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-rw-r--r--Master/texmf-dist/doc/optex/README120
-rw-r--r--Master/texmf-dist/doc/optex/omls.tex832
-rw-r--r--Master/texmf-dist/doc/optex/optex-doc.pdfbin0 -> 1380041 bytes
-rw-r--r--Master/texmf-dist/doc/optex/optex-doc.tex114
-rw-r--r--Master/texmf-dist/doc/optex/optex-math.tex1662
-rw-r--r--Master/texmf-dist/doc/optex/optex-techdoc.tex290
-rw-r--r--Master/texmf-dist/doc/optex/optex-userdoc.tex2019
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diff --git a/Master/texmf-dist/doc/optex/README b/Master/texmf-dist/doc/optex/README
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+OpTeX: the LuaTeX format based on Plain TeX and OPmac
+
+Author: Petr Olsak, <petr@olsak.net>
+
+This software is in public domain.
+
+See http://petr.olsak.net/optex
+
+Files:
+
+base/ ... basic set of macro files used when optex.fmt is generated
+ and more basic macros loaded on demand during document processing.
+demo/ ... examples: short document: op-demo.tex, short letter: op-letter.tex,
+ presentation slides: op-slides.tex.
+pkg/ ... external macros. Maybe, they can be created by other authors if
+ the macro file conforms to the rules given in the section 2.2.5
+ in the OpTeX documentation.
+doc/ ... PDF version of the OpTeX documentation and sources.
+
+History:
+
+<1.01> Mar. 2021
+ Minor code fixes (thanks to reports from users).
+ LibreCaslon font file added.
+ two new callbacks from new LuaTeX 1.13 added to optex.lua
+ active * (in lists) works as normal in math mode.
+ f-heros(\slides): additional font XITSMath loaded (to the base FiraMath font).
+ \_xhsize seting added to \margins.
+<1.00> Feb. 2021
+ The OMLS (OpTeX Markup Language Standard) was developed. It helps to create
+ convertors from/to OpTeX documents and similar applications.
+ \pdfunidef re-imeplemted.
+ \thisoutline introduced.
+ \verbchar introduced instead \activettchar.
+ Bugs fixing.
+<0.19> Jan. 2021
+ emoji support as pkg/emoji.opm.
+ non-braakable places generated by luavlna, suported as pkg/vlna.opm.
+ \begblock...\endblock introduced.
+ comment character allowed after \begtt.
+ more robust macros: \replstring, \table.
+ complete revision of documentation, spelling corrections.
+ Several bugs fixed.
+<0.18> Dec. 2020
+ Font support for next 9 families added.
+ Font selection system improved.
+ Documentation (especially about font selection system) corrected.
+ Macros supporting key=value included to the format.
+ \foreach macro improved.
+ Concept of multilang in bib rewritten.
+ \opwarning format changed (line numbers are printed too).
+ Several bugs fixed.
+<0.17> Nov. 2020
+ optex.lua introduced (instead external ltluatex.lua)
+ hyph.patterns are loaded directly by \patterns, not using lua code
+ \commentchars introduced (comments which are able to interrupt verbatim mode)
+<0.16> Oct. 2020
+ callback.register_x introduced, namespaces for packages corrected
+ kerkis and EBGaramond fontfiles added
+ little corrections
+ optex-math manual: Index added
+<0.15> Jun. 2020
+ Release for Overleaf - TL2020.
+ More vertical space above in \chap and \secc.
+<0.14> Jun. 2020
+ Typeseting Math with OpTeX: new document added.
+ Math macros corrected.
+ In-line verbatim in section titles allowed.
+ \eqbox implemented.
+ "\mnote up", "\displaylines to" (new features implemented)
+<0.13> May 2020
+ \table have more features: \tabskip, \table to, \table pxto, \vspan
+ The \eqalign reimplemented to be more flexible.
+ The boundary character ":" introduced in the \table.
+ \| undefined in 8bit math: bug fixed.
+ \isnextchar: \let\tmp=#1 -> \let\tmp= #1
+<0.12> May 2020
+ The external macro qrcode.opm introduced
+ New directory structure: base/, demo/, pkg/, doc/ introduced.
+ \load macro introduced
+ \newif: bug fixed, other bug fixed.
+<0.11> Apr. 2020
+ \phi, \varpi in Unicode: bug fixed
+ \mathstyles introduced.
+<0.10> Apr. 2020
+ Technical documentation added
+ \_famdecl instedad \_fontdecl in font family files (incompatible change).
+<0.09> Syntax highlighting implemented.
+<0.08> \numberedpar implmented. \emergencystretch=20pt added as default.
+ \inoval, \incircle, \clipinoval, \clipincircle imlemented.
+ \puttext, \putpic x,y instead -y,x (incompatible change!)
+ footnotes have separated color stack now.
+ \fnotelinks implemented.
+ Lists by \begitems...\enditems improved (\novspaces \_vspacehalf, \ilevel).
+<0.07> demos: op-letter.tex and op-slides.tex added.
+ \inkinspic, \transformbox, \slides added.
+ documentation improved and updated.
+<0.06> tables re-implemented, opmac-rest removed.
+ footnotes, marginal notes reimplemented.
+ sections.opm, graphics.opm, colors.opm, languages re-implemented
+ Cite-bib re-implemented.
+ Index, sorting re-implemented.
+<0.05> \boldmath reimplemented
+ \fontcolor, \letterspacing implemented
+ font catalogue improved
+<0.04> references.opl, hyperlinks.opl re-implemented.
+ \fontfam, f-* rewritten: no usage of boundary "..." in \_fontnamegen
+ \fnote{...} corrected: (parameter is not really parameter)
+ verbatim.opl re-implemented + doc added
+ file-ref.opl implemented (new \_Xrefversion{3})
+ bugfixing
+<0.03> optex-doc optex.1 included,
+ verbatim.opm re-implmented,
+ math-unicode implemented,
+ usebib.opm + bib-style.opm included
+ \catcodetable stack implemented
+ bugfixing of macros.
+ catcodes.opl: removed, one can use \catcodetable, ... primitives,
+ pdfuni-string: lua code for lua5.3 fixed.
+<0.02> Released.
diff --git a/Master/texmf-dist/doc/optex/omls.tex b/Master/texmf-dist/doc/optex/omls.tex
new file mode 100644
index 00000000000..bcc5749a512
--- /dev/null
+++ b/Master/texmf-dist/doc/optex/omls.tex
@@ -0,0 +1,832 @@
+\fontfam[lm]
+
+\adef<#1>{\ifcsname s:#1\endcsname
+ \link[s:#1]{}{\Blue$\langle$\hbox{\it#1\/}$\rangle$}%
+ \else {\Blue$\langle$\hbox{\it#1\/}$\rangle$}\fi}
+\everyintt={\catcode`<=13 \Red}
+\verbchar`
+\enlang
+\enquotes
+
+\def\r[#1]{\label[#1]\wlabel{\the\_itemnum}}
+\def\:{$\to$}
+\let\_narrowlastlinecentered=\ignoreit
+\_def\_printsecc#1{\_par
+ \_abovetitle{\_penalty-200}{\_medskip\_smallskip}
+ {\_seccfont \_noindent \_raggedright \_printrefnum[@\_quad]%
+ \_label[\the\_secnum.\the\_seccnum]\wlabel{\the\_secnum.\the\_seccnum}#1\_nbpar}%
+ \_nobreak \_belowtitle{\_medskip}%
+ \_firstnoindent
+}
+\def\.`{\bgroup\catcode`\ =12 \scancs}
+\def\scancs#1{\egroup
+ \immediate\_wref\Xknowncs{\string#1{\the\_secnum.\the\_seccnum}}%
+ \ea`\string#1%
+}
+\def\printcs#1{\ea\printcsred\csstring#1;~\ref[#1] \ }
+\def\printcsred,#1;{{\Red\tt \bslash#1}}
+\def\printknowncs{\ifx\knowncslist\undefined \let\knowncslist=\empty \fi
+ \ifx\knowncslist\empty TeX me again...\else
+ \_dosorting\knowncslist \ea\xargs \ea\printcs \knowncslist;\fi}
+
+\def\~`<#1>`{<#1>\sxdef{s:#1}{}\dest[s:#1]}
+
+\refdecl{
+ \def\knowncslist{}^^J
+ \def\Xknowncs#1#2{%
+ \sxdef{,\csstring#1}{#2}%
+ \global\ea\addto\ea\knowncslist\ea{\csname,\csstring#1\endcsname}%
+ }
+}
+\sdef{_item:c}{\pdfsave\llap{\pdfscale{1.3}{1.3}$\circ$\enspace}\pdfrestore}
+
+%\parindent=15pt \iindent=\parindent \ttindent=\parindent
+%\ttindent=0pt
+\everylist={\advance\ttindent by-1em}
+\hyperlinks \Green \Green
+\def\cskip{\par\nobreak}
+\def\begblock{\medskip\hbox\bgroup\vrule\vbox\bgroup\hrule\smallskip
+ \_fnset\leftskip=\parindent \rightskip=\parindent \medskip\noindent}
+\def\endblock{\medskip\hrule\egroup\vrule\egroup}
+
+\def\raggedright{\rightskip=10pt plus1fil\relax}
+\def\optexmanual{\ulink[http://petr.olsak.net/ftp/olsak/optex/optex-doc.pdf]{\OpTeX/ manual}}
+
+\titskip=1cm
+
+\hfill Version 0.1
+
+\tit \OpTeX/ Markup Language Standard
+
+{\it\hfil Petr Olšák, 2021}\bigskip
+
+The \OpTeX/ markup language standard (OMLS) declares a list of control
+sequences used in \OpTeX/ documents including their syntax and sematic. The
+listed control sequences in OMLS in section~\ref[listcs] in table~\ref[alistcs]
+are called {\it known} and other control sequences are {\it unknown}.
+
+The main reason for OMLS is to give instructions on how to program convertors
+from \OpTeX/ documents to another formats (Html, Markdown, \LaTeX/) or how
+to interpret the \OpTeX/ document sources in such applications as
+{\tt texcount} or text editors\fnote
+{We suppose advanced editor features: color highlighting, sections/chapters folding,
+ auto-completions, etc.}.
+These converters and applications are called {\it cnv-programs} in this document.
+
+We suppose that if you need absolute control over the typography of the
+document when it is converted to PDF pages, then you use \OpTeX/ itself. If
+you need to create other formats of the same document then you can use a
+cnv-program which accepts OMLS. The result is a document without
+typographical instructions like dimensions of pages, margins, paginations
+and headers, selection of a font-family, dimensions of the fonts, etc.\ You can
+imagine the result of such a conversion as a single Html page where more
+typographical features can be controlled in a different way, for example by
+an external CSS file. This is a reason why control sequences like `\fontfam` or
+`\margins` are ignored by cnv-programs.
+
+Obviously, \TeX/ and \OpTeX/ itself gives possibility to declare various
+input formats for various purposes. Sometimes (in very special cases) there
+exists a good reason to declare a different and special input format by
+\TeX/ macros. But if the source of the document respects the OMLS then it is
+reasonably transformable to other formats by cnv-programs. We hope that
+OMLS-ready documents cover a very large set of typical documents used these
+days.
+
+We suppose that cnv-programs work internally with strings of source lines
+without tokenization. This is one of the great differences in processing the
+document directly by \OpTeX/ and using a cnv-program. The second difference is
+that the expansion process of macros is not implemented in cnv-programs in
+its full range. We respect that the result of cnv-programs will be different
+than from processing directly by \OpTeX/. But this is not a bug, this is
+the feature. We concentrate on the fixed syntax and sematic given by OMLS of the
+\OpTeX/ document and we throw behind the head the typographical
+exactness of the document which can be done only directly by \TeX/ (and it is
+exactly described in \TeX/book, for example).
+
+\notoc\nonum\sec Table of contents
+
+\begmulti 2
+\maketoc
+\endmulti
+\vfil\break
+
+\sec Syntactical rules
+
+The syntactical elements are described as strings here. No \TeX/'s tokenization is
+taken into account. The rule with a smaller number has precedence.
+
+\begitems \style n
+* end of line or end of file \: \~`<eol>`.\r[eol]
+* `%%:` at beginning of the line \: \~`<cnv-declarator>`, see section~\ref[cnv-decl].
+* `<cnv-declarator><text><eol>` is interpreted specially.
+* space or a tab-character \: \~`<space>`.
+* non-empty sequence of `<space>`s \: \~`<spaces>`.\r[spcs]
+* an empty line or a line only with `<spaces>` \: \~`<empty-line>`.
+* a character `a`--`z` or `A`--`Z` \: \~`<letter>`.
+* a `<letter>` or `_` \: \~`<specletter>`.
+* a character different from previous rule or `<eol>` or `<spaces>` \: \~`<non-specletter>`
+* `\<non-specletter>` \: \~`<singlechar-control-sequence>`.\r[scs]
+* a non-empty sequence of `<specletter>`s \: \~`<letters-seq>`.
+* `\<letters-seq><non-specletter>` \: \~`<multiletter-control-sequence>``<non-specletter>`.
+* `%<text><eol>` \: `<comment>` and it is completely ignored including `<eol>`.\r[com]
+* `<spaces>` at beginning of the line marks that the line as {\it indented}.
+* `<spaces>` at beginning of the line \: are ignored.\r[bspace]
+* `<spaces><eol>` or `<eol>` \: `<spaces>`.\r[eolrm]
+* `<multileter-control-sequence><spaces>` \: `<multileter-control-sequence>`.\r[csspace]
+* `<multiletter-control-sequence>` or `<singlechar-control-sequence>` \: \~`<control-sequence>`.\r[cs]
+* `<spaces>` \: `<space>`.\r[sspace]
+* `~` \: non-breakable space.
+* text where all pairs `{` and `}` match at arbitrary level \: \~`<balanced-text>`.\r[balt]
+* `{<balanced-text>}` can be interpreted as a parameter of a `<control-sequence>`, see section~\ref[listcs].
+* The `{` alone not used by previous rule opens a group and the `}` alone closes the same group.\r[group]
+* There are two main modes: h-mode, v-mode\fnote
+ {this is great simplification of real \TeX/ modes.}.
+ The document processing starts in v-mode.
+* In v-mode: a `<non-space>` character or a control sequence listed
+ in table~\ref[vtohmode] swithes to h-mode.
+* In h-mode: an `<empty-line>` or a control sequence listed in table~\ref[htovmode] switches to v-mode.\r[htov]
+* The switching from v-mode to h-mode \: a paragraph begins.
+* The switching from h-mode to v-mode \: the current paragraph ends.
+* `$<text>$` or `$$<text>$$` \: process `<text>` in math-mode, see section~\ref[math].
+* a non-empty sequence of digits with optional `+` or `-` in the front \: \~`<number>`.
+* `<number>` with optional dot inside the sequence of digits \: \~`<decimal-number>`.
+* a pair of letters listed in the table~\ref[tex-units] \: \~`<tex-unit>`.
+* optional space, i.e.\ `<space>` or nothing \: \~`<o-space>`.
+* `<decimal-number><o-space><tex-unit><o-space>` \: \~`<dimen>`.
+* `<control-sequence>` not listed in table~\ref[alistcs] nor in configuration \: \~`<unknown-control-sequence>`.\r[unkncs]
+* `=<o-space>` or `<o-space>` \: \~`<o-equal>`.
+* `<unknown-control-sequence><o-equal><dimen>` \: should be completely ignored.\r[eqdim]
+* `<unknown-control-sequence><o-equal><number>` \: should be completely ignored.
+* `<unknown-control-sequence>=<o-space>{<balanced-text>}` \: should be completely ignored.
+* `<unknown-control-sequence>[<balanced-text>]` \: should be completely ignored.\r[ibkt]
+* `<unknown-control-sequence>` \: should be ignored.\r[ignore]
+* `<control-sequence>`s are processed as described in section~\ref[listcs] or
+ by a configuration of the cnv-program.
+\enditems
+
+\bigskip
+\label[vtohmode]\caption/t
+List of control sequences which switch from v-mode to h-mode.
+\cskip
+\begblock
+`\`<space>,
+`\hfil`,
+`\hfill`,
+`\hskip`,
+`\hss`,
+`\indent`,
+`\leavevmode`,
+`\noindent`,
+`\quad`,
+`\qquad`,
+`\vrule`.
+\endblock
+
+\bigskip
+\label[htovmode]\caption/t
+List of control sequences which switch from h-mode to v-mode.
+\cskip
+\begblock
+`\begblock`,
+`\begitems`,
+`\begmulti`,
+`\begtt`,
+`\bib`,
+`\bigskip`,
+`\bye`,
+`\caption`,
+`\chap`,
+`\cskip`,
+`\end`,
+`\endblock`,
+`\enditems`,
+`\endmulti`
+`\hrule`,
+`\medskip`,
+`\par`,
+`\sec`,
+`\secc`,
+`\secl`,
+`\smallskip`,
+`\vfil`,
+`\vskip`.
+\endblock
+
+\bigskip
+\label[tex-units]\caption/t
+List of \TeX/ units.
+\cskip
+\begblock
+`bp`,
+`cc`,
+`cm`,
+`dd`,
+`em`,
+`ex`,
+`in`,
+`mm`,
+`pc`,
+`pt`,
+`sp`.
+\endblock
+
+\nonum\secc Examples
+
+\begitems
+* `\%` is `<control-sequence>` by rules \ref[scs], \ref[cs]. It does not start
+ comment, because rule \ref[scs] has precedence before rule \ref[com].
+* `\%<space>`: the `<space>` is kept, but `\foo<space>`: the space is removed
+ by rule~\ref[csspace].
+* `wordA<spaces><eol><spaces>wordB` is `wordA<space>wordB` by rules~\ref[bspace],
+ \ref[eolrm], and~\ref[sspace].
+* `\kern-3pt` should be ignored, because `\kern` is `<unknown-control-sequence>` and rule
+ \ref[eqdim] is applied.
+* `\vskip42mm` should finalize paragraph in h-mode by rule~\ref[htov] and then it
+ is ignored by rule~\ref[eqdim] because `\vskip` is
+ `<unknown-control-sequence>` not listed in table~\ref[alistcs].
+* `\typosize[12/16]` is ignored by rule~\ref[ibkt].
+* `\foo{text}` is `{text}` (i.e. `text` in a group) by rules~\ref[ignore] and~\ref[group].
+\enditems
+
+\sec Scanning parameters
+
+If a control sequence listed in rules above or in the section~\ref[listcs]
+has a parameter, the parameter is scanned
+as a string with interpretation only those rules which are needed to
+determine the boundary of the parameters. For example `\tit <title><eol>`
+applies only rule~\ref[eol] during scanning the parameter, i.e.\ `<title>`
+is a string telemetered by the end of the line or the end of the file.
+Or `\fnote{<balanced-text>}` applies only rule~\ref[balt].
+
+If the parameter is in the format `{<something>}` then the `<something>` is
+always meant as `<balanced-text>`. We don't specify the type `<balanced-text>`
+explicitly here, so we refer to `\fnote{<text>}` and not
+`\fnote{<balanced-text>}`, for example.
+
+The spaces before the scanned parameter are optional
+and they are ignored. Spaces inside `{`...`}` are not ignored.
+
+If the parameter is in the format `{<something>}` and the first non-space
+character is not `{` then the parameter is this first non-space character or
+a `<control-sequence>` if the first non-space character is~`\`. For example
+`\fnote a` is equal to `\fnote{a}`. The difference from this rule is given
+for `\input`, `\verbinput`,`\inspic` and `\inkinspic` control sequences in
+section~\ref[listcs].
+
+If the parameter is scanned as a string already then
+all syntactical rules are applied when it is used. For example:
+\begtt
+\tit This is a title
+\endtt
+the parameter is scanned as `This is a title` and the rules~\ref[spcs]
+and~\ref[sspace] are applied when it is used.
+
+
+\sec Declaration and text parts of the document
+
+A typical \OpTeX/ document has two parts. A declaration part, where
+macros are defined by `\def` and friends, fonts and sizes are declared, etc.
+This part should be ignored by cnv-programs.
+The second part includes the document text with a markup using well-declared control
+sequences. The cnv-program has to interpret the second part.
+
+So, the cnv-program starts in declaration-skipping mode and it switches to
+the text mode later.
+
+When cnv-program is in declaration-skipping mode then all indented lines are
+ignored. And lines which begins by `}` or by a <control-sequence> not listed
+in table~\ref[textopen] are ignored too.
+
+If the line begins by a character other than `}` or by a <control-sequence>
+listed in table~\ref[textopen] then cnv-program switches to text mode. All
+texts are interpreted from this line including this one.
+
+User can say explicitly where the second part of the document starts by
+`%%:text` given at beginning of a line. Moreover, if `%%:decl` is given at
+beginning of a line, then all text between `%%:decl` and `%%:text` is
+ignored, only other possible `<cnv-declarator>`s are processed here.
+It means that the declaration part and the text part of the document can be
+simply determined by the pair `%%:decl` and `%%:text`.
+
+\bigskip
+\label[textopen]\caption/t
+List of control sequences which start the text mode.
+\cskip
+\begblock \raggedright
+`\address`,
+`\begblock`,
+`\begitems`,
+`\begmulti`,
+`\begtt`,
+`\bf`,
+`\bi`,
+`\bib`,
+`\caption`,
+`\cite`,
+`\clipinoval`,
+`\clipincircle`,
+`\ecite`,
+`\fnote`,
+`\frame`,
+`\hfil`,
+`\hfill`,
+`\ii`,
+`\iid`,
+`\incircle`,
+`\inkinspic`,
+`\inoval`,
+`\inspic`,
+`\it`,
+`\LaTeX`,
+`\LuaTeX`,
+`\maketoc`,
+`\mnote`,
+`\OpTeX`,
+`\putpic`,
+`\puttext`,
+`\rcite`,
+`\rm`,
+`\rotbox`,
+`\sec`,
+`\secc`,
+`\secl`,
+`\table`,
+`\TeX`,
+`\tit`,
+`\usebib`,
+`\verbinput`.
+\endblock
+
+
+\sec[cnv-decl] The `%%:` declarators
+
+The `%%:` declarators are ignored when the document is processed by \TeX/
+but they can give instructions to cnv-programs. The `%%:` must be placed at
+beginning of the line. The list of `%%:` declarators follows:
+
+\begitems
+* `%%:decl` -- the following text is ignored until `%%:text` occurs. Only
+ other `%%:` declarators are interpreted.
+* `%%:text` -- the following text must be interpreted in text mode.
+* `%%:to <format> <config-file>` -- if the cnv-program converts to the
+ <format> then it has to use the <config-file>. For example:
+ \begtt
+ %%:to html html-mydocument.cfg
+ %%:to markdown markdown-mydocument.cfg
+ %%:to latex preamble-mydocument.cfg
+ \endtt
+ The language of the config files are not a part of this standard, we
+ suppose something to be natural for used cnv-program. The config file should
+ give additional rules for interpreting control sequences not listed in the
+ section~\ref[listcs] (see rule~\ref[unkncs]). For example a tool for
+ defining a behavior of unknown control sequences can be here.
+ These definitions can depend on the converted document and on the output
+ format and they can be given in the configuration files.
+* `%%:app <application> <config-file>` -- behaves like `%%;to` but the
+ cnv-program name instead output format is given here.
+* `%%:do <format-or-app> <action>` -- does an `<action>` if `<format-or-app>`
+ is output format or used cnv\hbox{-}program name. The `<action>` syntax depends
+ on used cnv-program and it typicaly does a change in its configuration or
+ give a command to it.
+* `%%:skip <formats-or-apps>` -- ignores all following lines until another `%%:` occurs
+ if the output format or application name is included in the `<formats-or-apps>`
+ space-separated list. Example:
+ \begtt
+ %%:skip html markdown
+ This text is not interpreted when Html or Markdown output is generated.
+ %%:
+ \endtt
+ If the `<formats-or-apps>` is empty then the `%%:skip` is applied for
+ each cnv-program and for each output.
+* `%%:if <formats-or-apps>` -- processes following lines until another `%%:`
+ only if the output format or application name is included in the
+ `<formats-or-apps>` space-separated list. Other cnv-programs or output formats
+ not mentioned here skip these lines. Note that \TeX/ processes such lines always.
+ But you can use `\ignoreit{<text>}` which is processed as
+ `{<text>}` by cnv-programs (see rule~\ref[ignore]) but it is ignored by \OpTeX.
+ Example:
+ \begtt
+ %%:if html latex
+ \ignoreit{\input{file.tex}}
+ %%:
+ \endtt
+ The `file.tex` in this example is processed only if \LaTeX/ or Html output is generated.
+* `%%:use` -- the next single line is fully interpreted unless cnv-program ignores
+ declarations by `%%:decl` or because it is in declaration-skipping mode.
+ Example:
+ \begtt
+ %%:use
+ \verbchar` \picdir={img/}
+ \endtt
+ The example shows how cnv-program is able to read `\verbchar` or
+ `\picdir` settings in the declaration\hbox{-}skipping mode although these control
+ sequences are not listed in table~\ref[textopen].
+* `%%:quotes <qql> <qqr> <ql> <qr>` -- declares \~`<qql>` and \~`<qqr>` (left
+ and right double quotation marks), \~`<ql>` and \~`<qr>` (left and right single
+ quotation mark). They are used when `\"` or `\'` control sequences are
+ processed. Default: unset, i.e.\ `\"` and `\'` are interpreted as
+ unknown control sequences.
+\enditems
+
+
+\sec[listcs] List of known control sequences
+
+The phrase \"should be" is used very often when the interpretation of
+control sequences is declared here. It means that this is only a common
+interpretation, but differences are possible due to the type of the output
+format and used cnv-program. For example, when we convert to \LaTeX\, then
+`\-` and `\/` are not ignored but they are re-written without change to the
+output of the \LaTeX/ source file.
+
+\bigskip
+\label[alistcs]
+\caption/t List of known control sequences alphabeticaly sorted.
+\cskip
+\begblock
+\raggedright \printknowncs
+\endblock
+
+
+\secc Character-like control sequences
+
+\begitems
+* \.`\%`, \.`\$`, \.`\&`,\.`\#` respectively \: should be normal characters
+ `%`, `$`, `&`, `#` respectively.
+* \.`\bslash` \: normal character `\`.
+* \.`\space`, `\<space>`, `\<eol>` \: space.
+* `\,` \: should be small space or space.
+* \.`\quad`, \.`\qquad` \: should be bigger space or more spaces.
+* \.`\-`, \.`\/` \: should be ignored.
+* \.`\"<text>"` or \.`\'<text>'` \: `<qql><text><qqr>` or `<ql><text><qr>`,
+ only if `%%:quotes` are set.
+\enditems
+
+\secc Input files
+
+\begitems
+* \.`\input {<file-name>}` or `\input <file-name><space>` should redirect the
+ input to given file. At the end of the input-ed file or at \.`\endinput` the
+ reading of the current file continues. The file is read from the current
+ directory, but the <file-name> should include the full path to the file
+ or relative path starting from the current directory. First, the file
+ `<file-name>.tex` is tried to read and if it doesn't exist then
+ the file `<file-name>` is read.
+* \.`\picdir <o-equal>{<text>}` saves `<text>` to `<picdir-value>`. By
+ default, `<picdir-value>` is empty.
+* \.`\inspic {<file-name>}` or `\inspic <file-name><space>` should include the
+ given picture from the `<picdir-value><file-name>`.
+* \.`\inkinspic {<file-name>}` or `\inkinspic <file-name><space>` behaves like
+ `\inspic`.
+* \.`\verinput <ignore> (<lines>) <file-name><space>` should include the
+ <file-name> (only given lines) as a verbatim text, i.\,e. without any
+ syntactical interpretation.
+* \.`\usebib/<letter> (<style>) <file-names>` should use files from
+ `<file-names>` to generate the list of bib references. The `<file-names>`
+ is comma separated list (the `.bib` extension is appended to
+ each such file name). Only cited bib records should be used in this
+ bib-references, i.e. their label must be used in a `\cite[<labels>]` or
+ `\rcite[<labels>]` or `\ecite[<label>]`.
+ What bib fields are used in bib records depends on the cnv-program and
+ on its configuration. Maybe, simple cnv-programs should generate nothing here.
+\enditems
+
+\secc Titles
+
+\begitems
+* \.`\tit <title><eof>` should be a title of the document.
+* \.`\chap <title><eof>` or `\chap [<label>] <title><eof>` is the title of
+ first level.
+* \.`\sec <title><eof>` or `\sec [<label>] <title><eof>` is the title of
+ second level.
+* \.`\secc <title><eof>` or `\secc [<label>] <title><eof>` is the title of
+ third level.
+* \.`\secl<level> <title><eof>` is the title of given level.
+\enditems
+
+\secc Fonts
+
+\.`\rm` selects upright normal font (it is selected by default), \.`\it` selects
+italic, \.`\bf` selects upright bold font, \.`\bi` selects bold italic and
+\.`\tt` selects a monospaced font, \.`\em` select italic (if upright is current) or upright
+(if italic is current). The font sizes or other font features are typically ignored
+by cnv-programs. The actual font selection is closed at the end of the current group.
