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diff --git a/info/tex-nutshell/tex-nutshell.pdf b/info/tex-nutshell/tex-nutshell.pdf Binary files differindex 43af9c3cf5..35e5beae14 100644 --- a/info/tex-nutshell/tex-nutshell.pdf +++ b/info/tex-nutshell/tex-nutshell.pdf diff --git a/info/tex-nutshell/tex-nutshell.tex b/info/tex-nutshell/tex-nutshell.tex index 7ea0acc537..1b69d3160d 100644 --- a/info/tex-nutshell/tex-nutshell.tex +++ b/info/tex-nutshell/tex-nutshell.tex @@ -5,9 +5,12 @@ \emergencystretch=2em \hbadness=2100 +\def\thed#1{\ifnum#1<10 0\fi\the#1} + \catcode`<=13 \def<#1>{{\def\ { }\iindex{:#1}\iis {:#1} {$\langle\hbox{\it#1}\rangle$}}% $\def\,{\hskip1.5pt plus.3pt minus1.2pt}\,\langle\hbox{\it#1}\rangle\,$} +\def\l#1>{$\def\,{\hskip1.5pt plus.3pt minus1.2pt}\,\langle\hbox{\it#1}\rangle\,$} \everyintt={\catcode`<=13 \Blue} \onlyrgb \addto\_titfont\Blue @@ -34,6 +37,7 @@ \bgroup \lccode\string`\.=\string`\` \lowercase{\egroup \def\xx #1#2.{\i #2 \egroup `#1#2.}} \def\y`{\bgroup\_setverb\yy} \def\yy #1#2={\i #2 \egroup `#1#2=} +\def\z`{`\let<=\l} % Hyperlinks \hyperlinks\Red\Green @@ -41,7 +45,7 @@ -\tit \TeX/ in a nutshell +\tit \TeX/ in a Nutshell \author Petr Olšák @@ -57,15 +61,21 @@ or \ulink[http://petr.olsak.net/tbn.html]{\TeX/book naruby}. Try to type `texdoc texbytopic` in your system. -\ii OpTeX \ulink[http://petr.olsak.net/optex]{\OpTeX/} manual -supposes that the user knows the basics principles of \TeX/ itself. +\ii OpTeX The \ulink[http://petr.olsak.net/optex]{\OpTeX/} manual +supposes that the user already knows the basic principles of \TeX/ itself. If you are converting from \LaTeX/ to \OpTeX/ for example\fnote -{Congratulations to your decision:-)} +{Congratulations on your decision:-)} then you may welcome a summary document that presents these basic principles because \LaTeX/ manuals typically don't distinguish between \TeX/ features and features specially implemented by \LaTeX/ macros. +I would like to express my special thank to Barbara Beeton who read my text +very carefully and suggested hundreds language corrections and improvements +and also discovered many of my real mistakes. Thanks to her, my text is +better. But if there are any other mistakes then they are only mine and I'll be +pleased if you send me a bug report in such case. + \notoc\nonum\sec Table of contents \maketoc \outlines0 @@ -75,7 +85,7 @@ implemented by \LaTeX/ macros. The main principle of \TeX/ is that its input files can be a mix of the material which could be printed and \ii control~sequence {\em control sequences} -which gives a setting for build-in algorithms of \TeX/ or gives a special message +which give a setting for built-in algorithms of \TeX/ or give a special message to \TeX/ what to do with the inputted material. Each control sequence (typically a word prefixed by a backslash) has its @@ -83,23 +93,23 @@ Each control sequence (typically a word prefixed by a backslash) has its There are four types of meanings of control sequences: \begitems -* the control sequence can be a \ii register {\em register}, it means it represents a variable which +* the control sequence can be a \ii register {\em register}; this means it represents a variable which is able to keep a value. There are \ii primitive/register {\em primitive registers}. Their values influence - behavior of build-in algorithm (e.g. \i hsize `\hsize`, \i parindent `\parindent`, - \i hyphenpenalty `\hyphenpenalty`). On the other hand \ii decalared/register {\em declared registers} - are used by macros (e.g. \i medskipamount `\medskipamount` used in plain \TeX/ + behavior of built-in algorithms (e.g., \i hsize `\hsize`, \i parindent `\parindent`, + \i hyphenpenalty `\hyphenpenalty`). On the other hand \ii declared/register {\em declared registers} + are used by macros (e.g., \i medskipamount `\medskipamount` used in plain \TeX/ or \i ttindent `\ttindent` used by \ii OpTeX \OpTeX/). -* the control sequence can be a \ii primitive/command {\em primitive command}, it runs a build-in - algorithm (e.g. \i def `\def` declares a macro, \i halign `\halign` runs algorithm for +* the control sequence can be a \ii primitive/command {\em primitive command}, which runs a built-in + algorithm (e.g., \i def `\def` declares a macro, \i halign `\halign` runs the algorithm for tables, \i hbox `\hbox` creates a box in typesetting output). -* the control sequences can be a \ii character/constant {\em character constant} +* the control sequence can be a \ii character/constant {\em character constant} (declared by \i chardef `\chardef` or \i mathchardef `\mathchardef` primitive command) or a font selector (declared by \i font `\font` primitive command). -* the control sequence can be a \ii macro {\em macro}. When it is read then it is +* the control sequence can be a \ii macro {\em macro}. When it is read, it is replaced by its \ii replacement/text {\em replacement text} in the input queue. If there are more - macros in the replacement text, all macros are replaced too. It is so called + macros in the replacement text, all macros are replaced. This is called the \ii expansion/process {\em expansion process} which ends on the level of text to be printed or primitive commands or registers or character constants or font selectors. \enditems @@ -108,38 +118,39 @@ Example. When \TeX/ reads: \begtt \def\TeX{T\kern-.1667em\lower.5ex\hbox{E}\kern-.125emX} \endtt -in a macro file then the `\def` primitive command saves the information that +in a macro file, then the `\def` primitive command saves the information that \i TeX `\TeX` is a control sequence with meaning \"macro", the replacement text is -declared here and it is a mix of a material to be typeset: `T`, `E` and `X` +declared here, and it is a mix of a material to be typeset: `T`, `E` and `X` and primitive commands \i kern `\kern`, \i lower `\lower`, \i hbox `\hbox` with their parameters in given syntax. Each -primitive command has declared syntax, for example, `\kern` must be followed -by dimension specification in the format \"decimal number followed by a unit". -More about this primitive syntax is in the sections~\ref[reg], \ref[expand] and~\ref[main]. +primitive command has a declared syntax; for example, `\kern` must be followed +by a dimension specification in the format \"decimal number followed by a unit". +More about this primitive syntax is in sections~\ref[reg], \ref[expand] and~\ref[main]. When a control sequence `\TeX` with meaning \"macro" occurs in the -input stream then it is \ii expansion {\em expanded} to its replacement text, i.e the sequence of -typesetting material and primitive commands in our case of `\TeX` macro. -The logo \TeX/ is printed as a result of this processing. +input stream, then it is \ii expansion {\em expanded} to its replacement text, i.e.\ the sequence of +typesetting material and primitive commands. The `\TeX` macro +expands to `T\kern-.1667em\lower.5ex\hbox{E}\kern-.125emX` and +the logo \TeX/ is printed as a result of this processing. -None of the control sequences have their definitive meaning. The control sequence +None of the control sequences have their definitive meaning. A control sequence could change its meaning by re-defining it as a new macro (using `\def`), -redeclaring it as an arbitrary object in \TeX/ (using \i let `\let`) etc. +redeclaring it as an arbitrary object in \TeX/ (using \i let `\let`), etc. When you re-define a primitive control sequence then the access to its value -or build-in algorithm is lost. This is a reason why \ii OpTeX \OpTeX/ macros duplicate +or built-in algorithm is lost. This is a reason why \ii OpTeX \OpTeX/ macros duplicate all primitive sequences (\i hbox `\hbox` and `\_hbox`) with the same meaning and use -only \"private" control sequences (prefixed by `_`. So, user can re-define +only \"private" control sequences (prefixed by `_`). So, a user can re-define `\hbox` without the loss of the primitive command `\_hbox`. \sec Formats, engines -\TeX/ is able to start without any macros preloaded in so-called \ii ini-TeX/state {\em ini-\TeX/ +\TeX/ is able to start without any macros preloaded in the so-called \ii ini-TeX/state {\em ini-\TeX/ state} (the `-ini` option on the command line must be used). It knows only Cca 300 primitive registers and primitive commands at this state.\fnote -{Roughly speaking, if you know all these 300 primitive objects and all syntax -of primitive commands and all build-in algorithms then you know all about \TeX. -But starting to produce common documents from this primitive level without +{Roughly speaking, if you know all these 300 primitive objects and the syntax of all +primitive commands and all the built-in algorithms, then you know all about \TeX. +But starting to produce ordinary documents from this primitive level without macro support is nearly impossible.} When ini-\TeX/ reads macro files then new control sequences are declared as macros, declared registers, character constants or font @@ -147,28 +158,28 @@ selectors. The primitive command \i dump `\dump` saves the binary image of the \ (with newly declared control sequences) to the \ii format,format/file {\em format file} (`.fmt` extension). -The original intention of existence format files was to prepare a -collection of macro declarations, register settings and to load default fonts and -to dump this information to a file for later use. Such collection typically +The original intention of existing format files was to prepare a +collection of macro declarations and register settings, to load default fonts, and +to dump this information to a file for later use. Such a collection typically declares macros for the markup of documents and for typesetting design. This is the reason why we call these files {\em format files}: they give a format -of documents on the output side and declares markup rules for document source files. +of documents on the output side and declare markup rules for document source files. -When \TeX/ is started without `-ini` option then it tries to load a prepared +When \TeX/ is started without the `-ini` option, it tries to load a prepared format file into its memory and to continue with reading more macros or a real document (or both). The starting point is at the place where \i dump `\dump` was -processed during ini-\TeX/ state. If the format file is not specified +processed during the ini-\TeX/ state. If the format file is not specified explicitly (by `-fmt` option on the command line) then \TeX/ tries to read the format file with the same name which is used for running \TeX. For example `tex document` runs \TeX, it loads the format `tex.fmt` and reads the `document.tex`. Or `latex document` runs \TeX, it loads the format `latex.fmt` and reads the `document.tex`. -The `tex.fmt` is format file dumped when \ii plain~TeX/macros {\em plain \TeX/ macros}\fnote -{Plain \TeX/ macros were made by \ii Knuth/Donald Donald Knuth, the author of \TeX. It is a +The `tex.fmt` is the format file dumped when \ii plain~TeX/macros {\em plain \TeX/ macros}\fnote +{Plain \TeX/ macros were made by \iindex {Knuth,/Donald} Donald Knuth, the author of \TeX. It is a set of basic macros and settings which is used (more or less) as a subset of all other macro packages.} -were read and `latex.fmt` is format file dumped when \ii LaTeX/macros {\em \LaTeX/ macros} were read. +were read, and `latex.fmt` is the format file dumped when \ii LaTeX/macros {\em \LaTeX/ macros} were read. This is typically done when a \TeX/ distribution is installed without any user intervention. So, the user can run `tex document` or `latex document` without worry that these typical format files exist. @@ -176,23 +187,23 @@ worry that these typical format files exist. From this point of view, \LaTeX/ is nothing more than a format of \TeX/, i.e.~a collection of macro declarations and register settings. -A typical \TeX/ distributions have four common \ii TeX/engines {\em \TeX/ engines}, i.e.~programs -they implement classical \TeX/ algorithms with various extensions: +A typical \TeX/ distribution has four common \ii TeX/engines {\em \TeX/ engines}, i.e.~programs. +They implement classical \TeX/ algorithms with various extensions: \begitems * \TeX/ -- only classical \TeX/ algorithms by Donald Knuth, -* \ii pdfTeX pdf\TeX -- an extension supporting PDF output directly and +* \ii pdfTeX pdf\TeX/ -- an extension supporting PDF output directly and micro-typographical features, -* \ii XeTeX Xe\TeX/ -- an extension supporting Unicode and PDF output, +* \ii XeTeX \XeTeX/ -- an extension supporting Unicode and PDF output, * \ii luaTeX lua\TeX/ -- an extension supporting Lua programming, Unicode, micro-typographical features and PDF output. \enditems -Each of them are able to run in ini-\TeX/ state or with a format file. For +Each of them is able to run in ini-\TeX/ state or with a format file. For example the command `luatex -ini macros.ini` starts lua\TeX/ at ini-\TeX/ state, -read `macros.ini` file and final `\dump` command is supposed here to create -a format `macros.fmt`. Then user can use the command `luatex -fmt macros document` to -load `macros.fmt` and to process the `document.tex`. +reads the `macros.ini` file and the final `\dump` command is supposed here to create +a format `macros.fmt`. Then a user can use the command `luatex -fmt macros document` to +load `macros.fmt` and process the `document.tex`. Or the command `luatex document` processes lua\TeX/ with `document.tex` and with `luatex.fmt` which is a little extension of plain \TeX/ macros. Another example: `lualatex document` runs lua\TeX/ with `lualatex.fmt`. It is a format with @@ -207,72 +218,72 @@ primitive command \i input `\input<file name>` or \i font `\font<font selector>=<file name>` is used) then the rule \"first wins" is applied. \TeX/ looks at the current directory first or -somewhere to the \TeX/ installation second. The behavior in the second step +somewhere in the \TeX/ installation second. The behavior in the second step depends on the used \TeX/ distribution. For example \ii TeXlive \ulink[https://www.tug.org/texlive]{\TeX/live} programs are -linked with a \ii kpathsea {\em kpathsea} library and they do the following: Search the given -file in the current directory, then in \ii texmf~tree \code{~/texmf} tree (data are saved by -the user here), then in `texmf-local` tree (data are saved by the system administrator -here, they are not removed when \TeX/ distribution is upgraded), -then in `texmf-var` tree (data are saved automatically by programs from -\TeX/ distribution here) and then in `texmf-dist` tree (data from \TeX live +linked with a \ii kpathsea {\em kpathsea} library and they do the following: Search for the given +file in the current directory, then in the \ii texmf~tree \code{~/texmf} tree (data are saved by +the user here), then in the `texmf-local` tree (data are saved by the system administrator +here; they are not removed when the \TeX/ distribution is upgraded), +then in `texmf-var` tree (data are saved automatically by programs from the +\TeX/ distribution here), and then in the `texmf-dist` tree (data from the \TeX live distribution). Each directory tree can be divided into sub-trees: first level -`tex`, `fonts`, `doc` etc., second level is divided by \TeX/ engines or font types etc., -more levels are typically organized to keep a clarity. -New files in the current directory on in \code{~/texmf} tree are found without -doing something more, but new files in other places have to be registered by `texhash` -program (\TeX/ distribution does automatically this during its installation). +`tex`, `fonts`, `doc`, etc.; the second level is divided by \TeX/ engines or font types, etc.; +more levels are typically organized to keep clarity. +New files in the current directory or in the \code{~/texmf} tree are found without +doing anything more, but new files in other places have to be registered by the `texhash` +program (\TeX/ distributions do this automatically during their installation). \sec Processing the input -The lines from input files are transformed by the \ii tokenizer {\em tokenizer} first. -It reads input lines and generates a sequence of tokens. The main goals of -tokenizer is +The lines from input files are first transformed by the \ii tokenizer {\em tokenizer}. +It reads input lines and generates a sequence of tokens. These are the +main goals of the tokenizer: \begitems * It converts each control sequence to a single token characterized by its name. -* Another input material is tokenized as \"one token per character". -* The continuous sequence of more spaces is transformed into one space token. -* The end of the line is transfromed into space token, so the paragraph text - can continue in a next input line and one space token is between the last word +* Other input material is tokenized as \"one token per character". +* A continuous sequence of multiple spaces is transformed into one space token. +* The end of the line is transformed into a space token, so that paragraph text + can continue on the next input line and one space token is added between the last word on the previous line and the first word on the next line. -* Comment character `%` is ignored and all the text after it to the end of line - is ignored too. +* The comment character `%` is ignored and all the text after it to the end of line + is ignored too. No space is generated at the end of this line. * Spaces from the begining of each line are ignored. Thus, you can - use arbitrary indentation in your source file without change of the result. + use arbitrary indentation in your source file without changing the result. * Each empty line (or line with only spaces) is transformed to the token \i par `\par`. This token has primitive meaning: \"finalize the current paragraph". This implies the general rule in \TeX/ source files: paragraphs are terminated by empty lines. \enditems -The behavior of the tokenizer is not definitive. Tokenizer works with a table of +The behavior of the tokenizer is not definitive. The tokenizer works with a table of category codes. Any change of category codes of characters -(done by \i catcode {\let\,=\relax`\catcode`\code{`}`\<character>=<code>`} -primitive command) influences tokenizer processing. For +(done by the primitive command \i catcode {\let\,=\relax`\catcode`\code{`}`\<character>=<code>`}) influences tokenizer processing. For example, the verbatim environment is declared using setting all characters to normal meaning. -By default, there are the following characters with special meaning. Tokenizer -converts them or sets them as special tokens used in syntactical rules in +By default, there are the following characters with special meaning. The tokenizer +converts them or sets them as special tokens used in syntactic rules in \TeX/ later. The corresponding category codes are mentioned here as an index of the character. \begitems * `\`\c0\quad -- starts completion of a control sequence by the tokenizer. -* `{`\c1 and `}`\c2\quad -- opens and close group or have special syntactical meaning. - The main syntactical rule is: each subsequence of tokens treated by macros - or primitive commands must have these pairs o tokens balanced. There is no - exception. Tokenizer treats them as special tokens with meaning - \"opening character" and \"closing character". -* `%`\c{14}\quad -- comment character, removed by the tokenizer. +* `{`\c1 and `}`\c2\quad -- open and close group or have special syntactic meaning. + The main syntactic rule is: each subsequence of tokens treated by macros + or primitive commands must have these pairs of tokens balanced. There is no + exception. The tokenizer treats them as special tokens with meaning + \"opening character\c1" and \"closing character\c2". +* `%`\c{14}\quad -- comment character, removed by the tokenizer, along with + everything that follows it on the line. * `$`\c3, `&`\c4, `#`\c6, `^`\c7, `_`\c8, `~`\c{13}\quad -- tokenizer treats them as a special tokens with meaning: \ii math/mode/selector \"math-mode selector\c3", \ii table/separator \"table separator\c4", \ii parameter/prefix \"parameter prefix for macros\c6", \ii superscript/prefix \"superscript prefix in math\c7", - \ii subscript prefix \"subscript prefix in math\c8" + \ii subscript/prefix \"subscript prefix in math\c8", \ii active/character \"active character\c{13}" (the active character `~` is defined as no-breakable space in all typical formats). * Letters and other characters are tokenized as \"letter character\c{11}" or @@ -283,15 +294,15 @@ If you need to print these special characters you can use \ii -percent,-at,-dollar,-hash `\%`, `\&`, `\$`, `\#` or `\_`. These five control sequences are declared as \"print this character" in all typical \TeX/ formats. -Another possibility is to use a verbatim environment (it depends on used format) +Another possibility is to use a verbatim environment (it depends on the used format) Last alternative: you can use \i csstring {\let\,=\relax`\csstring\<character>`} in lua\TeX/, because lua\TeX/ disposes with the primitive command `\csstring` which converts `\<character>` to `<character>`\c{12}. -The \ii active~character \"active character\c{13}" +The \ii active/character \"active character\c{13}" can be declared by \i catcode `\catcode`\code{`}`\<character>=13`. -Such `<character>` behaves like `<control sequence>`. For example, you can +Such a `<character>` behaves like a `<control sequence>`. For example, you can define it by \i def `\def<character>{...