label} argument like their counterparts above, and generally behave in the same way. The difference is in how they construct the equation number: instead of using just @code{\eqnumber}, they also use another counter, @code{\subeqnumber}. @findex subeqnumber This counter is advanced by one at every @code{\eqsubdef} or @code{\eqsubdefn}, and reset to zero at every @code{\eqdef} or @code{\eqdefn}. You use @code{\eqref} to refer to subequations as well as main equations. To put the two together to construct the text that the label will produce, they use a macro @code{\eqsubreftext}. @findex eqsubreftext This macros takes two arguments, the ``main'' equation number (which, because the equation label can be defined as arbitrary text, as described in the previous section, might be anything at all) and the ``sub'' equation number (which is always just a number). Eplain's default definition just puts a period between them: @example \def\eqsubreftext#1#2@{#1.#2@}% @end example @noindent You can redefine @code{\eqsubreftext} to print however you like. For example, this definition makes the labels print as `2a', `2b', and so on. @example \newcount\subref \def\eqsubreftext#1#2@{% \subref = #2 % The space stops a . \advance\subref by 96 % `a' is character code 97. #1\char\subref @} @end example @noindent Sadly, we must define a new count register, @code{\subref}, instead of using the scratch count register @code{\count255}, because @samp{#1} might include other macro calls which use @code{\count255}. @node Indexing @section Indexing @cindex indexing @cindex sorting an index Eplain provides support for generating raw material for an index, and for typesetting a sorted index. A separate program must do the actual collection and sorting of terms, because @TeX{} itself has no support for sorting. Eplain can create hypertext links pointing from the index to the index terms; @pxref{Index hyperlinks}. @cindex URL for MakeIndex @pindex makeindex Eplain's indexing commands were designed to work with the program MakeIndex, available from CTAN hosts in @file{tex-archive/indexing/makeindex}; MakeIndex is also commonly included in prepackaged @TeX{} distributions. It is beyond the scope of this manual to explain how to run MakeIndex, and all of its many options. See @url{http://www.ctan.org/tex-archive/indexing/makeindex/} The basic strategy for indexing works like this: @enumerate @pindex .idx @r{files} @item For a document @file{foo.tex}, Eplain's indexing commands (e.g., @code{\idx}; see the section `Indexing terms' below) write the raw index material to @file{foo.idx}. @pindex .ind @r{files} @item MakeIndex reads @file{foo.idx}, collects and sorts the index, and writes the result to @file{foo.ind}. @item Eplain reads and typesets @file{foo.ind} on a subsequent run of @TeX{}. See the section `Typesetting an index' below. @end enumerate @pindex texi2dvi @noindent The @command{texi2dvi} program can help you automate this process, @pxref{Invoking Eplain}. @cindex multiple indexes @cindex indexes, multiple @findex defineindex If your document needs more than one index, each must have its own file. Therefore, Eplain provides the command @code{\defineindex}, which takes an argument that is a single letter, which replaces @samp{i} in the filenames and in the indexing command names described below. For example, @example \defineindex@{m@} @end example @noindent defines the command @code{\mdx} to write to the file @file{foo.mdx}. Eplain simply does @code{\defineindex@{i@}} to define the default commands. @menu * Indexing terms:: Specifying what to index. * Typesetting an index:: Printing the sorted output. * Customizing indexing:: Creating commands and specifying extra actions. @end menu @node Indexing terms @subsection Indexing terms @cindex indexing terms @cindex silent indexing Indexing commands in Eplain come in pairs: one command that only writes the index entry to the @samp{.idx} file (see above section), and one that also typesets the term being indexed. The former always starts with @samp{s} (for ``silent''). In either case, the name always includes @samp{@var{I}dx}, where @var{I} is the index letter, also described above. Eplain defines the index @samp{i} itself, so that's what we'll use in the names below. @cindex subterm in indexing The silent form of the commands take a subterm as a trailing optional argument. For example, @code{\sidx@{truth@}[definition of]} on page 75 makes an index entry that will eventually be typeset (by default) as @display truth definition of, 75 @end display @cindex trailing spaces and indexing commands @cindex spaces, trailing and indexing commands @cindex indexing and trailing spaces Also, the silent commands ignore trailing spaces. The non-silent ones do not. @menu * Indexing commands:: Making index entries. * Modifying index entries:: Ranges, see/see also, page number typesetting. * Proofing index terms:: Noting index entries in the margins. @end menu @node Indexing commands @subsubsection Indexing commands @cindex indexing commands Here are the commands. @itemize @bullet @item @findex sidx @findex idx @code{\sidx@{@var{term}@}[@var{subterm}]} makes an index entry for @var{term}, optionally with subterm @var{subterm}. @code{\idx@{@var{term}@}} also produces @var{term} as output. Example: @example \sidx@{truth@}[beauty of] The beauty of truth is \idx@{death@}. @end example Subterms at the second and further levels can also be specified in @var{subterm}, using the @code{\idxsubentryseparator} character to separate them. This character is by default @samp{!}. @item @findex sidxname @findex idxnameseparator @findex idxname @code{\sidxname@{@var{First M.}@}@{@var{von Last}@}[@var{subterm}]} makes an index entry for @samp{@var{von Last}, @var{First M.}}. You can change the @samp{, } by redefining @code{\idxnameseparator}. @code{\idxname@{@var{First M.