+The groups are given:
+\begitems
+* explicitly by `{` and `}` characters (which are not delimiters of
+ parameters of known control sequences),
+* implicitly: parameters of control sequences listed in table~\ref[groupcs]
+ are processed in a group and blocks of text enclosed by
+ `\begitems`...`\enditems`, `\begblock`...`\endblock`, `\begmulti`...`\endmulti`
+ are processed in a group.
+ Each item in `\table` is in a group.
+\enditems
+
+\label[groupcs]
+\caption/t Parameters of following control sequences are processed in a group.
+\cskip
+\begblock
+`\caption`,
+`\chap`,
+`\fnote`,
+`\mnote`,
+`\sec`,
+`\secc`,
+`\tit`.
+\endblock
+
+\secc Colors
+
+\.`\Red`, \.`\Green`, \.`\Blue`, \.`\Cyan`, \.`\Magenta`, \.`\Yellow`, \.`\White`,
+\.`\Black`, and \.`\Brown` should select the given color of the font. The selection
+is closed at the end of the current group (like font selectors).
+
+\secc Blockquotes
+
+The blockquote\fnote
+{The terminology is borrowed from Markdown.}
+is opened by \.`\begblock` and closed by \.`\endblock`.
+Blockquotes can contain multiple paragraphs and can contain nested
+blockquotes.
+
+\secc Lists
+
+The list is opened by \.`\begitems` and closed by \.`\enditems`. The `*` starts
+a new item in this environment. Nested lists are allowed.
+
+The type of items (ordered/unordered)
+is given by \.`\style <character>`, see section 1.4.5 in the
+\optexmanual. Default type is unordered (bullets are used).
+
+
+\secc Code blocks (verbatim texts)
+
+Code blocks are inline verbatim or display verbatim.
+
+\begitems
+* \.`\begtt <ignored><eol><text>\endtt<ignored><eol>` processes `<text>` in
+ \"display verbatim mode", i.\,e. there are no special characters, each character
+ is processed without special interpretation, the <eol>s are end of lines.
+ The text at the same line after `\begtt` and after `\endtt` (if any) is
+ ignored.
+* \.`\verbchar <character>` declares `<verbchar>`. By default, it is undeclared.\nl
+ New `\verbchar <character>` rewrites previous setting. The setting is
+ local in the group.
+* Inline verbatim is enclosed in the pairs of `<verbchar>`s.
+ The text between two `<verbchar>`s is processed without special interpretation.
+ Only possibly <eol>s are replaced by space.
+ Example:
+ \begtt
+ %%:use
+ \verbchar`
+ Now, `$this %text ~\` is processed as inline verbatim.
+ \endtt
+ gives: Now, `$this %text ~\` is processed as inline verbatim.
+* \.`\code{<text>}` processes `<text>` like inline verbatim, but
+ all `\<character>` are processed as `<character>`, specially `\{` and `\}`
+ are `{` and `}` but without taking them into `<balanced-text>` rule,
+ `\\` is `\` but do not create a `<control-sequence>`, etc.
+\enditems
+
+
+\secc Multicolumns
+
+\.`\begmulti <number><space>` opens the group and \.`\endmulti`
+closes the group. If output format allows multi-columns then
+the text enclosed between `\begmulti <number><space>` and matching
+`\endmulti` should be printed in `<number>` balanced columns.
+
+
+\secc Links
+
+\begitems
+* \.`\url{<text>}` creates `<text>` as an external link which points to `<text>`.
+ The `\<character>` is interpreted as `<character>` in `<text>` with one
+ exception: `\|` is ignored.
+* \.`\ulink[<url>]{<text>}` creates `<text>` as an external link which points
+ to `<url>`. The `\<character>` is interpreted as `<character>` only in
+ `<url>` parameter.
+* \.`\label[<label>]` sets the `<label>`. First following occurence of `\chap`, `\sec`,
+ `\secc`, `\caption` or `\eqmark` sets this `<label>` as bounded to its
+ position in the document.
+* \.`\ref[<label>]` should create an internal link to the position given by
+ `\chap`, `\sec`, `\secc`, `\caption` or `\eqmark`,
+ if `[<label>]` is used as the parameter of this control sequence
+ else if `<label>` is bounded here by previous `\label[<label>]`
+ The visual aspect of the link
+ is not declared by OMLS because we don't suppose that the chapters,
+ sections, equations, etc.\ are automatically numbered by exactly the same way as in
+ \OpTeX/. A recommendation should be: create a simple sequence of numbers over
+ all internal links.
+* \.`\pgref[<label>]` should be replaced by `??` if cnv-program generates single-page
+ output (like Html, Markdown). Unfortunately, we get the irrelevant phrases in the output:
+ \"{\tt The problem is shown at the page ??}".
+ Users can declare `%%:skip` for such cases.
+* \.`\bib[<label>]` or `\bib[<label>]<o-space>=<o-space>{<ignored>}` should open the new bib
+ record. More exactly, it closes previous paragraph (if h-mode is current)
+ and opens new h-mode. Then prints an auto-generated reference number in
+ `[...]`. Following text is interpreted as a bib record until the h-mode ends.
+* \.`\cite[<labels>]` should create internal links to corresponding bib
+ records generated by `\usebib` or by `\bib`. The `<labels>` is a comma-separated list
+ of labels used in `.bib` files or in `\bib` commands to indicate
+ the corresponding bib record. The labels should be replaced by auto-generated
+ reference numbers used in bib records. All reference numbers created by
+ single `\cite` should be enclosed by single `[...]`. These numbers are
+ internal links. If the cnv-program does not implement this complicated
+ bib machinery then `\cite[<labels>]` should print only `[<labels>]`.
+* \.`\rcite[<labels>]` does the same as `\cite[<labels>]` but doesn't print
+ outer `[...]`.
+* \.`\ecite[<label>]{<text>}` creates the link to corresponding bib record,
+ `<text>` is is hyperlinked (no the auto-generated reference number).
+* \.`\maketoc` should create a list of titles from all `\chap`, `\sec` and `\secc`
+ used in the document if they are not preceded by \.`\notoc`. All lines in
+ this list should include internal links to the position where the corresponding title
+ is used.
+\enditems
+
+\secc Tables
+
+\begitems
+* \.`\caption/<letter>` opens a caption. More exactly, if current mode is
+ h-mode, then switch to v-mode first (i.e.\ close the current paragraph).
+ Then switch from v-mode to h-mode and put a <caption-head>. The following
+ text should be interpreted as the caption text until h-mode ends.
+ If <letter> is `t` then <caption-head> is `Table` followed
+ by an auto-generated number. If the <letter> is `f` then <caption-head> is
+ `Figure` followed by an auto-generated number. The configuration of
+ cnv-programs shoud allow different words than default `Table` or `Figure` (for
+ example, if another language is used).
+* \.`\table<ignored>{<declaration>}{<data>}` should create a table. The fidelity
+ rate of created output depends heavily on the used cnv-program and the output
+ format. We don't suppose that all aspects of \OpTeX/ tables are implemented.
+ The following features are listed in their priority of implementation.
+ \begitems \style c
+ * Items in `<data>` are separated by `&`.
+ The last item in each row is separated by end-row separator: \.`\cr`, \.`\crl`, \.`\crll`,
+ \.`\crli`, \.`\crlli`, or \.`\crlp{<list>}`. If there are $n$ columns in
+ the table then we have $n-1$ `&` separators and one end-row separator
+ for each table row.
+ There can be an optional end-row separator at the first item in `<data>` and
+ it should be ignored. The `<data>` can end without the end-row separator, it
+ should be added here.
+ * Spaces around `&` and before end-row separator are ignored.
+ * \.`\noalign{<text>}` and \.`\tskip <dimen>` should be ignored.
+ * Colum declarators in <declaration> should be interpreted: `l` (left aligned), `c` (center
+ aligned), `r` (right aligned) or `p{<ignored>}` (paragraph-like item).
+ * The `<number><letter>` or `<number>{<text>}` should be interpreted as
+ `<number>`-times repeated `<letter>` or `<text>` in `<declaration>`.
+ * \.`\vspan<decimal-number>{<text>}` should be an item with only `<text>`.
+ * \.`\mspan<number>[<decl>]{<text>}` should create `<text>` as an item which
+ spans over `<number>` columns. It is used instead `<number>` real
+ items, i.e.\ `<number>`$-1$ separators `&` aren't used here.
+ * Rules in the table should be interpreted, i.e. `|` in <declaration>
+ should be not ignored and
+ various end-row separators should be distinguished (see \optexmanual,
+ section 1.4.6).
+ * The aligning of `p{<p-data>}` columns should be interpreded by reading
+ \.`\fL`, \.`\fR`, \.`\fC`, \.`\fS` and \.`\fX` control sequences in `<p-data>`.
+ See \optexmanual, section 1.4.6.
+ \enditems
+\enditems
+
+\secc Footnotes, marginal notes
+
+\begitems
+* \.`\fnote{<text>}` should create a footnote link as an auto-generated
+ reference number.
+ The `<text>` should be appended at the end of the document labeled by this
+ reference number. Another alternative (for Html output, for example): the mouse over
+ the reference number riases an auto-popup `<text>`.
+* \.`\fnotemark<number>` should create a pointer to a next declared
+ footnote as auto-generated reference number. The `<text>` of the footnote is
+ declared after that by \.`\fnotetext{<text>}`. Exact behavior: if the
+ reference number of the last processed `\fnote` is $n$ then
+ `\fnotemark<number>` uses the value
+ $n+{}$`<number>` as its reference number. A set of `\fnotemark`s
+ is followed by an equally large set of `\fnotetext{<text>}`. First one
+ have reference number $n+1$, second $n+2$, etc. When whole set of `\fnotetext{<text>}`
+ is processed then $n$ is reset to the last reference number used here.
+* \.`\mnote <ignored>{<text>}` should be created as auto-popup `<text>` or the `<text>`
+ is inserted at the margin.
+\enditems
+
+\secc Tagging for index
+
+We don't suppose that the cnv-program can generate the alphabetically sorted
+index. So, the markup for creating the index should be ignored:
+
+\begitems
+* \.`\ii <word><space>` (where `<word>` is a sequence of non-space characters)
+ should be ignored.
+* \.`\iid <word><space>` is `<word><space>` by default, but
+ if `,` or `.` follows after `<space>` then the `<space>` is removed.
+\enditems
+
+\secc Logos
+
+\.`\TeX`, \.`\LuaTeX`, \.`\OpTeX`, \.`\LaTeX`, respectively \:
+`TeX`, `LuaTeX`, `OpTeX`, `LaTeX`, respectively. If `/` follows
+these control sequences then it is ignored. Other logos should be declared
+in the configuration of the cnv-program.
+
+\secc What should be ignored
+
+\begitems
+* \.`\def<text>{<text>}` and other variants with \.`\gdef`, \.`\edef`, \.`\xdef`.
+ Reason: user can insert a special definition in the `%%:text` part of the
+ document in order to solve a problem. But cnv-program should ignore~it.
+* \.`\outlines{<text>}`, \.`\insertoutline{<text>}` and \.`\thisoutline{<text>}`.
+\enditems
+
+
+\sec[math] Math mode processing
+
+There are two math modes, inline: `$<formula>$` or display: `$$<formula>$$`.
+We suppose that `<formula>` will be processed by MathJax or similar
+software. So, the `<formula>` should be kept without changes in cnv-program
+output, but there are exceptions:
+
+\begitems
+* `$<sign><decimal-number>$` should be transformed to non-math text
+ `<sign><decimal-number>`. The `<sign>` is~`+` or~`-` or nothing.
+ The `<decimal-number>` can include `,` (comma) instead `.` (period).
+ If the `<sign>` is~`-` (character U+002D) then
+ it must be converted to `−` (character U+2212, math minus).
+* `{\bbchar <text>}` should be converted to `\mathbb{<text>}`, because
+ MathJax doesn't understand `\bbchar`. `$\bbchar <text>$` should be
+ converted to `$\mathbb{<text>}$`.
+* `{\frak <text>}` or `$\frak <text>$` \:
+ `\mathfrak{<text>}` or `$\mathfrak{<text>}$`.
+* `{\script <text>}` or `$\script <text>$` \:
+ `\mathscr{<text>}` or `$\mathscr{<text>}$`.
+* `\eqmark`, `\eqmark[<label>]` \: `\leqno (<num>)`, where `<num>` is
+ auto-generated number. Or it should be completely ignored.
+* It is strongly recommended to allow users to declare another replacement
+ rules over `<formula>` in configuration files of cnv-programs.
+\enditems
+
+
+\sec Notes on various conversions
+
+The cnv-programs behave differently because output formats have different
+concepts and are intended for different purposes. The following sections
+mention the main differences for typical conversions.
+
+\secc To Html
+
+The Html document is one single page. If we want to split the document to more
+pages, then we can use `%%:do html <action>` in positions where the document
+should be split (the syntax of `<action>` depends on the used cnv-program.)
+
+The design of Html pages should be declared by CSS files.
+
+Pictures inserted by `\inspic` should be inserted into the Html page as
+\code{<img src="...">}, so the picture files must be installed in
+the webserver to render the Html page correctly in a web browser.
+
+The `\maketoc` used in the \OpTeX/ document means that the Table of contents should
+be here. It should be generated by the cnv-program, two-pass processing is
+needed because the cnv-program needs to read all titles of `\chap`, `\sec` and
+`\secc`. Another approach is to read the `.ref` file produced by \OpTeX/.
+
+
+\secc To Markdown
+
+Markdown source file is \"one-page document" too. The principles a
+re similar to conversion to Html.
+
+\secc From Markdown
+
+The cnv-program which does such a reverse conversion should be very useful for
+people they prefer even clearer markup than in \OpTeX/.
+
+\secc To \LaTeX
+
+\LaTeX/ gives the same main feature as \OpTeX/: it can generate PDF
+output from a source file. But different macros, a different concept, and
+a different markup are used.
+
+The main reason for such conversion is that journal editors
+require \LaTeX/ source file, but user want to prepare their real document in
+more comfortable (\OpTeX/) markup and with more simple macros.
+
+This conversion should keep almost all features. For example, the
+`\pgref[<label>]` is converted to `\pageref{<label>}`. The cnv-program
+needs not to generate a Table of contents, bibliography references, etc. Only
+appropriate \LaTeX/ markup must be used.
+
+The contents of generated \LaTeX/ preamble should be configurable.
+
+
+\secc From \LaTeX
+
+The reverse conversion from \LaTeX/ to \OpTeX/ can be usable
+for people, they want to switch to creating their documents in \OpTeX/.
+
+The cnv-program must solve additional problem in this type of conversion.
+There are various math \LaTeX/ environments, they must be converted to
+plain~\TeX/ syntax of math typesetting. For example:\nl
+`\begin{array}...\end{array}` \: `\matrix{...}`,\nl
+`\begin{align*}...\end{align*}` \: `$$\eqalign{...}$$`\nl
+`\frac{...}{...}` \: `{...\over...}`.
+
+\bye
diff --git a/Master/texmf-dist/doc/optex/optex-doc.pdf b/Master/texmf-dist/doc/optex/optex-doc.pdf
new file mode 100644
index 00000000000..a4df4f013ab
--- /dev/null
+++ b/Master/texmf-dist/doc/optex/optex-doc.pdf
Binary files differ
diff --git a/Master/texmf-dist/doc/optex/optex-doc.tex b/Master/texmf-dist/doc/optex/optex-doc.tex
new file mode 100644
index 00000000000..9f2fadeeb4a
--- /dev/null
+++ b/Master/texmf-dist/doc/optex/optex-doc.tex
@@ -0,0 +1,114 @@
+%% This is part of the OpTeX project, see http://petr.olsak.net/optex
+
+% Run optex optex-doc
+% (three times) to generate OpTeX documentation including references and the index.
+
+\load [doc.opm] \let\enddocument=\endinput
+
+\typosize[10/12] % Main size (used in techdoc)
+
+\begingroup \typosize [11/13.5] % Different size used in useroc.
+
+\insertoutline{OpTeX} % PDF outlines generated from TOC
+
+% Title:
+
+\vglue1cm
+\centerline{\setfontsize{at50pt}\rm\OpTeX}
+\vskip-8mm
+
+\tit Format Based on Plain \TeX/ and OPmac\fnotemark1
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\hfill Version 1.01
+
+\centerline{\it Petr Olšák, 2020, 2021}
+
+\bigskip
+\centerline{\url{http://petr.olsak.net/optex}}
+
+\fnotetext {OPmac package is a set of simple additional macros to Plain \TeX{}.
+It enables users to take advantage of \LaTeX/ functionality but keeps
+Plain \TeX/ simplicity. See
+\url{http://petr.olsak.net/opmac-e.html} for more information about it.}
+
+\bigskip
+\noindent
+\OpTeX/ is \LuaTeX/ format with Plain \TeX/ and OPmac. Only \LuaTeX/ engine
+is supported.
+
+\OpTeX/ should be a modern Plain \TeX/ with power from OPmac (Fonts
+Selection System, colors, graphics, references, hyperlinks,
+indexing, bibliography, ...) with preferred Unicode fonts.
+
+The main goal of \OpTeX/ is:
+
+\begitems
+* \OpTeX/ keeps the simplicity (like in Plain \TeX/ and OPmac macros).
+* There is no old obscurities concerning various 8-bit encodings and
+ various engines.
+* \OpTeX/ provides a powerful Fonts Selection System (for Unicode font
+ families, of course).
+* \OpTeX/ supports hyphenations of all languages installed in your \TeX/ system.
+* All features from OPmac macros are copied. For example sorting words in
+ the Index\fnotemark1, reading `.bib` files directly\fnotemark1, syntax
+ highlighting\fnotemark1, colors, graphics, hyperlinks, references).
+ \fnotetext{All these features are implemented by \TeX/ macros, no external
+ program is needed.}
+* Macros are documented in the same place where code is.
+* User namespace of control sequences is separated from the internal namespace
+ of \OpTeX/ and primitives (`\foo` versus `\_foo`).
+ The namespaces for macro writers are designed too.
+\enditems
+
+If you need to customize your document or you need to use something
+very specific, then you can copy relevant parts of \OpTeX/ macros into your macro
+file and do changes to these macros here. This is a significant difference from
+\LaTeX/ or ConTeXt, which is an attempt to create a new user level with a
+plenty of non-primitive parameters and syntax hiding \TeX/ internals.
+The macros from \OpTeX/ are simple and straightforward because they solve only
+what is explicitly needed, they do not create a new user level for
+controlling your document. We are using \TeX/ directly in this case.
+You can use \OpTeX/ macros, understand them, and modify them.
+
+\OpTeX/ offers a markup language for authors of texts (like \LaTeX),
+i.\,e.\ the fixed set of tags to define the structure of the document. This
+markup is different from the \LaTeX{} markup. It may offer to write the
+source text of the document somewhat clearer and more attractive.
+
+The manual includes two parts: user documentation and technical
+documentation. The second part is generated directly from the sources of
+\OpTeX/. There are many hyperlinks from one part to second and vice versa.
+
+This manual describes \OpTeX/ features only. We suppose that the user knows \TeX/
+basics. They are described in many books. You can see a short
+document \ulink[http://petr.olsak.net/ftp/olsak/optex/tex-nutshell.pdf]
+{\TeX/ in nutshell} too.
+
+\vfil\break
+
+\insertoutline{CONTENTS} \outlines{0}
+
+\notoc\nonum \sec Contents
+\maketoc
+
+\thisoutline {USER DOCUMENTATION}
+
+\chap User documentation
+
+\input optex-userdoc
+\endgroup
+
+%\end
+
+\input optex-techdoc
+
+\vfil\break
+
+\def\_printchap#1{\noindent{\_printrefnum[@]\_secfont #1}\medskip}
+
+\nonum\chap Index
+
+\begmulti 3 \tt \makeindex \endmulti
+
+\bye
diff --git a/Master/texmf-dist/doc/optex/optex-math.tex b/Master/texmf-dist/doc/optex/optex-math.tex
new file mode 100644
index 00000000000..789dd5a1877
--- /dev/null
+++ b/Master/texmf-dist/doc/optex/optex-math.tex
@@ -0,0 +1,1662 @@
+%% This is part of the OpTeX project, see http://petr.olsak.net/optex
+
+% Run optex optex-math (two times) to generate this document
+% or look at PDF here: http://petr.olsak.net/ftp/olsak/optex/optex-math.pdf
+
+\fontfam[lmfonts]
+
+\font\ttlib=[LiberationMono-Regular]
+\def\ttspec{\let\_ttfont=\ttlib}
+
+\report
+
+\def\new #1 {\mnote{\Red$\blacktriangleleft$\,\sans\setfontsize{at9pt}\rm#1}}
+\fixmnotes\right
+\enquotes
+\verbchar`
+\catcode`\<=13
+\def<#1>{$\langle\hbox{\it#1\/}\rangle$}
+\everyintt={\catcode`\<=13 }
+\def\ss#1{$\vrule height3pt#1\vrule height3pt$}
+
+\addto\_secfont\Blue \addto\_seccfont\Blue
+\_def\_printsec#1{\_par
+ \_abovetitle{\_penalty-400}\_bigskip
+ {{\_secfont \_noindent \_raggedright \llap{\_printrefnum[@\_quad]}#1}\_nbpar}\_insertmark{#1}%
+ \_nobreak \_belowtitle{\_medskip}%
+ \_firstnoindent
+}
+\_def\_printsecc#1{\_par
+ \_abovetitle{\_penalty-200}\_medskip
+ {{\_seccfont \_noindent \_raggedright \llap{\_printrefnum[@\_quad]}#1}\_nbpar}%
+ \_nobreak \_belowtitle{\_medskip}%
+ \_firstnoindent
+}
+
+\def\i #1 {\ii .#1 \iis .#1 {{\code{\\#1}}}}
+\def\x`{\bgroup\_setverb\xx}
+\bgroup \lccode\string`\.=\string`\` \lowercase{\egroup \def\xx #1#2.{\i #2 \egroup `#1#2.}}
+
+
+\hyperlinks\Green\Green
+
+\insertoutline{MATH}
+\outlines{0}
+
+
+
+\tit Typesetting Math with \OpTeX/
+
+\hfill Version 03, January 2021
+
+\author Petr Olšák
+
+
+This document is a brief summary of typesetting math. It describes \TeX/,
+Plain \TeX/ and \OpTeX/ features concerned to math. The first two types of
+features are documented in \TeX/book in chapters 16, 17, and 18, but it is
+summarized here in short again in order to give a complete guide about math
+typesetting for \OpTeX/ users.
+
+\new {}
+The \OpTeX/ features which differs from standard \TeX/ or Plain \TeX/ are
+documented with the red triangle at the margin (like in this paragraph).
+Reader can simply distinguish between \"standard" features (given by
+\TeX/ or Plain \TeX/) and new \OpTeX/ features.
+
+There are more types of extensions: e\TeX, lua\TeX/, Unicode math and
+\OpTeX/ macros. The appropriate label (e\TeX, Lua\TeX/, Unicode, \OpTeX/)
+is appended to the red triangle to inform you about the extension type.
+Nevertheless, \OpTeX/ user doesn't have to worry about it, all extensions
+are available if Unicode Math font is loaded (e.g., by the command
+`\fonfam[lmfonts]`). See section 1.3.3 in \OpTeX/ documentation about
+loading Unicode math fonts.
+
+{\iindent=2em
+\bigskip
+\maketoc }
+\vfil\break
+
+\sec Basics structure of math formulas
+
+\secc General rules and terminology
+
+The \ii in-line/math in-line math (in the paragraph) is created by `$<math list>$`. The
+\ii display/math display math (a standalone line between paragraphs) is created by `$$<math list>$$`.
+More than one line can be here if an appropriate macro is used. In-line math is
+processed in a \TeX/ group in \ii in-line/math/mode {\em in-line math mode}. The display math is
+processed in a \TeX/ group in \ii display/math/mode {\em display math mode}. Spaces are
+ignored in math modes, so `$x+y$` and `$x + y$` gives the same result: $x+y$.
+
+The \ii math/list <math list> is a sequence of \ii math/atom,atom {\em math atoms} and
+\ii other/material {\em other material}.
+The math atoms are \ii single/math/object {\em single math objects} or
+\ii composed/math/atom composed math atoms.
+
+\begitems \hfuzz=.6pt
+* The single math object is a single character to be printed in math mode
+ like `x`, `+`, `\int`.
+* The math atom is constructed in general by `{<math list 1>}^{<math list 2>}_{<math list 3>}`.
+ It consists from \ii nucleus {\em nucleus} <math list 1>, \ii exponent exponent <math list 2>
+ and \ii subscript subscript <math list 3>. Each part of the atom should be empty.
+ If <math list 2> or <math list 3> is empty, we need not to write brackets and
+ the prefix `^` or `_`.
+ If the <math list 1> or <math list 2> or <math list 3>
+ consist only from a single math object then we need not use brackets.
+ For example
+ `x^2` is a math atom with `x` in the nucleus, `2` in the exponent, and with empty subscript.
+ Or `a_{i,j}` is a math atom with `a` in the nucleus, empty exponent, and `i,j` in the subscript.%
+ \fnote{In \OpTeX/, the character `_` can be interpreted as a part of
+ the control sequence name, not as the subscript constructor. But in common cases,
+ constructions of math atoms are interpreted exactly as in plain \TeX. See sections
+ 2.2.2 and 2.14 of \OpTeX/ documentation for more details. If you want to
+ be sure that `_` is just a subscript constructor in \OpTeX/ then you can set \code{\\catcode`\\_=8}
+ but after this, you cannot use control sequences with `_` character.}
+ The constructors for exponent `^` and subscript `_` can be used in arbitrary order
+ after the nucleus, for example, `z_1^{x+y}` is the same math atom as
+ `z^{x+y}_1`. The single math objects not followed by `^` nor `_` are
+ considered as math atoms with this object in the nucleus and with empty
+ exponent and subscript (this is a very common case).
+ \TeX/ assigns the \ii class {\em class} for each math atom, see section~\ref[class].
+* Other material can be \TeX/ box or glue (space) or `\kern` or `\vrule` etc.
+\enditems
+
+Example: The `Z = \int``_\Omega x^{2y} + z\, dx` generates
+$Z = \int_\Omega x^{2y} + z\, dx$ and it is <math list> which consists from:
+
+\begitems
+* `Z` is math atom with empty exponent and subscript, class: Ord,
+* `=` is math atom with empty exponent and subscript, class: Rel,
+* `\int``_\Omega` is math atom with empty exponent and with subscript `\Omega`, class: Op,
+* `x^{2y}` is math atom with exponent `2y` and empty subscript, class: Ord,
+ \begitems \let\_bullet=\circ
+ * `2` is math atom with empty exponent and subscript, class: Ord,
+ * `y` is math atom with empty exponent and subscript, class: Ord,
+ \enditems
+* `+` is math atom with empty exponent and subscript, class: Bin,
+* `z` is math atom with empty exponent and subscript, class: Ord,
+* `\,` is another material, the glue (space) in this case,
+* `d` is math atom with empty exponent and subscript, class: Ord,
+* `x` is math atom with empty exponent and subscript, class: Ord.
+\enditems
+
+\secc[class] Classes of math atoms
+
+\TeX/ assigns \ii class {\em a class} for each math atom.\fnote
+{Using terminology of \TeX/book, each single math object has its {\em class} but the
+ math atom has its {\em kind} derived from this class. I use only one word
+ for both meanings in this document.}
+This data type is used when
+\TeX/ decides about \ii horizontal/spacing horizontal spaces between atoms in the output. (Note
+that spaces in the input are ignored.) For example,
+`$xy$` prints two atoms without space between them but `$x+y$` is printed with
+small spaces around the `+` binary operator. Compare: $xy$ and $x+y$.
+
+The class is assigned depending on the nucleus of the atom. If the nucleus is
+not a single math object, i.e. it is constructed by `{<math list>}` with braces
+then the atom has its class Ord. If the nucleus is a single math object constructed
+without braces then the class of the atom depends on this single math
+object. Each single math object must be declared in \TeX/ with its default
+class. The following table lists the classes with typical examples.
+The full set of all math objects used in math typesetting
+is listed in section~\ref[objects] with their default classes.
+
+\bigskip
+\noindent\hfil\table{llll}{
+ & \ii class Class & Meaning & Example \crl
+ 0 & \iid Ord & ordinary object & variables, digits, $x, {\bbchar R}, \Gamma, 0, 1$ \cr
+ 1 & \iid Op & big opertator & $\sum, \int, \bigcup$ \cr
+ 2 & \iid Bin & binary operator & $+, \times, -, \pm, \cup$ \cr
+ 3 & \iid Rel & reations & $=, \ne, \leq, \supseteq, \succsim$ \cr
+ 4 & \iid Open & opening bracket & $\{, (, [, \langle$ \cr
+ 5 & \iid Close & closing bracket & $\}, ), ], \rangle$ \cr
+ 6 & \iid Punct & punctuation & comma \cr
+ & \iid Inner & left-right & \code{\\left...\\right} outputs, see section~\ref[delims]
+}
+\bigskip
+
+There are \ii horizontal/spacing,spacing three space types used
+by the algorithm for horizontal spacing in the math formulas.