}`. If a `<control sequence>` is @@ -299,37 +310,37 @@ listed in this document, the active character is meant too. {\emergencystretch=2em\par} Each control sequence is built by the tokenizer starting from `\`\c0. Its name is -a continuous sequence of letters\c{11} finalized by first non-letter. +a continuous sequence of letters\c{11} finalized by the first non-letter. Note that \OpTeX/ sets `_` as letter\c{11}, thus control sequence names can include this character. -\LaTeX/ sets the `@` as letter\c{12} when reading styles and macro files. +\LaTeX/ sets the `@` as letter\c{11} when reading styles and macro files. You can look to such files and you will see many such characters inside private control sequence names declared by \LaTeX/ macros. -If the first character after `\`\c0 is not letter\c{\ne11} then control sequence is +If the first character after `\`\c0 is not letter\c{\ne11}, then the control sequence is finalized with only this character in its name. So called \ii one~character/control~sequence {\em one-character control sequence} is created. Other control sequences are \ii multiletter/control~sequence {\em multiletter control sequences}. Spaces {\char9251}\c{10} after multi-letter control sequences are ignored, so the space can be used -as a terminating character of the control sequence. Another characters used -immediately after a control sequences are not ignored. So `\TeX !` and +as a terminating character of the control sequence. Other characters used +immediately after a control sequence are not ignored. So `\TeX !` and `\TeX!` gives the same result: the control sequence `\TeX` followed immediately by `!`\c{12}. -Tokenizer's output (a sequence of tokens) goes to \ii expand/processor {\em expand processor} -and its output goes to \ii main/processor {\em main processor} of \TeX. The expand processor -performs expansions of macros or a primitive command which is working at expand -processor level. See a summary of such commands in the section~\ref[expand]. +The tokenizer's output (a sequence of tokens) goes to the \ii expand/processor {\em expand processor} +and its output goes to the \ii main/processor {\em main processor} of \TeX. The expand processor +performs expansions of macros or a primitive command which is working at the expand +processor level. See a summary of such commands in section~\ref[expand]. -Main processor performs assignment of registers, declares macros by \i def `\def` -primitive command and runs all primitive commands at the main processor level. +The main processor performs assignment of registers, declares macros by the \i def `\def` +primitive command, and runs all primitive commands at the main processor level. Moreover, it creates the typesetting output as described in the next section. The very important difference between \TeX/ and other programs is that there are no strings, only sequences of tokens. We can return to the example -`\def\TeX{...}` above in the section~\ref[termi]. +`\def\TeX{...}` above in section~\ref[termi]. The token \i def `\def` is a control sequence with meaning \"declare a macro". It gets the following token \i TeX `\TeX` and declares it as a macro with replacement text, which is the sequence of tokens: @@ -347,111 +358,111 @@ If you are thinking like \TeX/ then you must forget the term \"string" because all texts in \TeX/ are preprocessed by the tokenizer when input lines are read and only sequences of tokens are manipulated inside \TeX/. -Tokenizer converts two `^`\c7`^`\c7 characters followed by ASCII uppercase +The tokenizer converts two `^`\c7`^`\c7 characters followed by an ASCII uppercase letter to the Ctrl-letter ASCII code. For example `^^M` is Ctrl-M (carriage return). It converts two `^`\c7`^`\c7 followed by two hexadecimal digits -(`0123456789abcdef`) to one-byte code, for example, `^^0d` is Ctrl-M too -because it has code 13. Moreover, tokenizer of \XeTeX/ or lua\TeX/ converts +(`0123456789abcdef`) to a one-byte code, for example, `^^0d` is Ctrl-M too +because it has code 13. Moreover, the tokenizer of \XeTeX/ or lua\TeX/ converts `^`\c7`^`\c7`^`\c7`^`\c7 followed by four hexadecimal digits or `^`\c7`^`\c7`^`\c7`^`\c7`^`\c7`^`\c7 followed by six hexadecimal digits to one -character with given Unicode. +character with a given Unicode. \sec Vertical and horizontal modes -When the main processor creates the typesetting output then it alternates +When the main processor creates the typesetting output, it alternates between vertical and horizontal mode. It starts in \ii vertical/mode,@ {\em vertical mode}: all materials are put vertically below in this mode. For example -\i hbox `\hbox{a}\hbox{b}\hbox{c}` creates c below b and b below a in vertical mode. +\i hbox `\hbox{a}\hbox{b}\hbox{c}` creates a above b above c in vertical mode. -If there is something incompatible with vertical mode principle: a special -command working only in horizontal mode or a character itself -then main processor switches to \ii horizontal/mode,@ {\em horizontal mode}: it opens -an unlimited horizontal data line for +If something is incompatible with the vertical mode principle --- a special +command working only in horizontal mode or a character itself --- +then the main processor switches to \ii horizontal/mode,@ {\em horizontal mode}: it opens +an unlimited horizontal data row for typesetting material and puts material next to each other. For example \i hbox `\hbox{a}\hbox{b}\hbox{c}` creates abc in horizontal mode. -When an empty line is scanned then tokenizer creates \i par `\par` token here and +When an empty line is scanned, the tokenizer creates a \i par `\par` token here and if the main processor is in horizontal mode, the `\par` command finalizes the -paragraph. More exactly it returns to the vertical mode, -it breaks the horizontal data line filled in previous horizontal mode +paragraph. More exactly it returns to vertical mode, +it breaks the horizontal data row filled in previous horizontal mode to parts with the \i hsize `\hsize` width. These parts are completed as -\ii box {\em boxes} and they are put one below second in the vertical mode. So, a +\ii box {\em boxes} and they are put one below another in vertical mode. So, a paragraph of \i hsize `\hsize` width is created. -Repeatedly: if there is something incompatible with current vertical mode +Repeatedly: if there is something incompatible with the current vertical mode (typically a character), then the horizontal mode is opened and all characters -(and spaces between them) are put to the horizontal data line. When empty line -is scanned then `\par` command is started and the horizontal -data line is broken to the lines of \i hsize `\hsize` width and next paragraph +(and spaces between them) are put to the horizontal data row. When an empty line +is scanned, then the `\par` command is started and the horizontal +data row is broken into lines of \i hsize `\hsize` width and the next paragraph is completed. -In the vertical mode, the material is cumulated in a vertical data column -called \ii main/vertical/list {\em main vertical list}. +In vertical mode, the material is accumulated in a vertical data column +called the \ii main/vertical/list {\em main vertical list}. If the height of this material is greater than \i vsize `\vsize` then its part with -maximal `\vsize` height is completed as a \ii page/box {\em page box} and shipped to +maximum `\vsize` height is completed as a \ii page/box {\em page box} and shipped to the \ii output/routine {\em output routine}. A programmer or designer can declare a design of pages using macros in the output routine: header, footer, pagination, -the position of the main page box etc. The output routine completes the main page -box with another material declared in the output routine and the result is +the position of the main page box, etc. The output routine completes the main page +box with other material declared in the output routine and the result is shipped out as one page of the document. The main processor continues in -the vertical mode with the rest of the unused material in the main vertical list. -Then it can switch to the horizontal mode if a character occurs etc... +vertical mode with the rest of the unused material in the main vertical list. +Then it can switch to horizontal mode if a character occurs, etc... The plain \TeX/ macro \i bye `\bye` (or primitive command \i end `\end`\fnote {\LaTeX/ format re-defines this primitive control sequence `\end` to another meaning which follows the logic of \LaTeX/'s markup rules.}) starts the last `\par` command, finalizes the last paragraph (if any), completes the last page -box, puts it to the output routine, finalizes the last page in it and \TeX/ +box, sends it to the output routine, finalizes the last page in it, and \TeX/ is terminated. There are \ii internal/vertical/mode {\em internal vertical mode} and \ii internal/horizontal/mode {\em internal horizontal mode}. -They are activated when the main processor is typesetting a material +They are activated when the main processor is typesetting material inside \i vbox `\vbox{...}` or \i hbox `\hbox{...}` primitive commands. More about boxes is in sections~\ref[boxes] and~\ref[main]. Understanding of switching between modes is very important for \TeX/ users. There are primitive commands which are context dependent on the current mode. -For example, \i par `\par` primitive command (generated by an empty line) does nothing +For example, the \i par `\par` primitive command (generated by an empty line) does nothing in vertical mode but it finalizes paragraph in horizontal mode and it causes -an error in math mode. Or \i kern `\kern` primitive command creates a vertical space in +an error in math mode. Or the \i kern `\kern` primitive command creates a vertical space in vertical mode or horizontal space in horizontal mode. -The following primitive commands used in the vertical mode starts the -horizontal mode: the first character of the paragraph (most common +The following primitive commands used in vertical mode start +horizontal mode: the first character of a paragraph (most common situation) or \i indent `\indent`, \i noindent `\noindent`, \i hskip `\hskip` (and its alternatives), \i vrule `\vrule`\fnote {The list is not fully completed, but most important commands -are mentioned here.} and plain \TeX/ macro \i leavevmode `\leavevmode`. -When the horizontal mode is opened, the indentation of the \i parindent `\parindent` width -is included. The exception is only if the horizontal mode is started by the -\i noindent `\noindent`, then the paragraph has no indentation. +are mentioned here.} and the plain \TeX/ macro \i leavevmode `\leavevmode`. +When horizontal mode is opened, an indentation of \i parindent `\parindent` width +is included. The exception is only if horizontal mode is started by +\i noindent `\noindent`; then the paragraph has no indentation. -The following primitive commands used in the horizontal mode finalizes the -paragraph and returns to the vertical mode: \i par `\par`, \i vskip `\vskip` (and its -alternatives), \i hrule `\hrule`, \i end `\end` and plain \TeX/ macro \i bye `\bye`. +The following primitive commands used in horizontal mode finalize the +paragraph and return to vertical mode: \i par `\par`, \i vskip `\vskip` (and its +alternatives), \i hrule `\hrule`, \i end `\end` and the plain \TeX/ macro \i bye `\bye`. \sec Groups in \TeX/ Each assignment to registers, declaration macros or font selecting is local -in groups. When the current group ends then the assignments done inside the -group are forgotten and the values when this group was opened are restored. +in groups. When the current group ends then the assignments made inside the +group are forgotten and the values in effect before this group was opened are restored. The groups can be delimited by `{` and `}` pair or by \i begingroup `\begingroup` and \i endgroup `\endgroup` primitive commands or by \i bgroup `\bgroup` and \i egroup `\egroup` control sequences declared by plain \TeX. For example, plain \TeX/ declares the macros \i rm `\rm` (selects roman font), \i bf `\bf` (selects bold font) and \i it `\it` (selects italics) and it initializes by -\i rm `\rm` font. User can write: +\i rm `\rm` font. A user can write: \begtt The roman font is here {\it here is italics} and the roman font continues. \endtt % Not only fonts but all registers are set locally inside a group. The macro -designer can declare a special environments with font selecting and with +designer can declare a special environment with font selection and with more special typographical parameters in groups. The following example is a test of understanding vertical and horizontal @@ -459,23 +470,23 @@ modes switching. \begtt {\hsize=5cm This is the first paragraph which should be formatted - to 5 cm width.} + to 5\,cm width.} But it is not true... \endtt % -Why the example above does not create the paragraph with a 5 cm width? -The empty line \i par (`\par`) command is placed {\em after} the group is finished, so the +Why does the example above not create the paragraph with a 5\,cm width? +The empty line \i par (`\par` command) is placed {\em after} the group is finished, so the \i hsize `\hsize` parameter has its previous value at the time when the paragraph is -completed, no value 5\,cm. The value of \i hsize `\hsize` register\fnote +completed, not the value 5\,cm. The value of the \i hsize `\hsize` register\fnote {and about twenty other registers which declare the paragraph design} is used when the paragraph is -completed, no at the beginning of the paragraph. This is the reason why -macro programmers put explicitly \i par `\par` command to macros before the local -environment is finished by the end of the group. Our example should look like +completed, not at the beginning of the paragraph. This is the reason why +macro programmers explicitly put a \i par `\par` command into macros before the local +environment is finished by the end of the group. Our example should look like this: \begtt -{\hsize=5cm This is the first ... to 5 cm width.\par} +{\hsize=5cm This is the first ... to 5\,cm width.\par} \endtt @@ -485,19 +496,19 @@ You can look at one character, say the `y`. It is represented by three dimensions: \ii height height (above baseline), \ii depth depth (below baseline) and \ii width width. Suppose that there are more characters printed in horizontal mode and -completed to a line of a paragraph. This line has its height equal to -the maximal height of characters inside it, it has the depth equal to maximal +completed as a line of a paragraph. This line has its height equal to +the maximum height of characters inside it, it has the depth equal to maximum depth of all characters inside it and it has its width. Such a sequence of -characters encapsulated to one typesetting element +characters encapsulated as one typesetting element with its height, depth and width is -called \ii box {\em box}. Boxes are placed next to each other (from left to +called a \ii box {\em box}. Boxes are placed next to each other (from left to right\fnote{There is an exception for special languages.