}@}@{@var{von Last}@}} also produces @var{First M. von Last} as output. (These commands are useful special cases of @code{\idx} and @code{\sidx}.) Example: @example \sidxname@{Richard@}@{Stark@} \idxname@{Donald@}@{Westlake@} has written many kinds of novels, under almost as many names. @end example @item @findex sidxmarked @findex idxmarked @code{\sidxmarked\@var{cs}@{@var{term}@}[@var{subterm}]} makes an index entry for @code{@var{term}[@var{subterm}]}, but @var{term} will be put in the index as @code{\@var{cs}@{term@}}, but still sorted as just @var{term}. @code{\idxmarked\@var{cs}@{@var{term}@}} also typesets @code{\@var{cs}@{term@}}. This provides for the usual ways of changing the typesetting of index entries. Example: @example \def\article#1@{``#1''@} \sidxmarked\article@{Miss Elsa and Aunt Sophie@} Peter Drucker's \idxmarked\article@{The Polanyis@} is a remarkable essay about a remarkable family. @end example @item @findex idxsubmarked @findex sidxsubmarked @code{\sidxsubmarked@{@var{term}@}\@var{cs}@{subterm@}} makes an index entry for @var{term}, @var{subterm} as usual, but also puts @var{subterm} in the index as @code{\@var{cs}@{term@}}. @code{\idxsubmarked@{@var{term}@}\@var{cs}@{subterm@}} also typesets @code{@var{term} \@var{cs}@{subterm@}}, in the unlikely event that your syntax is convoluted enough to make this useful. Example: @example \def\title#1@{@{\sl #1@}@} \sidxsubmarked@{Anderson, Laurie@}\title@{Strange Angels@} The \idxsubmarked@{Anderson@}\title@{Carmen@} is a strange twist. @end example @end itemize @cindex index entry general sorting @cindex sorting of index entries The commands above rely on MakeIndex's feature for separating sorting of an index entry's from its typesetting. You can use this directly by specifying an index entry as @code{@var{sort}@@@var{typeset}}. For example: @example \sidx@{Ap-weight@@$A_\pi$-weight@} @end example @noindent will sort as @code{Ap-weight}, but print with the proper math. The @code{@@} here is MakeIndex's default character for this purpose. See @url{http://www.ctan.org/tex-archive/indexing/makeindex/}. To make an index entry with an @code{@@} in it, you have to escape it with a backslash; Eplain provides no macros for doing this. @findex afterindexterm @r{hook} @cindex whatsits made by index entries After any index command, Eplain runs @code{\hookaction@{afterindexterm@}}. Because the index commands always add a whatsit item to the current list, you may wish to preserve a penalty or space past the new item. For example, given a conditional @code{\if@@aftersctnhead} set true when you're at a section heading, you could do: @example \hookaction@{afterindexterm@}@{\if@@aftersctnhead \nobreak \fi@} @end example @node Modifying index entries @subsubsection Modifying index entries @cindex modifying index entries' page numbers @cindex index entries' page numbers, modifying All the index commands described in the previous section take an initial optional argument before the index term, which modify the index entry's meaning in various ways. You can specify only one of the following in any given command, except that @code{begin} and @code{end} can be specified together with @code{pagemarkup=@var{cs}} (separate them with a comma without a following space, like this: @code{[begin,pagemarkup=defn]}). These work via MakeIndex's ``encapsulation'' feature. @xref{Customizing indexing}, if you're not using the default characters for the MakeIndex operators. The other optional argument (specifying a subterm) is independent of these. Here are the possibilities: @table @code @item begin @itemx end @findex begin @r{for index entries} @findex end @r{for index entries} @cindex index entries and ranges @cindex ranges and index entry These mark an index entry as the beginning or end of a range. The index entries must match exactly for MakeIndex to recognize them. Example: @example \sidx[begin]@{future@}[Cohen, Leonard] @dots{} \sidx[end]@{future@}[Cohen, Leonard] @end example @noindent will typeset as something like @display future, Cohen, Leonard, 65--94 @end display @item see @findex see @r{for index entries} @cindex see, and index entries @cindex cross-referencing index entries @cindex index entries, and cross-referencing This marks an index entry as pointing to another; the real index term is an additional (non-optional) argument to the command. Thus you can anticipate a term readers may wish to look up, yet which you have decided not to index. Example: @example \sidx[see]@{analysis@}[archetypal]@{archetypal criticism@} @end example @noindent becomes @display analysis, archetypal, @i{see} archetypal criticism @end display @item seealso @findex seealso @r{for index entries} Similar to @code{see} (the previous item), but also allows for normal index entries of the referencing term. Example: @example \sidx[seealso]@{archetypal criticism@}[elements of]@{dichotomies@} @end example @noindent becomes @display archetypal criticism, elements of, 75, 97, 114, @i{see also} dichotomies @end display (Aside for the academically curious: The archetypally critical book I took these dichotomous examples from is Laurence Berman's @cite{The Musical Image}, which I happened to co-design and typeset.) @item pagemarkup=@var{cs} This puts @code{\@var{cs}} before the page number in the typeset index, thus allowing you to underline definitive entries, italicize examples, and the like. You do @emph{not} precede the control sequence @var{cs} with a backslash. (That just leads to expansive difficulties.) Naturally it is up to you to define the control sequences you want to use. Example: @example \def\defn#1@{@{\sl #1@}@} \sidx[pagemarkeup=defn]@{indexing@} @end example @noindent becomes something like @example indexing, @code{\defn@{75@}} @end example @end table @node Proofing index terms @subsubsection Proofing index terms @cindex proofing index terms @cindex index terms, proofing @cindex margins, index terms in As you are reading through a manuscript, it is helpful to see what terms have been indexed, so you can add others, catch