+
+\begitems
+* \ii thin/space Thin space: \x`\thinmuskip` primitive register, `\,` macro. Used around Op atoms.
+* \ii medium/space Medium space: \x`\medmuskip` primitive register, `\>` macro. Used around Bin atoms.
+* \ii thick/space Thick space: \x`\thickmusip` primitive register, `\;` macro. Used around Rel atoms.
+\enditems
+
+\puttext 7.8cm -3.7cm {\rotbox{90}{Left atom}}
+\puttext 11.5cm -.5cm {Right atom}
+\puttext 8.2cm -4.4cm {\typosize[9/11]
+\thistable{\def\_enspace{ }}%
+\table {l|8c|} {
+ \omit & Ord & Op & Bin & Rel & Open & Close & Punct & \omit \hfil Inner \crlp{2-9}
+ Ord & 0 & 1 & 2 & 3 & 0 & 0 & 0 & 1 \cr
+ Op & 1 & 1 & & 3 & 0 & 0 & 0 & 1 \cr
+ Bin & 2 & 2 & & & 2 & & & 2 \cr
+ Rel & 3 & 3 & & 0 & 3 & 0 & 0 & 3 \cr
+ Open & 0 & 0 & & 0 & 0 & 0 & 0 & 0 \cr
+ Close & 0 & 1 & 2 & 3 & 0 & 0 & 0 & 1 \cr
+ Punct & 1 & 1 & & 1 & 1 & 1 & 1 & 1 \cr
+ Inner & 1 & 1 & 2 & 3 & 1 & 0 & 1 & 1 \crlp{2-9}
+}}
+
+\hangindent=-8.7cm \hangafter=0
+Ord atoms are printed without spaces between them. The spaces are not
+cumulated, so the rule about spaces mentioned above is only a rough idea.
+The exact rule for horizontal spaces is given for each pairs of atoms
+in the table here. The symbol 0 means no space, 1 thin space, 2 medium space,
+and 3 means thick space.
+
+\hangindent=-8.7cm \hangafter-2
+The Bin atom is automatically transformed to the
+Ord atom if no atom precedes or if Op, Bin, Rel, Open, or Punct atom
+precedes. And it is transformed to the Ord atom if Rel, Close or Punct atom
+follows. This corresponds to the empty cells in the table.
+Why such behavior? Compare \"\hbox{$0-3$}" and \"$-3$". The Bin atom in
+the second case behaves like Ord atom because it is \ii unary/minus {\em unary minus}.
+There is no space between the unary minus and the following object.
+
+All medium spaces and thick spaces and some thin spaces from this table are
+omitted if the <math list> is processed in
+\ii script/style,scriptscript/style script or scriptscript styles
+(smaller size). See section~\ref[styles] about math styles.
+
+You can overwrite the default class derived from the nucleus of the atom by
+\TeX/ primitives \x`\mathord`, \x`\mathop`, \x`\mathbin`, \x`\mathrel`, \x`\mathopen`,
+\x`\mathclose`, \x`\mathpunct` and \x`\mathinner`. They can precede a nucleus of
+the atom and they set the class of the atom.
+For example, `x \mathrel+ y` behaves like `x = y` from a spacing point of view but +
+is printed. Another example: `\mathop{\rm lim} z` creates the atom `lim` in
+roman font of class Op. So, the thin space is inserted between lim and $z$.
+
+There are more special kinds of math atoms: fractions, math accents,
+radicals. They are constructed in a special way (see next sections) but they behave
+like Ord atom in the horizontal spacing algorithm.
+
+\secc[styles] Math styles
+
+When a formula (or a sub-formula) is processed by \TeX/ then one from four
+\ii math/style,display/style,text/style,script/style,scriptscript/style
+styles is active: display style ($D$), text style ($T$), script style ($S$) or
+scriptscript style ($SS$).
+
+\ii T/style,D/style,S/style,SS/style The $T$ style is started in in-line math mode `$...$` and the $D$
+style is started in display math mode `$$...$$`. The first level of exponents or
+subscripts is processed in $S$ style and the second and more levels of
+exponents or indexes are processed in $SS$ style.
+There are special rules for math styles when fractions are constructed, see
+section~\ref[frac].
+
+The $D$ and $T$ styles use basic \ii font/size font size, $S$ uses smaller font size (typically
+70~\%) and $SS$ style uses more smaller font size (typically 50~\%). Next
+levels of \"more smaller fonts" are not used due to classical typographic rules.
+
+The \ii nucleus nucleus of \iid Op atoms (big operators, $\sum$, $\int$, etc.) have typically bigger versions
+of the character shape for $D$ style than for $T$ style.
+So, there are four sizes for such math
+objects: one size for each math style. All other math objects (with non Op
+class) are printed only in three sizes: The sizes for $T$ and $D$ styles are equal.
+
+The \iid Op atom puts its \iid exponent and \iid subscript above and below the nucleus in $D$
+style but right to the nucleus in other styles:
+$$
+ `\sum``_{i=1}^\infty` \quad \hbox{gives}\quad \sum_{i=1}^\infty \hbox{ in $D$ style and}
+ \quad \textstyle \sum_{i=1}^\infty \hbox{ in $T$ style}.
+$$
+This default behavior of the Op atom
+can be modified by placing \x`\limits` or \x`\nolimits` or
+\x`\displaylimits` \TeX/ primitive just after its nucleus before the constructors
+of exponent and/or index. The `\nolimits` puts exponent and subscript right
+to the nucleus (regardless of the current style) and `\limits` puts these
+objects above and below the nucleus (regardless of the current style). There
+can be more such primitives in a queue (due to a macro expansion, for
+instance). Then the last primitive in the queue wins.
+If the last primitive is \x`\displaylimits` then
+the default behavior is processed regardless there are \x`\limits` or \x`\nolimits`
+before it.
+$$
+ `\sum\nolimits``_{i=1}^\infty` \quad \hbox{gives}\quad \sum\nolimits_{i=1}^\infty
+ \hbox{ in $D$ style and}\quad \textstyle\sum\nolimits_{i=1}^\infty
+ \hbox{ in $T$ style}.
+$$
+Atoms of all other classes have their exponents and/or subscripts only right
+to their nucleus without any exception.
+
+The primitives \x`\displaystyle`, \x`\textstyle`, \x`\scriptstyle` and
+\x`\scriptscriptstyle` set the given style regardless the default rules. For
+example, you can create a formula in in-line math mode and in $D$ style by
+`$\displaystyle <fomula>$` or a formula in display mode and $T$ style can be printed
+by `$$\textstyle <fomrula>$$`.
+
+If a subformula is placed below something (below a line from root symbol,
+below a fraction line), then the processed style $D, T, S$ or $SS$ is
+\ii cramped/style {\em cramped}.
+The exponents are positioned slightly lower than in
+\ii non-cramped/style non-cramped style. The selectors `\displaystyle`\,\dots
+`\scriptscriptstyle` mentioned above select non-cramped style. The
+non-cramped style is selected when math mode starts too.
+\new \OpTeX/
+You can select a cramped style by the macro \x`\cramped` at the start of the
+math formula or after the math-style selectors: `\scriptstyle\cramped` for
+example.
+
+Several macros need to know what math style is currently processed (for
+example they need to draw something in an appropriate size). But it
+not possible simply due to the syntax of fractions (section~\ref[frac]).
+This syntax requires to process all math lists in two steps: the first step
+expands all macros and creates structured data of processed math list. The
+second step reads the output of the first step, switches between math
+styles and creates definitive output. So, macros (working in the first step)
+cannot know the current math
+style because it is set only in the second step. \TeX/ supports the primitive
+\x`\matchchioce``{<D>}{<T>}{<S>}{<SS>}` which prepares four math lists in the
+first step and only one of these four lists are used in the second step. We
+can put different macros into each of the four parameters of `\mathchoice`.
+Plain \TeX/ supports the macro \x`\mathpalette` which gives a more comfortable
+interface of \x`\mathchoice` to the macro programmer.
+The cramped/non-cramped variants of the current style are kept when `\mathchioce`
+is used.
+
+\new \OpTeX/
+We describe another interface for creating macros depending on the current
+style. You can use \x`\mathstyles``{<math list>}`. It
+behaves like `{<math list>}`, moreover, you can use the following commands inside such
+<math list>:
+\begitems
+* The macro \x`\currstyle`. It expands to
+ `\displaystyle`, `\textstyle`,
+ `\scriptstyle` or `\scriptscriptstyle` depending on the current math style
+ when the `\mathstyles` was opened.
+* The \x`\dobystyle``{<D>}{<T>}{<S>}{<SS>}` is expandable macro. It expands its
+ parameter `<D>`, `<T>`, `<S>` or `<SS>` depending on the current math style
+ when `\mathstyles` was opened.
+* The value of the \x`\stylenum` register is 0, 1, 2 or 3
+ depending on the current math style when `\mathstyles` was opened.
+\enditems
+%
+Example of usage of \x`\mathstyles`:
+\def\mysymbol{\mathbin\mathstyles
+ {\kern1pt\vrule height\mysymbolA width\mysymbolA\kern1pt}}
+\def\mysymbolA{\dobystyle{5pt}{5pt}{3.5pt}{2.5pt}}
+\begtt
+\def\mysymbol{\mathbin\mathstyles
+ {\kern1pt\vrule height\mysymbolA width\mysymbolA\kern1pt}}
+\def\mysymbolA{\dobystyle{5pt}{5pt}{3.5pt}{2.5pt}}
+Test: $a\mysymbol b_{c \mysymbol d}$ or $a\mysymbol b\over c$.
+\endtt
+This example gives Test: $a\mysymbol b_{c \mysymbol d}$ or $a\mysymbol b\over c$.
+
+The \x`\mathstyles` macro mentioned above uses \TeX/ primitive \x`\mathchoice`, so it
+creates four math lists and only one is used. It may take more
+computer time in special cases.
+\new Lua\TeX/
+Lua\TeX/ supports the \x`\mathstyle` primitive
+(no \"`s`" at the end of this control sequence) which
+expands to values 0 to 7 depending on the current style:
+$D, D', T, T', S, S', SS, SS'$
+(where $X'$ means cramped variant of the style). This primitive does
+not use `\mathchoice` but it simply ignores the fraction syntax, so
+`$a\mysymbol b\over c$` cannot work if `\mysymbol` is defined using the `\mathstyle`
+primitive. See section 7.3.1 of Lua\TeX/ documentation for more information.
+
+
+\secc[frac] Fractions
+
+The \iid fraction can be constructed by `{<numerator>`\x`\over``<denominator>}`. If the
+fraction is only a single object in the whole math mode (between dollars),
+you need not use the outer braces, so you can write `$1\over2$` to get $1\over2$.
+
+The \ii numerator,denominator <numerator> and <denominator> are printed in \"smaller" math style than
+current math style. More exactly the following schema is used.
+$D$: $T\over T$., $T$: $S\over S$, $S$: $SS\over SS$, $SS$: $SS\over SS$.
+For example
+$$
+ `{a+b \over c}` \quad \hbox{is printed as }
+ {a+b\over c} \hbox{ in $D$ style and as }
+ \textstyle {a+b\over c} \hbox{ in $T$ style}.
+$$
+
+The \LaTeX/ macro \x`\frac``{<numerator>}{<denominator>}` is not supported in
+Plain \TeX/ nor in \OpTeX/ but you can define such macro if you want.
+
+The syntax with \x`\over` is more preferred because it is more human-readable
+notation. You can write the fraction in the same manner as you can read it.
+You can compare: `$1\over2$` (one over two) with `$\frac12$` (frac twelve).
+
+Besides the `\over` primitive, there are analogical \TeX/ primitives which
+create \"generalized" fractions. The result is similar to `{<above>\over <below>}`
+but there is something extra:
+
+\begitems
+* `{<above>`\x`\atop``<below>}` does `{<above>\over<below>}` but
+ without the fractional rule.
+* `{<above>`\x`\above``<dimen><below>}` creates fractional rule with <dimen> thickness.
+* `{<above>`\x`\overwithdelims``<delim-l><delim-r><below>}` adds the <delim-l> left to
+ the fraction and the <delim-r> right to the fraction.
+* `{<above>`\x`\atopwithdelims``<delim-l><delim-r><below>}` is analogical to
+ `\overwithdelims` but without fractional rule.
+* `{<above>`\x`\abovewithdelims``<delim-l><delim-r><dimen><below>}` behaves as
+ `\overwithdelims` but the fractional rule has <dimen> thickness.
+\enditems
+%
+The `\...withdelims` variants read <delim-l> and <delim-r>, they must be
+declared as {\em math delimiter} in \TeX. They are vertically scalable
+math objects, typically brackets. See section~\ref[delims] for more
+information about math delimiters. Example:
+$$
+ `{n \atopwithdelims() k}`\quad \hbox{ creates }
+ {n \choose k} \hbox{ in $D$ style and }
+ \textstyle {n \choose k} \hbox{ in $T$ style}.
+$$
+The \x`\choose` macro is defined by `\def\choose{\atopwithdelims()}`, so the
+user can write `{n\choose k}` in order to get binomial coefficients.
+
+
+\secc[delims] Vertically scalable objects: math delimiters
+
+The vertically scalable objects are called \ii delimiters {\em delimiters}. For example,
+all types of brackets are declared as delimiters.
+This means that you can use a bracket in arbitrary
+vertical size.\fnote{
+This is not exactly true, because traditional typography says that they
+cannot be scaled continuously but by visible steps. This means that there is
+a sequence of increasing brackets in the font, the reader must see a difference
+between every two sizes of brackets.}
+
+The following objects are declared as delimiters (i.e.\ vertically scalable):
+
+\bigskip
+{\tt \adef!{\bslash}
+\table{l 14c}{
+ \rm source: & ( & ) & [ & ] & \code{\\\{} & \code{\\\}} & /
+ & !backslash & !langle & !rangle
+ & | & \code{\\|} & \cr
+ \rm output: &$($&$)$&$[$&$]$& $\{$ & $\}$ & $/$
+ & $\backslash$ & $\langle$ & $\rangle$
+ & $|$ & $\|$
+}
+\medskip
+\table{l 14c}{
+ \rm source: & !lfloor & !rfloor & !lceil & !rceil \cr
+ \rm output: & $\lfloor$ & $\rfloor$ & $\lceil$ & $\rceil$
+}
+\medskip
+\table{l 14c}{
+ \rm source: & !uparrow & !Uparrow & !dowarrow & !Downarrow
+ & !updownarrow & !Updownarrow \cr
+ \rm output: & $\uparrow$ & $\Uparrow$ & $\downarrow$ & $\Downarrow$
+ & $\updownarrow$ & $\Updownarrow$
+}}
+\bigskip
+\noindent \new Unicode
+If you can produce the characters $\langle$, $\rangle$,\fnote
+ {Do not confuse $\string<, >$ and $\langle, \rangle$. The first pair are Rel atoms
+ with meaning \"less than" or \"greater than", but the second pair are special
+ types of brackets. They are not directly available at computer keyboards without
+ using a keyboard macro.}
+$\lfloor$, $\rfloor$, ... $\updownarrow$, $\Updownarrow$
+directly in your text editor then you can use these Unicode characters in your source instead of control
+sequences `\langle`, `\rangle`, `\lfloor`, `\rfloor` ... `\updownarrow`, `\Updownarrow`.
+For many users (including me), there is more simple to type `\lfloor` than to find
+how to create the $\lfloor$ character in my text editor. Note that there exist
+text editors (Emacs, for example)
+enabling you to type `\lfloor` and this control sequence is immediately
+converted to the $\lfloor$ Unicode character.
+Your source text looks pretty and you can use classical \TeX/ sequences.
+
+\new Unicode
+There are more \ii delimiters delimiters, but it heavily depends on loaded Unicode Math
+font. For example, this document is printed in `latinmodern-math` font and
+there are six more delimiters `\lBrack`~$\lBrack$, `\rBrack`~$\rBrack$,
+`\lAngle` $\lAngle$, `\rAngle` $\rAngle$, `\lgroup` $\lgroup$, `\rgroup` $\rgroup$.
+See section~\ref[objects] for table of all Unicode symbols for math typesetting.
+
+Arbitrary tall formula can be surrounded by a pair of delimiters using
+\x`\left` and \x`\right` \TeX/ primitives: `\left<delim> <formula> \right<delim>`.
+The delimiters are scaled to the height and depth of the <formula>
+and vertically centered to the {\em math axis}.\fnote
+{Math axis is a horizontal line passing through the center of symbols $+$
+ and $-$. All vertically scalable objects are vertically centered with
+ respect to this axis.}
+Example:
+$$
+ `+ \left\{ \sum_{i=1}^\infty x_i \right)` \quad \hbox{ gives }
+ + \left\{ \sum_{i=1}^\infty x_i \right).
+$$
+The pair `\left<delim> <formula> \right<delim>` creates the formula in a
+\TeX/ group. Such group can be nested with another groups.
+Each `\left` must have its `\right` counterpart at the same group level.
+If you don't want to create visible delimiter, use dot instead <delim>.
+Example:
+$$
+ `\left. \int``_0^t e^{x^2}\,dx\, \right|_{t=42}` \quad \hbox{ gives }
+ \left. \int_0^t e^{x^2} \,dx\, \right|_{t=42}
+$$
+
+\new e\TeX/
+You can use \x`\middle``<delim>` inside the <formula> which is surrounded by
+`\left...\right`. Then the given <delim> is scaled to the same size like
+their `\left` and `\right` counterparts.
+
+When a delimiter is used without `\left` nor `\right` prefix, then it is the
+Open, Close, Ord or Bin atom by its natural meaning:
+$(, [, \{, \ldots, \lfloor, \lceil$ are Open atoms,
+$], ], \}, \ldots, \rfloor, \rceil$ are Close atoms,
+$/, \backslash, |, \|$ are Ord atoms and
+$\uparrow, \Uparrow, \ldots, \Updownarrow$ are Bin atoms. You can overwrite
+this default setting, for example `\mathclose(`. If delimiters are used with
+`\left` and `\right` prefixes then `\left<delim>` behaves like Open atom,
+`\right<delim>` behaves like Close atom and the math list
+`\left<delim><formula>\right<delim>` is encapsulated as a single Inner atom.
+The `\middle<delim>` behaves like Open atom at its left side and like Close
+atom at its right side.
+
+The sequence of increasing delimiters can be printed by the following
+macros:
+$$
+ `(` \to (,\quad \x`\big``(` \to \big(,\quad \x`\Big``(` \to \Big(,\quad
+ \x`\bigg``(` \to \bigg(, \quad \x`\Bigg``(` \to \Bigg(.
+$$
+The `\Bigg<delim>` is not the maximal size of the bracket. Try
+`\left(\vbox to5cm{}\right.`, for example. You can see that the font
+\"cheats" from certain sizes, because there are not all infinity number of
+sizes of brackets drawn in the font, of course.
+
+The `\big<delim>` creates Ord atom. We need to create Open atom
+for opening bracket and Close atom for closing bracket more often.
+Then we can use macros
+\x`\bigl``<delim>`,
+\x`\Bigl``<delim>`,
+\x`\biggl``<delim>`,
+\x`\Biggl``<delim>` for creating Open atoms and
+\x`\bigr``<delim>`,
+\x`\Bigr``<delim>`,
+\x`\biggr``<delim>`,
+\x`\Biggr``<delim>` for creating Close atoms. Unfortunately, the source is not
+too attractive when more sizes of brackets are used, but typographic
+traditions say that we have to distinguish brackets by the size in math
+mode if they are in equal types:
+$$
+ `\Bigl( f\bigl( 2(x+y) + z\bigr) \Bigr)'` \quad \hbox{gives }
+ \Bigl(f\bigl(2(x+y)+z\bigr)\Bigr)'.
+$$
+
+\secc Horizontally scalable objects: math accents
+
+Arbitrary wide formula can be covered by \ii math/accent,accent {\em scalable math accent}.
+Example:
+$$
+ \x`\overrightarrow`` {a+b+c+d+e+f}` \quad \hbox{gives } \overrightarrow {a+b+c+d+e+f}.
+$$
+The usage is: control sequence of selected math accent followed by `{<math list>}`.
+
+Standard scalable math accents are:
+\x`\overline` $\overline{abc}$,
+\x`\overbrace` $\overbrace{abc}$,
+\x`\overrightarrow` $\overrightarrow{abc}$,
+\x`\overleftarrow`~$\overleftarrow{abc}$,
+\x`\underline` $\underline{abc}$,
+\x`\underbrace` $\underbrace{abc}$.
+
+An Op atom is created. The exponents and subscripts are centered above
+and below the nucleus of this atom (regardless of the current style). Example:
+$$
+ `\overbrace {b\cdot b\cdot b \cdots b}^{k\times}` \quad \hbox{gives }
+ \overbrace {b\cdot b\cdot b \cdots b}^{k\times}
+$$
+There are scalable accents with a limited maximum width:
+\x`\widehat` $\widehat{abc}$ and \x`\widetilde` $\widetilde{abc}$. If the
+formula is wider than the font can cover then the widest variant from the
+font is used and it is horizontally centered.
+
+\new Unicode
+There are more scalable accents in Unicode math fonts:
+\x`\overparen` $\overparen{abc}$, \x`\underparen` $\underparen{abc}$,
+\x`\overbracket` $\overbracket{abc}$, \x`\underbracket` $\underbracket{abc}$,
+\x`\overleftrightarrow` $\overleftrightarrow{abc}$,
+\x`\overleftharpoon` $\overleftharpoon{abc}$,
+\x`\overrightharpoon` $\overrightharpoon{abc}$,
+
+
+\secc Fixed math accents
+
+Fixed \ii math/accent,accent math accents can be applied to single math object or to the `{<math list>}`.
+The accent is centered (with respect of slanting axis) and the result is a
+nucleus of Ord
+atom. For example `\dot x` gives $\dot x$. The list of fixed math accents
+follows: \x`\acute`` x` $\acute x$, \x`\bar`` x` $\bar x$,
+\x`\breve`` x` $\breve x$, \x`\check`` x` $\check x$,
+\x`\dot`` x` $\dot x$, \x`\ddot`` x` $\ddot x$,
+\x`\grave`` x` $\grave x$, \x`\hat`` x` $\hat x$,
+\x`\vec`` x` $\vec x$, \x`\tilde`` x` $\tilde x$.
+
+\new Unicode
+The additional fixed accents depends on used Unicode math font. The
+`latinmodern-math` supports:
+\x`\ovhook`` x` $\ovhook x$, \x`\ocirc`` x` $\ocirc x$,
+\x`\leftharpoonaccent`` x` $\leftharpoonaccent x$, \x`\rightharpoonaccent`` x` $\rightharpoonaccent x$,
+\x`\dddot`` x` $\dddot x$, \x`\ddddot`` x` $\ddddot x$,
+\x`\widebridgeabove`` x` $\widebridgeabove x$, \x`\asteraccent`` x` $\asteraccent x$.
+
+There exist one special math accent `'` (single quote, ASCII 39)
+which can be appended after a symbol like this: `f'`
+and it creates $f'$ (typical meaning is the
+derivation of the given function). You can put more such accents, for
+example `g'''` gives $g'''$.
+
+\secc Roots
+
+There is a macro \x`\sqrt``{<math list>}` to create \ii square/root square root. For example:
+$$
+ `\sqrt{\sqrt{\sqrt{x+1}+1}+1}` \quad \hbox{gives }
+ \sqrt{\sqrt{\sqrt{x+1}+1}+1}
+$$
+The \ii root $n$-th root is created by the macro \x`\root`` <n>\of{<math list>}`. For
+example `\root k+1\of x` gives $\root k+1\of x$.
+
+\secc Math alphabets
+
+Letters \ii math/alphabet $a\dots z$, $A\dots Z$ and $\alpha$\dots$\omega$ are printed in italic
+in math mode. This follows the traditional typographic rule.
+All other math symbols, digits, and uppercase Greek letters must be
+upright.\fnote
+{French typographic convention says that uppercase Greek letters have to be
+ in italic too. Use `\_itGreek` declaration in this case.}
+These rules are independent of the current variant of surrounding text font.
+
+If we want to use the letters or digits
+in another than this default shape, then we can use
+\ii math/alphabet/selector {\em math alphabet selectors}:
+\x`\mit`, \x`\rm`, \x`\it`, \x`\bf`, \x`\cal`.
+\new \OpTeX/
+\OpTeX/ supports more such selectors \x`\script`, \x`\frak`, \x`\bbchar`, \x`\bi`, see
+section 1.3.3 in the \OpTeX/ documentation. The math selectors have local
+validity in the group.
+
+The control sequences \x`\rm`, \x`\it`, \x`\bf`, and \x`\bi` act as variant selectors
+of fonts in non-math mode (text mode) and they act
+as math alphabet selectors in math mode. This \"overlaying" concept
+is given by Plain \TeX/. Example: math operators lim, sin, cos,
+log, etc.\ must be printed unslanted. We are using `\lim`, `\sin`, `\cos`,
+`\log` etc.\ in math mode in order to comply with this typographic convention. For
+example `\sin` is defined as:
+\begtt
+\def\sin {\mathop{\rm sin}\nolimits}
+\endtt
+The `\rm` is used here as math alphabet selector, no variant selector of
+text fonts.
+
+The list of all predefined `\rm`-like math operators follows: \x`\arccos`,
+\x`\arcsin`, \x`\arctan`, \x`\arg`, \x`\cos`, \x`\cosh`, \x`\cot`, \x`\coth`, \x`\deg`.
+\x`\det`, \x`\dim`, \x`\exp`, \x`\gcd`, \x`\hom`, \x`\inf`, \x`\ker`, \x`\lg`, \x`\lim`,
+\x`\liminf`, \x`\limsup`, \x`\ln`, \x`\log`, \x`\max`, \x`\min`, \x`\Pr`, \x`\scs`, \x`\sin`,
+\x`\sinh`, \x`\sup`, \x`\tan`, \x`\tanh`, You can define another such operator
+analogically.
+
+\new Unicode
+Unicode font can include the following math alphabets:
+\begtt \typosize[9/11]
+\_rmvariables % upright letters A-Z, a-z
+\_bfvariables % bold letters A-Z, a-z
+\_itvariables % italic letters A-Z, a-z
+\_bivariables % bold italic letters A-Z, a-z
+\_calvariables % calligraphic letters A-Z, a-z
+\_bcalvariables % calligraphic letters A-Z, a-z
+\_frakvariables % fraktur A-Z, a-z
+\_bfrakvariables % bold fraktur A-Z, a-z
+\_sansvaraibales % sans serif letters A-Z, a-z
+\_bsansvaraibales % bold sans serif letters A-Z, a-z
+\_isansvaraibales % slanted sans serif letters A-Z, a-z
+\_bisansvaraibales % bold slanted sans serif letters A-Z, a-z
+\_ttvariables % monospace, typewriter letters A-Z, a-z
+\_bbvariables % double struck A-Z, a-z
+\_rmdigits % upright digits 0..9
+\_bfdigits % bold digits 0..9
+\_sansdigits % sans serif digits 0..9
+\_bsansdigits % bold sans serif digits 0..9
+\_ttdigits % monospace typewriter digits 0..9
+\_bbdigits % double-struck digits 0..9
+\_rmgreek % upright Greek letters \alpha-\omega
+\_itgreek % slanted Greek letters \alpha-\omega
+\_bfgreek % bold Greek letters \alpha-\omega
+\_bigreek % bold italic Greek letters \alpha-\omega
+\_bsansgreek % bold sans serif Greek letters \alpha-\omega
+\_bisansgreek % bold slanted snas serif Greek letters \alpha-\omega
+\_itGreek % slanted Greek letters \Alpha-\Omega
+\_bfGreek % bold Greek letters \Alpha-\Omega
+\_biGreek % bold italic Greek letters \Alpha-\Omega
+\_bsansGreek % bold sans serif Greek letters \Alpha-\Omega
+\_bisansGreek % bold slanted snas serif Greek letters \Alpha-\Omega
+\endtt
+%
+Not all Unicode math fonts include all math alphabets listed here. Typically,
+the lowercase letters of calligraphic shape and all letters of
+bold calligraphic shape are missing.
+
+\new \OpTeX/
+\OpTeX/ defines internal math alphabet selectors as mentioned in the
+previous listing of math alphabets and sets as default:
+\begtt \typosize[10/12]
+\_itvariables \_rmdigits \_itgreek \_rmGreek
+\endtt
+%
+Moreover, it defines the alphabet selectors at user level (see section 1.3.3
+of the \OpTeX/ manual). For example
+\begtt \typosize[10/12]
+\def\rm {\_tryload\_tenrm \_inmath{\_rmavariables \_rmdigits}}
+\endtt
+%
+The first part
+\new \OpTeX/
+`\_tryload\_tenrm` is applicable for text fonts and the
+`\_inmath` part is processed only in math mode and sets the math alphabets.