}) -in horizontal mode or one above second in vertical mode. +in horizontal mode or one below another in vertical mode. The boxes can include individual characters or spaces or boxes. The boxes can include more boxes. Paragraph lines are boxes. The page box includes paragraph lines (boxes). The finalized page with a header, page box, pagination, -etc. is a box and it is shipped out to the PDF page. Understanding boxes is +etc., is a box and it is shipped out to the PDF page. Understanding boxes is necessary for macro programmers and designers. You can create an individual box by the primitive command @@ -505,90 +516,90 @@ You can create an individual box by the primitive command or \i vbox `\vbox{<vertical material>}`. The `<horizontal material>` is completed in internal horizontal mode and `<vertical material>` in internal vertical mode. Both cases open a group, create the material in a specified -mode and closes the group, where all settings are local. +mode and close the group, where all settings are local. The `<horizontal material>` can include individual characters, boxes, -horizontal \ii glue {\em glues} or \ii kern {\em kerns}. The glue is a special term for -stretchable or shrinkable and possible breakable spaces and the kern is a +horizontal \ii glue {\em glues} or \ii kern {\em kerns}. \"Glue" is a special term for +stretchable or shrinkable and possibly breakable spaces and \"kern" is a term used for fixed nonbreakable spaces. The `<vertical material>` can include boxes, vertical glues or kerns. No -individual characters. If you put an individual character in the -vertical mode (for example in the \i vbox `\vbox`) -then the horizontal mode is opened. At the end of \i vbox `\vbox`\fnote +individual characters. If you put an individual character in +vertical mode (for example in a \i vbox `\vbox`) +then horizontal mode is opened. At the end of a \i vbox `\vbox`\fnote {before the \i vbox `\vbox` group is closed} -or when \i par `\par` command is invoked, the opened paragraph is finished (with +or when the \i par `\par` command is invoked, the opened paragraph is finished (with current \i hsize `\hsize` width) and the resulting lines are vertically placed inside the \i vbox `\vbox`. -The completed boxes are unbreakable and they are treaded as a single object in +The completed boxes are unbreakable and they are treated as a single object in the surrounding printed material. -The line boxes of the paragraph have the fixed width \i hsize `\hsize`, so there must -be something stretchable or shrinkable in order to get desired fixed width -of lines. Typically the spaces between words have this feature\fnote {When +The line boxes of a paragraph have the fixed width \i hsize `\hsize`, so there must +be something stretchable or shrinkable in order to get the desired fixed width +of lines. Typically the spaces between words have this feature.\fnote {When the microtypographical feature \i pdfadjustspacing `\pdfadjustspacing` is activated, then not only spaces are stretchable and shrinkable but individual characters are -slightly deformed (by invisible amount) too.} These spaces have declared +slightly deformed (by an invisible amount) too.} These spaces have declared their \ii default/size/of~space {\em default size}, their \ii stretchability {\em stretchability} and their -\ii shrinkability {\em shrinkability} in the font metric data of currently used font. +\ii shrinkability {\em shrinkability} in the font metric data of the currently used font. -You can place such glue explicitly by the primitive command: +You can place such glue explicitly by the primitive command `\hskip`: \begtt \catcode`<=13 -\hsize <default size> plus<stretchability> minus<shrinkability> +\hskip <default size> plus<stretchability> minus<shrinkability> for example: -\hsize 10pt plus5pt minus2.5pt +\hskip 10pt plus5pt minus2.5pt \endtt % This example places the glue with 10\,pt default size, stretchable to 15\,pt\fnote {It can be stretchable ad absurdum (more than 15\,pt) but with very considerable \ii badness {\em badness} calculated by \TeX/ whenever glues are stretched -or shrank.} +or shrunk.} and shrinkable to 7.5\,pt as its minimal size. -All glues in one line are stretched or shrank equally but with weights given +All glues in one line are stretched or shrunk equally but with weights given from their stretchability/shrinkability values. You can do experiments of this feature if you say \i hbox `\hbox to<size>{...}`. Then the \i hbox `\hbox` is created with a given width. Probably, the glues inside -this \i hbox `\hbox` must be stretched or shrank. You can see in the log +this \i hbox `\hbox` must be stretched or shrunk. You can see in the log that the total \ii badness {\em badness} is calculated, it represents the amount of a -\"force" used to all glue included in such \i hbox `\hbox`. +\"force" used for all glue included in such an \i hbox `\hbox`. An infinitely stretchable (to an arbitrary positive value) or shrinkable (to an arbitrary negative value) glue -can exist. This glue is stretched/shrank and other glues with +can exist. This glue is stretched/shrunk and other glues with finite amounts of stretching or shrinking keep their default size in such case. You can put infinitely stretchable/\penalty0shrinkable \ii glue glue using the reserved unit \ii fil `fil` -in \i hskip `\hskip` command, for example +in an \i hskip `\hskip` command, for example the command \i hskip `\hskip 0pt plus 1fil` means zero default size but infinitely stretchable. There is a shortcut for such glue: \i hfil `\hfil`. When you type -`\hbox to\hsize{\hfil <text>\hfil}` then the `<text>` is centered. -But if the `<text>` is wider than \i hsize `\hsize` then \TeX/ reports an -\ii overfull/box `overfull \hbox`. If you want to center a wide `<text>` too, you can use -\i hss `\hss` instead \i hfil `\hfil`. The \i hss `\hss` primitive command is equal to -`\hskip 0pt plus1fil minus1fil`. The `<text>` printed by -`\hbox to\hsize{\hss<text>\hss}` is now centered in its arbitrary size. +\z`\hbox to\hsize{\hfil <text>\hfil}` then the \z`<text>` is centered. +But if the \z`<text>` is wider than \i hsize `\hsize` then \TeX/ reports an +\ii overfull/box `overfull \hbox`. If you want to center a wide \z`<text>` too, you can use +\i hss `\hss` instead of \i hfil `\hfil`. The \i hss `\hss` primitive command is equal to +`\hskip 0pt plus1fil minus1fil`. The \z`<text>` printed by +\z`\hbox to\hsize{\hss<text>\hss}` is now centered in its arbitrary size. A glue created with \ii fill `fill` stretchability or shrinkability (double ell) -is infinitely more stretchable or shrinkable than glues with only \ii fil `fil` unit. -So, glue with \ii fill `fill` are stretched or shrank and glues with only `fil` in +is infinitely more stretchable or shrinkable than glues with only a \ii fil `fil` unit. +So, glues with \ii fill `fill` are stretched or shrunk and glues with only `fil` in the same box keep their default size. For example, a macro declares centering -a `<text>` by -\i hbox `\hbox to\hsize{\hss <text>\hss}` and user can create the `<text>` in the form -\i hfill `\hfill <real text>`. Then `<real text>` is printed flushed right because +a \z`<text>` by +\i hbox \z`\hbox to\hsize{\hss <text>\hss}` and a user can create the \z`<text>` in the form +\i hfill \z`\hfill <real text>`. Then \z`<real text>` is printed flushed right because \i hfill `\hfill` is a shortcut to \i hskip `\hskip0pt plus1fill` and has greater priority than -glues with only \ii fil `fil` unit. +glues with only a \ii fil `fil` unit. -Common usage is \i hbox `\hbox to0pt{<text>\hss}` or `\hbox to0pt{\hss<text>}`. -The box with zero width is created and the text overlaps this dimension to -right (first example) or to left (second example). \ii plain~TeX Plain \TeX/ declares -macros for these cases: \i rlap `\rlap{<text>}` or \i llap `\llap{<text>}`. +Common usage is \i hbox \z`\hbox to0pt{<text>\hss}` or \z`\hbox to0pt{\hss<text>}`. +The box with zero width is created and the text overlaps the adjacent text to the +right (first example) or to the left (second example). \ii plain~TeX Plain \TeX/ declares +macros for these cases: \i rlap \z`\rlap{<text>}` or \i llap \z`\llap{<text>}`. The last line of each paragraph is finalized by a glue of type \i hfil `\hfil` by default. When you write \i hfill `\hfill <object>` in vertical mode (`<object>` is @@ -597,93 +608,106 @@ flushed right, because the paragraph is started by the `\hfill` space but finalized only by \i hfil `\hfil` space. If you type \i noindent `\noindent\hfil <object>` then the <object> is centered. And putting only `<object>` places it to the left -side because the common left side is default placement rule in the vertical +side because the common left side is the default placement rule in vertical mode. -The same principles concerned with horizontal glues are applicable for vertical -modes where glues are created by \i vskip `\vskip` commands instead `\hskip`. You can +The same principles that apply to horizontal glues are also applicable to vertical +modes where glues are created by \i vskip `\vskip` commands instead of `\hskip` +commands. You can write \i vbox `\vbox to<size>{...}` and do experiments. -If a glue is put to the horizontal data line in horizontal mode and +When the paragraph breaking algorithm decides about the suitable breakpoints for creating -lines with desired width \i hsize `\hsize`, then each glue is potentially breakable -point. Each glue can be preceded by a \ii penalty {\em penalty} value (created by +lines with the desired width \i hsize `\hsize`, then each glue is a potentially breakable +point. Each glue can be preceded by a \ii penalty {\em penalty} value (created by the \i penalty `\penalty` primitive) in the typical range --10000 to 10000. The paragraph breaking algorithm gets a penalty if it decides -to break line in the glue with given penalty value preceded. If no penalty -is declared for a given glue, then it is the same as a penalty equal to zero. -The penalty value 10000 or more -means \"impossible to break". The negative penalty means a bonus for paragraph -breaking algorithm. The penalty -10000 or less means \"you must break here". - -The paragraph breaking algorithm tries to find an optimum of breakpoints -positions concerning all penalties, to all badnesses of all created lines and to +$-10000$ to $10000$. The paragraph breaking algorithm gets a penalty if it decides +to break line at the glue preceded by the given penalty value. If no penalty +is declared for a given glue, then it is the same as a penalty equal to zero.\fnote +{More precisely: the paragraph breaking algorithm or page breaking algorithm +can break horizontal list to lines (or vertical list to pages) +at penalties (then it gets the given penalty) or at glues (then the penalty +is zero). The second case is possible only if no penalty nor glue precedes. +The item where the list is broken (penalty or glue), is discarded and all +immediatelly followed glues, penalties and kerns are discarded too. They are called +\ii discardable/item {\em discardable items}}. +The penalty value $10000$ or more +means \"impossible to break". A negative penalty means a bonus for the paragraph +breaking algorithm. The penalty $-10000$ or less means \"you must break here". + +The paragraph breaking algorithm tries to find an optimum of breakpoint +positions concerning to all penalties, to all badnesses of all created lines and to many more values not mentioned here in this brief document. -The analogical optimal breakpoint is found in the vertical material when \TeX/ +The analogous optimal breakpoint is found in vertical material when \TeX/ breaks it into pages. The concept \"box, penalty, glue" with the optimum-fit breaking -algorithms makes \TeX/ unique between many other typesetting software. +algorithms makes \TeX/ unique among many other typesetting software. -\sec Syntactical rules +\sec Syntactic rules -The primitive commands can get their parameters written after it. These -parameters must suit syntactical rules given for +A primitive command can get its parameters written after it. These +parameters must suit syntactic rules given for each primitive command. Some parameters are optional. For example \i hskip `\hskip<dimen> /plus<stretchability>. /minus<shrinkability>.` means that -the parameter `<dimen>` must follow (it must suit syntactical rules for +the parameter `<dimen>` must follow (it must suit syntactic rules for dimensions, see section \ref[reg]) then the optional parameter prefixed by keyword \ii plus `plus` can follow and then the optional parameter prefixed by \ii minus `minus` can follow. We denote the optional parameters by underline in this document. {\emergencystretch=2em\par} -The \ii keyword {\em keywords} (typically prefixes some parameters) may have optional spaces +\ii keyword {\em Keywords} (typically prefixes to some parameters) may have optional spaces around them. -If the syntactical rule mentions the pair `{`, `}` then these characters are +The explicit expressions of numbers (i.e.\ `75`, `"4B`, \code{`K}; see +section~\ref[reg]) should be terminated by one optional +space which is not printed. This space can serve as a termination character +which says that \"whole number is presented here; no more digits are expected". + +If the syntactic rule mentions the pair `{`, `}` then these characters are not definitive: other characters may be tokenized with this special meaning but it -is not common. The text between this pair must be \ii balabced/text {\em balanced} with respect to this -pair. For example the syntactic rule \i message `\message{<text>}` supposes that -`<text>` must not be `ab{cd` but `ab{c{}}d` is allowed for instance. +is not common. The text between this pair must be \ii balanced/text {\em balanced} with respect to this +pair. For example the syntactic rule \i message \z`\message{<text>}` supposes that +\z`<text>` must not be `ab{cd`, but `ab{c{}}d` is allowed for instance. -By default, all parameters read by primitive commands are got from input -stream tokenized and fully expanded by the expand processor. But +By default, all parameters read by primitive commands are got from the input +stream, tokenized and fully expanded by the expand processor. But sometimes, when \TeX/ reads parameters for a primitive command, the expand processor is deactivated. We denote these parameters by red color. For -example \i let `\let|<control sequence>=<token>;` means that these parameters -processed by `\let` command are not expanded. +example, \i let `\let|<control sequence>=<token>;` means that these parameters +processed by the `\let` command are not expanded. -Whenever a syntactical rule mentions the \ii equal/sign `=` character (see the previous example -with \i let `\let` command, then this is the equal sign tokenized as a normal character -and it is optional. The syntactical rule allows to omit it. Optional spaces +Whenever a syntactic rule mentions the \ii equal/sign `=` character (see the previous example +with the \i let `\let` command), then this is the equal sign tokenized as a normal character +and it is optional. The syntactic rule allows to omit it. Optional spaces are allowed around this equal sign. The concept of the optional parameters of primitive commands (terminated if something different from -the keyword follows) may bring troubles if a macro programmer -forget to terminate an uncomplete parameter text by \x`\relax` command +the keyword follows) may bring trouble if a macro programmer +forgets to terminate an incomplete parameter text by the \x`\relax` command (`\relax` does nothing but it can terminate a list of optional parameters of the previous command). Suppose, for example, that `\mycoolspace` is defined -by `\def\mycoolspace{\penalty42\hskip2mm}`. If an user write +by `\def\mycoolspace{\penalty42\hskip2mm}`. If a user writes `first\mycoolspace plus second` then \TeX/ reports the error `missing` `number,` `treated` `as` `zero` in the position of `s` character -and appends: \code{<to be read again> s}. An user who is unfamiliar with +and appends: \code{<to be read again> s}. A user who is unfamiliar with \TeX/ primitive commands and their parameters is totally lost. The correct definition looks like: `\def\mycoolspace{\penalty42\hskip2mm\relax}`. \sec[def] Principles of macros -Macros can be declared by \i def `\def` primitive command (or `\edef`, `\gdef`, -`\xdef` commands, see below). The syntax is +Macros can be declared by the \i def `\def` primitive command (or `\edef`, `\gdef`, +`\xdef` commands; see below). The syntax is `\def|<control sequence>/<parameters>.{<replacement text>};`. The `<parameters>` are a sequence of formal parameters of the declared macro written in the form `#1`, `#2`, etc. They must be numbered from one and incremented by one. -The maximal number of declared parameters is nine. +The maximum number of declared parameters is nine. These parameters can be used in the `<replacement text>`. This specifies the place where the real parameter is positioned when the macro is expanded. For example: @@ -700,14 +724,15 @@ example: Note that there are two possibilities of how to write real macro parameters when a macro is in use. The parameter is one token by default but if there is `{<something>}` then the parameter is `<something>`. The braces -here are delimiters for the real parameter. +here are delimiters for the real parameter (the \TeX/ group is not open/close +here). The example above shows a declaration of \ii unseparated/parameter,@ {\em unseparated parameters}. The parameters were declared by `#1` or `#1#2` with no text appended to such -declaration. But there is another possibility. +a declaration. But there is another possibility. Each formal parameter can have a text appended in its declaration, so -the general syntax of declaration of formal parameters is -`#1/<text1>.#2/<text2>.;` etc. If such `<text>` is appended then we say that +the general syntax of the declaration of formal parameters is +\z`#1/<text1>.#2/<text2>.` etc. If such \z`<text>` is appended then we say that the parameter is \ii separated/parameter,@ {\em separated} or \ii delimited/parameter,@ {\em delimited} by text. The same delimiter must be used when the macro is in use. For example @@ -719,38 +744,38 @@ The same delimiter must be used when the macro is in use. For example \endtt % In the example above the `#1` parameter is unseparated (one token is read as -a real parameter if not used the syntax `{<parameter>}`). The `#2` parameter +a real parameter if the syntax \z`{<parameter>}` is not used). The `#2` parameter is delimited by two dots and the `#3` parameter is delimited by space. -There should be a `<text0>` immediately before `#1` in the parameter -declaration. This means that the declared macro must be used with the same <text0> +There may be a \z`<text0>` immediately before `#1` in the parameter +declaration. This means that the declared macro must be used with the same \z`<text0>` immediately appended. If not, \TeX/ reports the error. -General rule for declaration a macro with three parameters should be: +The general rule for declaration of a macro with three parameters should be: \i def -`\def|<control sequence>/<text0>.#1/<text1>.#2/<text2>.#3/<text3>.{<replacement text>};`. +\z`\def|<control sequence>/<text0>.#1/<text1>.#2/<text2>.#3/<text3>.