miscellaneous errors, etc. (Speaking from bitter experience, I can say it is extremely error-prone to leave all indexing to the end of the writing, since it involves adding many @TeX{} commands to the source files.) @findex indexproofterm @findex indexprooffont @pindex cmtt8 So Eplain puts index terms in the margin of each page, if you set @code{\indexproofingtrue}. It is @code{false} by default. The terms are typeset by the macro @code{\indexproofterm}, which takes a single argument, the term to be typeset. Eplain's definition of @code{\indexproofterm} just puts it into an @code{\hbox}, first doing @code{\indexprooffont}, which Eplain defines to select the font @code{cmtt8}. With this definition long terms run off the page, but since this is just for proofreading anyway, it seems acceptable. @findex pageno @findex insidemargin @findex hoffset @findex outsidemargin @findex indexsetmargins On the other hand, we certainly don't want the index term to run into the text of the page, so Eplain uses the right-hand side of the page rather than the left-hand page (assuming a language read left to right here). So @code{\ifodd\pageno}, Eplain kerns by @code{\outsidemargin}, otherwise by @code{\insidemargin}. If those macros are undefined, @code{\indexsetmargins} defines them to be one inch plus @code{\hoffset}. @findex @@indexproof @r{insertion class} @findex indexproofunbox @findex makeheadline @cindex output routine and index proofing To get the proofing index entries on the proper page, Eplain defines a new insertion class @code{\@@indexproof}. To unbox any index proofing material, Eplain redefines @code{\makeheadline} to call @code{\indexproofunbox} before the original @code{\makeheadline}. Thus, if you have your own output routine, that redefines or doesn't use @code{\makeheadline}, it's up to you to call @code{\indexproofunbox} at the appropriate time. @node Typesetting an index @subsection Typesetting an index @cindex typesetting an index @cindex index typesetting @findex readindexfile The command @code{\readindexfile@{i@}} reads and typesets the @file{.ind} file that MakeIndex outputs (from the @file{.idx} file which the indexing commands in the previous sections write). Eplain defines a number of commands that support the default MakeIndex output. @findex indexfilebasename @findex jobname More precisely, @code{\readindexfile} reads @code{\indexfilebasename.@var{index-letter}nd}, where the @var{index-letter} is the argument. @code{\indexfilebasename} is @code{\jobname} by default, but if you have different indexes in different parts of a book, you may wish to change it, just as with bibliographies (@pxref{Citations}). @findex begin@{theindex@} @findex end@{theindex@} MakeIndex was designed to work with @LaTeX{}; therefore, by default the @file{.ind} file starts with @code{\begin@{theindex@}} and ends with @code{\end@{theindex@}}. If no @code{\begin} has been defined, Eplain defines one to ignore its argument and set up for typesetting the index (see below), and also defines a @code{\end} to ignore its argument. (In a group, naturally, since there is a primitive @code{\end}). @findex parindent @r{in indexes} @cindex index fonts @findex indexfonts @cindex double columns in indexes Eplain calls @code{\indexfonts}, sets @code{\parindent = 0pt}, and does @code{\doublecolumns} (@pxref{Multiple columns}) at the @code{\begin@{theindex@}}. @code{\indexfonts} does nothing by default; it's just there for you to override. (Indexes are usually typeset in smaller type than the main text.) @findex beginindex @r{hook} It ends the setup with @code{\hookrun@{beginindex@}}, so you can override anything you like in that hook (@pxref{Hooks}). For example: @example \hookaction@{beginindex@}@{\triplecolumns@} @end example @findex item @r{in indexes} @findex subitem @r{in indexes} @findex subsubitem @r{in indexes} @cindex index entry formatting @cindex formatting index entries @cindex space above index entries @cindex continued index entries @cindex index entry continuations MakeIndex turns each main index entry into an @code{\item}, subentries into @code{\subitem}, and subsubentries into @code{\subsubitem}. By default, the first line of main entries are not indented, and subentries are indented 1em per level. Main entries are preceded by a @code{\vskip} of @code{\aboveitemskipamount}, @code{0pt plus2pt} by default. Page breaks are encouraged before main entries (@code{\penalty -100}), but prohibited afterwards---Eplain has no provision for ``continued'' index entries. All levels do the following: @findex hangindent @r{for index entries} @findex raggedright @r{for index entries} @findex hyphenpenalty @r{for index entries} @example \hangindent = 1em \raggedright \hyphenpenalty = 10000 @end example @findex indexitem @r{hook} Each entry ends with @code{\hookrun@{indexitem@}}, so you can change any of this. For example, to increase the allowable rag: @example \hookaction@{indexitem@}@{\advance\rightskip by 2em@} @end example @findex indexspace @cindex index groupings Finally, MakeIndex outputs @code{\indexspace} between each group of entries in the @file{.ind} file. Eplain makes this equivalent to @code{\bigbreak}. @node Customizing indexing @subsection Customizing indexing @cindex customizing indexing @findex afterindexterm @cindex commas after index terms @cindex after index terms By default, MakeIndex outputs @samp{, } after each term in the index. To change this, you can add the following to your MakeIndex style (@file{.ist}) file: @example delim_0 "\\afterindexterm " delim_1 "\\afterindexterm " delim_2 "\\afterindexterm " @end example @noindent Eplain makes @code{\afterindexterm} equivalent to @code{\quad}. You can also change the keywords Eplain recognizes (@pxref{Modifying index entries}): @table @code @item \idxrangebeginword @findex idxrangebeginword `begin' @item \idxrangeendword @findex idxrangeendword `end' @item \idxseecmdword @findex idxseecmdword `see' @item \idxseealsocmdword @findex idxseealsocmdword `seealso' @end table You can also change the magic characters Eplain puts into the @file{.idx} file, in case you've changed them in the @code{.ist} file: @table @code @item \idxsubentryseparator @findex idxsubentryseparator @samp{!