+You can see the file `unimath-codes.opm` where all user-level selectors are
+defined. You can redefine them. For example, \OpTeX/ defines `\bf` as a math
+alphabet selector that selects sans serif bold in math. This is the common
+notation for vectors, tensors, and matrices. If you dislike this, then you can define:
+\begtt \typosize[10/12]
+\def\bf {\_tryloadbf\_tenbf \_inmath{\_bfvariables\_bfdigits\_bfgreek\_bfGreek}}
+\endtt
+
+
+\secc[objects] List of single math objects
+
+\new Unicode
+All \ii single/math/object single math objects are listed in the `unimath-table.opm` or
+`unicode-math-table.tex` file. You can
+look into this file. The codes, \TeX/ sequences, classes, and comments
+for all possible math codes are here. Maybe, your Unicode math font which is loaded
+does not support all these codes.
+\new \OpTeX/
+You can try all codes of the currently loaded font by
+\begtt
+\input print-unimath.opm
+\endtt
+The `unimath-table` is printed with characters available in the loaded font.
+\new \OpTeX/
+If the character is unsupported by the font then the slot is empty and only
+\TeX/ sequence and the class of the code is printed in the table.
+For example, this document loads `latimodern-math.otf` font.
+And the result from `\input print-unimath.opm` looks like the following ten
+pages.
+
+Unsupported characters can be replaced by characters from other Unicode math
+font, see
+\ulink[http://petr.olsak.net/optex/optex-tricks.html\#addumathfont]{OpTeX trick 0030}
+or section~\ref[newfam].
+
+
+\label[listA]\wlabel{}
+
+\bigskip
+\input print-unimath.opm
+\bigskip
+
+\label[listB]\wlabel{}
+
+It isn't very comfortable to find something in the previous table
+if you know the shape. You can try the online web tool \ii Detexify
+\ulink[https://detexify.kirelabs.org/classify.html]{Detexify}.
+You can draw the symbol here and the suggestion of \TeX/ sequence is
+printed.
+
+\def\g#1{{\tt\string#1}~$#1$}
+
+The generic \TeX/ sequences for the Greek letters \ii Greek/letters can be used:
+\g\alpha, \g\beta, \g\gamma, \g\delta, \g\varepsilon, \g\zeta, \g\eta,
+\g\theta, \g\iota, \g\kappa, \g\lambda, \g\mu, \g\nu, \g\xi,
+\g\omicron, \g\pi, \g\rho, \g\varsigma, \g\sigma, \g\tau, \g\upsilon,
+\g\varphi, \g\chi, \g\psi, \g\omega, \g\vardelta, \g\epsilon, \g\vartheta,
+\g\varkappa, \g\phi, \g\varrho, \g\varpi\
+and
+\g\Alpha, \g\Beta, \g\Gamma, \g\Delta, \g\Epsilon, \g\Zeta, \g\Eta, \g\Theta,
+\g\Iota, \g\Kappa, \g\Lambda, \g\Mu, \g\Nu, \g\Xi, \g\Omicron, \g\Pi, \g\Rho,
+\g\Sigma, \g\Tau, \g\Upsilon, \g\Phi, \g\Chi, \g\Psi, \g\Omega.
+
+\new \OpTeX/
+The variant of Greek letters in the output
+(upright, italic, bold, bold sans serif, etc.)
+written by the sequences `\alpha`, `\beta` etc. depends on the math alphabet
+selected by `\_itgreek`, `\_rmgreek`, etc. selectors. The user-level
+selectors `\bf` and `\bi` set `\_bsansgreek` and `\_bisansgreek`, so
+`{\bi\delta}` produces $\bi\delta$.
+
+\new Unicode
+All characters available in the math font can be accessed by \TeX/ control
+sequence or by directly using the Unicode character in the document source.
+Example:
+\begtt \adef/{}
+$$
+ \sum/_{k=0}^\infty e^{(\alpha+i\beta/_k)} =
+ e^\alpha \sum/_{k=0}^\infty e^{i\beta/_k} =
+ e^\alpha \sum/_{k=0}^\infty (\cos\beta/_k + i\sin\beta/_k).
+$$
+\endtt
+or
+\begtt \ttspec
+$$
+ ∑_{k=0}^∞ e^{(α + iβ_k)} = e^α ∑_{k=0}^∞ e^{iβ_k}
+ = e^α ∑_{k=0}^∞ (\cos β_k + i\sin β_k).
+$$
+\endtt
+both gives the same result:
+$$
+ ∑_{k=0}^∞ e^{(α + iβ_k)} = e^α ∑_{k=0}^∞ e^{iβ_k}
+ = e^α ∑_{k=0}^∞ (\cos β_k + i\sin β_k).
+$$
+\medskip
+
+
+\sec Other specialities
+
+\secc The `\not` prefix
+
+You can apply \x`\not` before a following math object.
+The slash $/$ is overprinted such math object, for example
+`$a \not= b$` gives $a \not= b$.
+
+\new \OpTeX/
+If there exists a direct Unicode character for the negation of a relation symbol
+(for example `\ne` creates $\ne$ directly as a character U+2260)
+then `\not<char>` expands to appropriate Unicode character.
+For example `\not=` expands to `\ne` or `\not\in` expands to `\notin`.
+If such character does not exist then
+the centered $/$ is overprinted over the next character.
+
+
+\secc The `\buildrel` macro: text over the relation
+
+The macro \x`\buildrel`` <text>\over <relation>` creates a new atom Rel with the
+<relation> and with the smaller <text> above this <relation>. Example:
+`$M \buildrel\rm def\over= X\cup Y$` gives $M\buildrel\rm def\over= X\cup Y$.
+
+
+\secc Spaces
+
+Spaces between atoms are created automatically as were mentioned in
+section~\ref[class]. But sometimes you have to help \TeX/ to create
+appropriate space. You can use following macros:
+
+\begitems
+* `\,` is \ii thin/space {\em thin space} used around Op atoms, after comma, etc.: \ss\,,
+* `\!` is \ii negative/thin/space negative thin space,
+* `\>` is \ii medium/space {\em medium space} used around Bin atoms: \ss\>,
+* `\;` is \ii thick/space {\em thick space} used around Rel atoms: \ss\;,
+* \x`\quad` is \ii em/space {\em em space}: \ss\quad,
+* \x`\qquad` is \ii double/em/space {\em double em space}: \ss\qquad.
+\enditems
+%
+Of course, you can use \ii direct/space {\em direct space} {\visiblesp`\ `} which is \TeX/ primitive
+and gives interword space: \ss\ \
+or you can use \x`\hskip`` <value>` to put arbitrary space.
+
+The space size of `\,`, `\!` resp. `\>`, resp. `\;` is given by
+`\thinmuskip`, resp. `\medmuskip`, resp. `\thickmuskip` values. You can see
+in the `plain.tex` file that these default values differ very little in their basic
+size but there is no stretchability/shrinkability in the `\,` space, there is small
+stretchability in the `\>` space, and more stretchability in the `\;` space.
+
+The registers \x`\thinmuskip`, \x`\medmuskip`, and \x`\thickmuskip` store so-called
+\ii mu/values {\em mu values} given by math unit `mu`. It is 1/18 em and this unit depends
+on the current font size used in the math formula ($S$ or $SS$ styles use
+smaller font size, the `mu` unit is smaller here). You can use \x`\muskip`
+instead `\hskip` or \x`\mukern` instead `\kern` if you want to use this
+special mu unit. It is allowed only in math mode.
+
+The \x`\quad` and \x`\qquad` spaces have fixed width and they can be used in text
+mode too. (\OpTeX/ allows to use `\,` in text mode too).
+Use `\quad` or `\qquad` if you want to separate more formulas created in
+single math mode. Examples of typical usage of spaces:
+
+\begtt \adef/{} \typosize[10/12]
+$$ \alpha\,(x+y), \qquad \int/_a^b \!\! f(x)\,{\rm d}x, \qquad \Gamma/_{\!i}. $$
+\endtt
+$$ \alpha\,(x+y), \qquad \int_a^b \!\! f(x)\,{\rm d}x, \qquad \Gamma_{\!i}. $$
+
+
+\secc Texts in math mode
+
+If you write `$Hello world!$` (i.e.\ Hello world in math mode), then you get
+$Hello world!$. It is interpreted as the product of variables $H$, and $e$, and
+$l^2$, and $o$, etc., followed by the symbol ! used for factorial.
+The non-ASCII letters (with accents) don't work at all because they are
+never used as symbols for variables. Spaces are ignored.
+
+If you want to write a short text in the math mode, then you can use
+`\hbox{<text>}`. The \x`\hbox` primitive initializes text mode regardless of
+the \"outer mode". Example:
+
+\begtt \adef/{} \typosize[10/12]
+$$ \sum/_{n=0}^\infty (-1)^n a_n \hbox{ converges, if $a_n\searrow 0$.} $$
+\endtt
+$$ \sum_{n=0}^\infty (-1)^n a_n \hbox{ converges, if $a_n\searrow 0$.} $$
+%
+Note the space before the word \"converges". The space before `\hbox` is
+irrelevant. Second notice: the example shows the text mode inside math mode
+and the in-line math mode inside this text mode. The same result can be
+produced by:
+
+\begtt \adef/{} \typosize[10/12]
+$$ \sum/_{n=0}^\infty (-1)^n a_n \hbox{ converges, if } a_n\searrow 0. $$
+\endtt
+%
+The difference can be visible if the formula $a_n\searrow 0$ includes a
+fraction, for example ${1\over2}a_n\searrow 0$. The first example prints the
+fraction in the text style and the second example prints it in the display style.
+
+The disadvantage of `\hbox` is that it starts in the text mode independently
+of the current style, but we want to use smaller font in $S$ or $SS$ styles.
+\new \OpTeX/
+You can use \x`\mathbox``{<text>}` in such situations. This macro behaves like
+`\hbox` but the text is appropriately smaller in $S$ and $SS$ styles.
+Example:
+$$
+ `{\mathbox{cena}\over\mathbox{výkon}}` \quad \hbox{gives }
+ {\mathbox{cena}\over\mathbox{výkon}} \hbox{ in $D$ style and }
+ \textstyle {\mathbox{cena}\over\mathbox{výkon}} \hbox{ in $T$ style.}
+$$
+Note that $\mathbox{cena}\over\mathbox{výkon}$ means $\rm price\over performance$
+and you can write `$\rm price\over performance$` when you are using only
+words without spaces and accented letters. But phrases with spaces or accented letters
+should be printed in text mode using `\hbox` or `\mathbox`.
+
+\secc `\vcenter`
+
+The \x`\vcenter` primitive behaves like `\vbox`, but it can be used only in
+math mode and its result is vertically centered to the math axis.
+For example, matrices, are created by tables in `\vcenter`.
+
+All big objects in math formula are centered on the math axis and the baseline is
+ignored. In the following example, we create a new big math operator by
+`\vcenter`:
+\begtt
+$$
+ \def\myop#1{\mathop{\vcenter{\frame{\vbox to2em{\vss\hbox{ $#1$ }\vss}}}}}
+ F(x) = \myop{x(i)}_{i=1}^\infty
+$$
+\endtt
+\vskip-2em
+$$
+ \def\myop#1{\mathop{\vcenter{\frame{\vbox to2em{\vss\hbox{ $#1$ }\vss}}}}}
+ F(x) = \myop{x(i)}_{i=1}^\infty
+$$
+
+
+\secc Three dots
+
+You can write `$1,2,\dots,n$` to get $1,2,\dots,n$. The \x`\dots` macro puts
+thin space between dots and after the last dot, so the five object: comma,
+dots, comma are exactly equidistant.
+
+Typographic conventions say that you have to use the repeating symbol
+before and after three dots (comma in the previous example) and the three dots
+should be at baseline if the repeating symbol is at baseline. Or they should be
+at the math axis if the repeating symbol is at the math axis. We have to use \x`\cdots` instead
+`\dots` in the second case. Example:
+$$
+ `a_1, a_2, \dots, a_n, \quad a_1 + a_2 + \cdots + a_n` \qquad
+ a_1, a_2, \dots, a_n, \quad a_1 + a_2 + \cdots + a_n
+$$
+\vskip-.7em
+There are \x`\vdots` $\vdots$, \x`\ddots` $\ddots$ and \x`\adots` $\adots$ which
+can be used in matrices.
+
+\new Unicode
+Three dots like the output of the `\dots` macro are present as a single
+character in fonts too. This character is called ellipsis. Font designers
+typically suggest this character with smaller spaces between dots than we
+need in math mode. So the rule about equidistant \"comma, three dots, comma"
+is not met when this character is used. You can try `$1,2,\unicodeellipsis, n$`
+and `$1+2+\unicodecdots + n$`. You get $1,2,\unicodeellipsis, n$ and
+$1+2+\unicodecdots + n$. If you feel that this is better, then you can set:
+`\let\dots=\unicodeellipsis \let\cdots=\unicodecdots`.
+
+The Unicode fonts includes compact variants `\unicodevdots` $\unicodevdots$,
+`\unicodeddots` $\unicodeddots$ and `\unicodeadots` $\unicodeadots$ too.
+
+
+\secc Phantoms and `\smash`
+
+The \x`\phantom``{<math list>}` macro creates an invisible subformula equal to
+the formula generated by <math list>. It has its size, so it can
+interfere with surrounding visible subformulas. This macro is very useful for
+aligning with special requirements. Examples are shown in
+sections~\ref[matrix] and~\ref[elines].
+
+The \x`\vphantom``{<math list>}` has only its vertical size (i.e.\ its height
+and depth), the width is zero. The \x`\hphantom``{<math list>}` has only its
+width.
+
+The \x`\smash``{<math list>}` is the opposite of `\vphantom`. It creates visible
+subformula but it has only its width. Its height and depth are zero.
+
+The result of these macros is the nucleus of an Ord atom. You can use `\mathop`,
+`\mathbin`, etc. primitives to change this class. For example
+`$a\mathrel{\phantom{=}}b$` creates the same formula as $a=b$ with the same
+distance from $a$ to $b$ but without the equal sign:
+$a\mathrel{\phantom{=}}b$.
+
+These macros work in the text mode too. Then their argument is
+the <horizontal list>.
+
+
+\sec Structured objects
+
+\secc[matrix] Matrices
+
+The macro \x`\matrix``{<data>}` creates a vertically centered table of items.
+The <data> includes <items> separated by `&` and rows are separated by
+`\cr`. The number of columns and rows are unlimited. Columns are printed centered
+and separated by the `\quad` space. The vertically scalable
+brackets around the table are not printed. You can use \x`\pmatrix``{<data>}`
+instead `\matrix{<data>}`: the vertically scalable parentheses () are inserted
+around the table. Examples:
+
+\begtt
+$$
+ {\bf A} = \pmatrix{a_{1,1} & a_{1,2} & \cdots & a_{1,n} \cr
+ a_{2,1} & a_{2,2} & \cdots & a_{2,n} \cr
+ \vdots & \vdots & \ddots & \vdots \cr
+ a_{m,1} & a_{m,2} & \cdots & a_{m,n} },
+$$
+\endtt
+$$
+ {\bf A} = \pmatrix{a_{1,1} & a_{1,2} & \cdots & a_{1,n} \cr
+ a_{2,1} & a_{2,2} & \cdots & a_{2,n} \cr
+ \vdots & \vdots & \ddots & \vdots \cr
+ a_{m,1} & a_{m,2} & \cdots & a_{m,n} },
+$$
+or:
+
+\begtt
+\def\qmatrix[#1]{\left[\matrix{#1}\right]}
+$$
+ \qmatrix[a&b&c\cr d&e&f\cr g&h&i] \cdot \qmatrix[x_1\cr x_2\cr x_3]
+ = \qmatrix[b_1\cr b_2\cr b_3].
+$$
+\endtt
+$$
+ \def\qmatrix[#1]{\left[\matrix{#1}\right]}
+ \qmatrix[a&b&c\cr d&e&f\cr g&h&i] \cdot \qmatrix[x_1\cr x_2\cr x_3]
+ = \qmatrix[b_1\cr b_2\cr b_3].
+$$
+
+If you need to align the columns by another way than to center, then you can
+use the phantom. Compare:
+
+\begtt
+$$
+ \pmatrix{ 1 & -1 & 0 \cr
+ 0 & 2 & 13 \cr
+ -3 & 0 & 5 } \quad \hbox{or} \quad
+ \def\0{\phantom0} \def\+{\phantom+}
+ \pmatrix { \+1 & -1 & \00 \cr
+ \+0 & \+2 & 13 \cr
+ -3 & \+0 & \05 }
+$$
+\endtt
+$$
+ \pmatrix{ 1 & -1 & 0 \cr
+ 0 & 2 & 13 \cr
+ -3 & 0 & 5 } \quad \hbox{or} \quad
+ \def\0{\phantom0} \def\+{\phantom+}
+ \pmatrix { \+1 & -1 & \00 \cr
+ \+0 & \+2 & 13 \cr
+ -3 & \+0 & \05 }
+$$
+
+\new\OpTeX/
+Another option to set the right aligned matrix is setting the \x`\lmfil`:
+Its value is used on the left side in each `\matrix` item. The right side is
+set directly to `\hfil`.
+\begtt
+$$
+ \lmfil={\hfill} % left matrix filler = \hfill
+ \pmatrix{ 1 & -1 & 0 \cr 0 & 2 & 13 \cr -3 & 0 & 5 }
+$$
+\endtt
+
+\new \OpTeX/
+If you want to draw a vertical line inside the matrix, you can use `\adef|`
+as in the following example:
+\begtt
+$$
+ \adef|{\kern-.2em&\strut\vrule&\kern-.2em}
+ \def\+{\phantom+}
+ \pmatrix{1 & 2 & 3 | 0 \cr 4 & 5 & 6 | 1 \cr 7 & 8 & 9 | 2 } \sim
+ \pmatrix{1 & \+2 & \+3 | 0 \cr 0 & -3 & -6 | 1 \cr 0 & -6 & -12 | 2} \sim
+ \pmatrix{1 & 2 & 3 | 0 \cr 0 & 1 & 2 | -1/3 \cr 0 & 0 & 0 | 1 }
+$$
+\endtt
+$$
+ \adef|{\kern-.2em&\strut\vrule&\kern-.2em}
+ \def\+{\phantom+}
+ \pmatrix{1 & 2 & 3 | 0 \cr 4 & 5 & 6 | 1 \cr 7 & 8 & 9 | 2 } \sim
+ \pmatrix{1 & \+2 & \+3 | 0 \cr 0 & -3 & -6 | 1 \cr 0 & -6 & -12 | 2} \sim
+ \pmatrix{1 & 2 & 3 | 0 \cr 0 & 1 & 2 | -1/3 \cr 0 & 0 & 0 | 1 }
+$$
+
+If you want to put something before the opening bracket in the matrix, you can
+use another `\matrix`. Example:
+
+\begtt
+$$
+ \adef|{\kern-.2em&\strut\vrule&\kern-.2em}
+ \def\+{\phantom+}
+ \def\r{{\bf r}}
+ \pmatrix{1 & 2 & 3 | 0 \cr 4 & 5 & 6 | 1 \cr 7 & 8 & 9 | 2 } \ \sim \
+ \matrix{\cr 2.\r - 4\cdot 1.\r: \cr 3.\r -7\cdot 1.\r: }
+ \pmatrix{1 & \+2 & \+3 | 0 \cr 0 & -3 & -6 | 1 \cr 0 & -6 & -12 | 2}
+$$
+\endtt
+$$
+ \adef|{\kern-.2em&\strut\vrule&\kern-.2em}
+ \def\+{\phantom+}
+ \def\r{{\bf r}}
+ \pmatrix{1 & 2 & 3 | 0 \cr 4 & 5 & 6 | 1 \cr 7 & 8 & 9 | 2 } \ \sim \
+ \matrix{\cr 2.\r - 4\cdot 1.\r: \cr 3.\r -7\cdot 1.\r: }
+ \pmatrix{1 & \+2 & \+3 | 0 \cr 0 & -3 & -6 | 1 \cr 0 & -6 & -12 | 2}
+$$
+
+Plain \TeX/ defines the \x`\bordermatrix` macro which allows you to create a
+top row above the brackets and left column before the opening bracket.
+\TeX/book shows the following example:
+
+\begtt
+$$
+ M = \bordermatrix{ &C&I&C'\cr
+ C&1&0&0 \cr I&1-b&0 \cr C'&0&a&1-a }
+$$
+\endtt
+$$
+ M = \bordermatrix{ &C&I&C'\cr
+ C&1&0&0 \cr I&1-b&0 \cr C'&0&a&1-a }
+$$
+
+The `\matrix` macro used in $D$ style creates all its items in $T$ style.
+\new \OpTeX/
+If you are using the `\matrix` macro in $T$ style or $S$ style (but not in
+fractions nor another matrices) then the resulting table is appropriately
+smaller and all its items are processed in $S$ style.
+If you are using `\matrix` in $SS$ style then the items are in $SS$ style too.
+The following example shows one-column matrix in script style:
+$$
+ `\sum``_{\matrix{i\in M\cr j\in N\cr k\in P}} x_{i,j,k}` \ \hbox{ creates: }
+ \sum_{\matrix{i\in M\cr j\in N\cr k\in P}} x_{i,j,k}
+$$
+
+
+\secc Cases
+
+The \x`\cases` macro can be used as in the following example:
+
+\begtt
+$$
+ f(x) = \cases{ 1 & for $x\le 0$, \cr
+ 100-x\over 100 & when $0 < x \le 100$, \cr
+ 0 & in other cases. }
+$$
+\endtt
+$$
+ f(x) = \cases{ 1 & for $x\le 0$, \cr
+ 100-x\over 100 & when $0\string< x\le 100$, \cr
+ 0 & in other cases. }
+$$
+
+The `\cases` macro behaves like a special `\matrix` with two left-aligned
+columns and with left vertically scaled brace $\{$.
+The first column is processed in math mode and $T$ style, the second column
+is processed in text mode. We have to use `$...$` in the second column if
+there is math material.
+
+
+\sec Lines in display mode
+
+\secc General principles
+
+The \ii display/math,display/math/mode
+`$$<formula>$$` finalizes previous paragraph, prints centered <formula> on
+single line with a vertical space above and below and opens next paragraph
+with no indentation.
+
+From \TeX/'s point of view, the text above `$$<formula>$$` plus text
+below is a single paragraph interrupted by display <formula>. If there is no
+text above (i.e. the opening `$$` are in vertical mode), then the internal
+`\noindent` is processed first and the empty line above <formula> is created.
+Thus, it is definitely a bad idea to open display mode in vertical mode: never
+put an empty line before `$$<formula>$$`. On the other hand, the empty line
+just after `$$<formula>$$` says that the paragraph is finalized by the
+<formula> and the next text (after the empty line) opens the next paragraph with
+indentation. Summary:
+
+\begitems
+* \"Text above `$$<formula>$$` text below": the <formula> interrupts the
+ paragraph with \"Text above" and \"text below". The \"text below" is
+ without indentation.
+* \"Text above `$$<formula>$$` empty line Text below": the \"Text below"
+ opens new paragraph with indentation.
+* \"Empty line `$$<formula>$$`" is bad practice.
+\enditems
+
+In contrast with the paragraph breaking, there is no built-in algorithm for
+breaking display <formula> to more lines. If the <formula> is too wide then
+overfull `\hbox` occurs and human must decide about splitting the <formula>
+to more lines. The macros `\displaylines` and `\eqalign` are intended to
+such task, see sections~\ref[dlines] and~\ref[elines].
+
+On the other hand, the in-line math <formula>, i.e.\ the `$<formula>$` in a
+paragraph, can be broken after a Bin atom (with penalty `\binoppenalty`) or
+after a Rel atom (with penalty `\relpenalty`). If you don't want to break
+such a formula at a specific place then use `\nobreak`, for example
+`$a+\nobreak b$`. If you want never to break such formulas then you can set
+`\binoppenalty=10000`, `\relpenalty=10000`. (Default values are 700 and 500.)
+
+
+\secc References to display lines
+
+The `$$<formula>`\x`\eqno``<mark>$$` \ii mark prints centered <formula> and the <mark> at
+right margin. The `$$<formula>`\x`\leqno``<mark>$$` prints centered <formula> and
+the <mark> at left margin. Examples:
+
+\begtt
+$$ a^2 + b^2 = c^2 \eqno (1) $$
+\endtt
+$$
+ a^2 + b^2 = c^2 \eqno (1)
+$$
+\begtt \aftergroup\nobreak
+$$ a^2 + b^2 = c^2 \leqno \rm Py $$
+\endtt
+$$\predisplaypenalty=10000
+ a^2 + b^2 = c^2 \leqno \rm Py
+$$
+The <mark> \ii mark is processed in math mode and $T$ style. If you want to put a
+text here then you have to use `\rm <text>` or `\hbox{<text>}`.
+
+\new \OpTeX/
+The auto-generated <mark> can be created by `$$<formula>`\x`\eqmark``$$`. The
+<label> can be used previously declared by \x`\label``[<label>]`.
+Then it is associated to such
+auto-generated <mark> and you can write a reference in the form
+`see equation~\ref[<label>]`. You can write `\eqmark[<label>]` instead of
+`\label[<label>]...\eqmark`. See the \OpTeX/ manual, section~1.4.3.
+
+\secc[dlines] The `\displaylines` macro
+
+This macro creates more horizontally centered formulas in one display mode.
+The syntax is
+\begtt \catcode`\<=13
+$$ \displaylines{
+ <formula> \cr
+ <formula> \cr
+ ... \cr
+ <formula>
+} $$
+\endtt
+Usage of \x`\displaylines` is more
+prefered than doing more display modes just behind each other.
+Example:
+\begtt
+$$ \displaylines{
+ (3x^3 + 4x^2 + 5x + 6) \cdot (x^6 + x^2 + 5) = \cr
+ = 3x^9 + 4x^8 + 5x^7 + 6x^6 + 3x^5 + 4x^4 + 20x^3 + 26x^2 + 25x + 30.
+} $$
+\endtt
+$$ \displaylines{
+ (3x^3 + 4x^2 + 5x + 6) \cdot (x^6 + x^2 + 5) = \cr
+ = 3x^9 + 4x^8 + 5x^7 + 6x^6 + 3x^5 + 4x^4 + 20x^3 + 26x^2 + 25x + 30.
+} $$
+
+The output from `\displaylines` macro is breakable to more pages because
+the lines are not encapsulated in one box. The macro uses a special feature of
+`\halign` primitive. The disadvantage is that you cannot use `\eqno` nor
+`\leqno` nor `\eqmark`.
+
+\new \OpTeX/
+\OpTeX/ provides alternative form: `\displaylines to<dimen> {<data>}`.
+Then the centered formulas are encapsulated in a `\vcenter` box of width <dimen> and
+usage of `\eqno` or `\leqno` or `\eqmark` is allowed.
+The individual lines have the form `\hbox to<dimen>` and formulas are centered using
+`\hss` from both sides. This means that you can set arbitrary <dimen>
+without visual change of the formulas. Use smaller <dimen> value than
+`\hsize` (or `\displaywidth`\fnote
+{`\displaywith` = `\hsize` in most cases but it is
+real display width when `\parshape` or `\hangindent` is used.})
+if you want to center formulas with `\eqno` appended.
+The internal \TeX/ rule says: the formula with `\eqno` (or `\leqno`) is centered
+if its width is less or equal `\displaywidth-4<mark-width>`. So
+\begtt \catcode`\<=13
+$$ \displaylines to\hsize-8em {<formula>\cr<formula>}\eqno (1) $$
+\endtt
+does global centering, because size of `(1)` is less than 2\,em.
+You can do more experiments with this example,
+for example `\diplaylines to\hsize{...}`
+puts the `\eqno` mark to the next line in the display environment. Read
+\TeX/book or \TeX/book naruby, where the precise explanation about such
+positioning is.
+
+\new \OpTeX/
+You can use \"`\displaylines to<dimen>`" for more applications. For example,
+you can put more
+\"`\displaylines to<dimen>`" in single display mode, one next to second in order
+to creating more centered columns with formulas; the width of such columns
+are controlled by the <dimen> parameter.