{<replacement text>};`. The rule \"everything must be balanced" is applied to separated parameters too. It means that `\Test AB{C..DEF G}.. H` from the example above reads `B{C..DEF G}` to the `#2` parameter and the `#3` parameter is empty because the space (the delimiter of `#3` parameter) immediately follows two dots. -The separated parameter could bring a potential problem when the user forgot the -delimiter or the delimiter is specified incorrectly. Then \TeX/ reports the -error. This error is reported when the first \i par `\par` is scanned to the +The separated parameter can bring a potential problem if the user forgets the +delimiter or the delimiter is specified incorrectly. Then \TeX/ reports an +error. This error is reported when the first \i par `\par` is scanned as part of the parameter (probably generated from an empty line). If you really want to scan -to the parameter more paragraphs including `\par` between them then you can -use \i long `\long` prefix before `\def`. For example `\long\def\scan#1\stop{...}` -reads the parameter of the `\scan` macro to the `\stop` control sequence -and this parameter could include more paragraphs. -If the delimiter is missing when \i long `\long` defined macro is processed then -\TeX/ reports the error at the end of the file. +as part of the parameter more paragraphs including `\par` between them, then you can +use the \i long `\long` prefix before `\def`. For example `\long\def\scan#1\stop{...}` +reads the parameter of the `\scan` macro up to the `\stop` control sequence, +and this parameter can include more paragraphs. +If the delimiter is missing when a \i long `\long` defined macro is processed, then +\TeX/ reports an error at the end of the file. When a real parameter of a macro is scanned then the expand processor is deactivated. When the `<replacement text>` is processed then the expand processor works -normally. It means that if parameters are used in `<replacement text>` then +normally. This means that if parameters are used in the `<replacement text>`, then they are expanded here. -If a macro declaration is used inside `<replacement text>` of another macro +If a macro declaration is used inside the `<replacement text>` of another macro then the number of `#` must be doubled for inner declaration. Example: \begtt @@ -764,24 +789,24 @@ then the number of `#` must be doubled for inner declaration. Example: \endtt Note the `%` characters used in the `\defmacro` definition. They mask -the end of lines. If you don't use them then the space tokens are here (generated -by tokenizer at the end of each line). The `<replacement text>` of `\defmacro` will be -`<space>\def#1...{...}<space>` in such case. Each usage of `\defmacro` +the end of lines. If you don't use them, then the space tokens are included here (generated +by the tokenizer at the end of each line). The `<replacement text>` of `\defmacro` will be +`<space>\def#1...{...}<space>` in such a case. Each usage of `\defmacro` generates two unwanted spaces. It is not a problem if `\defmacro` is used in the vertical mode because spaces are ignored in this mode. But if `\defmacro` is used in horizontal mode then -these spaces are printed\fnote -{More precisely, they are transformed into horizontal glues used between words.}. +these spaces are printed.\fnote +{More precisely, they are transformed into horizontal glues used between words.} The macro declaration behaves as another assignment, so the information about -such declaration is lost if it is used in a group and the group is left. -But you can use \i global `\global` prefix before \i def `\def` or the primitive +such a declaration is lost if it is used in a group and the group is left. +But you can use a \i global `\global` prefix before \i def `\def` or the primitive \i gdef `\gdef`. Then the assignment is global regardless of groups. -When `\def` or `\gdef` is processed then `<replacement text>` is read with +When `\def` or `\gdef` is processed then `<replacement text>` is read with the deactivated expand processor. We have alternatives \i edef `\edef` (expanded def) and \i xdef `\xdef` (global expanded def) which read their `<replacement text>` -expanded by expand processor. The summary of `\def` syntax is: +expanded by the expand processor. The summary of `\def` syntax is: \begtt \catcode`\|=13 \catcode`\/=13 \catcode`\<=13 \Blue \def|<control sequence>/<parameters>.{<replacement text>}; % local assignment @@ -790,41 +815,41 @@ expanded by expand processor. The summary of `\def` syntax is: \xdef|<control sequence>/<parameters>.{;<replacement text>} % global assignment \endtt -You can set \i tracingmacros `\tracingmacros=2` and you can see to log file how the macros are expanded. +If you set \i tracingmacros `\tracingmacros=2`, you can see in the log file how the macros are expanded. \sec Math modes -The `$`\c3`<math text>$`\c3 specifies a math formula inside the line of the +The `$`\c3`<math text>$`\c3 specifies a math formula inside a line of the paragraph. It processes the `<math text>` in a group and in \ii internal/math/mode,math/mode/internal {\em internal math mode}. The `$`\c3`$`\c3`<math text>$`\c3`$`\c3 generates a separate line with math formula(s). It processes the `<math text>` in a group and in -\ii display/math/mode,math/mode/display {\em dislay math mode}. +\ii display/math/mode,math/mode/display {\em display math mode}. -The fonts in math mode are selected by very specific manner which is independent -on current text font. Six different math object are automatically detected +The fonts in math mode are selected in a very specific manner which is independent +of the current text font. Six different math objects are automatically detected in math mode: \x`\mathord` (normal material), \x`\mathop` (big operators), \x`\mathbin` (binary operators), \x`\mathrel` (relations), \x`\mathopen` (open -brackets), \x`\mathclose` (close brackets), \x`\mathpunct` (punctuations). They +brackets), \x`\mathclose` (close brackets), \x`\mathpunct` (punctuation). They can be processed in four styles \x`\displaystyle` (default in the display mode), \x`\textstyle` (default in the internal math mode), \x`\scriptstyle` (used for -indexes or exponents, more small text) and \x`\scriptscriptstyle` -(used in indexes of indexes, smaller text). +indexes or exponents, smaller text) and \x`\scriptscriptstyle` +(used in indexes of indexes, even smaller text). -The math algorithms were implemented to \TeX/ by its author with very care. +The math typesetting algorithms were implemented in \TeX/ by its author with great care. All typographical traditions of math typesetting were taken into account. There are three chapters about math typesetting in his \TeX/book. Moreover, -there is the detailed appendix G with exact specification of generating math -formulas here. This topic is unfortunately out of the frame of this short +there is the detailed appendix G containing the exact specification of generating math +formulae. This topic is unfortunately out of the scope of this short text. -There is a good a piece of news: all formats (including \LaTeX/) take default \TeX/ +There is a good a piece of news: all formats (including \LaTeX/) take the default \TeX/ syntax for `<math text>`. So, \LaTeX/ manuals or \LaTeX/ documents -serves a good source if you want to get to know the rules of math typesetting +serve a good source if you want to get to know the rules of math typesetting by \TeX. There is only one significant difference. Fractions are constructed at the primitive level by the \x`\over` primitive: -`{<nominator>\over<denominator>}` but \LaTeX/ uses a macro \x`\frac` in the -syntax `\frac{<nominator>}{<denominator>}`. Plain \TeX/ users (including the +`{<numerator>\over<denominator>}` but \LaTeX/ uses a macro \x`\frac` in the +syntax `\frac{<numerator>}{<denominator>}`. Plain \TeX/ users (including the author of \TeX/) prefer the syntax which follows the principle \"how a human reads the formula". On the other hand, the \x`\frac` syntax is derived from machine languages. You can define the @@ -836,11 +861,11 @@ principle \"how a human reads the formula". On the other hand, the \ii register There are four types of registers used in \TeX: \begitems \def\!{\kern-1pt} -* \ii counter/type/register {\em Counters}, their values are integer numbers. Counters are declared by +* \ii counter/type/register {\em Counters}; their values are integer numbers. Counters are declared by \i newcount `\newcount|<register>;`\fnote {The declarators \x`\newcount`, \x`\newdimen`, \x`\newskip` and \x`\newtoks` - are plain \TeX/ macros used in all known \TeX/ formats. They provides - `<address>` allocation and uses the + are plain \TeX/ macros used in all known \TeX/ formats. They provide + `<address>` allocation and use the `\count<address>`\!, `\dimen<address>`\!, `\skip<address>` and `\toks<address>` \TeX/ registers. The \x`\countdef`, \x`\dimendef`, \x`\skipdef` and \x`\toksdef` primitive commands are used internally.} @@ -848,36 +873,36 @@ principle \"how a human reads the formula". On the other hand, the \TeX/ interprets primitive commands which represent an integer from an internal table as counter type register too (examples: \x`\catcode`\code{`A}, \x`\lccode`\code{`A}). -* \ii dimen/type/register {\em Dimen type}, their values are dimensions. They are declared by +* \ii dimen/type/register {\em Dimen type}; their values are dimensions. They are declared by \i newdimen `\newdimen|<register>;` or they are primitive registers (\x`\hsize`, for example). \TeX/ interprets primitive commands which represent a dimension value as dimen type register too (example: \i wd `\wd0`). -* \ii glue/type/register {\em Glue type}, their values are triples like in general +* \ii glue/type/register {\em Glue type}; their values are triples like in general \x`\hskip` parameters. They can be declared by \i newskip `\newskip|<register>;` or they are primitive registers (\x`\abovedisplayskip` for example).\fnote {Very similar {muglue type} for math glues exists too but it is not described in this text.} -* \ii token/type/register {\em Tokens lists}, their values are sequences of tokens. They are +* \ii token/type/register {\em Token lists}; their values are sequences of tokens. They are declared by \i newtoks `\newtoks|<register>;` or they are primitive registers (\x`\everypar` for example). \enditems -The following example shows, how registers are declared, how the value is -saved to the register and how to print the value of the register. +The following example shows how registers are declared, how a value is +saved to the register, and how to print the value of the register. \tmpnum=42 \tmpdim=-13cm \skip0=10mm plus 12mm minus1fil \toks0={abCd ef} \begtt \newcount \mynumber -\newdimen \mydimension +\newdimen \mydimen \newskip \myskip \newtoks \mytoks \mynumber = 42 -\mydimension = -13cm +\mydimen = -13cm \myskip = 10mm plus 12mm minus1fil \mytoks = {abCd ef} -To print these vaules use the primitive command "the": -\the\mynumber, \the\mydimension, \the\myskip, \the\mytoks. +To print these values use the primitive command "the": +\the\mynumber, \the\mydimen, \the\myskip, \the\mytoks. \bye \endtt % @@ -888,7 +913,7 @@ readable dimensions are converted to typographical points~(pt). The general syntactic rule for storing values to registers is `<register>=<value>` where the equal sign is optional and it can be surrounded by optional spaces. Syntactic rules for each type of `<value>` depending on -type of the register (i.\,e.\ `<number>`, `<dimen>`, `<skip>` and `<toks>`) follows. +type of the register (i.e.\ `<number>`, `<dimen>`, `<skip>` and `<toks>`) follows. \begitems \let\_aboveliskip=\relax * The `<number>` could be @@ -903,15 +928,16 @@ type of the register (i.\,e.\ `<number>`, `<dimen>`, `<skip>` and `<toks>`) foll * {\let\,=\relax \code{`}`<character>`} (the prefix is the reverse single quote \code{`}). It returns the code of the `<character>`. Examples: \code{`}`A` or one-character control sequence \code{`\\A}). - Both examples represent the number 65. Unicode of the character - are taken here if lua\TeX/ or Xe\TeX/ are used; + Both examples represent the number 65. The Unicode of the character + is taken here if lua\TeX/ or \XeTeX/ is used; * \i numexpr `\numexpr<num. expression>`.\fnote - {This is a feature of e\TeX/ extension. It is implemented in pdf\TeX, Xe\TeX/ and lua\TeX.} + {This is a feature of the $\varepsilon$\TeX/ extension. It is implemented in pdf\TeX, \XeTeX/ and lua\TeX.} The `<num. expression>` uses operators `+`, `-`, `*` and \code{/} and brackets `(`, `)` in normal sense. The operands are `<number>`s. It is terminated by something incompatible with the syntactic rule of `<num. expression>` or by `\relax`. - If the result is non-integer, then it is rounded (no truncated). + The `\relax` (if it is used as a separator) is removed. + If the result is non-integer, then it is rounded (not truncated). \enditems * The `<dimen>` could be \begitems \style - @@ -923,15 +949,16 @@ type of the register (i.\,e.\ `<number>`, `<dimen>`, `<skip>` and `<toks>`) foll 1\,sp = $2^{-16}$\,pt = \TeX/ accuracy.} or \ii mm `mm` or \ii cm `cm` or \ii in `in` or \ii bp `bp` (big point) or \ii dd `dd` (Didot point) or \ii pc `pc` (pica) or - \ii cc `cc` (cicero) or \ii sp `sp` or \ii em `em` (quad of current font) or + \ii cc `cc` (cicero) or \ii sp `sp` (scaled point) or \ii em `em` (quad of current font) or \ii ex `ex` (ex~height of current font) or a register of dimen type; * \i dimexpr `\dimexpr<dimen expression>`. The `<dimen expression>` uses operators `+`, `-`, `*` and \code{/} and - brackets `(`, `)` in normal sense. The operands of `+` and `-` are + brackets `(`, `)` in their normal sense. The operands of `+` and `-` are `<dimen>`s, the operators of `*` or \code{/} are the pair `<dimen>` and `<number>` (in this order). The `<dimen expression>` - is terminated by something what is incompatible with - syntactic rule of `<dimen expression>` or by `\relax`. + is terminated by something incompatible with the + syntactic rule of `<dimen expression>` or by `\relax`. The `\relax` (if it + is used as a separator) is removed. \enditems * The `<skip>` could be: \begitems \style - @@ -942,8 +969,8 @@ type of the register (i.\,e.\ `<number>`, `<dimen>`, `<skip>` and `<toks>`) foll \enditems * The `<toks>` could be \begitems \style - -* `/<expandafters>.{|<text>};`. The `<expandafters>` is typically a sequence of - `\expandafter` primitive commands (zero or more). The `<text>` is +* `/<expandafters>.`\z`{|<text>};`. The `<expandafters>` is typically a sequence of + `\expandafter` primitive commands (zero or more). The \z`<text>` is scanned without expansion but the exception can be given by `<expandafters>`. \enditems @@ -954,7 +981,7 @@ The main processor reads input tokens (from the output of activated or deactivated expand processor) in two contexts: \ii do/something/context,context/do/something {\em do something} or {\em read parameters}. By default it is in the context {\em do something}. When a -primitive which allows a parameters is read, main processor reads the +primitive which allows parameters is read, the main processor reads the parameters in the context \ii read/parameters/context,context/read/parameters {\em read parameters}. Whenever the main processor reads a register in the context @@ -966,7 +993,7 @@ compliant to the appropriate syntactic rule, \TeX/ reports an error. Examples of register manipulations: \begtt -\newcount\mynumber \newdimen\mydimension \newdimen\myskip +\newcount\mynumber \newdimen\mydimen \newdimen\myskip \hsize = .7\hsize % see the rule for <dimen>, unit could be a register \hoffset = \dimexpr 10mm - (\parindent + 1in) \relax % usage of \dimexpr \myskip = 10pt plus15pt minus 3pt @@ -974,7 +1001,7 @@ Examples of register manipulations: \mynumber = \mydimen % \mynumber = 10*2^16 because \mydimen = 10*2^16 sp \endtt % -Each dimension is saved internally as an integer multiple of `sp` unit in +Each dimension is saved internally as an integer multiple of the `sp` unit in \TeX. When we need a conversion `<dimen>` $\to$ `<number>`, then simply the internal unit `sp` is omitted. @@ -988,7 +1015,7 @@ value given by plain \TeX/ follows. * \y`\hoffset=0pt`, \y`\voffset=0pt` give left margin and top margin of the page. They are - calculated from \ii page/origin {\em page origin} which is defined by coordinates + calculated from the \ii page/origin {\em page origin} which is defined by coordinates \y`\pdfvorigin=1in` and \y`\pdfhorigin=1in` measured from left upper corner of the page. @@ -998,22 +1025,22 @@ value given by plain \TeX/ follows. paragraph. * \y`\leftskip=0pt`, \y`\rightskip=0pt`. Glues added to each line in the - paragraph from the left and the right side. If the stretchability is decared here, + paragraph from the left and the right side. If the stretchability is declared here, then the paragraph is ragged left/right. -* \y`\parskip=0pt plus 1pt` is vertical space between paragraphs. +* \y`\parskip=0pt plus 1pt` is the vertical space between paragraphs. * \y`\baselineskip=12pt`, \y`\lineskiplimit=0pt`, \y`\lineskip=1pt`. \ii baselineskiprule The {\em `\baselineskip` rule} says: - Two consecutive lines in vertical list have baseline distance given + Two consecutive lines in the vertical list have the baseline distance given by \x`\baselineskip` by default. The appropriate real glue is inserted between the lines. But if this real glue (between boxes) is less than \x`\lineskiplimit` - then only \x`\lineskip` between boxes is inserted. + then only \x`\lineskip` is inserted between the boxes. -* \y`\topskip=10pt` is the distance between top of page box and the baseline of +* \y`\topskip=10pt` is the distance between the top of the page box and the baseline of the first line. * \y`\linepenalty=10`, @@ -1030,14 +1057,14 @@ value given by plain \TeX/ follows. \y`\interlinepenalty=0`, \y`\floatingpenalty=0`, \y`\outputpenalty=0`. - These penalties are put to various places in the vertical or horizontal - list. Most important are \x`\clubpenalty` (below the first line of a paragraph) - and \x`\widowpenalty` (before last line of paragraph). Typographical rules - give us to set these register to 10000 (no page break is allowed here). - -* \y`\looseness=0` allows to create a \"suboptimal" paragraph. The page-building - algorithm tries to builds the paragraph with \x`\loosenes` lines more than - the optimal solution. If the \x`\tolerance` has not sufficiently large value + These penalties apply to various places in the vertical or horizontal + list. Most important are \x`\clubpenalty` (inserted below the first line of a paragraph) + and \x`\widowpenalty` (inserted before the last line of a paragraph). Typographical rules + often demand us to set these registers to 10000 (no page break is allowed here). + +* \y`\looseness=0` allows us to create of a \"suboptimal" paragraph. The