} @item \idxencapoperator @findex idxencapoperator @samp{|} @item \idxbeginrangemark @findex idxbeginrangemark @samp{(} @item \idxendrangemark @findex idxendrangemark @samp{)} @end table There is no macro for the @code{actual} (@samp{@@} by default) character, because it's impossible to make it expand properly. @findex idxpagenum @cindex see also index entries and sorting You can change the (imaginary) page number that ``see also'' entries sort as by redefining @code{\idxmaxpagenum}. This is 99999 by default, which is one digit too many for old versions of MakeIndex. @findex indexseeword @findex indexseealsowords @findex seevariant @findex indexsee @findex indexseealso The words output by Eplain for ``see'' and ``see also'' index entries are defined by @code{\indexseeword} and @code{\indexseealsowords} respectively. You can change the typeface used for these words by redefining @code{\seevariant}. And finally, the macros @code{\indexsee} and @code{\indexseealso} actually produce the ``see @dots{}'' entries, so you can redefine them if you want something entirely different. If you do redefine them, make them take two parameters, the term being referenced and the @code{\idxmaxpagenum} (the latter should normally be ignored). See the example below. @findex see @r{for index entries} @cindex see, and index entries @cindex cross-referencing index entries @cindex index entries, and cross-referencing @cindex commas in cross-referencing index entries Unfortunately, it is impossible to reliably control the commas produced by MakeIndex in front of ``see @dots{}'' entries in the @file{.ind} file, either at MakeIndex level or at Eplain level. However, the @pindex sed @command{sed} script named @command{trimsee} @pindex trimsee distributed with Eplain in the @file{test} directory can be used to filter out these commas from the output of MakeIndex. For example, suppose you want the following style for your ``see @dots{}'' entries: @display analysis, archetypal (@i{see} archetypal criticism) archetypal criticism, elements of, 75, 97, 114 (@i{see also} dichotomies) @end display @noindent You would need to redefine these macros in your @TeX{} file: @example \def\indexsee#1#2@{(@{\seevariant \indexseeword\/ @}#1)@} \def\indexseealso#1#2@{(@{\seevariant \indexseealsowords\/ @}#1)@} @end example @noindent and then filter out the commas in front of the ``see @dots{}'' entries by running the following command to produce the @file{.ind} file (assuming the name of the @file{.idx} file is @file{myfile.idx} and the @file{trimsee} script is placed in the current directory): @example prompt$ cat myfile.idx | makeindex | ./trimsee > myfile.ind @end example By default, @file{trimsee} uses default page list separators and default ``see @dots{}'' command names. If you set up MakeIndex to use different page list separator or change the names of @code{\indexsee} and @code{\indexseealso} commands, it is possible to adjust the @file{trimsee} script through its command line options, which are the following: @table @option @item -i @var{is} Use @var{is} as a regular expression matching separator before ``see @dots{}'' commands in the input (default: @samp{, \+}). @item -o @var{os} Use @var{os} as a separator to replace @var{is} before ``see @dots{}'' commands (default: @samp{ }). @item -s @var{see} Use @var{see} as a regular expression matching ``see @dots{}'' commands (default: @samp{\\indexsee}). @item -h @itemx --help Print a usage message. @item -v @itemx --version Print version. @end table @file{trimsee} reads input from the standard input, and directs its output to the standard output. @node Justification @section Justification @cindex centering @cindex left-justification @cindex right-justification @cindex justification Eplain defines three commands to conveniently justify multiple lines of text: @code{\flushright}, @code{\flushleft}, and @code{\center}. @findex flushright @findex flushleft @findex center They all work in the same way; let's take @code{\center} as the example. To start centering lines, you say @code{\center} inside a group; to stop, you end the group. Between the two commands, each end-of-line in the input file also starts a new line in the output file. The entire block of text is broken into paragraphs at blank lines, so all the @TeX{} paragraph-shaping parameters apply in the usual way. This is convenient, but it implies something else that isn't so convenient: changes to any linespacing parameters, such as @code{\baselineskip}, will have @emph{no effect} on the paragraph in which they are changed. @TeX{} does not handle linespacing changes within a paragraph (because it doesn't know where the line breaks are until the end of the paragraph). The space between paragraphs is by default one blank line's worth. You can adjust this space by assigning to @code{\blanklineskipamount}; @findex blanklineskipamount @r{in justified text} this (vertical) glue is inserted after each blank line. Here is an example: @example @{\center First line. Second line, with a blank line before. @} @end example This produces: @center First line. @center @center Second line, with a blank line before. You may wish to use the justification macros inside of your own macros. Just be sure to put them in a group. For example, here is how a title macro might be defined: @example \def\title@{\begingroup\titlefont\center@} \def\endtitle@{\endgroup@} @end example @node Tables @section Tables @cindex tables @cindex alignments Eplain provides a single command, @code{\makecolumns}, @findex makecolumns to make generating one particular kind of table easier. More ambitious macro packages might be helpful to you for more difficult applications. The