+Or, you can give an exception for several lines:
+
+\begtt \catcode`\<=13
+$$\displaylines to 10cm {<formula>\hfill \cr
+ <formula>\cr
+ <formula>\cr
+ \hfill <formula>}
+$$
+\endtt
+The example above gives similar result as the \LaTeX/ `multline` environment:
+$$\displaylines to \hsize {
+ (3x^3 + 4x^2 + 5x + 6) \cdot (x^6 + x^2 + 5) = \hfill \cr
+ = 3x^9 + 3x^5 + 15x^3 + 4x^8 + 4x^4 + 20x^2 + 5x^7 + 5x^3 + 25x
+ + 6x^6 + 6x^2 + 30 = \cr
+ \hfill = 3x^9 + 4x^8 + 5x^7 + 6x^6 + 3x^5 + 4x^4 + 20x^3 + 26x^2 + 25x + 30. }
+$$
+
+
+\secc[elines] The `\eqalign` macro
+
+The \ii .eqalign \iis .eqalign {{\code{\\eqalign}}} usage is:
+\begtt \catcode`\<=13
+$$ \eqalign { <left-side> & <right-side> \cr
+ <left-side> & <right-side> \cr
+ ... \cr
+ <left-side> & <right-side>
+} $$
+\endtt
+The `\vcenter` box is created with two columns, left column is right aligned
+and right column is left aligned. Example:
+
+\vbox{
+\begtt
+$$ \eqalign{
+ x + 2y + 3z &= 600 \cr
+ 12x + y - 3z &= 7 \cr
+ 4x - y + 5z &= -5 \cr
+} $$
+\endtt
+\vskip-5.7\baselineskip
+{\hsize=1.35\hsize
+$$ \eqalign{
+ x + 2y + 3z &= 600 \cr
+ 12x + y - 3z &= 7 \cr
+ 4x - y + 5z &= -5 \cr
+} $$}}
+
+\bigskip\noindent
+The tab \"`&`" should be used just before a relation, i.e. `&=` is right, `=&`
+is wrong. All lines are aligned to the used tab.
+
+Maybe you want more precise alignment in the example above. You can use
+`\phantom`:
+
+\par\nobreak\vbox{
+\begtt
+$$ \def\1{\phantom1} \def\+{\phantom+}
+ \eqalign{
+ x + 2y + 3z &= 600 \cr
+ 12x + \1y - 3z &= \+7 \cr
+ 4x - \1y + 5z &= -5 \cr
+} $$
+\endtt
+\vskip-5.7\baselineskip
+{\hsize=1.35\hsize
+$$ \def\1{\phantom1} \def\+{\phantom+}
+ \eqalign{
+ x + 2y + 3z &= 600 \cr
+ 12x + \1y - 3z &= \+7 \cr
+ 4x - \1y + 5z &= -5
+} $$}}
+\bigskip
+Another typical usage of the `\eqalign` macro:
+
+\begtt \typosize[10/12]
+$$ \eqalign{
+ p(x)\,q(x) &= (3x^3 + 4x^2 + 5x + 6) \cdot (x^6 + x^2 + 5) = \cr
+ &= 3x^9 + 4x^8 + 5x^7 + 6x^6 + 3x^5 + 4x^4 + 20x^3 + 26x^2 + 25x + 30.
+} $$
+\endtt
+$$ \eqalign{
+ p(x)\,q(x) &= (3x^3 + 4x^2 + 5x + 6) \cdot (x^6 + x^2 + 5) = \cr
+ &= 3x^9 + 4x^8 + 5x^7 + 6x^6 + 3x^5 + 4x^4 + 20x^3 + 26x^2 + 25x + 30.
+} $$
+
+In \OpTeX/, \new\OpTeX/
+the `\eqalign` macro is more flexible. You can set the
+`\baselineskip` value by the \x`\eqlines` parameter and math style
+by the \x`\eqstyle` parameter.
+For example, you need to put the system of \"equations" as a subscript of a sum
+operator:
+\begtt \typosize[10/12] \adef/{}
+$$
+ \sum/_{\eqlines{\baselineskip=.7\baselineskip}\eqstyle{\scriptstyle}\eqalign{
+ i &\in A \cr
+ \quad j &\in B\cup C \cr
+ m &\in C }}
+ i + j + m
+$$
+\endtt
+$$
+ \sum_{\eqlines{\baselineskip=.7\baselineskip}\eqstyle{\scriptstyle}\eqalign{
+ i &\in A \cr
+ \quad j &\in B\cup C \cr
+ m &\in C }}
+ i + j + m
+$$
+
+\indent \new\OpTeX/
+You can write more equation systems one next second:
+\begtt
+$$\eqalign{
+ x + y + z &= 1 && a + b + c &= -1 \cr
+ u + v &= 20 && f + g &= -20 \cr
+ i &= j
+}$$
+\endtt
+You can use the third column for centered equations
+without aligning point. For example:
+\begtt \catcode`\<=13
+$$ \left( \eqspace=0pt \eqalign{&& <first equation>\cr
+ && <second equation>} \right) $$
+\endtt
+The \x`\eqspace` is additional space used in the third column to separate
+equation systems one next second.
+
+\new \OpTeX/
+\OpTeX/ extensions summary:
+\begitems
+* `\eqlines` and `\eqstyle` set baselineskip and math style of the formulas.
+* `\eqalign` allows more than two columns:
+ The first column is right-aligned (no space). The second is left-aligned (no space).
+ The third column (if used)
+ is centered with `\eqspace/2` at the left and right boundary of the column.
+ The fourth is the same as the first. The fifth is the same as second etc. The number
+ of columns that can be used in `\eqalign` is unlimited.
+\enditems
+
+\secc The `\eqalign` macro with references
+
+You can give common mark to whole equation system by
+`$$\eqalign{<data>}\eqno <mark>$$`. If you want to give marks to individual
+lines of the equation system, then you can use another macro:
+\x`\eqalignno`. The usage is similar as `\eqalign` but the
+third column (if used) is intended to the equation mark. Example:
+
+\begtt
+$$ \eqalignno{
+ x + 2y + 3z &= 600 & \rm(A) \cr
+ 12x + y - 3z &= 7 & \rm(B) \cr
+ 4x - y + 5z &= -5 & \rm(C) \cr
+} $$
+\endtt
+\vskip-\baselineskip
+$$ \eqalignno{
+ x + 2y + 3z &= 600 & \rm(A) \cr
+ 12x + y - 3z &= 7 & \rm(B) \cr
+ 4x - y + 5z &= -5 & \rm(C) \cr
+} $$
+
+The `\leqalignno` macro is similar to `\eqalignno` but the marks are at the left
+margin. The \OpTeX/ extensions of `\eqalign` are not available in
+`\eqalignno` nor `\leqalignno` macros.
+
+\new \OpTeX/
+You can use auto-generated marks by `\eqmark` macro:
+`$$\eqalign{<data>}\eqmark$$` or:
+\begtt
+$$ \eqalignno{
+ x + 2y + 3z &= 600 & \eqmark[A] \cr
+ 12x + y - 3z &= 7 & \eqmark[B] \cr
+ 4x - y + 5z &= -5 & \eqmark[C] \cr
+} $$
+\endtt
+
+
+\sec Concept of loading math fonts
+
+\secc[fams] Math families
+
+\TeX/ can use more than one math font in math mode. This was a
+necessity in the old days when only 128-characters fonts existed.
+Each math font used in math mode has its \ii math/family {\em math family} represented by a number.
+Math family is a collection of three (almost) equal fonts in three sizes:
+first for `\textstyle` and `\displaystyle`, second for `\scriptstyle`
+and third for `\scriptscriptstyle`.
+
+\new Unicode
+When Unicode math font is loaded then it includes all three optical sizes and
+all characters needed for typesetting math formula.
+Theoretically, we can use only one math family with this single font. But more math families
+(i.e.\ more fonts in math mode) is still possible. You can combine
+characters from more fonts (Unicode fonts and old TFM fonts together) in one math formula.
+
+\new \OpTeX/
+\OpTeX/ loads the main Unicode math font into math family 1. The math
+families 2 and 3 are reserved for specific \TeX/nical reasons, family 4 is
+used for `\script` font and families 5, 6, 7, etc. can be used by user for
+loading more fonts. The default macro for loading math fonts looks like:
+
+\begtt \typosize[10/12]
+\_def\_normalunimath{%
+ \_loadumathfamily 1 {\_unimathfont}{} % Main Unicode math font
+ \_loadmathfamily 4 rsfs % \script (old TFM font)
+ \_setunimathdimens % set dimen parameters used in math formulas internally
+}%
+\let\_normalmath=\_normalunimath % this is done when Unicode math is initialized
+\endtt
+%
+Whenever \OpTeX/ needs to resize math fonts (for example in footnotes or
+titles), it calls the `\_normalmath` macro to reload all math
+families to the desired size. If you want to add the next font, you can add
+`\_loadunimathfamily <family> {<Unicode-font>}{<features>}` or
+`\_loadmathfamily <family> <TFM-font>` into the `\_normalmath` macro.
+The example in section~\ref[newfam] shows how to do it.
+
+\secc Two variants of math fonts: normal and bold
+
+All math formulas in the whole document need only one Unicode font (or only one collection
+of math fonts as mentioned in section~\ref[fams]). But this
+is not really true if titles are in bold font. If a math formula is present in
+such a bold title then all characters of this formula must be bolder.
+For example \"normal" variables must be in bold italic in titles, symbols
+like `+` `=` must be bold and \"normal bold" letters
+(e.g., indicating vectors in math formula) must be extra bold in titles.
+It means that all fonts from the collection of math fonts must be bolder.
+We need a second collection of math fonts with bolder
+shape. Unfortunately, it is not always available.
+
+\new \OpTeX/
+If you have bold variant of used Unicode math font, then you can use
+\ii .loadmath \iis .loadmath {{\code{\\loadmath}}} \x`\loadboldmath` command, for example:
+\begtt
+\loadmath {[xitsmath-regular]}
+\loadboldmath {[xitsmath-bold]} \to {[xitsmath-regular]}
+\endtt
+%
+\OpTeX/ uses `\_normalmath` macro for loading collection of math fonts in
+\"normal" cases and `\_boldmath` macro for bold titles. The font declared by
+\x`\loadboldmath` is used in second case. But if the bold variant of the font is
+not available (this is unfortunately more typical), then \OpTeX/ uses faked
+bold of main Unicode math font (the `embolden` internal font feature is
+used). So, the default `\_boldmath` macro defined by \OpTeX/ looks like:
+
+\begtt \typosize[10/12]
+\_def\_boldunimath{%
+ \_ifx\_unimathboldfont \_undefined
+ \_loadumathfamily 1 {\_unimathfont}{embolden=1.7;} % Main faked bold
+ \_else
+ \_loadumathfamily 1 {\_unimathboldfont}{} % Main real bold font
+ \_fi
+ \_loadmathfamily 4 rsfs % rsfs in not in bold, unfortunately
+ \_setunimathdimens
+}%
+\let\_boldmath=\_boldunimath % this is done when Unicode math is initialized
+\endtt
+
+\secc[newfam] Example of using additional math font
+
+The font `bbold10.tfm` includes double stroked characters, for example,
+double stroked plus, double stroked Greek letters and digits.
+Try to run `pdftex testfont`, then answer the question about the name of the
+font: `bbold10` and then type command `\table\end`. The `testfont.pdf` is
+printed with the table of characters of this font.
+Most of these characters cannot be found in Unicode math fonts.
+
+\new \OpTeX/
+We show an example of how to add this font to the collection of used math fonts.
+We can re-define the `\_normalmath` macro by:
+\begtt \typosize[10/12]
+\addto\_normalmath {\_loadmathfamily 5 bbold }
+
+\_regtfm bbold 0 bbold5 5.5 bbold6 6.5 bbold7 7.5 bbold8 8.5 bbold9
+ 9.5 bbold10 11.1 bbold12 15 bbold17 * % using all bbold*.tfm
+\_normalmath % reload the math fonts collection
+\endtt
+%
+The string \"`bbold`" is declared by `\_regtfm` as a collection of all
+`bbold*.tfm` fonts, the optical sizes are supported.
+
+\addto\_normalmath {\_loadmathfamily 5 bbold }
+\_regtfm bbold 0 bbold5 5.5 bbold6 6.5 bbold7 7.5 bbold8 8.5 bbold9
+ 9.5 bbold10 11.1 bbold12 15 bbold17 * % using all bbold*.tfm
+\_normalmath
+\Umathchardef \bbplus 2 5 "2B
+\Umathchardef \bble 3 5 "3C
+\Umathchardef \bbge 3 5 "3E
+
+Finally, we must to declare new \TeX/ sequences for accessing the characters
+from the new font, for example:
+
+\begtt \typosize[10/12]
+\Umathchardef \bbplus 2 5 "2B
+\Umathchardef \bble 3 5 "3C
+\Umathchardef \bbge 3 5 "3E
+\endtt
+%
+The \x`\Umathchardef` \TeX/ primitive declares new \TeX/ sequence used in math
+typesetting. The first parameter is a class number (2 means Bin, 3 means Rel,
+see the table in the section~\ref[class]). The second parameter is a math
+family number. It is 5, see the redefinition of the `\_normalmath` macro above.
+The third parameter is a slot in the font. Now you can try to use these characters:
+$$
+ `a \bbplus b \bbge c` \quad \hbox{gives} \quad a \bbplus b \bbge c.
+$$
+%
+Maybe, you want to declare a special math selector which can be used as
+`$\bball a+b>c$` in order to get $\bbchar a \bbplus b \bbge c$.
+Then you can define:
+
+\begtt \typosize[10/12]
+\def\bball {\bbchar \Umathcodenum `+ \bbplus
+ \Umathcodenum `> \bbge
+ \Umathcodenum `< \bble }
+\endtt
+
+If you want to add all double stroked Greek letters into `\bball`
+selector, then you can do something like this:
+
+\begtt \typosize[10/12]
+\def\setbbgreek #1 {\tmpnum=#1\xargs\setbbgreekA}
+\def\setbbgreekA #1{\Umathcode \_ea`#1 0 5 \tmpnum \advance\tmpnum by1 }
+
+\addto\bball {%
+ \setbbgreek "0B \alpha \beta \gamma \delta \epsilon \zeta \eta
+ \theta \iota \kappa \lambda \mu \nu \xi \pi \rho \sigma
+ \tau \upsilon \phi \chi ;
+ \setbbgreek "7F \omega ;
+ \setbbgreek "00 \Gamma \Delta \Theta \Lambda \Xi \Pi \Sigma \Upsilon
+ \Phi \Psi \Omega ; }
+\endtt
+%
+The \x`\Umathcode`` <input-code> <class> <family> <font-slot>` primitive is used
+here. The control sequences `\alpha`, `\beta`, `\gamma` etc. are macros which expand
+to the Unicode character of appropriate (non-math) Greek letter. We set the
+Umathcode to such character, for example
+\code{\\Umathcode `}$\_rmgreek\alpha$` 0 5 "0B` is processed.
+
+The bold variant of the font `bbold*.tfm` is not available, unfortunately.
+We have to settle for normal version of the font in the `\_boldmath` macro:
+
+\begtt \typosize[10/12]
+ \addto \_boldmath {\_loadmathfamily 5 bbold }
+\endtt
+
+Another approach of using more Unicode math fonts in a single formula is
+shown in
+\ulink[http://petr.olsak.net/optex/optex-tricks.html\#addumathfont]{OpTeX trick 0030}.
+
+\sec Index
+
+Control sequences listed at pages \pgref[listA]--\pgref[listB] are not
+mentioned here again.
+
+\begmulti 3
+\makeindex
+\endmulti
+
+\bye
diff --git a/Master/texmf-dist/doc/optex/optex-techdoc.tex b/Master/texmf-dist/doc/optex/optex-techdoc.tex
new file mode 100644
index 00000000000..4ae25a9c7ec
--- /dev/null
+++ b/Master/texmf-dist/doc/optex/optex-techdoc.tex
@@ -0,0 +1,290 @@
+%% This is part of the OpTeX project, see http://petr.olsak.net/optex
+
+% This file is read from optex-doc.tex
+% Use: optex optex-doc
+% (three times) to create whole documentation including all references and the index.
+
+\load [doc.opm]
+
+\thisoutline {TECHNICAL DOCUMENTATION}
+
+\chap Technical documentation
+
+This documentation is written in the source files `*.opm` between
+the `\_doc` and `\_cod` pairs or after the `\_endcode` command.
+When the format is generated by
+\begtt
+luatex -ini optex.ini
+\endtt
+then the text of the documentation is ignored and the format `optex.fmt` is
+generated. On the other hand, if you run
+\begtt
+optex optex-doc.tex
+\endtt
+then the same `*.opm` files are read when the second chapter of this
+documentation is printed.
+
+A knowledge about \TeX/ is expected from the reader.
+You can see a short document
+\ulink[http://petr.olsak.net/ftp/olsak/optex/tex-nutshell.pdf]{\TeX/ in a Nutshell}
+or more detail
+\ulink[https://eijkhout.net/texbytopic/texbytopic.html]{\TeX/ by topic}.
+
+Notices about hyperlinks.
+If a control sequence is printed in red color in this documentation then
+this denotes its \"main documentation point". Typically, the listing where
+the control sequence is declared follows immediately. If a control sequence is
+printed in the blue color in the listing or in the text
+then it is an active link that points (usually) to the main documentation point.
+The main documentation point can be an active link that points to a previous
+text where the control sequence was
+mentioned. Such occurrences are active links to the main documentation point.
+
+\sec[init] The main initialization file
+
+The `optex.ini` file is read as the main file when the format is generated.
+
+{\everytt={\typosize[8/10]\_let\_printverbline=\_printcodeline \medskip}
+ \def\docfile{optex.ini}
+
+\verbinput (-4) optex.ini
+%
+Category codes are set first. Note that the `_` is set to category code
+\"letter", it can be used as a part of control sequence names.
+Other category codes are set as in the plain \TeX/.
+
+\verbinput (6-20) optex.ini
+%
+The \`\optexversion` and \`\fmtname` are defined.
+
+\verbinput (22-25) optex.ini
+%
+We check if \LuaTeX/ engine is used at `-ini` state. And the `^^J` character
+is set as `\newlinechar`.
+
+\verbinput (27-36) optex.ini
+%
+The basic macros for macro file syntax is defined, i.\,e.\
+`\_endcode`, `\_doc` and `\_cod`.
+The `\_codedecl` will be re-defined later.
+
+\verbinput (38-42) optex.ini
+%
+Individual `*.opm` macro files are read.
+
+\verbinput (44-87) optex.ini
+%
+The file `optex.lua` is embedded into the format as byte-code.
+It is documented in section~\ref[lua].
+
+\verbinput (89-92) optex.ini
+
+The `\everyjob` register is initialized and the format is saved by
+the `\dump` command.
+
+\verbinput (94-102) optex.ini
+
+}
+
+\printdoctail prefixed.opm
+\secc The implementation of the namespaces
+\printdoc prefixed.opm
+
+\sec pdf\TeX/ initialization
+\printdoctail luatex-ini.opm
+\printdoc luatex-ini.opm
+
+\sec Basic macros
+We define first bundle of basic macros.
+\printdoc basic-macros.opm
+
+\sec Allocators for \TeX/ registers
+\printdoctail alloc.opm
+\printdoc alloc.opm
+
+\sec If-macros, loops, is-macros
+\printdoc if-macros.opm
+
+\sec Setting parameters
+\printdoctail parameters.opm
+\printdoc parameters.opm
+
+\sec More \OpTeX/ macros
+The second bundle of \OpTeX/ macros is here.
+\printdoc more-macros.opm
+
+\sec Using key=value format in parameters
+\printdoctail keyval.opm
+\printdoc keyval.opm
+
+\sec Plain \TeX/ macros
+All macros from plain \TeX/ are rewritten here.
+Differences are mentioned in the documentation below.
+\printdoc plain-macros.opm
+
+\sec Preloaded fonts for text mode
+\printdoctail fonts-preload.opm
+\printdoc fonts-preload.opm
+
+\printdoctail fonts-resize.opm
+\printdoc fonts-resize.opm
+
+\printdoctail fonts-select.opm
+\secc Implementation of the Font Selection System
+\printdoc fonts-select.opm
+
+\sec [math-preload] Preloaded fonts for math mode
+\printdoctail math-preload.opm
+\printdoc math-preload.opm
+
+\sec[math-macros] Math macros
+\printdoc math-macros.opm
+
+\sec Unicode-math fonts
+\printdoctail math-unicode.opm
+
+\sec[opmac-fonts] Scaling fonts in document (high-level macros)
+These macros are documented in section~\ref[sizes] from the user point of view.
+\printdoc fonts-opmac.opm
+
+\sec[output] Output routine
+\printdoctail output.opm
+\printdoc output.opm
+
+\sec Margins
+The `\margins` macro is documented in the section~\ref[marg].
+\printdoc margins.opm
+
+\sec[colors] Colors
+\printdoctail colors.opm
+\printdoc colors.opm
+
+\sec[ref-file] The \code{.ref} file
+\printdoctail ref-file.opm
+\printdoc ref-file.opm
+
+\sec[references] References
+\printdoctail references.opm
+\printdoc references.opm
+
+\sec Hyperlinks
+\printdoctail hyperlinks.opm
+\printdoc hyperlinks.opm
+
+\sec[maketoc] Making table of contents
+\printdoc maketoc.opm
+
+\sec PDF outlines
+\secc Nesting PDF outlines
+\printdoctail outlines.opm
+\printdoc outlines.opm
+\secc Strings in PDF outlines
+\printdoctail pdfuni-string.opm
+\printdoc pdfuni-string.opm
+
+\sec[sections] Chapters, sections, subsections
+\printdoc sections.opm
+
+\sec[lists] Lists, items
+\printdoc lists.opm
+
+\sec Verbatim, listings
+\secc[verb] Inline and \"display" verbatim
+\printdoc verbatim.opm
+\secc[hisyntax] Listings with syntax highlighting
+\printdoctail hi-syntax.opm
+\printdoc hi-syntax.opm
+
+\sec Graphics
+\printdoctail graphics.opm
+\printdoc graphics.opm
+
+\sec[table] The \code{\\table} macro, tables and rules
+\printdoctail table.opm
+\secc[table.impl] Implemetation of the \code{\\table} macro and friends
+\printdoc table.opm
+
+\sec Balanced multi-columns
+\printdoc multicolumns.opm
+
+\sec Citations, bibliography
+\secc[bib] Macros for citations and bibliography preloaded in the format
+\printdoc cite-bib.opm
+\secc[usebib] The \code{\\usebib} command
+\printdoctail usebib.opm
+\secc The \code{usebib.opm} macro file loaded when \code{\\usebib} is used
+\printdoc usebib.opm
+
+\secc[isobib] Usage of the \code{bib-iso690} style
+{\everyintt={\catcode`\<=13 \visiblesp}
+\printdoctail bib-iso690.opm }
+
+\secc Implementation of the \code{bib-iso690} style
+\printdoc bib-iso690.opm
+
+\sec[makeindex] Sorting and making Index
+\printdoc makeindex.opm
+
+\sec[fnotes] Footnotes and marginal notes
+\printdoc fnotes.opm
+
+\sec Styles
+ \OpTeX/ provides three styles: `\report`, `\letter` and `\slides`.
+ Their behavior is documented in user part of the manual in the section
+ \ref[styles] and `\slides` style (for presentations) is documented in
+ `op-slides.pdf` which is an example of the presentation.
+\secc \code{\\report} and \code{\\letter} styles
+\printdoc styles.opm
+\secc[slides] \code{\\slides} style for presentations
+\printdoc slides.opm
+
+\sec Logos
+\printdoc logos.opm
+
+\sec Multilingual support
+\secc Lowercase, uppercase codes
+\printdoctail uni-lcuc.opm
+\secc Hyphenations
+\printdoc hyphen-lan.opm
+\printdoctail hyphen-lan.opm
+\secc[langphrases] Multilingual phrases and quotation marks
+\printdoc languages.opm
+
+\sec Other macros
+Miscellaneous macros are here.
+\printdoc others.opm
+
+\sec[lua] Lua code embedded to the format
+
+The file `optex.lua` is loaded into the format in `optex.ini` as byte-code
+and initialized by `\everyjob`, see section~\ref[init].
+
+The file implements part of the functionality from `luatexbase` namespace,
+nowadays defined by \LaTeX/ kernel. `luatexbase` deals with modules,
+allocators, and callback management. Callback management is a nice extension
+and is actually used in \OpTeX/. Other functions are defined more or less just
+to suit luaotfload's use.
+
+\newtoks \_hisyntaxlua
+\_hisyntaxlua={%
+ \_hicolor C \Green
+ \_replfromto {--}{^^J} {\z C{--#1}^^J}%
+}
+
+{\everytt={\typosize[8/10]\_let\_printverbline=\_printcodeline \medskip}
+ \commentchars-- \def\docfile{optex.lua} \ttline=-1
+ \_def\_printcomments{\_medskip
+ {\_catcodetable0 \_typosize[10/12]\_everypar={}\_scantextokens\_ea{\_vcomments}\par}%
+ \_bigskip
+ }
+
+\verbinput \hisyntax{lua} (4-) optex.lua
+}
+
+
+\sec Printing documentation
+\printdoctail doc.opm
+\printdoc doc.opm
+
+\enddocument
+
diff --git a/Master/texmf-dist/doc/optex/optex-userdoc.tex b/Master/texmf-dist/doc/optex/optex-userdoc.tex
new file mode 100644
index 00000000000..a70cedcf4d8
--- /dev/null
+++ b/Master/texmf-dist/doc/optex/optex-userdoc.tex
@@ -0,0 +1,2019 @@
+%% This is part of the OpTeX project, see http://petr.olsak.net/optex
+
+% This file is read from optex-doc.tex
+% Use: optex optex-doc (three times) to create whole documentation.
+
+\let\new=\relax
+
+\sec Starting with \OpTeX/
+%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\new
+\OpTeX/ is compiled as a format for \LuaTeX/. Maybe there is a command
+`optex` in your \TeX/ distribution. Then you can write into the command line
+
+\begtt
+optex document
+\endtt
+%
+You can try to process `optex op-demo` or `optex optex-doc`.
+
+If there is no `optex` command, see more information about installation
+\OpTeX/ at \url{http://petr.olsak.net/optex}.
+
+A minimal document should be
+
+\begtt
+\fontfam[LMfonts]
+Hello World! \bye
+\endtt
+
+The first line \~`\fontfam[LMfonts]` tells that Unicode Latin Modern
+fonts (derived from Computer Modern) are used. If you omit this line then
+preloaded Latin Modern fonts are used but preloaded fonts cannot be in
+Unicode\fnote
+{This is a technical limitation of \LuaTeX/ for fonts downloaded in formats:
+only 8bit fonts can be preloaded.}.
+So the sentence `Hello World` will be OK without the first line, but you
+cannot print such sentence in other languages (for example `Ahoj světe!`)
+where Unicode fonts are needed
+because the characters like `ě` are not mapped correctly in preloaded
+fonts.
+
+A somewhat larger example with common settings should be:
+
+\begtt \catcode`!=0
+\fontfam[Termes] % selecting Unicode font family Termes (section !ref[fontfam])
+\typosize[11/13] % setting default font size and baselineskip (sec. !ref[sizes])
+\margins/1 a4 (1,1,1,1)in % setting A4 paper, 1 in margins (section !ref[marg])
+\cslang % Czech hyphenation patterns (section !ref[lang])
+
+Tady je zkušební textík v českém jazyce.
+\bye
+\endtt
+%
+You can look at `op-demo.tex` file for a more complex, but still simple example.
+
+\sec Page layout
+%%%%%%%%%%%%%%%%
+
+\secc[marg] Setting the margins
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+The \^`\margins` command declares margins of the document. This command have
+the following parameters:
+
+\begtt \catcode`\<=13
+\margins/<pg> <fmt> (<left>,<right>,<top>,<bot>)<unit>
+ example:
+\margins/1 a4 (2.5,2.5,2,2)cm
+\endtt
+
+Parameters are:
+
+\begitems
+* <pg> \dots\ `1` or `2` specifies one-page or two-pages design.
+* <fmt> \dots\ paper format (a4, a4l, a5, letter, etc. or user defined).
+* <left>, <right>, <top>, <bot> \dots\ gives the amount of left, right,
+ top and bottom margins.
+* <unit> \dots\ unit used for values <left>, <right>, <top>, <bot>.
+\enditems
+
+Each of the parameters <left>, <right>, <top>, <bot> can be empty.
+If both <left> and <right> are nonempty then `\hsize` is set. Else `\hsize`
+is unchanged. If both <left> and <right> are empty then typesetting area is
+centered in the paper format. The analogical rule works when <top> or <bot>
+parameter is empty (`\vsize` instead `\hsize` is used). Examples:
+
+\begtt
+\margins/1 a4 (,,,)mm % \hsize, \vsize untouched,
+ % typesetting area centered
+\margins/1 a4 (,2,,)cm % right margin set to 2cm
+ % \hsize, \vsize untouched, vertically centered
+\endtt
+
+If `<pg>=1` then all pages have the same margins. If `<pg>=2` then the
+declared margins are true for odd pages. The margins at the even pages are
+automatically mirrored in such case, it means that <left> is replaced by
+<right> and vice versa.