page-building + algorithm tries to build the paragraph with \x`\looseness` lines more than + the optimal solution. If the \x`\tolerance` does not have a sufficiently large value then this setting is simply ignored. It is reset to zero after each paragraph is completed. @@ -1052,8 +1079,8 @@ value given by plain \TeX/ follows. \y`\adjdemerits=10000`, \y`\hfuzz=0.1pt`, \y`\vfuzz=0.1pt` -are parameters for paragraph building algorithm not described here in -detail. +are parameters for the paragraph building algorithm (not described here in +detail). * \y`\hbadness=1000`, \y`\vbadness=1000`. \TeX/ reports a warning about \iid badness on the terminal @@ -1075,22 +1102,22 @@ detail. \y`\tracinggroups=0`, \y`\tracingassigns=0`. If these registers have positive values then \TeX/ reports details about - the processing of build-in + the processing of built-in algorithms to the log file. If \i tracingonline `\tracingonline>0` then the same - output is on the terminal. + output is shown on the terminal. * \y`\showboxbreadth=5`, \y`\showboxdepth=3`, \y`\errorcontextlines=5`. - The amount of information when boxes are traced to the log file or an error is + The amount of information shown when boxes are traced to the log file or an error is reported. * \y`\language=0`. - \TeX/ is able to load more hyphenation patters for more + \TeX/ is able to load more hyphenation patterns for more languages. This register points to the index of currently used hyphenation patterns. Zero means English. -* \y`\lefthyphenmin=2`, \y`\righthyphenmin=3`. Maximal letters left or right of +* \y`\lefthyphenmin=2`, \y`\righthyphenmin=3`. Maximum letters left or right in hyphenated words. * \y`\defaulthyphenchar=`\code{`}`\-`. This character is used when words are @@ -1101,9 +1128,9 @@ detail. * \y`\hangafter=1`, \y`\hangindent=0pt`. If \x`\hangindent` is positive, then after \x`\hangafter` lines all following - lines are indented. Negative/positive values of \x`\hangindent` or \x`\hangafter` does + lines are indented. Negative/positive values of \x`\hangindent` or \x`\hangafter` applies indentation from left or right and from the top or bottom of the paragraph. - The \x`\hangindet` is set to 0 after each paragraph. + The \x`\hangindent` is set to 0 after each paragraph. * \y`\mag=1000`. Magnification factor of all used dimensions. The value 1000 means 1:1. @@ -1112,11 +1139,11 @@ detail. use this character in the `\string` primitive. * \y`\newlinechar=-1`. If positive, this character is interpreted as the end of - the line when printing to the log or by \x`\write` primitive command. + the line when printing to the log or by the \x`\write` primitive command. * \y`\endlinechar=`\code{`}`^^M`. This character is appended to the end of each input - line. Tokenizer converts it (Ctrl-M character) to the space token. + line. The tokenizer converts it (the Ctrl-M character) to the space token. * \y`\time=now`, \y`\day=now`, @@ -1125,19 +1152,24 @@ detail. starts to process the document. The \x`\time` counts minutes after midnight. +* \y`\prevdepth=*` includes the depth of the last box in vertical mode. + +* \y`\prevgraph=*` includes the number of lines of the paragraph when `\par` + finishes. + * \y`\overfullrule=5pt`. A rectangle to this width is appended after each \ii overfull/box overfull `\hbox`. -* \y`\mathsurround=0pt` is space inserted around formula from internal math mode. +* \y`\mathsurround=0pt` is the space inserted around a formula in internal math mode. * \y`\abovedisplayskip=12pt plus3pt minus9pt`, \y`\abovedisplayshortskip=0pt plus3pt`, \y`\belowdisplayskip=12pt plus3pt minus9pt`, \y`\belowdisplayshortskip=7pt plus3pt minus 4pt`. - These spaces are inserted above and below the formula generated in math display + These spaces are inserted above and below a formula generated in math display mode. -* \y`\tabskip=0pt` is used by `\halign` primitive command for creating tables. +* \y`\tabskip=0pt` is used by the `\halign` primitive command for creating tables. * \y`\output={\plainoutput}`, \y`\everypar={}`, \y`\everymath={}` \y`\everydisplay={}`, @@ -1145,104 +1177,104 @@ detail. \y`\everyvbox={}` \y`\everycr={}`, \y`\everyjob={}`. - These tokens lists are processed when algorithms of \TeX/ reach a corresponding - situation: opens output routine, paragraph, internal math mode, display - math mode, \x`\vbox`, \x`\hbox`. Or it is at the end of the line in the table or it + These token lists are processed when an algorithm of \TeX/ reaches a corresponding + situations respectively: opens output routine, paragraph, internal math mode, display + math mode, \x`\vbox`, \x`\hbox`, is at the end of a line in a table, or starts the job. \enditems \sec[expand] Expandable primitive commands -Notes about notation in this and the following sections. -If the documented command is from e\TeX{} extension -(i.\,e.\ implemented in pdf\TeX, Xe\TeX/ -and lua\TeX) then one * is prefixed. If it is from pdf\TeX/ extension -(implemented in Xe\TeX/ and lua\TeX/ too) then two ** are prefixed. +Notes about notation are in this and the following sections. +If the documented command is from the $\varepsilon$\TeX{} extension +(i.e.\ implemented in pdf\TeX, \XeTeX/ +and lua\TeX) then one * is prefixed. If it is from the pdf\TeX/ extension +(implemented in \XeTeX/ and lua\TeX/ too) then two ** are prefixed. If it is~a~lua\TeX/ only command then three *** are prefixed. \begitems -* \i string `\string|<control sequence>;` expand to an \x`\escapechar` (if positive) +* \i string `\string|<control sequence>;` expands to an \x`\escapechar` (if positive) followed by the name of the control sequence. All characters of the output - are \"other characters\c{12}", only spaces (if exist) + are \"other characters\c{12}", only spaces (if any exist) are kept as space tokens {\char9251}\c{10}. * \*\*\*\i csstring `\csstring|<control sequence>;` works like`\string` but without `\escapechar`. -* \*\i detokenize `\detokenize/<expandafters>.{|<text>};` re-tokenizes all tokens in the text. - Control sequences used in <text> are re-tokenized like `\string` primitive, spaces - are tokens {\char9251}\c{10} and all other tokens are set as \"other +* \*\i detokenize `\detokenize/<expandafters>.`\z`{|<text>};` re-tokenizes all tokens in the text. + Control sequences used in \z`<text>` are re-tokenized like the `\string` primitive, spaces + are tokens {\char9251}\c{10}, and all other tokens are set as \"other characters\c{12}". -* \i the `\the|<register>;` expands to the value of the register. Examples were in - previous section. The output is tokenized like the output of `\detokenize`. +* \i the `\the|<register>;` expands to the value of the register. Examples appear in the + previous section. The output is tokenized like of `\detokenize`. The exception is `\the|<tokens register>;`: the output is the value - of the `<tokens register>` without re-tokenizing and expand processor - does not expand this output in `\edef`\, `\write`, `\message` etc. arguments. + of the `<tokens register>` without re-tokenizing and the expand processor + does not expand this output in `\edef`, `\write`, `\message`, etc., arguments. -* \i scantoken `\scantokens/<expandafters>.{|<text>};` re-tokenizes <text> using actual - tokenizer setting. The behavior is the same as to write `<text>` to a +* \i scantoken `\scantokens/<expandafters>.`\z`{|<text>};` re-tokenizes \z`<text>` using the actual + tokenizer setting. The behavior is the same as when writing \z`<text>` to a virtual file and reading this file immediately. -* \*\*\*\i scantextokens `\scantextokens/<expandafters>.{|<text>};` is the same as +* \*\*\*\i scantextokens `\scantextokens/<expandafters>.`\z`{|<text>};` is the same as `\scantokens` but removes problems with end-of-virtual-file. * \i meaning `\meaning|<token>;` expands to the meaning of the `<token>`. The text is - tokenized like in the `\detokenze` output. + tokenized like the `\detokenize` output. -* \i csname \i endcsname `\csname<text>\endcsname` creates a control sequence with name <text>. - If it is not defined, then it gets the `\relax` meaning. +* \i csname \i endcsname \z`\csname<text>\endcsname` creates a control sequence with name \z`<text>`. + If it is not already defined, then it gets the `\relax` meaning. For example `\csname TeX\endcsname` is the same as `\TeX`. - The `<text>` must be expandable to characters only. Non-expandable + The \z`<text>` must be expandable to characters only. Non-expandable control sequences (a primitive command at the main processor level, a register, a character constant, a font selector) are disallowed here. \TeX/ reports the - error `missing \encsname` when this rule isn't compliant. + error `missing \endcsname` when this rule isn't compliant. Example: `\csname foo:\the\mynumber\endcsname` expands to control sequence `\foo:42` if the `\mynumber` is a register with the value 42. - Another example: macro programmer should implement key/value dictionary + Another example: a macro programmer should implement a key/value dictionary using this primitive: \begtt \def\keyval #1 #2 {\expandafter\def\csname dict:#1\endcsnme{#2}} \def\value #1 {\csname dict:#1\endcsname} -\kyval Peter 21 % key=Peter, value=21, saved to the dictionary - % it does \def\dict:Peter{21} -\value Peter % expands to \dict:Peter and it expands to 21. +\keyval Peter 21 % key=Peter, value=21, saved to the dictionary + % it does \def\dict:Peter{21} +\value Peter % expands to \dict:Peter which expands to 21. \endtt -* \i expandafter `\expandafer|<token 1><token 2>;` does transformation - `<token 1><expanded token2>`. The token processor will expand `<token 1>` - after such transformation. The `<expanded token2>` is only the first level of +* \i expandafter \z`\expandafter|<token 1><token 2>;` does the transformation + \z`<token 1><expanded token2>`. The token processor will expand \z`<token 1>` + after such a transformation. The \z`<expanded token2>` is only the first level of expansion. For example, a macro is transformed to its `<replacement text>` but without expansion of `<replacement text>` at this time. - Or `\csname...\endcsname` pair creates a control sequence but does not + Or the `\csname...\endcsname` pair creates a control sequence but does not expand it at this time. - If `<token 2>` is not expandable then \x`\expandafter` silently does + If \z`<token 2>` is not expandable then \x`\expandafter` silently does nothing. - The example above (the `\keyval` macro) shows usage of \x`\expandafter`. - We need not define `\csname` by `\def`, we want to define + The example above (the `\keyval` macro) shows the usage of \x`\expandafter`. + We need not define `\csname` by `\def`; we want to define a `\dict:key`. The \x`\expandafter` helps here. - The `<token 2>` should be another \x`\expandafter`. We can see + The \z`<token 2>` should be another \x`\expandafter`. We can see \x`\expandafter` chains in many macro files. For example `\expandafter A\expandafter B\expandafter CD` is processed as - `ABC<expanded D>`. + \z`ABC<expanded D>`. - The `/<expandafters>.{|<text>};` syntax rule enables to prepare `|<text>;` using + The `/<expandafters>.`\z`{|<text>};` syntax rule enables us to prepare \z`|<text>;` by `\expandafter`(s). For example \i detokenize `\detokenize{\macro}` expands to `\`\c{12}`m`\c{12}`a`\c{12}`c`\c{12}`r`\c{12}`o`\c{12}. But if you need to detokenize the `<replacement text>` of the `\macro` then use `\detokenize\expandafter{\macro}`. Not only `\expandafter`s should be - here. Expand processor does full expansion here until the opening brace + here. The expand processor does full expansion here until an opening brace `{`\c{1} is found. * \i if \i else \i fi The general rule for all `\if*` commands is `<if condition><true text>/\else<false text>.\fi`. The `<if condition>` is evaluated and `<true text>` or `<false text>` is skipped or processed depending on the result of `<if condition>`. - When the expand processor is skipping the text due to `\if*` command then it + When the expand processor is skipping the text due to an `\if*` command, it expands nothing in the skipped text. But it is noticing all control sequences with meaning `\if*`, `\else` and `\fi` during skipping in order to skip correctly all nested `\if*.../\else....\fi` constructions. @@ -1250,7 +1282,7 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. The following `<if condition>`s are possible: \_printitem={$\circ$\enspace} -* \i if `\if<token 1><token 2>` is true if +* \i if \z`\if<token 1><token 2>` is true if \begitems \removelastskip \style a * both tokens are characters with the same Unicode (or ASCII code in classical \TeX) or * both tokens are control sequences @@ -1261,20 +1293,20 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \removelastskip \noindent Example: you can say `\let\test=a` then `\if\test a` returns true. -* \i ifx `\ifx|<token 1><token 2>;` is true if the meanings of `<token 1>` - and `<token 2>` are the same. +* \i ifx \z`\ifx|<token 1><token 2>;` is true if the meanings of \z`<token 1>` + and \z`<token 2>` are the same. * \i ifnum `\ifnum<number 1><relation><number 2>`. The `<relation>` could be - \code{<} or \code{=} or \code{>}. It returns true if the comparison of two + \code{<} or \code{=} or \code{>}. It returns true if the comparison of the two numbers is true. * \i ifodd `\ifodd<number>` returns true if the `<number>` is odd. * \i ifdim `\ifdim<dimen><relation><dimen>` The `<relation>` could be - \code{<} or \code{=} or \code{>}. It returns true if the comparison of two + \code{<} or \code{=} or \code{>}. It returns true if the comparison of the two dimensions is true. -* \x`\iftrue` returns constantly true, \x`\iffalse` returns constanty false. +* \x`\iftrue` returns constantly true, \x`\iffalse` returns constantly false. * \x`\ifhmode`, \x`\ifvmode`, \x`\ifmmode` -- true if the current mode is horizontal, vertical, math. @@ -1287,31 +1319,31 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. returns true if the specified `<box number>` represents \x`\hbox`, \x`\vbox`, void box respectively. -* \i ifcat `\ifcat<token 1><token 2>` is true if catogory codes of `<token 1>` - and `<token 2>` equals. +* \i ifcat \z`\ifcat<token 1><token 2>` is true if the category codes of \z`<token 1>` + and \z`<token 2>` are equal. -* \i ifeof `\ifeof<file number>` is true, of the file attached to the `<file number>` - by \x`\openin` primitive does not exist or the end of file was reached by +* \i ifeof `\ifeof<file number>` is true if the file attached to the `<file number>` + by the \x`\openin` primitive does not exist, or the end of file was reached by the \x`\read` primitive. \_printitem{$\bullet$\enspace} * \*\i unless `\unless<if condition>` negates the result of `<if condition>` before skipping or processing the following text. -* \i ifcase `\ifcase<number><case 0>\or<case 1>\or<case 2>...\or<case n>/\else<else text>.\fi`. - It processes the branch given by `<number>`. It processes `<else text>` - (or nothing if no `<else text>` is declared) when a branch with given +* \i ifcase `\ifcase<number><case 0>\or<case 1>\or<case 2>` `...` `\or<case n>/\else<else text>.\fi`. + This processes the branch given by `<number>`. It processes `<else text>` + (or nothing if no `<else text>` is declared) when a branch with a given `<number>` does not exist. * \i noexpand `\noexpand|<token>;`. The expand processor does not expand the `<token>` if it is expanding the text in `\edef`, `\write`, `\message` or similar lists. -* \*\i unexpanded `\unexpanded/<expandafters>.{|<text>};` returns `<text>` and applies - `\noexpand` to all tokens in the `<text>`. +* \*\i unexpanded `\unexpanded/<expandafters>.`\z`{|<text>};` returns \z`<text>` and applies + `\noexpand` to all tokens in the \z`<text>`. * \*\i numexpr `\numexpr<num. expression>`, \i dimexpr \*`\dimexpr<dimen expression>`. - Documented in the `<dimen>` and `<number>` syntax rules in the section~\ref[reg]. + Documented in the `<dimen>` and `<number>` syntax rules in section~\ref[reg]. * \i number `\number<number>`, \i romannumeral `\romannumeral<number>` prints <number> in decimal digits or as a roman numeral (with lowercase letters). @@ -1332,48 +1364,48 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. * \i input `\input<file name><space>` (classical \TeX) or \ `\input"<file name>"` \ or \ `\input{<file name>}` \ opens the given `<file name>` and starts to read input from it. If the `<file name>` - doesn't exist then \TeX/ tries to open again \,{\def\,{\kern-1pt}`<file name>.tex`}. - If it doesn't exist even this, \TeX/ reports an error. + doesn't exist then \TeX/ tries again to open \,{\def\,{\kern-1pt}`<file name>.tex`}. + If that doesn't exist, \TeX/ reports an error. The alternative syntax with `"..."` or `{...}` allows having spaces in the file names. -* \i endinput `\endinput`. The current line is the last line of the inputted file. File +* \i endinput `\endinput`. The current line is the last line of the file being input. The file is closed and reading continues from the place where `\input` of this file was started. `\endinput` done in the main file causes future reading from the - terminal and headache of users. + terminal and a headache for the user. -* \*\*\*\i directlua `\directlua {<text>}` runs a Lua script given in `<text>`. +* \*\*\*\i directlua \z`\directlua {<text>}` runs a Lua script given in \z`<text>`. \enditems \sec[main] Primitive commands at the main processor level -{\bf Commands used for declaration control sequences} - +{\bf Commands used for declaration of control sequences} +\par\nobreak\medskip\nobreak \begitems -* \x`\def` \x`\edef` \x`\gdef` \x`\xdef` were documented in the section~\ref[def]. +* \x`\def` \x`\edef` \x`\gdef` \x`\xdef` were documented in section~\ref[def]. -* \x`\long` is prefix, it can be used before `\def` `\edef` `\gdef` `\xdef`. +* \x`\long` is a prefix; it can be used before `\def`, `\edef`, `\gdef`, `\xdef`. The declared macro accepts the control sequence `\par` in its parameters. -* \*\x`\private` is prefix, it can be used before `\def` `\edef` `\gdef`, `\xdef`. +* \*\x`\private` is a prefix; it can be used before `\def`, `\edef`, `\gdef`, `\xdef`. The declared macro is not expanded by the expand processor in \x`\write`, - \x`\message`, \x`\edef` etc. parameters. + \x`\message`, \x`\edef`, etc., parameters. -* \x`\outer` is prefix, can be used before `\def` `\edef` `\gdef`, `\xdef`. +* \x`\outer` is a prefix; it can be used before `\def`, `\edef`, `\gdef`, `\xdef`. The declared macro must be used only when the main processor is in the context {\em do something} or \TeX/ reports an error. -* \x`\global` is a prefix, it can be used before each assignment (commands +* \x`\global` is a prefix; it can be used before any assignment (commands from this subsection and `<register>=<value>` settings). The assignment is global regardless of the current group. * \i chardef `\chardef|<control sequence>;=<number>`, \i mathchardef `\mathchardef|<control sequence>;=<number>` \ declares a constant <number>. When the main processor is in the context - \"do something" and it gets a \x`\chardef`-ed control sequence, it prints - the character with Unicode (ASCII code) <number> to the typesetting output. + {\em do something} and it gets a \x`\chardef`-ed control sequence, it prints + the character with Unicode (ASCII code) `<number>` to the typesetting output. If it gets a \x`\mathchardef`-ed control sequence, it prints a math object (it works only in math mode, not documented here). @@ -1381,7 +1413,7 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. an equivalent to the `\count<number>` which is a register of counter type. The `<number>` here means an address in the array of registers of counter type. The `\count0` is reserved for the page - number. The macro programmer uses rarely direct addresses (1 to 9), more + number. Macro programmers rarely use direct addresses (1 to 9), more common is using the allocation macro `\newcount|<control sequence>;`. * \x`\dimendef`, \x`\skipdef`, \x`\muskipdef`, \x`\toksdef` followed by @@ -1394,7 +1426,7 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. * \i font `\font|<font selector>;=<file name><space>/<size specification>.