files @file{ruled.tex} and @file{TXSruled.tex}, available from @samp{lifshitz.ph.utexas.edu} in @file{texis/tables}, is the only one I know of. Many tables are homogenous, i.e., all the entries are semantically the same. The arrangement into columns is to save space on the page, not to encode different meanings. In this kind of the table, it is useful to have the column breaks chosen automatically, so that you can add or delete entries without worrying about the column breaks. @code{\makecolumns} takes two arguments: the number of entries in the table, and the number of columns to break them into. As you can see from the example below, the first argument is delimited by a slash, and the second by a colon and a space (or end-of-line). The entries for the table then follow, one per line (not including the line with the @code{\makecolumns} command itself). @code{\parindent} defines the space to the left of the table. @code{\hsize} defines the width of the table. So you can adjust the position of the table on the page by assignments to these parameters, probably inside a group. You can also control the penalty at a page break before the @code{\makecolumns} by setting the parameter @code{\abovecolumnspenalty}. @findex abovecolumnspenalty Usually, the table is preceded by some explanatory text. You wouldn't want a page break to occur after the text and before the table, so Eplain sets it to @code{10000}. But if the table produced by @code{\makecolumns} is standing on its own, @code{\abovecolumnspenalty} should be decreased. If you happen to give @code{\makecolumns} a smaller number of entries than you really have, some text beyond the (intended) end of the table will be incorporated into the table, probably producing an error message, or at least some strange looking entries. And if you give @code{\makecolumns} a larger number of entries than you really have, some of the entries will be typeset as straight text, probably also looking somewhat out of place. Here is an example: @example % Arrange 6 entries into 2 columns: \makecolumns 6/2: % This line doesn't have an entry. one two three four five six Text after the table. @end example This produces `one', `two', and `three' in the first column, and `four', `five', and `six' in the second. @node Margins @section Margins @cindex margins, changing @TeX{}'s primitives describe the type area in terms of an offset from the upper left corner, and the width and height of the type. Some people prefer to think in terms of the @dfn{margins} at the top, bottom, left, and right of the page, and most composition systems other than @TeX{} conceive of the page laid out in this way. Therefore, Eplain provides commands to directly assign and increment the margins. @table @code @itemx \topmargin = @var{dimen} @itemx \bottommargin = @var{dimen} @itemx \leftmargin = @var{dimen} @item \rightmargin = @var{dimen} @findex topmargin @findex bottommargin @findex leftmargin @findex rightmargin These commands set the specified margin to the @var{dimen} given. The @code{=} and the spaces around it are optional. The control sequences here are not @TeX{} registers, despite appearances; therefore, commands like @code{\showthe\topmargin} will not do what you expect. @itemx \advancetopmargin by @var{dimen} @itemx \advancebottommargin by @var{dimen} @itemx \advanceleftmargin by @var{dimen} @item \advancerightmargin by @var{dimen} @findex advancetopmargin @findex advancebottommargin @findex advanceleftmargin @findex advancerightmargin These commands change the specified margin by the @var{dimen} given. @end table Regardless of whether you use the assignment or the advance commands, Eplain always changes the type area in response, not the other margins. For example, when @TeX{} starts, the left and right margins are both one inch. If you then say @code{\leftmargin = 2in}, the right margin will remain at one inch, and the width of the lines (i.e., @code{\hsize}) @findex hsize will decrease by one inch. When you use any of these commands, Eplain computes the old value of the particular margin, by how much you want to change it, and then resets the values of @TeX{}'s primitive parameters to correspond. Unfortunately, Eplain cannot compute the right or bottom margin without help: you must tell it the full width and height of the final output page. It defines two new parameters for this: @table @code @item \paperheight @findex paperheight The height of the output page; default is 11truein. @item \paperwidth @findex paperwidth The width of the output page; default is 8.5truein. @end table If your output page has different dimensions than this, you must reassign to these parameters, as in @example \paperheight = 11truein \paperwidth = 17truein @end example @node Multiple columns @section Multiple columns @cindex double column output @cindex triple column output @cindex quadruple column output @cindex multiple column output Eplain provides for double, triple, and quadruple column output: say @code{\doublecolumns}, @findex doublecolumns @code{\triplecolumns}, @findex triplecolumns or @code{\quadcolumns}, @findex quadcolumns and from that point on, the manuscript will be set in columns. To go back to one column, say @code{\singlecolumn}. @findex singlecolumn @cindex column balancing with @code{\singlecolumn} @cindex balancing of columns with @code{\singlecolumn} You may need to invoke @code{\singlecolumn} to balance the columns on the last page of output. @findex columnfill @cindex column eject @cindex eject in multicolumns @findex pagetotal To do a ``column eject'', i.e., move to the top of the next column, do @code{\columnfill}. This does not actually force an eject, however: it merely inserts a kern of size @code{\@@normalvsize} minus @code{\pagetotal} (@code{\@@normalvsize} being the usual height of the page; to implement multicolumns, Eplain multiplies @code{\vsize} itself by the number of columns). In most circumstances, a column break will