+
+\OpTeX/ declares following paper formats: a4, a4l (landscape~a4),
+a5, a5l, a3, a3l, b5, letter and user can declare another own format by \~`\sdef`:
+
+\begtt
+\sdef{_pgs:b5l}{(250,176)mm}
+\sdef{_pgs:letterl}{(11,8.5)in}
+\endtt
+
+The `<fmt>` can be also in the form `(<width>,<height>)<unit>` where `<unit>` is
+optional. If it is missing then `<unit>` after margins specification is
+used. For example:
+
+\begtt
+\margins/1 (100,200) (7,7,7,7)mm
+\endtt
+%
+declares the paper 100$\times$200\,mm with all four margins 7\,mm. The spaces
+before and after <fmt> parameter are necessary.
+
+The command \^`\magscale[<factor>]` scales the whole typesetting area.
+\new The fixed point of such scaling is the upper left corner of the paper sheet.
+Typesetting (breakpoints etc.) is unchanged. All units are relative after
+such scaling. Only paper format's dimensions stay unscaled. Example:
+
+\begtt
+\margins/2 a5 (22,17,19,21)mm
+\magscale[1414] \margins/1 a4 (,,,)mm
+\endtt
+%
+The first line sets the `\hsize` and `\vsize` and margins for final
+printing at a5 format. The setting on the second line centers the scaled
+typesetting area to the true a4 paper while breaking points for paragraphs
+and pages are unchanged. It may be usable for
+review printing. After the review is done, the second line can be commented out.
+
+\secc Concept of the default page
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\OpTeX/ uses \"output routine" for page design.
+It is very similar to the Plain \TeX/ output routine.
+There is \^`\headline` followed by \"page body" followed by
+\^`\footline`. The \^`\headline` is empty by default and it can be used
+for running headers repeated on each page. The \^`\footline` prints
+centered page number by default. You can set the \^`\footline` to empty
+using \^`\nopagenumbers` macro.
+
+The margins declared by \^`\margins` macro (documented in the previous
+section~\ref[marg]) is concerned to the page body,
+i.e.\ the \^`\headline` and \^`\footline` are placed to the top and bottom
+margins.
+
+The distance between the \^`\headline` and the top of the page body is given by
+the \^`\headlinedist` register. The distance between bottom of the page body and
+the \^`\footline` is given by \^`\footlinedist`. The default values are:
+
+\begtt
+\headline = {}
+\footline = {\_hss\_rmfixed \_folio \_hss} % \folio expands to page number
+\headlinedist = 14pt % from baseline of \headline to top of page body
+\footlinedist = 24pt % from last line in pagebody to baseline of footline
+\endtt
+
+The page body should be divided into top insertions (floating tables and
+figures) followed by a real text and followed by footnotes.
+Typically, the only real text is here.
+
+The \^`\pgbackground` tokens list is empty by default but it can be used for
+creating a background of each page (colors, picture, watermark for example).
+The macro \^`\draft` uses this register and puts big text DRAFT as a watermark
+to each page. You can try it.
+
+More about the page layout is documented in sections~\ref[oparams] and~\ref[output].
+
+\secc Footnotes and marginal notes
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+The Plain \TeX/'s macro \^`\footnote` can be used as usual. But a new macro
+\^`\fnote{<text>}` is defined. The footnote mark is added automatically and it
+is numbered
+\new
+on each chapter from one\fnote
+{You can declare \^`\fnotenumglobal` if you want footnotes numbered in whole
+document from one or \^`\fnotenumpages` if you want footnotes numbered at each
+page from one. Default setting is \^`\fnotenumchapters`}.
+The <text> is scaled to 80 \%.
+User can redefine footnote mark or scaling, as shown in the section~\ref[fnotes].
+
+The \^`\fnote` macro is fully applicable only in \"normal outer" paragraph.
+It doesn't work inside boxes (tables, for example). If you are solving such
+a case then you can use the command \^`\fnotemark``<numeric-label>` inside the box: only the
+footnote mark is generated here. When the box is finished you can use
+\^`\fnotetext{<text>}`. This macro puts the <text> to the footnote.
+The <numeric-label> has to be `1` if only one such command is in the box.
+Second \^`\fnotemark` inside the same box has to have the parameter `2` etc.
+The same number of \^`\fnotetext`s have to be written
+after the box as the number of \^`\fnotemark`s inserted inside the box.
+Example:
+
+\begtt
+Text in a paragraph\fnote{First notice}... % a "normal" footnote
+\table{...}{...\fnotemark1...\fnotemark2...} % two footnotes in a box
+\fnotetext{Second notice}
+\fnotetext{Third notice}
+...
+\table{...}{...\fnotemark1...} % one footnote in a box
+\fnotetext{Fourth notice}
+\endtt
+
+The marginal note can be printed by the \^`\mnote{<text>}` macro. The <text>
+is placed to the right margin on the odd pages and it is placed to the left
+margin on the even pages. This is done after second \TeX{} run because the
+relevant information is stored in an external file and read from it again.
+If you need to place the notes only to the fixed margin write
+\^`\fixmnotes\right` or \^`\fixmnotes\left`.
+
+The <text> is formatted as a little paragraph with the maximal width
+\^`\mnotesize` ragged left on the left margins or ragged right on the right
+margins. The first line of this little paragraph has its vertical position
+given by the position of \^`\mnote` in the text. The exceptions are possible
+by using the `up` keyword: \~`\mnote`` up<dimen>{<text>}`.
+You can set such <dimen> to each \^`\mnote` manually in final printing
+in order to margin notes do not overlap. The positive value of <dimen>
+shifts the note up and negative value shifts it down. For example
+\^`\mnote`` up 2\baselineskip{<text>}` shifts this marginal note two lines up.
+
+\sec Fonts
+%%%%%%%%%%
+
+\secc[fontfam] Font families
+%%%%%%%%%%%%%%%%%%%%%%%
+
+You can select the font family by \^`\fontfam[<Family-name>]`.
+The argument <Family-name> is case insensitive and spaces are ignored in it. For
+example, \^`\fontfam[LM Fonts]` is equal to \^`\fontfam[LMfonts]` and it is equal
+to \^`\fontfam[lmfonts]`. Several aliases are prepared, thus
+\^`\fontfam[Latin Modern]` can be used for loading Latin Modern family too.
+
+If you write \^`\fontfam[?]` then all font families registered in \OpTeX/
+are listed on the terminal and in the log file.
+If you write \^`\fontfam[catalog]` then a catalog of all fonts registered in
+\OpTeX/ and available in your \TeX/ system is printed. The instructions
+on how to register your own font family are appended in the catalog.
+
+If the family is loaded then {\em font modifiers} applicable in such font family
+are listed on the terminal: (`\caps`, `\cond` for example).
+And there are four basic {\em variant selectors} (\^`\rm`, \^`\bf`, \^`\it`, \^`\bi`).
+The usage of variant selectors is the same as in Plain \TeX:
+`{\it italics text}`, `{\bf bold text}` etc.
+
+The font modifiers (`\caps`, `\cond` for example) can
+be used before a variant selector and they
+can be (independently) combined: `\caps\it` or `\cond\caps\bf`. The
+modifiers keep their internal setting until the group ends or until another
+modifier that negates the previous feature is used. So
+`{\caps \rm First text \it Second text}`
+gives {\caps \rm First text \it Second text}.
+
+The font modifier without following variant selector does not change the font
+actually, it only prepares data used by next variant selectors.
+There is one special variant selector \^`\currvar` which does not change the
+selected variant but reloads the font due to (maybe newly
+specified) font modifier(s).
+
+The context between variants \^`\rm` $\leftrightarrow$ \^`\it` and
+\^`\bf` $\leftrightarrow$ \^`\bi` is kept by the \^`\em`
+macro (emphasize text).
+It switches from current \^`\rm` to \^`\it`, from current \^`\it` to \^`\rm`, from
+current \^`\bf` to \^`\bi` and from current \^`\bi` to \^`\bf`.
+The italics correction `\/` is inserted automatically, if needed. Example:
+
+\begtt
+This is {\em important} text. % = This is {\it important\/} text.
+\it This is {\em important} text. % = This is\/ {\rm important} text.
+\bf This is {\em important} text. % = This is {\bi important\/} text.
+\bi This is {\em important} text. % = This is\/ {\bf important} text.
+\endtt
+
+\new
+More about the \OpTeX/ Font Selection System is written in the technical
+documentation in the section~\ref[fontsystem].
+You can mix more font families in your document, you can
+declare your own variant selectors or modifiers, etc.
+
+\secc[sizes] Font sizes
+%%%%%%%%%%%%%%%%%%%%%
+
+The command \^`\typosize[<fontsize>/<baselineskip>]` sets the font size of text and
+math fonts and baselineskip. If one of these two parameters is empty, the
+corresponding feature stays unchanged. Don't write the unit of these
+parameters. The unit is internally set to \^`\ptunit` which is 1pt by default.
+You can change the unit by the command \^`\ptunit=<something-else>`,
+for instance \^`\ptunit=1mm` enlarges all font sizes declared by \^`\typosize`.
+Examples:
+
+\begtt
+\typosize[10/12] % default of Plain TeX
+\typosize[11/12.5] % font 11pt, baseline 12.5pt
+\typosize[8/] % font 8pt, baseline unchanged
+\endtt
+
+The commands for font size setting described in this section
+have local validity. If you put them into a group,
+the settings are lost when the group is finished. If you set
+something relevant with paragraph shape (baselineskip given by
+\^`\typosize` for example) then you must first finalize the
+paragraph before closing the group:
+`{\typosize[12/14] ...<text of paragraph>... \par}`.
+
+The command \^`\typoscale[<font-factor>/<baselineskip-factor>]`
+sets the text and math fonts
+size and baselineskip as a multiple of the current fonts size and
+baselineskip. The factor is written in \"scaled"-like way, it means that 1000
+means factor one. The empty parameter is equal to the parameter 1000,
+i.e. the value stays unchanged. Examples:
+
+\begtt
+\typoscale[800/800] % fonts and baselineskip re-size to 80 %
+\typoscale[\magstep2/] % fonts bigger 1,44times (\magstep2 expands to 1440)
+\endtt
+
+First usage of \^`\typosize` or \^`\typoscale` macro in your document sets so-called {\em main values}, i.\,e.\ main font size and main baselineskip. They are internally
+saved in registers \^`\mainfosize` and \^`\mainbaselineskip`.
+
+\new
+The \^`\typoscale` command does scaling with respect to current values by default.
+If you want to do it with respect to the main values, type \^`\scalemain` immediately
+before \^`\typoscale` command.
+
+\begtt
+\typosize[12/14.4] % first usage in document, sets main values internally
+\typosize[15/18] % bigger font
+\scalemain \typoscale[800/800] % reduces from main values, no from current.
+\endtt
+
+The \^`\typosize` and \^`\typoscale` macros initialize the font family by `\rm`.
+You can re-size only the current font by the command
+\^`\thefontsize[<font-size>]` or the font can be rescaled by
+\^`\thefontscale[<factor>]`. These macros don't change math fonts sizes nor
+baselineskip.
+
+\new
+There is \"low level" \^`\setfontsize{<size-spec>}` command which behaves like
+a font modifier and sets given font size used by next variant selectors.
+It doesn't change the font size immediately, but the following variant selector
+does it. For example \^`\setfontsize{at15pt}`\^`\currvar` sets current variant to 15pt.
+
+If you are using a font family with \"optical sizes feature" (i.\,e.\ there
+are more recommended sizes of the same font which are not scaled
+linearly; a good example is Computer Modern aka Latin Modern fonts)
+then the recommended size is selected by all mentioned commands automatically.
+
+More information about resizing of fonts is documented in the
+section~\ref[setfontsize].
+
+\secc Typesetting math
+%%%%%%%%%%%%%%%%%%%%%
+
+See the additional document
+\ulink[http://petr.olsak.net/ftp/olsak/optex/optex-math.pdf]
+{Typesetting Math with \OpTeX/} for more details about this issue.
+
+\OpTeX/ preloads a collection of 7bit Computer Modern math fonts
+and AMS fonts in its format for math typesetting.
+You can use them in any size and in the \^`\boldmath` variant.
+%
+\new
+Most declared text font families (see \^`\fontfam` in the section~\ref[fontfam])
+are configured with a recommended Unicode
+math font. This font is automatically loaded unless you specify
+\^`\noloadmath` before first \^`\fontfam` command. See log file for more
+information about loading text font family and Unicode math fonts. If you
+prefer another Unicode math font, specify it by \^`\loadmath{[<font-file>]}`
+or \^`\loadmath{<font-name>}` before first \^`\fontfam` command.
+
+Hundreds math symbols and operators like in AMS\TeX/ are accessible.
+For example `\alpha` $\alpha$, `\geq`~$\geq$, `\sum` $\sum$,
+`\sphericalangle` $\sphericalangle$, `\bumpeq`, $\bumpeq$. See AMS\TeX/
+manual or
+\ulink[http://petr.olsak.net/ftp/olsak/optex/optex-math.pdf]
+{Typesetting Math with \OpTeX/} for complete list of math symbols.
+
+The following math alphabets are available:
+
+\begtt \catcode`\$=3 \catcode`/=0 \medmuskip=0mu \adef{ }{ }
+\mit % mathematical variables $abc-xyz,ABC-XYZ$
+\it % text italics $/it abc-xyz,ABC-XYZ$
+\rm % text roman $/rm abc-xyz,ABC-XYZ$
+\cal % normal calligraphics $/cal ABC-XYZ$
+\script % script $/script ABC-XYZ$
+\frak % fracture $/frak abc-xyz,ABC-XYZ$
+\bbchar % double stroked letters $/bbchar ABC-XYZ$
+\bf % sans serif bold $/bf abc-xyz,ABC-XYZ$
+\bi % sans serif bold slanted $/bi abc-xyz,ABC-XYZ$
+\endtt
+
+The last two selectors \^`\bf` and \^`\bi` select the sans serif fonts in math regardless of the current text font family. This is a common notation for vectors and
+matrices. You can re-declare them, see section~\ref[unimath-codes] where
+definitions of Unicode math variants of \^`\bf` and \^`\bi` selectors are documented.
+
+The math fonts can be scaled by \^`\typosize` and \^`\typoscale` macros.
+Two math fonts collections are prepared: \^`\normalmath` for normal weight
+and \^`\boldmath` for bold. The first one is set by default, the second one
+is usable for math formulae in titles typeset in bold, for example.
+
+\new
+You can use \^`\mathbox{<text>}` inside math mode. It behaves as `{\hbox{<text>}}`
+(i.e. the <text> is printed in horizontal non-math mode)
+but the size of the <text> is adapted to the context of math size (text or script or
+scriptscript).
+
+\sec Typical elements of the document
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\secc[chap] Chapters and sections
+%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+The documents can be divided into chapters (\^`\chap`),
+sections (\^`\sec`), subsections (\^`\secc`) and they can be titled
+by \^`\tit` command. The parameters are separated by the end of current line (no
+braces are used):
+
+\begtt \catcode`\<=13
+\tit Document title <end of line>
+\chap Chapter title <end of line>
+\sec Section title <end of line>
+\secc Subsection title <end of line>
+\endtt
+
+The chapters are automatically numbered by one number, sections by two numbers
+(chapter.section), and subsections by three numbers. If there are no chapters
+then sections have only one number and subsections two.
+
+The implicit design of the titles of chapter etc.\ is implemented in the
+macros \^`\_printchap`, \^`\_printsec` and \^`\_printsecc`. A designer can simply change
+these macros if he/she needs another behavior.
+
+The first paragraph after the title of chapter, section, and subsection is
+not indented but you can type `\let`\^`\_firstnoindent=\relax` if you need all
+paragraphs indented.
+
+If a title is so long then it breaks into more lines in the output. It is better to hint at the
+breakpoints because \TeX/ does not interpret the meaning of the title.
+Users can put the \^`\nl` (means newline) to the breakpoints.
+
+If you want to arrange a title to more lines in your source file then you can
+use `^^J` at the end of each line (except the last one).
+When `^^J` is used, then the reading of the title continues at the next line.
+The \"normal" comment character `%` doesn't work in titles.
+You can use \^`\nl`{\visiblesp` ^^J`} if you want to have corresponding lines in the source
+and the output.
+
+The chapter, section, or subsection isn't numbered if the \^`\nonum` precedes.
+And the chapter, section, or subsection isn't delivered to the table of
+contents if \^`\notoc` precedes. You can combine both prefixes.
+
+\secc[cap] Another numbered objects
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+Apart from chapters, sections, and subsections, there are another
+automatically numbered objects: equations, captions for tables and
+figures. The user can declare more numbered objects.
+
+If the user writes the \^`\eqmark` as the last element of the display mode then
+this equation is numbered. The equation number is printed in brackets. This number
+is reset in each section by default.
+
+If the \^`\eqalignno` is used, then user can put \^`\eqmark` to the last column
+before `\cr`. For example:
+
+\begtt
+\eqalignno{
+ a^2+b^2 &= c^2 \cr
+ c &= \sqrt{a^2+b^2} & \eqmark \cr}
+\endtt
+
+Another automatically numbered object is a caption which is tagged by \^`\caption/t` for
+tables and \^`\caption/f` for figures. The caption text follows.
+The \^`\cskip` can be used between \^`\caption` text and the real object (table
+or figure). You can use two orders: `<caption>\cskip <object>` or
+`<object>\cskip <caption>`.
+The \^`\cskip` creates appropriate vertical space between them. Example:
+
+\begtt
+\caption/t The dependency of the computer-dependency on the age.
+\cskip
+\noindent\hfil\table{rl}{
+ age & value \crl\noalign{\smallskip}
+ 0--1 & unmeasured \cr
+ 1--6 & observable \cr
+ 6--12 & significant \cr
+ 12--20 & extremal \cr
+ 20--40 & normal \cr
+ 40--60 & various \cr
+ 60--$\infty$ & moderate}
+\endtt
+
+This example produces:
+
+\medskip
+\caption/t The dependency of the computer-dependency on the age.
+\cskip
+\noindent\hfil\table{rl}{
+ age & value \crl\noalign{\smallskip}
+ 0--1 & unmeasured \cr
+ 1--6 & observable \cr
+ 6--12 & significant \cr
+ 12--20 & extremal \cr
+ 20--40 & normal \cr
+ 40--60 & various \cr
+ 60--$\infty$ & moderate}
+\medskip
+
+You can see that the word \"Table" followed by a number is added by the macro
+`\caption/t`.
+The caption text is centered. If it occupies more lines then the
+last line is centered.
+
+The macro \^`\caption/f` behaves like \^`\caption/t` but it is intended for
+figure captions with independent numbering.
+The word (Table, Figure) depends on the selected language (see
+section~\ref[lang] about languages).
+
+If you wish to make the table or figure as a floating object, you need to use
+Plain \TeX/ macros \^`\midinsert` or \^`\topinsert` terminated by \^`\endinsert`.
+Example:
+
+\begtt
+\topinsert % table and its caption printed at the top of the current page
+ <caption and table>
+\endinsert
+\endtt
+%
+The pair \^`\midinsert`...\^`\endinsert` prefers to put the enclosed object
+to the current place. Only if this is unable due to page breaking, it
+behaves like \^`\topinsert`...\^`\endinsert`.
+
+\new
+There are five prepared counters `A`, `B`, `C`, `D` and `E`.
+They are reset in each chapter and section\fnote
+{This feature can be changed, see the section~\ref[sections] in the technical documentation.}.
+They can be used in context of \^`\numberedpar` `<letter>{<text>}`
+macro. For example:
+\begtt
+\def\theorem {\numberedpar A{Theorem}}
+\def\corollary {\numberedpar A{Corollary}}
+\def\definition {\numberedpar B{Definition}}
+\def\example {\numberedpar C{Example}}
+\endtt
+%
+Three independent numbers are used in this example. One for Theorems and Corollaries
+second for Definitions and third for Examples. The user can write
+`\theorem Let $M$ be...` and the new paragraph is started with the text:
+{\bf Theorem 1.4.1.} Let $M$ be...
+You can add an optional parameter in brackets. For example,
+`\theorem [(L'Hôpital's rule)] Let $f$, $g$ be...`
+is printed like {\bf Theorem 1.4.2 (L'Hôpital's rule).} Let $f$, $g$ be...
+
+\secc References
+%%%%%%%%%%%%%%%
+
+Each automatically numbered object documented in
+sections \ref[chap] and \ref[cap] can be referenced
+\new
+if optional parameter
+`[<label>]` is appended to \^`\chap`, \^`\sec`,
+\^`\secc`, \^`\caption/t`, \^`\caption/f` or \^`\eqmark`. The alternative syntax is
+to use \^`\label[<label>]` before mentioned commands (not necessarily directly
+before). The reference is realized by \^`\ref[<label>]` or \^`\pgref[<label>]`.
+Example:
+
+\begtt
+\sec[beatle] About Beatles
+
+\noindent\hfil\table{rl}{...} % the table
+\cskip
+\caption/t [comp-depend] The dependency of the comp-dependency on the age.
+
+\label[pythagoras]
+$$ a^2 + b^2 = c^2 \eqmark $$
+
+Now we can point to the section~\ref[beatle] on the page~\pgref[beatle]
+or write something about the equation~\ref[pythagoras]. Finally there
+is an interesting Table~\ref[comp-depend].
+\endtt
+
+If there are forward referenced objects then users have to run \TeX{} twice.
+During each pass, the working `*.ref` file (with references data) is created
+and this file is used (if it exists) at the beginning of the document.
+
+You can use the \^`\label[<label>]` before the `\theorem`, `\definition` etc.\
+(macros defined with `\numberedpar`) if you want to reference these numbered objects.
+You can't use `\theorem[<label>]` because the optional parameter
+is reserved to another purpose here.
+
+You can create a reference to whatever else by commands
+\^`\label[<label>]`\^`\wlabel{<text>}`. The connection between <label> and
+<text> is established. The \^`\ref[<label>]` will print <text>.
+
+By default, labels are not printed, of course. But if you are preparing a
+draft version of your document then you can declare \^`\showlabels`. The labels
+are printed at their destination places after such a declaration.
+
+\secc Hyperlinks, outlines
+%%%%%%%%%%%%%%%%%%%%%%%%%
+
+If the command \^`\hyperlinks` `<color-in> <color-out>` is used at the beginning of
+the document, then the following objects are hyperlinked in the PDF output:
+
+\begitems
+* numbers and texts generated by \^`\ref` or \^`\pgref`,
+* numbers of chapters, sections, subsections, and page numbers in the table of contents,
+* numbers or marks generated by \~`\cite` command (bibliography references),
+* texts printed by \~`\url` or \~`\ulink` commands.
+\enditems
+
+The last object is an external link and it is colored by
+<color-out>. Other links are internal and they are colored by
+<color-in>. Example:
+
+\begtt
+\hyperlinks \Blue \Green % internal links blue, URLs green.
+\endtt
+
+You can use another marking of active links: by frames which are visible in
+the PDF viewer but invisible when the document is printed. The way to do it
+is to define the macros \^`\_pgborder`, \^`\_tocborder`, \^`\_citeborder`,
+\^`\_refborder` and \^`\_urlborder` as the triple of RGB components of the used
+color. Example:
+
+\begtt
+\def\_tocborder {1 0 0} % links in table of contents: red frame
+\def\_pgborder {0 1 0} % links to pages: green frame
+\def\_citeborder {0 0 1} % links to references: blue frame
+\endtt
+
+By default, these macros are not defined. It means that no frames are created.
+
+The hyperlinked footnotes can be activated by \^`\fnotelinks` `<color-fnt> <color-fnf>`
+where footnote marks in the text have `<color-fnt>` and the same footnote marks
+in footnotes have <color-fnf>. You can define relevant borders
+\^`\_fntborder` and \^`\_fnfborder` analogically as \^`\_pgborder` (for example).
+
+There are \"low level" commands to create the links. You can specify the
+destination of the internal link by \^`\dest[<type>:<label>]`. The
+active text linked to the \^`\dest` can be created by
+\^`\ilink[<type>:<label>]{<text>}`. The `<type>` parameter is one of
+the `toc`, `pg`, `cite`, `ref`, or another special for your purpose.
+These commands create internal links only when \^`\hyperlinks` is declared.
+
+The \^`\url` macro prints its parameter in \~`\tt` font and creates a potential
+breakpoints in it (after slash or dot, for example). If the \^`\hyperlinks`
+declaration is used then the parameter of \^`\url` is treated as an external URL link.
+An example: `\url{http://www.olsak.net}` creates \url{http://www.olsak.net}.
+The characters \code{\%}, `\`, `#`, `{`, and `}` have to be protected by
+backslash in the \^`\url` argument, the other special characters `~`,
+`^`, `&` can be written as single character\fnote
+{More exactly, there are the same rules as for `\code` command, see
+section~\ref[verbatim].}.
+You can insert the `\|` command
+in the `\url` argument as a potential breakpoint.
+
+If the linked text have to be different than the URL, you can use
+\^`\ulink[<url>]{<text>}` macro. For example:
+`\ulink[http://petr.olsak.net/optex]{\OpTeX/ page}`
+outputs to the text
+\ulink[http://petr.olsak.net/optex]{\OpTeX/ page}.
+The characters \code{\%}, `\`, `#`, `{`, and `}` must by escaped in
+the <url> parameter.
+
+The PDF format provides {\em outlines} which are notes placed in the special frame of
+the PDF viewer. These notes can be managed as a structured and hyperlinked
+table of contents of the document. The command \^`\outlines{<level>}` creates
+such outlines from data used for the table of contents in the document. The
+<level> parameter gives the level of opened sub-outlines
+in the default view. The deeper levels can be opened by mouse click on the
+triangle symbol after that.
+
+\new
+If you are using a special unprotected macro in section titles then \^`\outlines` macro
+may crash. You must declare a variant of the macro for outlines case which is
+expandable. Use \~`\regmacro` in this case. See the section \ref[toc] for more information
+about \~`\regmacro`.
+
+The command \^`\insertoutline{<text>}` inserts a next entry into PDF outlines at
+the main level~0. These entries can be placed before the table of contents (created
+by \^`\outlines`) or after it. Their hyperlink destination is in the place
+where the \^`\insertoutline` macro is used.
+
+The command \^`\thisoutline{<text>}` uses <text> in the outline instead of default
+title text for the first following `\chap`, `\sec`, or `\secc`.
+Special case: \^`\thisoutline{\relax}` doesn't create any outline for the following
+`\chap`, `\sec`, or `\secc`.
+
+\secc Lists
+%%%%%%%%%%
+
+The list of items is surrounded by \^`\begitems` and \^`\enditems` commands.
+The asterisk (`*`) is active within this environment and it starts one item.
+The item style can be chosen by the \^`\style` parameter written after \^`\begitems`:
+
+\begtt
+\style o % small bullet
+\style O % big bullet (default)
+\style - % hyphen char
+\style n % numbered items 1., 2., 3., ...
+\style N % numbered items 1), 2), 3), ...
+\style i % numbered items (i), (ii), (iii), ...
+\style I % numbered items I, II, III, IV, ...
+\style a % items of type a), b), c), ...
+\style A % items of type A), B), C), ...
+\style x % small rectangle
+\style X % big rectangle
+\endtt
+
+For example:
+
+\begtt
+\begitems
+* First idea
+* Second idea in subitems:
+ \begitems \style i
+ * First sub-idea
+ * Second sub-idea
+ * Last sub-idea
+ \enditems
+* Finito
+\enditems
+\endtt
+%
+produces:
+
+\begitems
+* First idea
+* Second idea in subitems:
+ \begitems \style i
+ * First sub-idea
+ * Second sub-idea
+ * Last sub-idea
+ \enditems
+* Finito
+\enditems
+
+Another style can be defined by the command \~`\sdef{_item:<style>}{<text>}`.
+Default item can be set by \^`\defaultitem={<text>}`.
+The list environments can be nested. Each new level of items is indented by
+next multiple of \^`\iindent` value which is set to `\parindent` by default.
+The \^`\ilevel` register says what level of items is currently processed.
+Each \^`\begitems` starts \^`\everylist` tokens register. You can set, for
+example:
+\begtt
+\everylist={\ifcase\ilevel\or \style X \or \style x \else \style - \fi}
+\endtt
+
+You can say \^`\begitems` \^`\novspaces` if you don't want vertical spaces above
+and below the list. The nested item list is without vertical spaces
+automatically. More information about the design of lists of items should be
+found in the section~\ref[lists].
+
+A \"selected block of text" can be surrounded by
+\^`\begblock`\dots\^`\endblock`. The default design of blocks of text is
+indented text in smaller font. The blocks of text can be nested.
+
+\secc Tables
+%%%%%%%%%%%
+
+The macro \^`\table{<declaration>}{<data>}` provides similar <declaration>
+of tables as in \LaTeX: you can use letters `l`, `r`, `c`, each letter declares
+one column (aligned to left, right, center, respectively).