` declares `<font selector>` of a font implemented in the `<file name>.tfm`. The - `<size specifiaction>` can be `at<dimen>` or `scaled<factor>`. + `<size specification>` can be `at<dimen>` or `scaled<factor>`. The `<factor>` equal to {\tt 1000} means 1:1. New syntax (supported by Unicode engines) is @@ -1403,9 +1435,9 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \font|<font selector>;="[<font file>]/:<font features>." /<size specification>. \endtt % - The `<font file>` is file name without `.otf` nor `.ttf` extension. + The `<font file>` is a file name without an `.otf` or `.ttf` extension. The `<font features>` are font features prefixed by `+` or `-` and - separated by semicolon. The {\let\,=\relax `otfinfo -f <file name>.otf`} command + separated by a semicolon. The {\let\,=\relax `otfinfo -f <file name>.otf`} command (on command line) can list them. Lua\TeX/ supports alternative syntax: `{...}` instead of `"..."`. Example: `\font\test={[texgyretermes-regular]:+onum;-liga} at12pt`. @@ -1414,10 +1446,10 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. the same meaning as `<token>` has. The `<token>` can be whatever, a character or a control sequence. -* \i futurelet `\futurelet|<control sequence><token 1><token 2>;` works in two steps. - In the first step it does `\let|<control sequence>=<token 2>;` and in the - second step `<token 1><token 2>` is processed with activated token - processor. Typically `<token 1>` is a macro that needs to know the next token. +* \i futurelet \z`\futurelet|<control sequence><token 1><token 2>;` works in two steps. + In the first step it does \z`\let|<control sequence>=<token 2>;` and in the + second step \z`<token 1><token 2>` is processed with activated token + processor. Typically \z`<token 1>` is a macro that needs to know the next token. \enditems \noindent {\bf Commands for box manipulation} @@ -1425,37 +1457,37 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \begitems * \i hbox `\hbox{<cmds>}` or `\hbox to<dimen>{<cmds>}` or `\hbox spread<dimen>{<cmds>}` creates a box. The material inside this box is a `<horizontal list>` - generated by `<cmds>` in the horizontal mode in a group. The width of the box is natural width - of the `<horizontal list>` or `<dimen>` given by \ii to `to<dimen>` parameter or - it is spread by `<dimen>` given by \ii spread `spread<dimen>` + generated by `<cmds>` in horizontal mode in a group. The width of the box is the natural width + of the `<horizontal list>` or `<dimen>` given by the \ii to `to<dimen>` parameter or + it is spread by the `<dimen>` given by the \ii spread `spread<dimen>` parameter. The height of the box is the maximum of heights of all elements in - the `<horizontal list>`. The depth of the box is maximum of depths of all - such elements. These elements are put to the common baseline (exceptions + the `<horizontal list>`. The depth of the box is the maximum of depths of all + such elements. These elements are set on the common baseline (exceptions can be given by \x`\lower` or \x`\raise` commands). * \i vbox `\vbox{<cmds>}` or `\vbox to<dimen>{<cmds>}` or `\vbox spread<dimen>{<cmds>}` creates a box. The material inside this box is a `<vertical list>` - generated by `<cmds>` in the vertical mode in a group. The height of the + generated by `<cmds>` in vertical mode in a group. The height of the box is the natural height of the `<vertical list>` (eventually modified by values from \ii to `to` or \ii spread `spread` parameters) without the depth of the last element. The depth of the last element is set as the depth of the box. The width of the box is the maximum of widths of elemens in the `<vertical list>`. - All elements are put to the + All elements are placed at the common left margin of the box (exceptions can be given by \x`\moveleft` or \x`\moveright` commands). * \i vtop `\vtop{<cmds>}` (with optional `to` or `spread` - parameters) is equal as `\vbox`, + parameters) is the same as `\vbox`, but the baseline of the resulting box goes through the baseline of the first element in - the `<vertical list>` (note that `\vbox` has its baseline equal to the + the `<vertical list>` (note that `\vbox` has its baseline equal to the baseline of the last element inside). * \i vcenter `\vcenter{<cmds>}` (with optional `to` or `spread` parameters) is equal to `\vbox`, but its \ii math/axis {\em math axis}\fnote - {Math axis is a horizontal line which goes through centers of + and $-$ - symbols. Its distance from baseline is declared in the math font metrics.} + {The math axis is a horizontal line which goes through centers of + and $-$ + symbols. Its distance from the baseline is declared in the math font metrics.} is exactly in the middle of the box. So its baseline is appropriately shifted. The `\vcenter` can be used only in math modes but given `<cmds>` are processed in vertical mode. @@ -1469,21 +1501,21 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. * \i setbox `\setbox<box number>=<box>`. \TeX/ has a set of \ii box/register {\em box registers} addressed by `<box number>` and accessed via \i box `\box<box number>` or alternatives described below. - The `\setbox` command saves given `<box>` to the register addressed by + The `\setbox` command saves the given `<box>` to the register addressed by `<box-number>`. - Macro programmers use only 0 to 9 `<box numbers>` directly. Other + Macro programmers use only 0 to 9 \z`<box numbers>` directly. Other addresses to box registers should be allocated by the \i newbox `\newbox|<control sequence>;` macro. The `|<control sequence>;` is equivalent to a `<box number>`, not to the box register itself. - The `\setbox` command does an assignment, so \x`\global` prefix is needed + The `\setbox` command does an assignment, so the \x`\global` prefix is needed if you want to use the saved box outside the current group. * \i box `\box<box number>` returns the box from `<box number>` box - register. Example: you can do `\setbox0=\hbox{abc}`. This `\hbox` is - not printed but saved to the register 0. At different place you can use - `\box0` which prints `\hbox{abc}` or you can do + register. Example: you can do `\setbox0=\hbox{abc}`. This `\hbox` isn't + printed but saved to the register 0. At a different place you use + `\box0`, which prints `\hbox{abc}`, or you can do `\setbox0=\hbox{cde\box0}` which saves the `\hbox{cde\hbox{abc}}` to the register~0. @@ -1495,7 +1527,7 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. * \i wd `\wd<box number>`, `\ht<box number>`, `\dp<box number>`. You can measure or use the width, height and depth of a box saved in a register addressed - by `<box nuber>`. Examples `\mydimen=\ht0`, `\hbox to\wd0{...}`. + by `<box number>`. Examples `\mydimen=\ht0`, `\hbox to\wd0{...}`. You can re-set the dimensions of a box saved in a register addressed by `<box number>`. For example \i setbox `\setbox0=\hbox{abc}` `\wd0=0pt` `\box0` gives the same result as \i hbox `\hbox to0pt{abc}` but without the warning about @@ -1504,23 +1536,23 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. * \i unhbox `\unhbox<box number>`, \kern-.4pt\i unvbox `\unvbox<box number>`, \kern-.4pt\i unhcopy `\unhcopy<box number>`, \kern-.4pt\i unvcopy `\unvcopy<box number>` do the same work as `\box` or `\copy` but they don't return the whole - box but only it contents, i.\,e.~a horizontal or vertical material. + box but only its contents, i.e.~the horizontal or vertical material. Example: try to do \i setbox `\setbox0=\hbox{abc}` and later `\setbox0=\hbox{cde\unhbox0}` saves the \i hbox `\hbox{cdeabc}` to the box register~0. The \x`\unhbox` and \x`\unhcopy` commands return the \x`\hbox` contents and \x`\unvbox`, \x`\unvcopy` commands return the \x`\vbox` contents. If incompatible - contents is saved then \TeX/ reports an error. You can test the type of + contents are saved, then \TeX/ reports an error. You can test the type of saved contents by \x`\ifhbox` or \x`\ifvbox`. * \i vsplit `\vsplit<box number> to<dimen>` does a column break. The `<vertical material>` saved in the box `<box number>` is broken - to a first part of `<dimen>` height and the rest remains in the - box `<box number>`. The broken part is completed as `\vbox` which is the + into a first part of `<dimen>` height and the rest remains in the + box `<box number>`. The broken part is saved as a `\vbox` which is the result of this operation. For example, you can say `\newbox\column` `\setbox\column=\vbox{...}` and later - `\setbox0=\vsplit\column to5cm`. The `\box0` is `\vbox` with first 5cm of + `\setbox0=\vsplit\column to5cm`. The `\box0` is a `\vbox` containing the first 5cm of saved material. * \x`\lastbox` returns the last box in the current vertical or horizontal @@ -1530,38 +1562,38 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \noindent {\bf Commands for rules (lines in the typesetting output) and patterns} \begitems -* \x`\hrule` creates a horizontal line in current vertical - list. If it is used in a horizontal mode, it finishes the paragraph by +* \x`\hrule` creates a horizontal line in the current vertical + list. If it is used in horizontal mode, it finishes the paragraph by \x`\par` first. `\hrule /width<dimen>. /height<dimen>. /depth<dimen>.` creates (in general, with given parameters) a full rectangle (something like a box, but it isn't treated as the box) with given - dimensions. Default values are: \"width"=width of outer `\vbox`, - \"height"=0.4\,pt, \"depth"=0\,pt. + dimensions. Default values are: \"width"~=width of outer `\vbox`, + \"height"~=0.4\,pt, \"depth"~=0\,pt. {\emergencystretch=2em\par} -* \x`\vrule` creates a vertical line in current horizontal - list. If it is used in a vertical mode, it opens the horizontal mode +* \x`\vrule` creates a vertical line in the current horizontal + list. If it is used in vertical mode, it opens the horizontal mode first. `\vrule /width<dimen>. /height<dimen>. /depth<dimen>.` creates (in general, with given parameters) a full rectangle with given - dimensions. Default values are: \"width"=0.4\,pt, - \"height"=height of outer `\hbox`, \"depth"=depth of outer `\hbox`. + dimensions. Default values are: \"width"~=0.4\,pt, + \"height"~=height of outer `\hbox`, \"depth"~=depth of outer `\hbox`. {\emergencystretch=2em\par} - The optional parameters of `\hrule` and `\vrule` could be specified in + The optional parameters of `\hrule` and `\vrule` can be specified in arbitrary order and they can be specified more than once. In such a case, the rule \"last wins" is applied. -* \i leaders `\leaders<rule><glue>` crates a glue +* \i leaders `\leaders<rule><glue>` creates a glue (maybe shrinkable or stretchable) filled by a full rectangle. The `<rule>` is \x`\vrule` or \x`\hrule` (maybe with its optional parameters). - If the `<glue>` is specified by \x`\hskip` command + If the `<glue>` is specified by an \x`\hskip` command (maybe with its optional parameters) or by its alternatives \x`\hss`, \x`\hfil`, \x`\hfill`, then the resulting glue is horizontal (can be used only in horizontal mode) and its dimensions are: width derived from `<glue>`, height plus depth derived from `<rule>`. - If the `<glue>` is specified by \x`\vskip` command + If the `<glue>` is specified by a \x`\vskip` command (maybe with its optional parameters) or by its alternatives \x`\vss`, \x`\vfil`, \x`\vfill`, then the resulting glue is vertical (can be used only in vertical mode) and its dimensions @@ -1569,11 +1601,11 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. * \i leaders `\leaders<box><glue>` creates a vertical or horizontal glue filled by a pattern of repeated `<box>`. The positions of boxes are - calculated from the boundaries of the outer box. It is used for dots patterns + calculated from the boundaries of the outer box. It is used for the dots patterns in the table of contents. \i cleaders `\cleaders<box><glue>` does the same, but the pattern of boxes is centered in the space derived by the <glue>. Spaces between boxes are not~inserted. - \i xleaders `\xleadres<box><glue>` does the same, but the spaces between + \i xleaders `\xleaders<box><glue>` does the same, but the spaces between boxes are inserted equally. \enditems @@ -1581,24 +1613,24 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \begitems * \x`\par` closes horizontal mode and finalizes a paragraph. -* \x`\indent`, \x`\noindent`. They leave the vertical mode and open paragraph +* \x`\indent`, \x`\noindent`. They leave vertical mode and open a paragraph with/without paragraph indentation. If horizontal mode is current then - `\indent` inserts an empty box of `\parindent` width, `\noindent` does + `\indent` inserts an empty box of `\parindent` width; `\noindent` does nothing. * \x`\hskip`, \x`\vskip`. They insert a horizontal/vertical glue. Documented in - the section~\ref[boxes]. + section~\ref[boxes]. * \x`\hfil`, \x`\hfill`, \x`\hss`, \x`\vfil`, \x`\vfill`, \x`\vss` are alternatives of \x`\hskip`, \x`\vskip`. -* \i kern `\kern<dimen>` puts nonbreakable horizontal/vertical space +* \i kern `\kern<dimen>` puts unbreakable horizontal/vertical space depending on the current mode. -* \i penalty `\penalty<number>` puts the penalty `<number>` to the current +* \i penalty `\penalty<number>` puts the penalty `<number>` on the current horizontal/vertical list. * \i char `\char<number>` prints the character with code \kern-2pt`<number>`\kern-2pt. The \"character itself" does the same. * \i accent `\accent<number><character>` places an accent with code `<number>` above the `<character>`. -* \ii -space `\`{\tt\char9251} is \ii control/space control space. In +* \ii -space `\`{\tt\char9251} is the \ii control/space control space. In horizontal mode, it inserts the space glue (like normal space but without modification by the \x`\spacefactor`). In vertical mode, it opens horizontal mode and puts the space. Note that normal space does nothing in vertical @@ -1614,57 +1646,57 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. The `\hyphenchar<font>` is used as a hyphenation character. It is set to \x`\defaulthyphenchar` value when the font is loaded, but it can be changed. * \ii -italiccorr \code{\\/} does an - \ii italics/correction italics correction. + \ii italic/correction italic correction. It puts a little space if the last character is slanted. -* \x`\unpenalty`, \x`\unskip` removes last penalty / last glue +* \x`\unpenalty`, \x`\unskip` removes the last penalty/last glue from the current horizontal/vertical list. -* \i vadjust `\vadjust{<cmds>}`. It works in horizontal mode. The `<cmds>` - must create a `<vertcal list>` and `\vadjust` saves a pointer to this list +* \i vadjust `\vadjust{<cmds>}`. This works in horizontal mode. The `<cmds>` + must create a `<vertical list>` and `\vadjust` saves a pointer to this list into the current horizontal list. When `\par` creates lines of the paragraph and distributes them to a vertical list, each line with the pointer from `\vadjust` has the corresponding `<vertical list>` immediately appended after this line. -* `\insert<number>{<cmds>}`. The `<cmds>` create a `<verical list>` and - `\insert` saves a pointer to such `<vertical list>` into the current list. +* `\insert<number>{<cmds>}`. The `<cmds>` create a `<vertical list>` and + `\insert` saves a pointer to such a `<vertical list>` into the current list. The output routine can work with such `<vertical list>`\kern-2pts. The footnotes or \ii floating~object {\em floating objects} (tables, figures) are implemented by the `\insert` primitive. -* \i halign `\halign{<declaration>\cr<row 1>\cr<row 2>\cr...\cr<row n>\cr}` +* \i halign `\halign{<declaration>\cr`\z`<row 1>\cr<row 2>\cr...\cr<row n>\cr}` creates a table of boxes in vertical mode. The `<declaration>` declares one or more column patterns separated by `&`\c4. The rows use the same character to separate the items of the table in each row. The `\halign` works in two passes. First it saves all items to boxes and the second pass - performs `\hbox to`~$\Blue w$ for each saved items, where $\Blue w$ - is the maximal width of items in each actual column. + performs `\hbox to`~$\Blue w$ for each saved item, where $\Blue w$ + is the maximum width of items in each actual column. Detailed documentation of `\halign` is out of scope of this manual. Only one example follows: the macro `\putabove` puts `#1` above `#2` - centered. The width of resulting box is equal to max of widths of these + centered. The width of the resulting box is equal to the maximum of widths of these two parameters. The `<declaration>` `\hfil##\hfil` means that the items - will be centered: + will be centered:\nl `\def\putabove#1#2{\vbox{\halign{\hfil##\hfil\cr#1\cr#2\cr}}}`. * \x`\valign` does the same as `\halign` but rows $\leftrightarrow$ columns. - It is not used commonly. + It is not commonly used. * \x`\cr`, \x`\crcr`, \x`\span`, \x`\omit`, \i noalign `\noalign{<cmds>}` are primitives used by `\halign` and `\valign`. \enditems -\noindent {\bf Commands for registers calculation} +\noindent {\bf Commands for register calculations} \begitems * \i advance `\advance<register>/by.<value>` does (formally) `<register>=<register>+<value>`. The `<register>` is counter type or dimen - type. The `<value>` is `<number>` or `<dimen>` (depending on type of the + type. The `<value>` is `<number>` or `<dimen>` (depending on the type of `<register>`). * \i multiply `\multiply<register>/by.