be forced after this kern (during the column splitting operation when the whole page is output), as desired. @findex gutter The columns are separated by the value of the dimen parameter @code{\gutter}. Default value is two picas. @findex gutterbox If you want to add vertical material between the columns, use @code{\gutterbox}. For example, to put a vertical line between columns, define @code{\gutterbox} as @example \def\gutterbox@{\vbox to \dimen0@{\vfil\hbox@{\vrule height\dimen0@}\vfil@}@}% @end example The dimension counter @code{\dimen0} contains the height of the column. All the @code{\@dots{}columns} macros insert the value of the glue parameter @code{\abovecolumnskip} @findex abovecolumnskip before the multicolumn text, and the value of the glue parameter @code{\belowcolumnskip} @findex belowcolumnskip after it. The default value for both of these parameters is @code{\bigskipamount}, i.e., one linespace in plain @TeX{}. The macros take into account only the insertion classes @cindex insertion classes defined by plain @TeX{}; namely, footnotes and @code{\topinsert}s. If you have additional insertion classes, you will need to change the implementation. Also, Eplain makes insertions the full page width. There is no provision for column-width insertions. @node Footnotes @section Footnotes @cindex footnotes, numbered The most common reference mark for footnotes is a raised number, incremented on each footnote. The @code{\numberedfootnote} @findex numberedfootnote macro provides this. It takes one argument, the footnote text. If your document uses only numbered footnotes, you could make typing @code{\numberedfootnote} more convenient with a command such as: @example \let\footnote = \numberedfootnote @end example After doing this, you can type your footnotes as @code{\footnote@{@var{footnote text}@}}, instead of as @code{\numberedfootnote@{@var{footnote text}@}}. Eplain keeps the current footnote number in the count register @code{\footnotenumber}. So, to reset the footnote number to zero, as you might want to do at, for example, the beginning of a chapter, you could say @code{\footnotenumber=0}. Plain @TeX{} separates the footnote marker from the footnote text by an en space (it uses the @code{\textindent} macro). In Eplain, you can change this space by setting the dimension register @code{\footnotemarkseparation}. @findex footnotemarkseparation The default is still an en. You can produce a space between footenotes by setting the glue register @code{\interfootnoteskip}. @findex interfootnoteskip The default is zero. @code{\parskip} is also set to zero by default before the beginning of each footnote (but not for the text of the footnote). You can also control footnote formatting in a more general way: Eplain expands the token register @code{\everyfootnote} @findex everyfootnote before a footnote is typeset, but after the default values for all the parameters have been established. For example, if you want your footnotes to be printed in seven-point type, indented by one inch, you could say: @example \everyfootnote = @{\sevenrm \leftskip = 1in@} @end example By default, an @code{\hrule} is typeset above each group of footnotes on a page. You can control the dimensions of this rule by setting the dimension registers @code{\footnoterulewidth} @findex footnoterulewidth and @code{\footnoteruleheight}. @findex footnoteruleheight The space between the rule and the first footnote on the page is determined by the dimension register @code{\belowfootnoterulespace}. @findex belowfootnoterulespace If you don't want any rule at all, set @code{\footenoteruleheight=0pt}, and, most likely, @code{\belowfootnoterulespace=0pt}. The defaults for these parameters typeset the rule in the same way as plain @TeX{}: the rule is 0.4 points high, 2 true inches wide, with 2.6 points below it. The space above the rule and below the text on the page is controlled by the glue register @code{\skip\footins}. The default is a plain @TeX{} @code{\bigskip}. Eplain can create hypertext links for the footnote marks; @pxref{Footnote hyperlinks}. @node Fractions @section Fractions @cindex fractions Exercise 11.6 of @cite{The @TeX{}book} describes a macro @code{\frac} @findex frac for setting fractions, but @code{\frac} never made it into plain @TeX{}. So Eplain includes it. @code{\frac} typesets the numerator and denominator in @code{\scriptfont0}, slightly raised and lowered. The numerator and denominator are separated by a slash. The denominator must be enclosed in braces if it's more than one token long, but the numerator need not be. (This is a consequence of @code{\frac} taking delimited arguments; see page@tie{}203 of @cite{The @TeX{}book} for an explanation of delimited macro arguments.) For example, @code{\frac 23/@{64@}} turns `23/64' into @tex \leavevmode \kern-.1em \raise .5ex \hbox{\the\scriptfont0 23}@comment \kern-.1em $/$@comment \kern-.15em \lower .25ex \hbox{\the\scriptfont0 64}@comment @end tex @ifinfo 23/64 (you can't see the difference in the Info file)@comment @end ifinfo . @node Paths @section Paths @cindex pathnames, breaking @cindex filenames, breaking @cindex electronic mail addresses, breaking When you typeset long pathnames, electronic mail addresses, or other such ``computer'' names, you would like @TeX{} to break lines at punctuation characters within the name, rather than trying to find hyphenation points within the words. For example, it would be better to break the email address @code{letters@@alpha.gnu.ai.mit.edu} at the @samp{@@} or a @samp{.}, rather than at the hyphenation points in @samp{letters} and @samp{alpha}. @findex path If you use the @code{\path} macro to typeset the names, @TeX{} will find these good breakpoints. The argument to @code{\path} is delimited by any character other other than @samp{\} which does not appear in the name itself. @samp{|} is often a good choice, as in: @example \path|letters@@alpha.gnu.ai.mit.edu| @end example @findex discretionaries You can control the exact set of characters at which breakpoints will be allowed by calling @code{\discretionaries}. This takes the same sort of delimited argument; any character in the argument will henceforth be a valid breakpoint within @code{\path}. The default set is essentially all the punctuation characters: @example \discretionaries |~!