+These letters can be combined by the `|` character (vertical line). Example
+
+\begtt
+\table{||lc|r||}{ \crl
+ Month & commodity & price \crli \tskip2pt
+ January & notebook & \$ 700 \cr
+ February & skateboard & \$ 100 \cr
+ July & yacht & k\$ 170 \crl}
+\endtt
+%
+generates the result:
+
+\vskip-\medskipamount
+\noindent\hfil\table{||lc|r||}{ \crl
+ Month & commodity & price \crli \tskip2pt
+ January & notebook & \$ 700 \cr
+ February & skateboard & \$ 100 \cr
+ July & yacht & k\$ 170 \crl}
+\medskip
+
+Apart from `l`, `r`, `c` declarators, you can use the `p{<size>}` declarator
+which declares the column with paragraphs of given width. More precisely,
+a long text in the table cell is printed as a multiline paragraph with given width.
+By default, the paragraph is left-right justified. But there are
+alternatives:
+
+\begitems
+* `p{<size>`\^`\fL}` fit left, i.e.\ left justified, ragged right,
+* `p{<size>`\^`\fR}` fit right, i.e.\ right justified, ragged left,
+* `p{<size>`\^`\fC}` fit center, i.e.\ ragged left plus right,
+* `p{<size>`\^`\fS}` fit special, short one-line pararaph centered,
+ long paragraph normal,
+* `p{<size>`\^`\fX}` fit extra, left-right justified but last line centered.
+\enditems
+
+You can use `(<text>)` in the <declaration>. Then this text is applied in
+each line of the table. For example `r(\kern10pt)l` adds more 10\,pt space
+between `r` and `l` rows.
+
+An arbitrary part of the <declaration> can be repeated by a <number>
+prefixed. For example `3c` means `ccc` or `c 3{|c}` means
+`c|c|c|c`. Note that spaces in the <declaration> are ignored and you
+can use them in order to more legibility.
+
+The command `\cr` used in the <data> part of the table
+is generally known from Plain \TeX. It marks the end of each row in the table.
+Moreover \OpTeX/ defines following similar commands:
+
+\begitems
+* \^`\crl` \dots\ the end of the row with a horizontal line after it.
+* \^`\crll` \dots\ the end of the row with a double horizontal line after it.
+* \^`\crli` \dots\ like \^`\crl` but the horizontal line doesn't intersect the
+ vertical double lines.
+* \^`\crlli` \dots\ like \^`\crli` but horizontal line is doubled.
+* \^`\crlp{<list>}` \dots\ like \^`\crli` but the lines are drawn only in the
+ columns mentioned in comma-separated `<list>` of their numbers.
+ The <list> can include `<from>-<to>` declarators, for example
+ \^`\crlp{1-3,5}` is equal to \^`\crlp{1,2,3,5}`.
+\enditems
+
+The \^`\tskip``<dimen>` command works like the `\noalign{\vskip<dimen>}`
+immediately after `\cr*` commands but it doesn't interrupt the vertical lines.
+
+\new
+You can use the following parameters for the \^`\table` macro. Default values are listed
+too.
+
+\begtt
+\everytable={} % code used in \vbox before table processing
+\thistable={} % code used in \vbox, it is removed after using it
+\tabiteml={\enspace} % left material in each column
+\tabitemr={\enspace} % right material in each column
+\tabstrut={\strut} % strut which declares lines distance in the table
+\tablinespace=2pt % additional vert. space before/after horizontal lines
+\vvkern=1pt % space between lines in double vertical line
+\hhkern=1pt % space between lines in double horizontal line
+\tabskip=0pt % space between columns
+\tabskipl=0pt \tabskipr=0pt % space before first and after last column
+\endtt
+
+Example: if you do \^`\tabiteml={$\enspace}`\^`\tabitemr={\enspace$}` then
+the \^`\table` acts like \LaTeX's array environment.
+
+If there is an item that spans to more than one column in the table then
+the macro \^`\multispan{<number>}` (from Plain \TeX) can help you. Another
+alternative is
+the command \^`\mspan``<number>[<declaration>]{<text>}`
+which spans <number> columns and formats the <text> by the
+<declaration>. The <declaration> must include a declaration of only one column
+with the same syntax as common \^`\table` <declaration>.
+If your table includes vertical rules and you want to
+create continuous vertical rules by \^`\mspan`, then use rule declarators `|`
+after `c`, `l` or `r` letter in \^`\mspan` <declaration>. The
+exception is only in the case when \^`\mspan` includes the first
+column and the table have rules on the left side. The example of \^`\mspan`
+usage is below.
+
+The \^`\frame{<text>}` makes a frame around <text>. You can put the whole \^`\table`
+into \^`\frame` if you need double-ruled border of the table. Example:
+
+\begtt
+\frame{\table{|c||l||r|}{ \crl
+ \mspan3[|c|]{\bf Title} \crl \noalign{\kern\hhkern}\crli
+ first & second & third \crlli
+ seven & eight & nine \crli}}
+\endtt
+%
+creates the following result:
+
+\hfil\frame{\table{|c||l||r|}{\crl
+ \mspan3[|c|]{\bf Title} \crl \noalign{\kern\hhkern}\crli
+ first & second & third \crlli
+ seven & eight & nine \crli}}
+\bigskip
+
+The \^`\vspan``<number>{<text>}` shifts the <text> down in order it looks
+like to be in the center of the <number> lines (current line is first).
+You can use this for creating tables like in the following example:
+
+\begtt \typosize[8.7/11]
+\thistable{\tabstrut={\vrule height 20pt depth10pt width0pt}
+ \baselineskip=20pt \tablinespace=0pt \rulewidth=.8pt}
+\table{|8{c|}}{\crlp{3-8}
+ \mspan2[c|]{} & \mspan3[c|]{Singular} & \mspan3[c|]{Plural} \crlp{3-8}
+ \mspan2[c|]{} & Neuter & Masculine & Feminine & Masculine & Feminine & Neuter \crl
+ \vspan2{I} & Inclusive & \mspan3[c|]{\vspan2{O}} & \mspan3[c|]{X} \crlp{2,6-8}
+ & Exclusive & \mspan3[c|]{} & \mspan3[c|]{X} \crl
+ \vspan2{II} & Informal & \mspan3[c|]{X} & \mspan3[c|]{X} \crlp{2-8}
+ & Formal & \mspan6[c|]{X} \crl
+ \vspan2{III} & Informal & \vspan2{O} & X & X & \mspan2[c|]{X} &\vspan2{O} \crlp{2,4-7}
+ & Formal & & \mspan4[c|]{X} & \crl
+}
+\endtt
+
+\puttext 8.9cm -4cm {\pdfsave\pdfscale{.5}{.5}\rlap{%
+\thistable{\tabstrut={\vrule height 20pt depth10pt width0pt}
+ \baselineskip=20pt \tablinespace=0pt \rulewidth=.8pt}
+\table{|8{c|}}{\crlp{3-8}
+ \mspan2[c|]{} &\mspan3[c|]{Singular} &\mspan3[c|]{Plural} \crlp{3-8}
+ \mspan2[c|]{} & Neuter & Masculine & Feminine & Masculine & Feminine & Neuter \crl
+ \vspan2{I} & Inclusive & \mspan3[c|]{\vspan2{O}} &\mspan3[c|] X \crlp{2,6-8}
+ & Exclusive & \mspan3[c|]{} &\mspan3[c|] X \crl
+ \vspan2{II} & Informal & \mspan3[c|] X &\mspan3[c|] X \crlp{2-8}
+ & Formal & \mspan6[c|] X \crl
+ \vspan2{III} & Informal & \vspan2{O} & X & X &\mspan2[c|] X & \vspan2{O} \crlp{2,4-7}
+ & Formal & &\mspan4[c|] X & \crl
+}}\pdfrestore}
+
+\hangindent=-7.5cm \hangafter=0
+You can use \^`\vspan` with non-integer parameter too if you feel that the
+result looks better, for example \^`\vspan2.1{text}`.
+
+\hangindent=-7.5cm \hangafter=0
+The rule width of tables and implicit width of all `\vrule`s and `\hrule`s
+can be set by the command \^`\rulewidth=<dimen>`. The default value given
+by \TeX/ is 0.4\,pt.
+
+\hangindent=-7.5cm \hangafter=-2
+The `c`, `l`, `r` and `p` are default \"declaration letters" but you can define
+more such letters by `\def\_tabdeclare<letter>{<left>##<right>}`.
+More about it is in technical documentation in section~\ref[table.impl].
+See the definition of the \^`\_tabdeclarec` macro, for example.
+
+The `:` columns boundary declarator is described in section~\ref[table.bound].
+The tables with given width can be declared by `to<size>` or `pxto<size>`.
+More about it is in section~\ref[table.w].
+Many tips about tables can be seen on the site
+\url{http://petr.olsak.net/optex/optex-tricks.html}.
+
+\label[verbatim]\secc Verbatim
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+The display verbatim text have to be surrounded by the \^`\begtt` and
+\^`\endtt` couple.
+The in-line verbatim have to be tagged (before and after)
+by a character which is declared by
+\^`\verbchar``<char>`. For example \code{\\verbchar`}
+declares the character \code{`}
+for in-line verbatim markup.
+And you can use \code{`\\relax`} for
+verbatim `\relax` (for example).
+\new
+Another alternative of printing in-line
+verbatim text is \~`\code{<text>}` (see below).
+
+If the numerical register \^`\ttline` is set to the non-negative value then
+display verbatim will number the lines. The first line has the number
+\^`\ttline+1` and when the verbatim ends then the \^`\ttline` value is equal to the
+number of the last line printed. Next \^`\begtt...`\^`\endtt` environment will follow
+the line numbering. \OpTeX/ sets \^`\ttline=-1` by default.
+
+The indentation of each line in display verbatim is controlled by
+\^`\ttindent` register. This register is set to the `\parindent` by default.
+Users can change the values of the `\parindent` and \^`\ttindent` independently.
+
+The \^`\begtt` command starts the internal group in which the catcodes are changed.
+\new
+Then the \^`\everytt` tokens register is run. It is empty by default and the user can
+control fine behavior by it. For example, the catcodes can be re-declared here. If
+you need to define an active character in the \^`\everytt`, use \~`\adef` as in the
+following example:
+
+\begtt \adef@{\string\endtt}
+\everytt={\adef!{?}\adef?{!}}
+\begtt
+Each occurrence of the exclamation mark will be changed to
+the question mark and vice versa. Really? You can try it!
+@
+\endtt
+%
+The \~`\adef` command sets its parameter as active {\it after\/}
+the parameter of \^`\everytt` is read. So you don't have to worry about active
+categories in this parameter.
+
+There is an alternative to \^`\everytt` named \^`\everyintt` which is used for
+in-line verbatim surrounded by an \^`\verbchar` or processed by the \~`\code`
+command.
+
+The \^`\everytt` is applied to all \^`\begtt...`\^`\endtt` environments (if it is not
+declared in a group). There are tips for such global `\everytt` definitions here:
+
+\begtt \adef!{\char9251 }
+\everytt={\typosize[9/11]} % setting font size for verbatim
+\everytt={\ttline=0} % each listing will be numbered from one
+\everytt={\visiblesp} % visualization!of!spaces
+\endtt
+
+\new
+If you want to apply a special code only for one \^`\begtt...`\^`\endtt`
+environment then don't set any \^`\everytt` but put desired material at the
+same line where \^`\begtt` is. For example:
+
+\begtt \adef@{\string\endtt}
+\begtt \adef!{?}\adef?{!}
+Each occurrence of ? will be changed to ! and vice versa.
+@
+\endtt
+
+The in-line verbatim surrounded by a \^`\verbchar` doesn't work in
+parameter of macros and macro definitions. (It works in titles declared by
+\~`\chap`, \~`\sec` etc. and in \~`\fnote`s, because these macros are
+specially defined in \OpTeX/).
+\new
+You can use more robust command \^`\code{<text>}` in problematic
+situations, but you have to escape the following characters in the <text>:
+`\`, `#`, `%`, braces (if the braces are unmatched in the <text>),
+and space or `^` (if there are more than one subsequent spaces or `^` in
+the <text>). Examples:
+
+\begtt
+\code{\\text, \%\#} ... prints \text, %#
+\code{@{..}*&^$ $} ... prints @{..}*&^$ $ without escaping, but you can
+ escape these characters too, if you want.
+\code{a \ b} ... two spaces between a b, the second must be escaped
+\code{xy\{z} ... xy{z ... unbalanced brace must be escaped
+\code{^\^M} ... prints ^^M, the second ^ must be escaped
+\endtt
+
+You can print verbatim listing from external files by the \^`\verbinput` command.
+Examples:
+
+\begtt
+\verbinput (12-42) program.c % listing from program.c, only lines 12-42
+\verbinput (-60) program.c % print from begin to the line 60
+\verbinput (61-) program.c % from line 61 to the end
+\verbinput (-) program.c % whole file is printed
+\verbinput (70+10) program.c % from line 70, only 10 lines printed
+\verbinput (+10) program.c % from the last line read, print 10 lines
+\verbinput (-5+7) program.c % from the last line read, skip 5, print 7
+\verbinput (+) program.c % from the last line read to the end
+\endtt
+
+\new
+You can insert additional commands for \^`\verbinput` before
+the first opening bracket. They are processed in the local group.
+For example, `\verbinput \hsize=20cm (-) program.c`.
+
+The \~`\ttline` influences the line numbering by the same way as in
+\~`\begtt...`\~`\endtt` environment. If \~`\ttline=-1` then real line numbers are
+printed (this is the default). If \code{\\ttline<-1} then no line
+numbers are printed.
+
+The \^`\verbinput` can be controlled by \^`\everytt`, \^`\ttindent` just like
+in \~`\begtt...`\~`\endtt`.
+
+The \~`\begtt`...\~`\endtt` pair or \~`\verbinput` can be used for listings of
+codes. Automatic syntax highlighting is possible, for example
+`\begtt` \^`\hisyntax{C}` activates colors for C programs. Or
+`\verbinput` \^`\hisyntax{HTML} (-) file.html` can be used for HTML or XML codes.
+\OpTeX/ implements C, Python, \TeX/, HTML and XML syntax highlighting.
+More languages can be declared, see the section~\ref[hisyntax].
+
+If the code is read by \^`\verbinput` and there are comment lines prefixed
+by two characters then
+you can set them by \~`\commentchars``<first><second>`. Such comments are
+fully interpreted by \TeX/ (i.e. not verbatim).
+Section~\ref[verb] (page \pgref[commentchars]) says more about this feature.
+
+\sec Autogenerated lists
+%%%%%%%%%%%%%%%%%%%%%%%%
+
+\secc[toc] Table of contents
+%%%%%%%%%%%%%%%%%%%%%%
+
+The \^`\maketoc` command prints the table of contents of all \~`\chap`, \~`\sec`
+and \~`\secc` used in the document. These data are read from the external `*.ref` file, so
+you have to run \TeX/ more than once (typically three times if the table of
+contents is at the beginning of the document).
+
+Typically, we don't want to repeat the name of the section \"Table of contents"
+in the table of contents again. The direct usage
+of \~`\chap` or \~`\sec` isn't recommended here because the table of contents
+is typically not referenced to itself. You can print the unnumbered and unreferenced
+title of the section like this:
+
+\begtt
+\nonum\notoc\sec Table of Contents
+\endtt
+If you need a customization of the design of the TOC, read the
+section~\ref[maketoc].
+
+\new
+If you are using a special macro in section or chapter titles
+and you need different behavior of such macro in other cases then use
+\^`\regmacro{<case-toc>}{<case-mark>}{<case-outline>}`.
+The parameters are applied locally in given cases. The \^`\regmacro` can be
+used repeatedly: then its parameters are accumulated (for more macros).
+If a parameter is empty then original definition is used in given case.
+For example:
+
+\begtt
+% default value of \mylogo macro used in text and in the titles:
+\def\mylogo{\leavevmode\hbox{{\Red\it My}{\setfontsize{mag1.5}\rm Lo}Go}}
+% another variants:
+\regmacro {\def\mylogo{\hbox{\Red My\Black LoGo}}} % used in TOC
+ {\def\mylogo{\hbox{{\it My}\/LoGo}}} % used in running heads
+ {\def\mylogo{MyLoGo}} % used in PDF outlines
+\endtt
+
+\secc Making the index
+%%%%%%%%%%%%%%%%%%%%%
+
+The index can be included in the document by the \^`\makeindex` macro. No external
+program is needed, the alphabetical sorting is done inside \TeX/ at macro
+level.
+
+The \^`\ii` command (insert to index) declares the word separated by the space
+as the index item. This declaration is represented as an invisible item on the
+page connected to the next visible word. The page number of the page where
+this item occurs is listed in the index entry. So you can type:
+
+\begtt
+The \ii resistor resistor is a passive electrical component ...
+\endtt
+
+You cannot double the word if you use the \^`\iid` instead of \^`\ii`:
+
+\begtt
+The \iid resistor is a passive electrical component ...
+or:
+Now we'll deal with the \iid resistor .
+\endtt
+
+Note that the dot or comma has to be separated by space when \^`\iid` is
+used. This space (before dot or comma) is removed by the macro in
+the current text.
+
+The multiple-words entries are commonly arranged in the index as follows:
+
+\medskip
+
+linear~dependency 11, 40--50
+
+--- independency 12, 42--53
+
+--- space 57, 76
+
+--- subspace 58
+
+\medskip
+
+To do this you have to declare the parts of the index entries by the `/` separator.
+Example:
+
+\begtt
+{\bf Definition.}
+\ii linear/space,vector/space
+{\em Linear space} (or {\em vector space}) is a nonempty set of...
+\endtt
+
+The number of the parts of one index entry (separated by `/`) is unlimited. Note, that you can
+spare your typing by the comma in the \~`\ii` parameter. The previous example
+is equivalent to `\ii linear/space \ii vector/space`~.
+
+Maybe you need to propagate to the index the similar entry to the
+linear/space in the form of space/linear. You can do this by the shorthand `,@`
+at the end of the \~`\ii` parameter. Example:
+
+\begtt
+\ii linear/space,vector/space,@
+is equivalent to:
+\ii linear/space,vector/space \ii space/linear,space/vector
+\endtt
+
+If you really need to insert the space into the index entry, write `~`.
+
+The \~`\ii` or \~`\iid` commands can be preceded by \^`\iitype` `<letter>`, then such
+reference (or more references generated by one \~`\ii`) has the specified type.
+The page numbers of such references should be formatted
+specially in the index. \OpTeX/ implements only \^`\iitype` `b`,
+\^`\iitype` `i` and \^`\iitype` `u`:
+the page number in bold or in italics or underlined is printed
+in the index when these types are used. The default index type is empty, which
+prints page numbers in normal font. The \TeX/book index is a good example.
+
+The \^`\makeindex` creates the list of alphabetically sorted index entries
+without the title of the section and without creating more columns. \OpTeX/
+provides other macros \^`\begmulti` and \^`\endmulti` for more columns:
+
+\begtt \catcode`\<=13
+\begmulti <number of columns>
+<text>
+\endmulti
+\endtt
+The columns will be balanced. The Index can be printed by the following
+code:
+
+\begtt
+\sec Index
+\begmulti 3 \makeindex \endmulti
+\endtt
+
+Only \"pure words" can be propagated to the index by the \~`\ii` command. It
+means that there cannot be any macro, \TeX/ primitive, math selector, etc.
+But there is another possibility to create such a complex index entry. Use
+\"pure equivalent" in the \~`\ii` parameter and map this equivalent to a
+real word that is printed in the index. Such mapping is done by
+\^`\iis` command. Example:
+
+\begtt
+The \ii chiquadrat $\chi$-quadrat method is ...
+If the \ii relax `\relax` command is used then \TeX/ is relaxing.
+...
+\iis chiquadrat {$\chi$-quadrat}
+\iis relax {\code{\\relax}}
+\endtt
+%
+The \^`\iis` `<equivalent> {<text>}` creates one entry in the \"dictionary
+of the exceptions". The sorting is done by the <equivalent> but the
+<text> is printed in the index entry list.
+
+The sorting rules when \^`\makeindex` runs depends on the current language.
+See section~\ref[lang] about languages selection.
+
+\secc Bib\TeX/ing
+%%%%%%%%%%%%%%%%
+
+The command \^`\cite[<label>]` (or
+\hbox{\^`\cite[<label-1>,<label-2>,...,<label-n>]`})
+creates the citation in the form [42] (or [15,~19,~26]).
+If \^`\shortcitations` is declared at the beginning of the document then
+continuous sequences of numbers are re-printed like this:
+\hbox{[3--5,~7,~9--11]}. If
+\^`\sortcitations` is declared then numbers generated by one \^`\cite` command
+are sorted upward.
+
+If \^`\nonumcitations` is declared then the marks instead of numbers are generated
+depending on the used bib-style. For example, the citations look like
+[Now08] or [Nowak, 2008].
+
+The \^`\rcite[<labels>]` creates the same list as \^`\cite[<labels>]` but without
+the outer brackets. Example: `[\rcite[tbn], pg.~13]` creates [4,~pg.~13].
+
+The \^`\ecite[<label>]{<text>}` prints the `<text>` only, but the entry labeled
+<label> is decided as to be cited. If \~`\hyperlinks` is used then <text>
+is linked to the references list.
+
+You can define alternative formating of \^`\cite` command. Example:
+
+\begtt \catcode`\<=13
+\def\cite[#1]{(\rcite[#1])} % \cite[<label>] creates (27)
+\def\cite[#1]{$^{\rcite[#1]}$} % \cite[<label>] creates^{27}
+\endtt
+
+The numbers printed by \^`\cite` correspond to the same numbers generated in
+the list of references. There are two possibilities to generate this
+references list:
+
+\begitems
+* Manually using \~`\bib[<label>]` commands.
+* By \~`\usebib/<type> (<style>) <bib-base>` command which reads `*.bib`
+ files directly.
+\enditems
+
+\new
+Note that another two possibilities documented in OPmac (using external
+Bib\TeX/ program) isn't supported because Bib\TeX/ is an old program that does not
+support Unicode. And Biber seems to be not compliant with Plain \TeX.
+
+\medskip\noindent
+{\bf References created manually using \^`\bib[<label>]` command.}
+
+\begtt
+\bib [tbn] P. Olšák. {\it\TeX{}book naruby.} 468~s. Brno: Konvoj, 1997.
+\bib [tst] P. Olšák. {\it Typografický systém \TeX.}
+ 269~s. Praha: CSTUG, 1995.
+\endtt
+
+If you are using \~`\nonumcitations` then you need to declare the <marks>
+used by \~`\cite` command. To do it you must use long form of the \^`\bib`
+command in the format \^`\bib[<label>] = {<mark>}`. The spaces around
+equal sign are mandatory. Example:
+
+\begtt
+\bib [tbn] = {Olšák, 2001}
+ P. Olšák. {\it\TeX{}book naruby.} 468~s. Brno: Konvoj, 2001.
+\endtt
+
+\noindent
+{\bf Direct reading of `.bib` files} is possible by \^`\usebib` macro.
+This macro reads and uses macro package `librarian.tex` by Paul Isambert.
+The usage is:
+
+\begtt \catcode`\<=13
+\usebib/c (<style>) <bib-base> % sorted by \cite-order (c=cite),
+\usebib/s (<style>) <bib-base> % sorted by style (s=style).
+% example:
+\nocite[*] \usebib/s (simple) op-biblist % prints all from op-biblist.bib
+\endtt
+
+The <bib-base> is one or more `*.bib` database source files (separated by
+spaces and without extension) and the <style> is the part of the filename
+`bib-<style>.opm` where the formatting of the references list is
+defined. \OpTeX/ supports `simple` or `iso690` styles. The features of
+the `iso690` style is documented in the section~\ref[isobib] in detail.
+The \^`\usebib` command is more documented in section~\ref[usebib].
+
+Not all records are printed from <bib-base> files: the command \^`\usebib`
+selects only such bib-records which were used in \~`\cite` or \^`\nocite`
+commands in your document. The \^`\nocite` behaves as \~`\cite` but prints
+nothing. It tells only that the mentioned bib-record should be printed in the
+reference list. If \^`\nocite[*]` is used then all records from <bib-base>
+are printed.
+
+\sec Graphics
+%%%%%%%%%%%%%
+
+\secc Colors
+%%%%%%%%%%%
+
+\OpTeX/ provides a small number of color selectors:
+{\Blue `\Blue`},
+{\Red `\Red`},
+{\Brown `\Brown`},
+{\Green `\Green`},
+{\Yellow `\Yellow`},
+{\Cyan `\Cyan`},
+{\Magenta `\Magenta`},
+{`\White`},
+{\Grey `\Grey`},
+{\LightGrey `\LightGrey`} and
+`\Black`. User can define more
+such selectors by setting four CMYK components
+\new
+or three RGB components. For example
+
+\begtt
+\def \Orange {\setcmykcolor{0 0.5 1 0}}
+\def \Purple {\setrgbcolor{1 0 1}}
+\endtt
+
+\new
+The command \^`\morecolors` reads more definitions of color selectors from
+the \LaTeX/ file `x11nam.def`.
+There are about 300 color names like
+`\DeepPink`, `\Chocolate` etc. If there are numbered variants of the same
+name, then the letters B, C, etc. are appended to the name in \OpTeX/. For example
+`\Chocolate` is Chocolate1, `\ChocolateB` is Chocolate2 etc.
+
+\new
+The color selectors work locally in groups by default but with limitations. See
+the technical documentation, section~\ref[colors] for more information.
+
+The basic colors \^`\Blue`, \^`\Red`, \^`\Cyan`, \^`\Yellow` etc.\ are defined
+with CMYK components using \^`\setcmykcolor`.
+On the other hand, you can define a color with three
+RGB components and \^`\morecolors` defines such RGB colors.
+By default, the color model isn't converted but only stored to
+PDF output for each used color. Thus, there may be a mix of color
+models in the PDF output which is not a good idea. You can overcome this
+problem by declaration \^`\onlyrgb` or \^`\onlycmyk`. Then only the selected color
+model is used for PDF output and if a used color is declared by another color
+model then it is converted.
+The \^`\onlyrgb` creates colors more bright (usable for computer
+presentations). On the other hand, CMYK makes colors more true\fnote
+{Printed output is more equal to the monitor preview especially if you are
+using ICC profile for your printer.}
+for printing.
+
+\new
+You can define your color by a linear combination of previously defined colors using
+\^`\colordef`. For example:
+
+\begtt
+\colordef \myCyan {.3\Green + .5\Blue} % 30 % green, 50 % blue, 20% white
+\colordef \DarkBlue {\Blue + .4\Black} % Blue mixed with 40 % of black
+\colordef \myGreen{\Cyan+\Yellow} % exact the same as \Green
+\colordef \MyColor {.3\Orange+.5\Green+.2\Yellow}
+\endtt
+%
+The linear combination is done in CMYK subtractive color space by default
+(RGB colors used in \^`\colordef` argument are converted first).
+If the resulting component is greater than 1 then it is truncated to 1.
+If a convex linear combination (as in the last example above) is used then it
+emulates color behavior on a painter's palette.
+You can use \^`\rgbcolordef` instead of \^`\colordef` if you want to mix colors
+in the additive RGB color space.
+
+\def\coloron#1#2#3{%
+ \setbox0=\hbox{{#2#3}}\leavevmode
+ \localcolor \rlap{#1\strut \vrule width\wd0}\box0
+}
+The following example defines the macro for the
+\coloron\Yellow\Brown{colored text on the colored background}. Usage:
+`\coloron<background><foreground>{<text>}`
+
+The `\coloron` can be defined as follows:
+
+\begtt
+\def\coloron#1#2#3{%
+ \setbox0=\hbox{{#2#3}}%
+ \leavevmode \rlap{#1\strut \vrule width\wd0}\box0
+}
+\coloron\Yellow\Brown{The brown text on the yellow background}
+\endtt
+
+\secc Images
+%%%%%%%%%%%
+
+The \^`\inspic` `{<filename>.<extension>}` or
+\^`\inspic` `<filename>.<extension><space>`
+inserts the picture stored in
+the graphics file with the name `<filename>.<extension>` to the document.
+You can set the picture width by \^`\picw=<dimen>`
+before \^`\inspic` command which declares the width of the picture.
+The image files can be in the PNG, JPG, JBIG2 or PDF format.
+
+The \^`\picwidth` is an equivalent register to `\picw`. Moreover, there is an
+\^`\picheight` register which denotes the height of the picture. If both
+registers are set then the picture will be (probably) deformed.
+
+The image files are searched in \^`\picdir`. This token list is empty
+by default, this means that the image files are searched in the
+current directory. Example: \^`\picdir={img/}` supposes that image files are
+in `img` subdirectory. Note: the directory name must end by `/` in
+the \^`\picdir` declaration.
+
+Inkscape\fnote
+{A powerful and free Wysiwyg editor for creating vector graphics.}
+is able to save a picture to PDF and labels of the picture to another
+file\fnote
+{Chose \"Omit text in PDF and create LaTeX file" option.}.