<number>` does `<register>=<register>*<number>`. * \i divide `\divide<register>/by.<number>` does `<register>=<register>`\code{/}`<number>`. If the `<register>` is number type then the result is truncated. -* See \*`\numexpr` and \*`\dimexpr`, expandable primitives documented in the +* See \*`\numexpr` and \*`\dimexpr`, expandable primitives documented in sections~\ref[reg] and~\ref[expand]. \enditems @@ -1673,25 +1705,25 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \begitems * \i catcode `\catcode<number>` is category code of the character with `<number>` code. Used by tokenizer. -* \i lccode `\lccode<number>` is lower case alternative to the - `\char<number>`. If it is zero then lower case alternative doesn't exist - (for example for punctuation). Used by `\lowercase` primitive and when +* \i lccode `\lccode<number>` is the lowercase alternative to the + `\char<number>`. If it is zero then a lowercase alternative doesn't exist + (for example for punctuation). Used by the `\lowercase` primitive and when breaking points are calculated from hyphenation patterns. -* \i uccode `\uccode<number>` is upper case alternative to the - `\char<number>`. If it is zero, then the upper case alternative doesn't exist. - Used by `\uppercase` primitive. -* \i lowercase \i uppercase `\lowercase/<expandafters>.{|<text>};`, \ - `\uppercase/<expandafters>.{|<text>};` transform `|<text>;` to - lowercase / uppercase using current `\lccode` or `\uccode` values. - Returns transformed `|<text>;` where catcodes of tokens and +* \i uccode `\uccode<number>` is the uppercase alternative to the + `\char<number>`. If it is zero, then the uppercase alternative doesn't exist. + Used by the `\uppercase` primitive. +* \i lowercase \i uppercase `\lowercase/<expandafters>.`\z`{|<text>};`, \ + `\uppercase/<expandafters>.`\z`{|<text>};` transform \z`|<text>;` to + lowercase/uppercase using the current `\lccode` or `\uccode` values. + Returns transformed \z`|<text>;` where catcodes of tokens and tokens of type `<control sequence>` are unchanged. -* \i sfcode `\sfcode<number>` is spacefactor code of the `\char<number>`. +* \i sfcode `\sfcode<number>` is the spacefactor code of the `\char<number>`. The `\spacefactor` register keeps (roughly speking) the `\sfcode` of the last printed character. The glue between words is modified (roughly speaking) by this `\spacefactor`. The value 1000 means factor 1:1 (no modification is done). It is used for enlarging spaces after periods and other punctuation in English texts.\fnote{ - This feature is not compliant with another typographical traditions, so + This feature is not compliant with other typographical traditions, so the `\frenchspacing` macro which sets all `\sfcodes` to 1000 is used very often.} {\emergencystretch=2em\par} \enditems @@ -1699,33 +1731,33 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \noindent {\bf Commands for reading or writing text files} \begitems -* Note, that main input stream is controlled by `\input` and `\endinput` - expandable primitive commands documented in the section~\ref[expand]. +* Note that the main input stream is controlled by `\input` and `\endinput` + expandable primitive commands documented in section~\ref[expand]. -* \i openin `\openin<file num>=<file name><space>` - (or `\openin<file num>={<file name>}`) opens the +* \i openin `\openin<file number>`\,`=`\,`<file name><space>` \ + (or `\openin`\,`<file number>`\,`=`\,`{<file name>}`) \ opens the file `<file name>` for reading and creates a file descriptor - connected to the `<file num>`\fnote - {Note that `<file num>` is an addresses to the file descriptor. Macro - programmers don't use these addresses directly but by + connected to the `<file number>`.\fnote + {Note that `<file number>` is an address to the file descriptor. Macro + programmers don't use these addresses directly but by the \i newread `\newread|<control sequence>;` and - \i newwrite `\newwrite|<control sequence>;` allocation macros.}. - If the file doesn't exist nothing happens but - macro programmer can test this case by `\ifeof<file num>`. - -* \i read `\read<file num>to|<control sequence>;` does - `\def|<control sequence>{<replacement text>};` where - the `<replacement text>` is tokenized next line from the file declared by - `\openin` as `<file num>`. - -* \i openout `\openout<file num>=<file name><space>` - (or `\openout<file num>="<file name>"`) \ opens the `<file name>` for - writing and creates a file descriptor connected to `<file num>`. - If the file does exist, then its contents are removed. + \i newwrite `\newwrite|<control sequence>;` allocation macros.} + If the file doesn't exist nothing happens but a + macro programmer can test this case by `\ifeof<file number>`. + +* \i read `\read<file number>to|<control sequence>;` does + `\def|<control sequence>{<replacement text>};`\nl where + the `<replacement text>` is the tokenized next line from the file declared by + `\openin` as `<file number>`. + +* \i openout `\openout<file number>=<file name><space>` + (or `\openout<file number>="<file name>"`) \ opens the `<file name>` for + writing and creates a file descriptor connected to `<file number>`. + If the file already exists, then its contents are removed. {\emergencystretch=2em\par} -* \i write `\write<file num>|{<text>};` writes a line of `<text>` - to the file declared by `\openout` as `<file num>`. But this isn't done +* \i write `\write<file number>`\z`|{<text>};` writes a line of \z`<text>` + to the file declared by `\openout` as `<file number>`. But this isn't done immediately. \TeX/ does not know the value of the current page when the `\write` command is processed because the paragraph building and page building algorithms are processed @@ -1733,86 +1765,86 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. page to the file in order to read it again and to create a Table of contents or an Index. - `\write<file num>|{<text>};` saves `|<text>;` into memory and puts a + `\write<file number>`\z`|{<text>};` saves \z`|<text>;` into memory and puts a pointer to this memory into the typesetting output. When the page is shipped out (by output routine), then all such pointers from this page are - processed: the `<text>` is expanded at this time and its expansion - is saved to the file. If (for example) the `<text>` includes + processed: the \z`<text>` is expanded at this time and its expansion + is saved to the file. If (for example) the \z`<text>` includes `\the\pageno` then it is expanded to the correct page number of this page. -* \i closein `\closein<file num>`, \i closeout `\closeout<file num>` +* \i closein `\closein<file number>`, \i closeout `\closeout<file number>` closes the open file. It is done automatically when \TeX/ terminates its job. -* \x`\immediate` is the prefix. It can be used before `\openout`, `\write` and - `\closeout` in order to do the desired action immediately (without waiting to +* \x`\immediate` is a prefix. It can be used before `\openout`, `\write` and + `\closeout` in order to do the desired action immediately (without waiting for the output routine). \enditems \noindent {\bf Others primitive commands} - +\par\nobreak\medskip\nobreak \begitems -* \x`\relax` does nothing. Used for terminating uncomplete optional +* \x`\relax` does nothing. Used for terminating incomplete optional parameters, for example. * \x`\begingroup` opens group, \x`\endgroup` closes group. - The `{`\c1 and `}`\c2 does the same but moreover, they are syntactic + The `{`\c1 and `}`\c2 do the same but moreover, they are syntactic constructors for primitive commands and math lists (in math mode). These two types of groups (declared by mentioned commands or - by mentioned characters) cannot be mixed, i.\,e.\ + by mentioned characters) cannot be mixed, i.e.\ `\begingroup...}` gives an error. Plain \TeX/ declares - \x`\bgroup` and \x`\egroup` control sequences as an equivalent to - `{`\c1 and `}`\c2. They can be used instead `{`\c1 and~`}`\c2 when we - need to open / close a group, to create a math list or when a box is constructed. - For example `\hbox\bgroup<text>\egroup` is syntactically correct. + \x`\bgroup` and \x`\egroup` control sequences as equivalents to + `{`\c1 and `}`\c2. They can be used instead of `{`\c1 and~`}`\c2 when we + need to open/close a group, to create a math list, or when a box is constructed. + For example, \z`\hbox\bgroup<text>\egroup` is syntactically correct. * \i aftergroup `\aftergroup|<token>;` saves the `|<token>;` and puts it back in the input queue immediately after the current group is closed. - Then expand processor expands it (if it is expandable). More - `\aftergroup`s in one group creates a queue of `|<token>;`s used after + Then the expand processor expands it (if it is expandable). More + `\aftergroup`s in one group create a queue of `|<token>;`s used after the group is closed. * \i afterassignment `\afterassignment|<token>;` saves the `|<token>;` - and puts it back immediately after a following assignment (`<register>=<vaue>`, - `\def` etc.) is done. -* \x`\lastskip`, \x`\lastpenalty` returns the value of last element in the - current horizontal or vertical list if it is glue / penalty. It returns - zero value if the element is not found as the last. -* \x`\ignorespaces` ignores spaces in horizontal mode until + and puts it back immediately after a following assignment (`<register>=<value>`, + `\def`, etc.)\ is done. +* \x`\lastskip`, \x`\lastpenalty` return the value of the last element in the + current horizontal or vertical list if it is a glue/penalty. It returns + zero if the element found is not the last. +* \x`\ignorespaces` ignores spaces in horizontal mode until the next primitive command occurs. -* \i mark `\mark{<text>}` saves `<text>` to memory and puts a pointer to it in the - typesetting output. The `<text>` is used as expansion output of - \x`\firstmark`, \x`\topmark` and \x`\botmark` expansion primitives in output - the routine. +* \i mark \z`\mark{<text>}` saves \z`<text>` to memory and puts a pointer to it in the + typesetting output. The \z`<text>` is used as expansion output of + \x`\firstmark`, \x`\topmark` and \x`\botmark` expansion primitives in + the output routine. * \i parshape `\parshape<number>`% {\def<#1>{\,$\langle\it#1\rangle$\,}% `<I1><W1><I2><W2>...<In><Wn>` enables to set arbitrary shape of the paragraph. The `<number>` declares the amount of data: the `<number>` pairs of `<dimen>`s follow. - The $i$-th line of the paragraph is shifted by `<Ii>` to right and + The $i$-th line of the paragraph is shifted by `<Ii>` to the right and its width is `<Wi>`.} The `\parshape` data are re-set after each paragraph to zero values (normal paragraph). -* \i special `\special{<text>}` puts the message `<text>` to the typesetting output. It - behaves as a zero-dimension pointer to `<text>` and it can be read by +* \i special \z`\special{<text>}` puts the message \z`<text>` into the typesetting output. It + behaves as a zero-dimension pointer to \z`<text>` and it can be read by printer drivers. It is recommended to not use this old technology when PDF output is created directly. * \i shipout `\shipout<box>` outputs the `<box>` as one page. Used in the \ii output/routine output routine. * \x`\end` completes the last page and terminates the job. -* \x`\dump` dumps the memory image to the `\jobname.fmt` and terminates the job. -* \i patterns `\patterns{<data>}` reads hyphenation patterns for current +* \x`\dump` dumps the memory image to a file named `\jobname.fmt` and terminates the job. +* \i patterns `\patterns{<data>}` reads hyphenation patterns for the current \x`\language`. * \i hyphenation `\hyphenation{<data>}` reads hyphenation exceptions for current \x`\language`. -* \i message `\message{<text>}` prints `<text>` on the terminal and to the +* \i message \z`\message{<text>}` prints \z`<text>` on the terminal and to the log file. -* \i errmessage `\errmessage{<text>}` behaves like `\message{<text>}` but +* \i errmessage \z`\errmessage{<text>}` behaves like \z`\message{<text>}` but \TeX/ treats it as an error. -* Job processing modes can be set by \x`\scrollmode` (don't pause at the - errors), \x`\nonstopmode` (don't pause at the errors and missing files), - \x`\batchmode` (\x`\nonstopmode` plus no output on the terminal). Default is +* Job processing modes can be set by \x`\scrollmode` (don't pause at + errors), \x`\nonstopmode` (don't pause at errors or missing files), + \x`\batchmode` (\x`\nonstopmode` plus no output to the terminal). Default is \x`\errorstopmode` (stop at errors). -* \x`\inputlineno` includes the number of current line from current inputted - file. +* \x`\inputlineno` includes the number of the current line from current file + being input. * \i show `\show|<control sequence>;`, \ \i showbox `\showbox<box number>`, - \ \x`\showlists` \ and \ + \ \x`\showlists`, \ and \ \i showthe `\showthe|<register>;` \ are tracing commands. \TeX/ prints desired result on the terminal and to the log file and pauses. \enditems @@ -1821,62 +1853,62 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. (available in pdf\TeX, \XeTeX/ and lua\TeX) \begitems -* \i pdfliteral `\pdfliteral{<text>}` puts the `<text>` interpreted +* \i pdfliteral \z`\pdfliteral{<text>}` puts the \z`<text>` interpreted in a low level PDF language to the typesetting output. All PDF constructs defined in the PDF specification are allowed. The dimensions of the `\pdfliteral` object in the output are considered zero. So, if - `<text>` moves the current typesetting point then the notion about its - position from \TeX/ point of view differs from the real position. - A good practice is to close `<text>` to `q...Q` PDF commands. + \z`<text>` moves the current typesetting point then the notion about its + position from the \TeX/ point of view differs from the real position. + A good practice is to close \z`<text>` to `q...Q` PDF commands. The command `\pdfliteral` is typically used for generating graphics and for linear transformation. -* \i pdfcolorstack `\pdfcolorstack<number><op>{<text>}` (where `<op>` is `push` - or `pop` or `set`) behaves like `\pdfliteral{<text>}` and it is used for - color switchers. For example when `<text>` is `1 0 0 rg` then red color is - selected. \TeX/ sets the colors stack at the top of each page to the - colors stack opened at the bottom of the previous page. +* \i pdfcolorstack `\pdfcolorstack<number><op>`\z`{<text>}` (where `<op>` is `push` + or `pop` or `set`) behaves like \z`\pdfliteral{<text>}` and it is used for + color switchers. For example when \z`<text>` is `1 0 0 rg` then the red color is + selected. \TeX/ sets the color stack at the top of each page to the + color stack opened at the bottom of the previous page. * \i pdfximage `\pdfximage` `/height<dimen>.` `/depth<dimen>.` `/width<dimen>.` `/page<number>.{<file name>}` loads the image from `<file name>` to the PDF output and returns the - number of such data object in the \x`\pdflastximage` register. Allowed - formats are PDF, JPG, PNG. The image is not drawn at this moment. Macro + number of such a data object in the \x`\pdflastximage` register. Allowed + formats are PDF, JPG, PNG. The image is not drawn at this moment. A macro programmer can save `\mypic=\pdflastximage` and draw the image by \i pdfrefximage `\pdfrefximage\mypic` (maybe repeatedly). Data of - the image are loaded to PDF output only once. - The `\pdfximage` allows more parameters, + the image are loaded to the PDF output only once. + The `\pdfximage` allows more parameters; see pdf\TeX/ documentation. -* \i pdfsetmatrix {\def<#1>{$\,\langle{\it#1}\rangle\,$}`\pdfsetmatrix {<a><b><c><b>}` +* \i pdfsetmatrix {\def<#1>{$\,\langle{\it#1}\rangle\,$}`\pdfsetmatrix {<a><b><c><d>}` multiplies the current transformation matrix (used for linear transformations) by `\matrix{<a>&<c>\cr <b>&<d>}`.} * \i pdfdest `\pdfdest name{<label>}<type>\relax` declares a destination of a hyperlink. The `<label>` must match with the `<label>` used in - `\pdfoutline` or `\pdfstartlink`. The `<type>` declares the behavior of - pdf viewer when the hyperlink is used. For example `xyz` means without changes + `\pdfoutline` or `\pdfstartlink`. The `<type>` declares the behavior of the + pdf viewer when the hyperlink is used. For example, `xyz` means without changes of the current zoom (if not specified). Other types should be `fit`, `fith`, `fitv`, `fitb`. -* \i pdfstartlink - `\pdfstartlink /height<dimen>. /depth<dimen>. /<attributes>. /goto name{<label>}.` - declares a begining of a hyperlink. A text (will be sensitive on mouse clik) +* \i pdfstartlink + `\pdfstartlink` `/height<dimen>.` `/depth<dimen>.` `/<attributes>.` `/goto name{<label>}.` + declares the beginning of a hyperlink. A text (will be sensitive on mouse click) immediately follows and it is terminated by \x`\pdfendlink`. The height - and depth of sensitive area and the `<label>` used in `\pdfdest` are declared - here. More parameters are allowed, see the pdf\TeX/ documentation. -* \i pdfoutline `\pdfoutline /goto name{<label>}. /count<number>. {<text>}` - creates one item with `<text>` in PDF outlines. `<label>` must be used + and depth of the sensitive area and the `<label>` used in `\pdfdest` are declared + here. More parameters are allowed; see the pdf\TeX/ documentation. +* \i pdfoutline \z`\pdfoutline /goto name{<label>}. /count<number>. {<text>}` + creates one item with \z`<text>` in PDF outlines. `<label>` must be used somewhere by `\pdfdest name{<label>}`. The `<number>` is the number of direct descentants in the outlines tree. -* \i pdfinfo `\pdfinfo {<key>(<text>)}` saves to PDF the information which +* \i pdfinfo `\pdfinfo {<key>`\z`(<text>)}` saves to PDF the information which can be listed by the command `pdfinfo <file>.pdf` on the command line for - example. More `<key>(<text>)` should be here. The `<key>` can be + example. More `<key>`\z`(<text>)` should be here. The `<key>` can be \code{/Author}, \code{/Title}, \code{/Subject}, - \code{/Kyewords}, \code{/Creator}, \code{/Producer}, + \code{/Keywords}, \code{/Creator}, \code{/Producer}, \code{/CreationDate}, \code{/ModDate}. The last two keywords need - a special format of the `<text>` value. All `<text>` values (including - `<text>` used in the `\pdfoutline`) must be ASCII encoded or they can use + a special format of the \z`<text>` value. All \z`<text>` values (including + \z`<text>` used in the `\pdfoutline`) must be ASCII encoded or they can use a very special PDFunicode encoding. -* \x`\pdfcatalog` enables to set a default behavior of PDF viewer when it starts. +* \x`\pdfcatalog` enables us to set of a default behavior of the PDF viewer when it starts. * \x`\pdfsavepos` saves an internal invisible point to the typesetting output. These points are processed when the page is shipped out: the numeric registers - \x`\pdflastxps` and \x`\pdflastypos` get values about absolute position of + \x`\pdflastxpos` and \x`\pdflastypos` get values for the absolute position of this invisible point (measured from the left upper corner of the page in `sp` units). The macro programmer can follow `\pdfsavepos` by the `\write` command and save these absolute positions to a text file which can be read in the next run @@ -1891,34 +1923,34 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. `\pdffontexpand <font selector> <stretching> <shrinking> <step>` declares a possibility to deform the characters from the font given by `<font selector>`. This deformation is used when stretching or shrinking - paragraph lines or doing `\hbox to{...