@@$%^&*()_+`-=#@{@}[]:";'<>,.?\/| @end example @findex specialpathdelimiters @r{(conditional)} If for some reason you absolutely must use @code{\} as the delimiter character for @code{\path}, you can set @code{\specialpathdelimiterstrue}. (Other delimiter characters can still be used.) @TeX{} then processes the @code{\path} argument about four times more slowly. @cindex URL for @file{path.sty} The @code{\path} macro comes from @file{path.sty}, written by Nelson Beebe and Philip Taylor and available at @url{http://www.ctan.org/tex-archive/macros/latex/contrib/misc/path.sty}. @node Logos @section Logos @cindex logos @cindex names, of @TeX{} variants Eplain redefines the @code{\TeX} @findex TeX macro of plain @TeX{} to end with @code{\null}, so that the proper spacing is produced when @code{\TeX} is used at the end of a sentence. The other @dots{}@TeX{} macros listed here do this, also. Eplain defines @code{\AMSTeX}, @cindex AMS@TeX{} @findex AMSTeX @code{\BibTeX} @cindex Bib@TeX{} @findex BibTeX @code{\AMSLaTeX}, @cindex AMS@LaTeX{} @findex AMSLaTeX @code{\LAMSTeX}, @cindex LAMS@TeX{} @findex LAMSTeX @code{\LaTeX} @cindex @LaTeX{} @findex LaTeX @code{\MF}, @cindex Metafont @findex MF and @code{\SLiTeX} @cindex SLi@TeX{} @findex SLiTeX to produce their respective logos. (Sorry, the logos are not shown here.) Some spelling variants of these are also supported. @cindex URL for @file{texnames.sty} All these macros come from @file{texnames.sty}, compiled by Nelson Beebe and available at @url{http://www.ctan.org/tex-archive/info/biblio/texnames.sty}. @node Boxes @section Boxes @cindex black boxes @cindex rectangles The solid rectangle that Eplain uses as a marker in unordered lists (@pxref{Lists}) is available by itself: just say @code{\blackbox}. @findex blackbox You can create black boxes of arbitrary size with @code{\hrule} or @code{\vrule}. @cindex open boxes @cindex boxes, open You can also get unfilled rectangles with @code{\makeblankbox}. @findex makeblankbox This takes two explicit arguments: the height and depth of the rules that define the top and bottom of the rectangle. (The two arguments are added to get the width of the left and right borders, so that the thickness of the border is the same on all four sides.) It also uses, as implicit arguments, the dimensions of @code{\box0} to define the dimensions of the rectangle it produces. (The contents of @code{\box0} are ignored.) Here is an example. This small raised open box is suitable for putting next to numbers in, e.g., a table of contents. @example \def\openbox@{% \ht0 = 1.75pt \dp0 = 1.75pt \wd0 = 3.5pt \raise 2.75pt \makeblankbox@{.2pt@}@{.2pt@} @} @end example Finally, you can put a box around arbitrary text with @code{\boxit}. @findex boxit This takes one argument, which must itself be a (@TeX{}) box, and puts a printed box around it, separated by @code{\boxitspace} @findex boxitspace white space (3 points by default) on all four sides. For example: @example \boxit@{\hbox@{This text is boxed.@}@} @end example The reason that the argument must be a box is that when the text is more than one line long, @TeX{} cannot figure out the line length for itself. Eplain does set @code{\parindent} to zero inside @code{\boxit}, since it is very unlikely you would want indentation there. (If you do, you can always reset it yourself.) @code{\boxit} uses @code{\ehrule} and @code{\evrule} so that you can easily adjust the thicknesses of the box rules. @xref{Rules}. @node Checking for PDF output @section Checking for PDF output @cindex URL for pdf@TeX{} @cindex PDF output @pindex pdftex @pindex .pdf @r{files} pdf@TeX{} is a @TeX{} variant that can output both @file{.dvi} and @file{.pdf} (Adobe's Portable Document Format) files (see @url{http://www.ctan.org/tex-archive/systems/pdftex/}). You might sometimes want to know whether the target format is @file{.pdf} or @file{.dvi}. The @code{\ifpdf} @findex ifpdf switch can be used to detect pdf@TeX{} in PDF mode: @example \ifpdf This text is produced when pdfTeX is in PDF mode. \else This text is produced when pdfTeX is in DVI mode, or when some program other than pdfTeX is used. \fi @end example Keep in mind that @code{\ifpdf} is set based on the value of the @code{\pdfoutput} @findex pdfoutput primitive of pdf@TeX{} at the time Eplain is loaded. If you change the value of @code{\pdfoutput} after you load Eplain, @code{\ifpdf} will not reflect the change. @cindex URL for @file{ifpdf.sty} @cindex Oberdiek, Heiko Eplain defines @code{\ifpdf} by incorporating Heiko Oberdiek's @file{ifpdf.sty}, which is available at @url{http://www.ctan.org/tex-archive/macros/latex/contrib/oberdiek/ifpdf.sty}. @node Loading LaTeX packages @section Loading @LaTeX{} packages @cindex @LaTeX{} packages @cindex packages, @LaTeX{} @pindex .sty @r{files} @pindex .cls @r{files} Eplain provides a limited support for loading @LaTeX{} packages (@file{.sty} files---not @file{.cls}). This will mostly work for packages which were designed with plain @TeX{} compatibility in mind, which means that most @LaTeX{} packages cannot be loaded. The packages which are known to work are listed below (@pxref{Packages known to work}). If you discover a working package which is not in the list, please report it to the Eplain mailing list (@pxref{Introduction}). @cindex graphics collection, @LaTeX{} @cindex @LaTeX{} graphics collection @pindex miniltx.tex @cindex Carlisle, David @cindex Rahtz, Sebastian To set up a pseudo-@LaTeX{} environment for the packages, Eplain uses @file{miniltx.tex} (@url{http://www.ctan.org/tex-archive/macros/plain/graphics/miniltx.tex}) from