+This second file should be read by \TeX/to print labels
+in the same font as document font. \OpTeX/ supports this feature by
+\^`\inkinspic` `{<filename>.pdf}` command. It reads and displays
+both: PDF image and labels generated by Inkscape.
+
+If you want to create vector graphics (diagrams, schema, geometry
+skicing) then you can do it by Wysiwyg graphics editor (Inkscape, Geogebra for
+example), export the result to PDF and include it by \^`\inspic`.
+If you want to \"program" such pictures then Tikz package is recommended.
+It works in Plain \TeX/ and \OpTeX.
+
+\secc PDF transformations
+%%%%%%%%%%%%%%%%%%%%%%%%
+
+All typesetting elements are transformed by linear
+transformation given by the current transformation matrix. The
+`\pdfsetmatrix` `{<a> <b> <c> <d>}` command makes the internal multiplication
+with the current matrix so linear transformations can be composed.
+One linear transformation given by the `\pdfsetmatrix` above transforms
+the vector $[0,1]$ to [<a>,\,<b>] and $[1,0]$ to [<c>,\,<d>].
+The stack-oriented commands `\pdfsave` and `\pdfrestore` gives a possibility of
+storing and restoring the current transformation matrix and the position of the current point.
+This position has to be the same from \TeX{}'s point of
+view as from the transformation point of view when `\pdfrestore` is processed.
+Due to this fact the `\pdfsave\rlap{<transformed text>}\pdfrestore`
+or something similar is recommended.
+
+\OpTeX/ provides two special transformation macros
+\^`\pdfscale` and \^`\pdfrotate`:
+
+\begtt \catcode`\<=13
+\pdfscale{<horizontal-factor>}{<vertical-factor>}
+\pdfrotate{<angle-in-degrees>}
+\endtt
+
+These macros simply call the properly `\pdfsetmatrix` command.
+
+It is known that the composition of transformations is not commutative. It
+means that the order is important. You have to read the transformation
+matrices from right to left. Example:
+
+\begtt
+First: \pdfsave \pdfrotate{30}\pdfscale{-2}{2}\rlap{text1}\pdfrestore
+ % text1 is scaled two times and it is reflected about vertical axis
+ % and next it is rotated by 30 degrees left.
+second: \pdfsave \pdfscale{-2}{2}\pdfrotate{30}\rlap{text2}\pdfrestore
+ % text2 is rotated by 30 degrees left then it is scaled two times
+ % and reflected about vertical axis.
+third: \pdfsave \pdfrotate{-15.3}\pdfsetmatrix{2 0 1.5 2}\rlap{text3}%
+ \pdfrestore % first slanted, then rotated by 15.3 degrees right
+\endtt
+%
+\par\nobreak\bigskip\smallskip
+This gives the following result.
+First: \pdfsave \pdfrotate{30}\pdfscale{-2}{2}\rlap{text1}\pdfrestore
+second: \pdfsave \pdfscale{-2}{2}\pdfrotate{30}\rlap{text2}\pdfrestore
+third: \pdfsave \pdfrotate{-15.3}\pdfsetmatrix{2 0 1.5 2}\rlap{text3}\pdfrestore
+\par\nobreak\bigskip\penalty0%\bigskip
+
+You can see that \TeX/ knows nothing about dimensions of transformed material,
+it treats it as with a zero dimension object.
+\new
+The \^`\transformbox{<transformation>}{<text>}`
+macro solves the problem. This macro puts the transformed
+material into a box with relevant dimensions. The <transfromation> parameter
+includes one or more transformation commands `\pdfsetmatrix`, `\pdfscale`,
+`\pdfrotate` with their parameters. The <text> is transformed text.
+
+Example: \~`\frame{\transformbox{\pdfscale{1}{1.5}\pdfrotate{-10}}{moj}}`
+creates \frame{\transformbox{\pdfscale{1}{1.5}\pdfrotate{-10}}{moj}}.
+
+The \^`\rotbox{<deg>}{<text>}` is shortcut for
+\^`\transformbox{\pdfrotate{<deg>}}{<text>}`.
+
+\secc Ovals, circles
+%%%%%%%%%%%%%%%%%%%%
+
+\new
+The \^`\inoval{<text>}` creates a box like this: \inoval{text}.
+Multiline text can be put in an oval by the command \^`\inoval{\vbox{<text>}}`.
+Local settings can be set by
+\^`\inoval[<settings>]{<text>}` or you can re-declare global settings by
+\^`\ovalparams={<settings>}`. The default settings are:
+
+\begtt
+\ovalparams={\roundness=2pt % diameter of circles in the corners
+ \fcolor=\Yellow % color used for filling oval
+ \lcolor=\Red % line color used in the border
+ \lwidth=0.5bp % line width in the border
+ \shadow=N % use a shadow effect
+ \overlapmargins=N % ignore margins by surrounding text
+ \hhkern=0pt \vvkern=0pt} % left-righ margin, top-bottom margin
+\endtt
+The total distance from text to oval boundary is `\hhkern+\roundness` at the left and right
+sides and
+`\vvkern+\roundness` at the top and bottom sides of the text.
+
+If you need to set a parameters for the <text> (color, size, font etc.),
+put such setting right in front of the <text>:
+\^`\inoval{<text settings><text>}`.
+
+\new
+The \^`\incircle[\ratio=1.8]{<text>}` creates a box like this \incircle[\ratio=1.8]{text}.
+The \^`\ratio` parameter means width/height. The usage is analogical like for oval.
+The default parameters are
+
+\begtt
+\circleparams={\ratio=1 \fcolor=\Yellow \lcolor=\Red \lwidth=0.5bp
+ \shadow=N \ignoremargins=N \hhkern=2pt \vvkern=2pt}
+\endtt
+
+\new
+The macros \^`\clipinoval` `<x> <y> <width> <height> {<text>}`
+and \^`\clipincircle` (with the same parameters)
+print the `<text>` when a clipping path (oval or cirle with given
+`<with>` and `<height>` shifted its center by `<x>` to right and by `<y>` to up)
+is used.
+The `\roundness=5mm` is default for \^`\clipinoval` and user can change it.
+Example:
+
+\begtt
+\clipincircle 3cm 3.5cm 6cm 7cm {\picw=6cm \inspic{myphoto.jpg}}
+\endtt
+
+\secc Putting images and texts wherever
+
+\new
+The \^`\puttext` `<x> <y> {<text>}` puts the `<text>` shifted by `<x>` right and by
+`<y>` up from the current point of typesetting and does not change the
+position of the current point. Assume a coordinate system with origin in the
+current point. Then \^`\puttext` `<x> <y> {<text>}` puts the text at the
+coordinates `<x>`, `<y>`. More exactly the left edge of its baseline is at that
+position.
+
+\new
+The \^`\putpic` `<x> <y> <width> <height> {<image-file>}` puts an image
+given by `<image-file>` (including extension) of given
+`<width>` and `<height>` at given position (its left-bottom corner).
+You can write \^`\nospec` instead `<width>` or `<height>` if this parameter
+is not specified.
+
+\sec Others
+%%%%%%%%%%%
+
+\secc[lang] Using more languages
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\OpTeX/ prepares hyphenation patterns for all languages if such patterns are
+available in your \TeX/ system.
+\new
+Only USenglish patterns (original from Plain \TeX/) are preloaded.
+Hyphenation patterns of all other languages are loaded on demand when you first use
+the `\<iso-code>lang` command in your document.
+For example \^`\delang` for German, \^`\cslang` for
+Czech, \^`\pllang` for Polish. The <iso-code> is a shortcut
+of the language (mostly from ISO 639-1).
+You can list all available languages by \^`\langlist`
+macro. This macro prints now:
+
+\medskip
+{\typosize[8.5/11.5]\emergencystretch=4em \hbadness=4000
+\noindent \langlist
+\par}
+\medskip
+
+\new
+For compatibility with e-plain macros, there is the command
+\^`\uselanguage{<language>}`. The parameter <language> is long-form of
+language name, i.e.\ \^`\uselanguage{Czech}` works the same as \^`\cslang`.
+The \^`\uselanguage` parameter is case insensitive.
+
+For compatibility with \csplain/, there are macros \^`\ehyph`, \^`\chyph`,
+\^`\shyph` which are equivalent to \^`\enlang`, \^`\cslang` and \^`\sklang`.
+
+You can switch between language patterns by `\<iso-code>lang` commands mentioned
+above. Default is \^`\enlang`.
+
+\OpTeX/ generates three phrases used for captions and titles in technical
+articles or books: \"Chapter", \"Table" and \"Figure". These phrases need to be known
+in used language and it depends on the previously used language selectors
+`\<iso-code>lang`. \OpTeX/ declares these words only for few languages:
+\new
+Czech, German, Spanish, French, Greek, Italian, Polish, Russian, Slovak and
+English, If you need to use these words in other languages or you want to
+auto-generate more words in your macros, then you can declare it by
+\~`\sdef` or \^`\_langw` commands as shown in section~\ref[langphrases].
+
+The \~`\makeindex` command needs to know the sorting rules used in your language.
+\OpTeX/ defines only a few language rules for sorting: Czech,
+Slovak and English. How to declare sorting rules for more languages are
+described in the section~\ref[makeindex].
+
+If you declare `\<iso-code>quotes`, then the control sequences `\"` and `\'`
+should be used like this: `\"<quoted text>"` or `\'<quoted text>'`
+(note that the terminating character is the same but it isn't escaped).
+This prints language-dependent normal or alternative quotes around
+<quoted text>. The language is specified by <iso-code>. \OpTeX/ declares
+quotes only for Czech, German, Spanish, French, Greek, Italian, Polish,
+Russian, Slovak and English (\^`\csquotes`, \^`\dequotes`, \dots, \^`\enquotes`).
+You can simply define your own quotes as shown in section~\ref[langphrases].
+The `\"` is used for quotes visually more similar to the `"` character which
+can be primary quotes or secondary quotes depending on the language rules.
+Maybe you want to alternate the meaning of these two types of quotes. Use
+`\<isocode>quotes\altquotes` in such case.
+
+\secc[styles] Pre-defined styles
+%%%%%%%%%%%%%%%%%%%%%%%
+
+\OpTeX/ defines three style-declaration macros \~`\report`, \~`\letter` and
+\~`\slides`. You can use them at the beginning of your document if you are
+preparing these types of documents and you don't need to create your own
+macros.
+
+The \^`\report` declaration is intended to create reports. It
+sets default font size to 11\,pt and `\parindent` (paragraph indentation) to 1.2\,em.
+The `\tit` macro uses smaller font because we assume that \"chapter level"
+will be not used in reports. The first page has no page number, but the next pages
+are numbered (from number~2). Footnotes are numbered from one in the whole
+document. The macro `\author <authors><end-line>` can be used when
+\^`\report` is declared. It prints `<authors>` in italics at the center of the
+line. You can separate authors by `\nl` to more lines.
+
+The \^`\letter` declaration is intended to create letters.
+See the files `op-letter-*.tex` for examples.
+The \^`\letter` style sets default
+font size to 11\,pt and `\parindent` to 0\,pt. It sets half-line space
+between paragraphs. The page numbers are not printed. The \^`\subject` macro
+can be used, it prints the word \"Subject:" or \"Věc" (or something else
+depending on current language) in bold. Moreover, the \^`\address` macro
+can be used when \^`\letter` is declared. The usage of the \^`\address` macro
+looks like:
+
+\begtt \catcode`\<=13
+\address
+ <first line of address>
+ <second line of address>
+ <etc.>
+ <empty line>
+\endtt
+
+It means that you need not use any special mark at the end of lines: the ends
+of lines in the source file are the same as in printed output. The
+\^`\address` macro creates `\vtop` with address lines. The width of such
+`\vtop` is equal to the widest line used in it. So, you can use
+`\hfill\address...` to put the address box to the right side of the
+document. Or you can use `<prefixed text>\address...` to put
+`<prefixed text>` before the first line of the address.
+
+The \^`\slides` style creates a simple presentation slides. See an example
+in the file `op-slides.tex`. Run `optex op-slides.tex` and see the documentation of
+\^`\slides` style in the file `op-slides.pdf`.
+
+Analogical declaration macro `\book` is not prepared. Each book needs
+individual typographical care. You need to create specific macros for
+design.
+
+\secc Loading other macro packages
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+You can load more macro packages by `\input{<file-name>}` or by
+\^`\load[<file-names>]`. The first case (`\input`) is \TeX/ primitive command, it can be
+used in the alternative old syntax `\input <filename><space>` too. The
+second case (\^`\load`) allows specifying a comma-separated list of included files.
+Moreover, it loads each macro file only once, it sets
+temporarily standard category codes during loading and it tries to
+load `<filename>.opm` or `<filename>.tex` or `<filename>`, the first occurence
+wins. Example:
+\begtt
+\load [qrcode, tikz]
+\endtt
+%
+does `\input qrcode.opm` \,and `\input tikz.tex` \,and it saves
+local information about the fact that these file names
+`qrcode` and `tikz` were already used, i.\,e. next \^`\load` will skip them.
+
+It is strongly recommended to use the `\load` macro for loading external
+macros if you need them. On the other hand, if your source document is structured
+to more files (with individual chapters or sections), use simply the `\input` primitive.
+
+The macro packages intended to \OpTeX/ have the name `*.opm`.
+The following packages are distributed as part of \OpTeX/:
+\begitems
+* `qrcode.opm` enables to create QR codes.
+* `vlna.opm` enables to protect of one-letter prepositions and more things automatically.
+* `emoji.opm` defines `\emoji{<name>}` command for colored emoticons.
+* `plain-at.opm` defines the old names from plain \TeX/.
+\enditems
+See the directory `optex/pkg/` and these files for more information about
+them.
+
+\secc Lorem ipsum dolor sit
+%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\new
+A designer needs to concentrate on the design of the output and maybe he/she
+needs material for testing macros. There is the possibility to generate a
+neutral text for such experiments. Use \^`\lorem[<number>]` or
+\^`\lorem[<from>-<to>]`. It prints a paragraph (or paragraphs) with neutral
+text. The numbers <number> or <from>, <to> must be in the range 1 to 150
+because there are 150 paragraphs with neutral text prepared for you.
+The \^`\lipsum` macro is equivalent to \^`\lorem`. Example: \^`\lipsum[1-150]`
+prints all prepared paragraphs.
+
+\secc Logos
+%%%%%%%%%%
+
+\new
+The control sequences for typical logos can be terminated by optional `/`
+which is ignored when printing. This makes logos more legible in the source file:
+
+\begtt
+We are using \TeX/ because it is cool. \OpTeX/ is better than \LaTeX.
+\endtt
+
+\secc The last page
+%%%%%%%%%%%%%%%%%%%
+
+The number of the last page (it may be different from the number of pages) is
+expanded by \^`\lastpage` macro. It expands to `?` in first \TeX/ run and to
+the last page in next \TeX/ runs.
+
+There is an example for footlines in the format \"current page / last page":
+
+\begtt
+\footline={\hss \fixedrm \folio/\lastpage \hss}
+\endtt
+
+\new
+The \^`\lastpage` expands to the last \^`\folio` which is a decimal
+number or Roman numeral (when \^`\pageno` is negative). If you need to know
+the total pages used in the document, use \^`\totalpages` macro. It expands to
+zero (in first \TeX/ run) or to the number of all pages in the document
+(in next \TeX/ runs).
+
+\secc Use \OpTeX/
+%%%%%%%%%%%%%%%%%
+
+\new
+The command \^`\useOpTeX` (or \^`\useoptex`) does nothing in \OpTeX/ but it causes
+an error (undefined control sequence) when another format is used. You can
+put it as the first command in your document:
+
+\begtt
+\useOpTeX % we are using OpTeX format, no LaTeX :)
+\endtt
+
+\sec Summary
+%%%%%%%%%%%%
+
+\def\ttref#1'{\ea\~\ea`\csname#1\endcsname`}
+
+\begtt \typosize[9/11]\adef&{\kern.25em}\adef~#1'{\ea\~\ea`\csname#1\endcsname`}
+~tit' Title (terminated by end of line)
+~chap' Chapter Title (terminated by end of line)
+~sec' Section Title (terminated by end of line)
+~secc' Subsection Title (terminated by end of line)
+
+~maketoc' % table of contents generation
+~ii' item1,item2 % insertion the items to the index
+~makeindex' % the index is generated
+
+~label' [labname] % link target location
+~ref' [labname] % link to the chapter, section, subsection, equation
+~pgref' [labname] % link to the page of the chapter, section, ...
+
+~caption'/t % a numbered table caption
+~caption'/f % a numbered caption for the picture
+~eqmark' % a numbered equation
+
+~begitems' % start a list of the items
+~enditems' % end of list of the items
+~begblock' % start a block of text
+~endblock' % end of block of text
+~begtt' % start a verbatim text
+~endtt' % end verbatim text
+~verbchar' X % initialization character X for in-text verbatim
+~code' % another alternative for in-text verbatim
+~verbinput' % verbatim extract from the external file
+~begmulti' num % start multicolumn text (num columns)
+~endmulti' % end multicolumn text
+
+~cite' [labnames] % refers to the item in the lits of references
+~rcite' [labnames] % similar to \cite but [] are not printed.
+~sortcitations' ~shortcitations' ~nonumcitations' % cite format
+~bib' [labname] % an item in the list of references
+~usebib'/? (style) bib-base % direct using of .bib file, ? in {s,c}
+
+~load' [filenames] % loadaing macro files
+~fontfam' [FamilyName] % selection of font family
+~typosize' [font-size/baselineskip] % size setting of typesetting
+~typoscale' [factor-font/factor-baselineskip] % size scaling
+~thefontsize' [size] ~thefontscale' [factor] % current font size
+
+~inspic' file.ext % insert a picture, extensions: jpg, png, pdf
+~table' {rule}{data} % macro for the tables like in LaTeX
+
+~fnote' {text} % footnote (local numbering on each page)
+~mnote' {text} % note in the margin (left or right by page number)
+
+~hyperlinks' {color-in}{color-out} % PDF links activate as clickable
+~outlines' {level} % PDF will have a table of contents in the left tab
+
+~magscale'[factor] % resize typesetting, line/page breaking unchanged
+~margins'/pg format (left, right, top, bottom)unit % margins setting
+
+~report' ~letter' ~slides' % style declaration macros
+\endtt
+
+\sec API for macro writers
+%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+All \TeX/ primitives and almost all \OpTeX/ macros are accesible by two
+names: `\foo` (public or user name space) and `\_foo` (private name space).
+For example `\hbox` and `\_hbox` means the same \TeX/ primitive. More about
+it is documented in section~\ref[prefixed].
+
+If this manual refers `\foo` then `\_foo` equivalent exists too. For example,
+we mention the `\addto` macro below. The `\_addto` equivalent exists too, but it
+is not explicitly mentioned here. If we refer only `\_foo` then its public
+equivalent does not exist. For example, we mention the `\_codedecl` macro below, so
+this macro is not available as `\codedecl`.
+
+If you are writing a document or macros specific for the document, then use
+simply user namespace (`\foo`). If you are writing more general macros,
+then use private namespace (`\_foo`), but you should declare your own namespace
+by \~`\_namespace` macro and you have to follow the naming discipline described in
+section~\ref[pkg-namespace].
+
+The alphabetically sorted list of macros typically usable for macro writers follows.
+More information about such macros can be found in the technical documentation.
+You can use hyperlinks here in order to go to the appropriate place of the technical
+documentation.
+
+\medskip \noindent
+\^`\addto`` \macro{<text>}` adds <text> at the end of `\macro` body.\nl
+\^`\adef` `<char>{<body>}` defines <char> active character with meaning <body>.\nl
+\^`\afterfi` `{<text>}<ignored>\fi` expands to `\fi<text>`.\nl
+\^`\bp`` {<dimen expression>}` expands \TeX/ dimension to decimal number in `bp` without unit.\nl
+\~`\_codedecl`` <sequence> {<info>}` is used at beginning of macro files.\nl
+\~`\colordef`` \macro {<mix of colors>}` declares `\macro` as color switch.\nl
+\^`\cs` `{<string>}` expands `\<string>`.\nl
+\~`\_doc` `...` \~`\_cod` encloses documenation text in the macro code.\nl
+\^`\eoldef`` \macro #1{<body>}` defines `\macro` with parameter separated to end of line.\nl
+\~`\_endcode` closes the part of macro code in macro files.\nl
+\~`\_endnamespace` closes name space declared by \~`\_namespace`.\nl
+\~`\eqbox`` [<label>]{<text>}` creates `\hbox{<text>}` with common width across whole document.\nl
+\^`\expr`` {<expression>}` expands to result of the <expression> with decimal numbers.\nl
+\~`\fontdef`` \f {<font spec.>}` declares `\f` as font switch.\nl
+\~`\fontlet` `\fa=\fb <sizespec.>` declares `\fa` as the same font switch
+ like `\fb` at given <sizespec.>.\nl
+\^`\foreach` `<list>\do <parameters>{<what>}` is exapandable loop over <list>.\nl
+\^`\foreachdef` `\macro <parameters>{<what>}` declares expandable `\macro` as loop over <list>.\nl
+\^`\fornum` `<from>..<to>\do {<what>}` is expanadable loop with numeric variable.\nl
+\^`\incr` `<counter>` increases and \^`\decr` `<counter>` decreases `<counter>` by one globally.\nl
+\^`\ignoreit` `<one>`, \^`\ignoresecond` `<one><two>` ignores given parameter.\nl
+`\expandafter` \^`\ignorept` `\the<dimen>` expands to decimal number <dimen> without `pt`.\nl
+\~`\isempty`, \~`\istoksempty`, \~`\isequal`, \~`\ismacro`, \~`\isdefined`, \~`\isinlist`
+\~`\isfile`, \~`\isfont` do various tests. Example: \~`\isinlist\list{<text>}\iftrue` does
+ `\iftrue` if <text> is in `\list`.\nl
+\^`\isnextchar`` <char>{<text1>}{<text2>}` performs <text1> if next
+ character is <char>, else <text2>.\nl
+\~`\kv` `{<key>}` expands to value when key-value parameters are used.\nl
+\^`\loop` `...` \^`\repeat` is classical Plain \TeX/ loop.\nl
+\^`\mathstyles`` {<math list>}` enables to create macros dependent on current math style.\nl
+\~`\_namespace`` {<pkg>}` declares name space used by package writers.\nl
+\^`\newcount`, \^`\newdimen` etc. are classical Plain \TeX/ allocators.\nl
+\^`\newif` `\iffoo` declares boolean `\iffoo` as in Plain \TeX/.\nl
+\^`\_newifi` `\_iffoo` declares boolean `\_iffoo`.\nl
+\^`\opinput`` {<filename>}` reads file like `\input` but with standard catcodes.\nl
+\^`\optdef`` \macro [<opt-default>] <parameters>{<body>}` defines `\macro` with [opt.parameter].\nl
+\^`\opwarning` `{<text>}` prints <text> to the terminal and .log file as warning.\nl
+\~`\private`` <sequence> <sequence> ... ;` declares <sequence>s for private name space.\nl
+\~`\public`` <sequence> <sequence> ... ;` declares <sequence>s for public name space.\nl
+\~`\readkv` `\macro` reads parameters from `\macro` in key-value format.\nl
+\^`\replstring`` \macro{<stringA>}{<stringB>}` replaces all <stringA> to <stringB> in `\macro`.\nl
+\^`\sdef` `{<string>}<parameters>{<body>}` behaves like `\def\<string><parameters>{<body>}`.\nl
+\^`\setctable` and \^`\restorectable` manipulate with stack of catcode tables.\nl
+\^`\slet` `{<stringA>}{<stringB>}` behaves like `\let\<stringA>=\<stringB>`\nl
+\^`\sxdef` `{<string>}<parameters>{<body>}` behaves like `\xdef\<string><parameters>{<body>}`.\nl
+\^`\trycs`` {<string>}{<text>}` expands `\<string>` if it is defined else expands <text>.\nl
+\^`\useit` `<one>`, \^`\usesecond` `<one><two>` uses given parameter.\nl
+\^`\wlog`` {<text>}` writes <text> to .log file.\nl
+\^`\wterm`` {<text>}` writes <text> to the terminal and .log file.\nl
+\^`\xargs`` <what> <token> <token> ... ;` repeats <what><token> for each <token>.\nl
+\unpenalty\unskip
+
+\sec Compatibility with Plain \TeX/
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+All macros of Plain \TeX/ are re-written in \OpTeX/. Common macros should
+work in the same sense as in original Plain \TeX. Internal control sequences
+like `\p@` or `\f@@t` are removed and mostly replaced by control sequences
+prefixed by `_` (like `\_this`). If you need to use the basic set of old Plain
+\TeX/ control sequences like `\p@` (for example you are reading an old macro file),
+use `\load[plain-at]`.
+
+All primitives and common macros have two
+control sequences with the same meaning: in prefixed and unprefixed form.
+For example `\hbox` is equal to `\_hbox`.
+Internal macros of \OpTeX/ have and use only prefixed form. User should use
+unprefixed forms, but prefixed forms are accessible too because the `_` is
+set as a letter category code globally (in macro files and users document too). User
+should re-define unprefixed forms of control sequences without worries that
+something internal will be broken (only the sequence `\par` cannot be
+re-defined without change of internal \TeX/ behavior because it is
+hard-coded in \TeX/, unfortunately).
+
+\new
+The Latin Modern 8bit fonts instead Computer Modern 7bit fonts are
+preloaded in the format, but only a few ones. The full family set is ready to
+use after the command \~`\fontfam[LMfonts]` which reads the fonts in OTF
+format.
+
+\new
+Plain \TeX/ defines `\newcount`, `\bye` etc. as `\outer` macros. \OpTeX/
+doesn't set any macro as `\outer`. Macros like `\TeX`, `\rm` are defined as
+`\protected`.
+
+\new
+The text accents macros `\"`, `\'`, `\v`, `\u`, `\=`, `\^`, `\.`, `\H`,
+`\~`, \code{\\`}, `\t` are undefined\fnote
+{The math accents macros like `\acute`, `\bar`, `\dot`, `\hat` still work.}
+in \OpTeX/. Use real
+letters like á, ř, ž in your source document instead of these old accents macros.
+If you really want to use them, you can initialize them by the \^`\oldaccents`
+command. But we don't recommend it.
+
+\new
+The default paper size is not set as the letter with 1\,in margins but as A4 with
+2.5\,cm margins. You can change it, for example by
+\^`\margins/1 letter (1,1,1,1)in`. This example sets the classical Plain \TeX/
+page layout.
+
+\new
+The origin for the typographical area is not at the top left 1\,in 1\,in coordinates
+but at the top left paper corner exactly. For example, `\hoffset` includes directly left
+margin.
+
+The tabbing macros `\settabs`\iindex{settabs} and `\+` (from Plain \TeX/)
+are not defined in \OpTeX/ because they are obsolete. But you can use the
+\ulink[http://petr.olsak.net/optex/optex-tricks.html\#tabs]{\OpTeX/ trick 0021}
+if you really need such feature.
+
+The `\sec` macro is reserved for sections but original Plain \TeX/ declares this
+control sequence for math secans.
+
+\enddocument
+
+
+\sec Dependencies
+%%%%%%%%%%%%%%%%%
+
+When `optex.fmt` is created then the following must be installed
+
+\begitems
+* The `\luatex` program.
+* Latin moder font metrics
+ `ec-lmr10.tfm`, `ec-lmbx10.tfm`, `ec-lmri10.tfm`,
+ `ec-lmbxi10.tfm`, `ec-lmtt10.tfm` (for basic text font initializing).
+* Computer rmodern font metrics
+ `cmr10.tfm`, `cmmi10.tfm`, `cmsy10.tfm`, `cmex10.tfm` (for basic math
+ initializing). If there are more Computer Modern fonts then they are read
+ too.
+* The file `hyphen.tex` form plain \TeX.
+\enditems
+
+When `\fontfam` is used then the ability of Unicode fonts reading
+is initialized using Lua scripts: `ltluatex.lua` (from \LaTeX/ package),
+`luaotfload-main.lua` and more 20 similar `.lua` files (from `luaotfload`
+package).
+
+When a font family is needed using `\fontfam` then such font family must be
+installed in the OTF format otherwise, the `\fontfam` command is ignored
+(only warning about no-existent font family is printed).
+
+When `\cslang`, `\delang` etc. commands are used in the document
+then the hyphenation patterns of relevant languages must be installed.
+Moreover the Lua script `luatex-hyphen.lua` (from `hyph-utf8` package)
+and data file `language-dat.lua` (from `hyphen-base` package)
+must be installed.
+
+When `\usebib` command is used then `librarian.tex` file
+(from the `librarian` macro package) must be installed.
+
+When `\morecolors` command is used then `x11nam.def` file
+(from the `xcolor` package) must be installed.
+
+When `\lorem` command is used then `lipsum.ltd.tex` file
+(from the `lipsum` package) must be installed.
+