}` in general. I.\,e.\ not only glues are + paragraph lines or doing `\hbox to{...}` in general. I.e.\ not only glues are stretchable and shrinkable. The numeric parameters are given in 1/1000 - of the font size. `<stretching>` and `<shrinking>` are maximal allowed - values. The stretching nor shrinking are not applied continuously but by - given `<step>`. - To activate this feature you must to set the \x`\pdfadjustspacing` + of the font size. `<stretching>` and `<shrinking>` are the maximum allowed + values. The stretching or shrinking are not applied continuously but by + the given `<step>`. + To activate this feature you must set the \x`\pdfadjustspacing` numeric register to a positive value. * \i rpcode \i lpcode `\rpcode <font selector><char. code>=<number>`, - `\lpcode <font selector><char. code>=<number>` allows to declare + `\lpcode <font selector><char. code>=<number>` allows the declaration of hanging punctuation. Such punctuation is slightly moved to the right margin (if `\rpcode` is declared and the character is at the right margin) - or to left margin (for `\lpcode` analogically). - The `<number>` gives the amount of such moving in 1/1000 of the font size. - To activate this feature you must to set \x`\pdfprotrudechars` to - a positive value (2 or more means better algorithm). + or to the left margin (for `\lpcode` by analogy). + The `<number>` gives the amount of such movement in 1/1000 of the font size. + To activate this feature you must set \x`\pdfprotrudechars` to + a positive value (2 or more means a better algorithm). * \i letterspacefont `\letterspacefont |<control sequence>; <font selector> <number>` declares a new font selector `|<control sequence>;` as a font given by the `<font selector>`. Additional space declared by `<number>` is added - between each two characters when the font is used. Tne `<number>` is 1/1000 of - font size. Unicoded fonts support analogical + between each two characters when the font is used. The `<number>` is 1/1000 of + the font size. Unicode fonts support an analogous `letterspace=<number>` font feature. -* The same syntax like `\rpcode` have the following commands: - \x`\knbscode` (added space after the character) - \x`\stbscode` (added stretchability of the glue after the character) - \x`\shbscode` (added shrinkability after the character) - \x`\knbccode` (added kenr before the character) +* The following commands have the same syntax as `\rpcode`: + \x`\knbscode` (added space after the character), + \x`\stbscode` (added stretchability of the glue after the character), + \x`\shbscode` (added shrinkability after the character), + \x`\knbccode` (added kern before the character), \x`\knaccode` (added kern after the character). To activate this feature you must to set \x`\pdfadjustinterwordglue` to a positive value. @@ -1928,28 +1960,28 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \noindent {\bf Commands used in math mode} \begitems -* \x`\displaystyle`, \x`\textstyle`, \x`\scriptstyle`, \x`\scriptscriptstye` - switches to specified style. +* \x`\displaystyle`, \x`\textstyle`, \x`\scriptstyle`, \x`\scriptscriptstyle` + switch to the specified style. * \x`\mathord`, \x`\mathop`, \x`\mathbin`, \x`\mathrel`, \x`\mathopen`, \x`\mathclose`, - \x`\mathpunct` followed by `{<math list>}` create an math object of given type. -* \i over `{<nominator>\over<denominator>}` creates a fraction. + \x`\mathpunct` followed by `{<math list>}` create a math object of the given type. +* \i over `{<numerator>\over<denominator>}` creates a fraction. The primitive commands \x`\atop` (without fraction rule), \i above `\above<dimen>` (fraction rule with given thickness) should be used in the same manner. The commands \x`\atopwithdelims`, \x`\overwithdelims`, - \x`\abovewithdelims` allow to specify brackets around the generalized + \x`\abovewithdelims` allow us to specify brackets around the generalized fraction. * \i left \i right `\left<delimiter><formula>\right<delimiter>` creates a math `<formula>` and gives `<delimiter>`s around it with an appropriate size - (comparable with the size of the formula). The `<delimiter>`s are brackets - typically. -* The exponents and scripts are typically at the right side of the previous + (compatible with the size of the formula). The `<delimiter>`s are typically + brackets. +* Exponents and scripts are typically at the right side of the preceding math object. But if this object is a \"big operator" (summation, integral) then exponents and scripts are printed above and below this operator. The commands \x`\limits`, \x`\nolimits`, \x`\displaylimits` used before exponents and scripts constructors - (`^`\c7 and `_`\c8) declares an exception from this rule. + (`^`\c7 and `_`\c8) declare an exception from this rule. * \i eqno `$$<formula>\eqno<mark>$$` puts the `<mark>` to the right - margin as `\llap{$<mark>$}`. Analogically + margin as `\llap{$<mark>$}`. Analogously, \i leqno `$$<formula>\leqno<mark>$$` puts it to the left margin. \enditems @@ -1959,11 +1991,11 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \begitems * \x`\newcount`, \x`\newdimen`, \x`\newskip`, \x`\newmuskip`, \x`\newtoks` - folowed by a `|<control sequence>;` allocate a new register of given type + followed by a `|<control sequence>;` allocate a new register of the given type and set it as the `|<control sequence>;`. \x`\newbox`, \x`\newread`, \x`\newwrite` - folowed by a `|<control sequence>;` allocate a new address to given data - (to a box register or to a file descriptor) and set is as the + followed by a `|<control sequence>;` allocate a new address to given data + (to a box register or to a file descriptor) and set it as the `|<control sequence>;`. All these allocation macros are declared as `\outer` in plain \TeX/, unfortunately. This brings problems when you need to use them in @@ -1973,94 +2005,94 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. as a boolean variable. It must begin with `if`; for example `\newif\ifsomething`. Then you can set values by `\somethingtrue` or `\somethingfalse` and you can use this variable by - `\ifsoemthing` which behaves like others `\if`\code{*} primitive commands. + `\ifsoemthing` which behaves like other `\if`\code{*} primitive commands. \enditems \noindent{\bf Vertical skips} \begitems * \x`\bigskip` does \x`\vskip` by one line, \x`\medskip` does `\vskip` by - one half of line and \x`\smallskip` does the vertical skip by one quarter of line. + one half of a line and \x`\smallskip` does the vertical skip by one quarter of a line. The registers \x`\bigskipamount`, \x`\medskipamount` and \x`\smallskipamount` are allocated for this purpose. * \x`\nointerlineskip` ignores the \x`\baselineskip` rule - %(see the section~\ref[reg]) + %(see section~\ref[reg]) for the following box in the current vertical list. This box is appended immediately after the previous box. - \x`\offitnerlineskip` ignores the \x`\baselineskip` rule for all following + \x`\offinterlineskip` ignores the \x`\baselineskip` rule for all following boxes until the current group is closed. * All vertical glues at the top of the page inserted by \x`\vskip` are - ignored. Macro \x`\vglue` behaves like `\vskip` primitive command but its glue + ignored. Macro \x`\vglue` behaves like the `\vskip` primitive command but its glue is not ignored at the top of the page. -* Sometimes we must switch off the \x`\baselineskip` rule (by \x`\offinterlineskip` - macro for example). This is common in the tables. But we need to keep the - baseline distances equal. Then the \x`\strut` can be inserted to each +* Sometimes we must switch off the \x`\baselineskip` rule (by the \x`\offinterlineskip` + macro for example). This is common in tables. But we need to keep the + baseline distances equal. Then the \x`\strut` can be inserted on each line. It is an invisible box with zero width and with height+depth=`\baselineskip`. * \x`\normalbaselines` sets the registers for vertical placement \x`\baselineskip`, \x`\lineskip` and \x`\lineskiplimit` to default values given - by the format. User can set other values for a while and then he/she can use + by the format. The user can set other values for a while and then he/she can restore `\normalbaselines`. \enditems \noindent{\bf Penalties} - +\par\nobreak\medskip\nobreak \begitems -* \x`\break` puts penalty -10000, so line/page break is forced here. - \x`\nobreak` puts penalty 10000, so line/page break is disabled here. - It should be preceded before a glue, which is \"protected" by this penalty. - \x`\allowbreak` puts penalty 0, it allows breaking similar as in normal space. -* \x`\goodbreak` puts penalty -500 in vertical mode, this is \"recommended" +* \x`\break` puts penalty $-10000$, so a line/page break is forced here. + \x`\nobreak` puts penalty 10000, so a line/page break is disabled here. + It should be specified before a glue, which is \"protected" by this penalty. + \x`\allowbreak` puts penalty 0; it allows breaking similar to a normal space. +* \x`\goodbreak` puts penalty $-500$ in vertical mode, this is a \"recommended" point for a page break. * \x`\filbreak` breaks the page only if it is \"almost full" or if a big object - (that doesn't fit the current page) follows. The bottom of such page is - filled by a vertical glue, i.\,e. the default typographical rule about equal + (that doesn't fit the current page) follows. The bottom of such a page is + filled by a vertical glue, i.e.\ the default typographical rule about equal positions of all bottoms of common pages is broken here. -* \x`\eject` puts penalty -10000 in vertical list, i.\,e.\ it breaks the page. +* \x`\eject` puts penalty $-10000$ in the vertical list, i.e.\ it breaks the page. \enditems \noindent{\bf Miscellaneous macros}\par\nobreak\medskip\nobreak \begitems -* \i magstep `\magstep<number>` expands to a magnification factor $1.2^x$ where $x$ is +* \i magstep `\magstep<number>` expands to a magnification factor $1.2^x$ where $x$ is the given `<number>`. This follows old typographical traditions that all sizes (of fonts) are distinguished by factors 1, 1.2, 1.44, etc. - For example `\magstep2` expands to 1440, because $1.2^2=1.44$ + For example, `\magstep2` expands to 1440, because $1.2^2=1.44$ and 1000 is factor 1:1 in \TeX/. The \x`\magstephalf` macro expands to 1095 which corresponds to $1.2^{(1/2)}$. * \x`\nonfrenchspacing` sets special space factor codes (bigger spaces after - periods, commas, semicolons etc.). This follows English typographical + periods, commas, semicolons, etc.). This follows English typographical traditions. \x`\frenchspacing` sets all space factors as 1:1 (usable for non English texts). -* \x`\endgraf` is equavalent to \x`\par`, \x`\bgroup` and \x`\egroup` are +* \x`\endgraf` is equivalent to \x`\par`; \x`\bgroup` and \x`\egroup` are equivalents to `{`\c1 and `}`\c2. -* \x`\space` expands to space, \x`\empty` is empty macro and \x`\null` is empty +* \x`\space` expands to space, \x`\empty` is an empty macro and \x`\null` is an empty \i hbox `\hbox{}`. * \x`\quad` is horizontal space 1\,em (size of the font), \x`\qquad` is double `\quad`, - \x`\enspace` is kern 0.5\,em \x`\thinspace` is kern 1/6\,em and + \x`\enspace` is kern 0.5\,em, \x`\thinspace` is kern 1/6\,em, and \x`\negthinspace` makes kern $-$1/6\,em. -* \i loop \i repeat `\loop <body 1><if condition><body 2>\repeat` - repeats `<body 1>` and `<body 2>` in a loop until `<if condition>` returns - false. Then `<body 2>` is not processed and the loop is finished. +* \i loop \i repeat `\loop` \z`<body 1><if condition><body 2>\repeat` + repeats \z`<body 1>` and \z`<body 2>` in a loop until the `<if condition>` returns + false. Then \z`<body 2>` is not processed and the loop is finished. * \x`\leavevmode` opens a paragraph like `\indent` but it does nothing if - the horizontal mode is opened already. + the horizontal mode is already in effect. -* \i line `\line{<text>}` creates a box of line width (which is \x`\hsize`). +* \i line \z`\line{<text>}` creates a box of line width (which is \x`\hsize`). \x`\leftline`, \x`\rightline`, \x`\centerline` do the same as - `\line` but `<text>` is shifted left / right / is centered. + `\line` but \z`<text>` is shifted left / right / is centered. -* \i rlap `\rlap{<text>}` makes a box of zero size, the `<text>` is stuck - outright. \i llap `\llap{<text>}` does the same and the `<text>` is pushed +* \i rlap \z`\rlap{<text>}` makes a box of zero size, the \z`<text>` is stuck + out to the right. \i llap \z`\llap{<text>}` does the same and the \z`<text>` is pushed left. -* \x`\ialign` is equal to `\halign` but the values of registers used by +* \x`\ialign` is equal to `\halign` but the values of the registers used by `\halign` are set to default. -* \x`\hang` starts the paragraph where all lines (exception first) are +* \x`\hang` starts the paragraph where all lines (except for the first) are indented by `\parindent`. * \i textindent `\texindent{<mark>}` starts a paragraph with `\llap{<mark>}`. @@ -2070,7 +2102,7 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \i itemitem `\itemitem{<mark>}` can be used for the second level of items. * \x`\narrower` sets wider margins for paragraphs (`\parindent` is appended - to both sides), i.\,e.\ the paragraphs are narrower. + to both sides); i.e.\ the paragraphs are narrower. * \x`\raggedright` sets the paragraph shape with the ragged right margin. \x`\raggedbottom` sets the page-setting shape with the ragged bottoms. @@ -2079,26 +2111,26 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \noindent{\bf Floating objects} \begitems -* \i footnote `\footnote{<mark>}{<text>}` creates a footnote with given - `<mark>` and `<text>`. +* \i footnote `\footnote{<mark>}`\z`{<text>}` creates a footnote with given + `<mark>` and \z`<text>`. * \i midinsert \i topinsert \i endinsert - `\topinsert<object>\endinsert` create the <object> as a - \ii floating~object {\em floating object}. It is printed on the top + `\topinsert<object>\endinsert` creates the `<object>` as a + \ii floating~object {\em floating object}. It is printed at the top of the current page or on the next page. `\midinsert<object>\endinsert` does the same as `\topinsert` but it tries if the `<object>` fits on the current page. If it is true then it is printed to - its current position, no floating object is created. + its current position; no floating object is created. \enditems \noindent{\bf Controlling of input, output} \begitems -* \x`\obeyspaces` sets the space as normal, i.\,e. it deactivates special - treatment of spaces by tokenizer: more spaces will be more spaces and - spaces from the left line are not ignored. -* \x`\obeylines` sets end of lines as `\par`. Each line in the input is +* \x`\obeyspaces` sets the space as normal, i.e.\ it deactivates special + treatment of spaces by the tokenizer: more spaces will be more spaces and + spaces at the beginning of the line are not ignored. +* \x`\obeylines` sets the end of each line as `\par`. Each line in the input is one paragraph in the output. * \x`\bye` finalizes the last page (or last pages if more floating objects @@ -2116,26 +2148,29 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. * \i choose `{<above>\choose<below>}` creates a combination number with brackets around it. -* \i sqrt `\sqrt{<math list>}` creates the square root symbol. - \i root `\root<n>\of{<math list>}` creates a general root symbol. +* \i sqrt `\sqrt{<math list>}` creates the square root symbol + with the `<math list>` under it. + +* \i root \z`\root<n>\of{<math list>}` creates a general root symbol + with the order of the root `<n>`. * \i cases {\def<#1>{\,$\langle#1\rangle$\,}% - `\cases{<case 1>&<condition 1>\cr...\cr<case n>&<condition n>}` - creates a list of variants (preceded by the brace $\{$) in the math mode. + \z`\cases{<case 1>&<condition 1>\cr...\cr<case n>&<condition n>}` + creates a list of variants (preceded by a brace $\{$) in math mode. -* \i matrix `\matrix{<a>&<b>...&<e>\cr...\cr<u>&<v>...&<z>}` +* \i matrix \z`\matrix{<a>&<b>...&<e>\cr...\cr<u>&<v>...&<z>}` creates a matrix of given values in math mode (without brackets around it). `\pmatrix{<data>}` does the same but with (). * \i displaylines `$$\displaylines{<formula 1>\cr...\cr<formula n>}$$` - prints more (centered) formulae in the display mode. + prints multiple (centered) formulae in display mode. * \i eqalign `$$\eqalign{<form.1 left>&<form.1 right>\cr...\cr<form.n left>&<form.n right>}$$`\hfil\break - prints more formulae aligned by `&` character in the display mode. + prints multiple formulae aligned by `&` character in display mode. -* \x`\eqalignno` behaves like `\eqalign` but second `&` followed by a `<mark>` - can be in some lines. These lines have `<mark>` in the right margin. +* \x`\eqalignno` behaves like `\eqalign` but a second `&` followed by a `<mark>` + can be in some lines. These lines place the `<mark>` in the right margin. \x`\leqalignno` does the same as `\eqalignno` but `<mark>` is put to the left margin. } @@ -2143,6 +2178,8 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \raggedbottom +\vfil\break + \nonum\sec Index \iis LaTeX/macros {\LaTeX/ macros} @@ -2159,7 +2196,7 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \iis -space {{\code{\\}{\tt\char9251}}} \iis -italiccorr {{\code{\\/}}} \iis -hyphen {{\code{\\-}}} -\iis TeXlive {\TeX live} +\iis TeXlive {\TeX/live} \iis baselineskiprule {\code{\\baselineskip} rule} \iis -comma {{\code{\\,}}} \iis -greater {{\code{\\>}}} @@ -2173,9 +2210,9 @@ If it is~a~lua\TeX/ only command then three *** are prefixed. \vfill \noindent -Petr Olšák {petr@olsak.net}\nl +Petr Olšák {\tt petr@olsak.net}\nl Czech Technical University in Prague\nl -Version of the text: 0.2 (\the\year/\the\month/\the\day) +Version of the text: 0.5 (\the\year-\thed\month-\thed\day) \break |