the @LaTeX{} graphics collection, written by David Carlisle and Sebastian Rahtz (the collection is available at @url{http://www.ctan.org/tex-archive/macros/latex/required/graphics/}). Eplain extends @file{miniltx.tex} to provide some additional features, e.g., support for package options. @menu * The \usepackage command:: Command to load packages. * Environment for loading packages:: Environment for the \usepackage commands. * Packages known to work:: Supported packages. * Packages known not to work:: Packages known not to work with Eplain. @end menu @node The \usepackage command @subsection The @code{\usepackage} command @findex usepackage @code{\usepackage} loads a @LaTeX{} package. Its syntax is similar to that of @LaTeX{}'s @code{\usepackage} command: @example \usepackage[@var{options}]@{@var{packages}@}[@var{version}] @end example @noindent where @var{options} is a comma-separated list of package options, @var{packages} is a comma-separated list of packages to load (without the @file{.sty} suffix), and @var{version} is a package version number given as a date in the format @samp{YYYY/MM/DD}. If an older version of the package is found, a warning is issued. If several packages are loaded within a single @code{\usepackage} command, the @var{options} will be applied to each of the packages. As usual, parameters in square brackets are optional and can be omitted (together with the square brackets). For example: @example \usepackage[foo,bar]@{pack1,pack2@}[2005/08/29] @end example @noindent will load packages @samp{pack1} and @samp{pack2}, each with the options @samp{foo} and @samp{bar}, and will check that each of the packages are dated 2005/08/29 or newer. @node Environment for loading packages @subsection Environment for loading packages @findex beginpackages @findex endpackages Some packages request that certain commands are executed after all packages have been loaded. In @LaTeX{}, this means that the commands are executed at the beginning of the document, after the so-called @dfn{preamble}. Neither plain @TeX{} nor Eplain have any kind of preamble; therefore, Eplain requires that all packages be loaded inside a @code{\beginpackages...\endpackages} block, for example: @example \beginpackages \usepackage[foo,bar]@{pack1@} \usepackage@{pack2@} \endpackages @end example @noindent This requirement enables Eplain to execute the ``delayed'' commands at the end of the @code{\beginpackages...\endpackages} block. For the same reason, it is advisable to specify only one such block per document, just like there is only one preamble in @LaTeX{}. @node Packages known to work @subsection Packages known to work @cindex @LaTeX{} packages @cindex packages, @LaTeX{} The following table lists packages that had been tested and are known to work with Eplain, and locations where you can find manuals for these packages. Some of the short descriptions of the packages were taken from the documentation for those packages. @table @asis @item autopict (@samp{2001/06/04 v1.1j Picture mode autoload file}) @pindex autopict.sty @url{http://tug.org/eplain/ltpictur.pdf} @cindex picture mode @findex begin@{picture@} @findex end@{picture@} This is the @LaTeX{} ``picture mode'', started by @code{\begin@{picture@}} and ended by @code{\end@{picture@}} (in @LaTeX{}, this package is not explicitly loaded since it is part of the @LaTeX{} kernel). It provides commands to draw simple figures inside your document without resorting to any external tools. @item color (@samp{1999/02/16 v1.0i Standard LaTeX Color (DPC)}) @pindex color.sty @itemx graphics (@samp{2001/07/07 v1.0n Standard LaTeX Graphics (DPC,SPQR)}) @pindex graphics.sty @itemx graphicx (@samp{1999/02/16 v1.0f Enhanced LaTeX Graphics (DPC,SPQR)}) @pindex graphicx.sty @url{http://www.ctan.org/tex-archive/macros/latex/required/graphics/grfguide.pdf} @cindex graphics collection, @LaTeX{} @cindex @LaTeX{} graphics collection @cindex color @cindex rotation @cindex scaling These packages are from the @LaTeX{} graphics collection. They provide commands for changing text/page colors, text rotation and scaling, and much more. @item psfrag (@samp{1998/04/11 v3.04 PSfrag (MCG)}) @pindex psfrag.sty @url{http://www.ctan.org/tex-archive/macros/latex/contrib/psfrag/pfgguide.pdf} @cindex Encapsulated PostScript @cindex EPS @pindex .eps @r{files} PSfrag allows the user to precisely overlay Encapsulated PostScript (EPS) files with arbitrary (La)@TeX{} constructions. In order to accomplish this, the user places a simple text ``tag'' in the graphics file, as a ``position marker'' of sorts. Then, using simple (La)@TeX{} commands, the user instructs PSfrag to remove that tag from the figure, and replace it with a properly sized, aligned, and rotated (La)@TeX{} equation. @item url (@samp{2005/06/27 ver 3.2 Verb mode for urls, etc.}) @pindex url.sty @url{http://www.ctan.org/tex-archive/macros/latex/contrib/misc/url.sty} @cindex pathnames, breaking @cindex filenames, breaking @cindex electronic mail addresses, breaking This package provides a form of @code{\verbatim} that allows line breaks at certain characters or combinations of characters, accepts reconfiguration, and can usually be used in the argument to another command. It is intended for email addresses, hypertext links, directories/paths, etc., which normally have no spaces. Eplain can create hypertext links with the @code{\url} command; @pxref{URL hyperlinks}. @end table @node Packages known not to work @subsection Packages known not to work @cindex @LaTeX{} packages @cindex packages, @LaTeX{} The following packages are known not to work with Eplain: @table @asis @item pict2e (@samp{2005/07/15 v0.2r Improved picture commands (HjG,RN)}) @pindex pict2e.sty @url{http://www.ctan.org/tex-archive/macros/latex/contrib/pict2e/} @item xcolor (@samp{2005/06/06 v2.03 LaTeX color extensions (UK)}) @pindex xcolor.sty @url{http://www.ctan.org/tex-archive/macros/latex/contrib/xcolor/} @end table