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+%D \module
+%D [ file=math-ali,
+%D version=2008.10.20,
+%D title=\CONTEXT\ Math Macros,
+%D subtitle=Math Alignments,
+%D author={Hans Hagen, Taco Hoekwater \& Aditya Mahajan},
+%D date=\currentdate,
+%D copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
+%C details.
+
+\writestatus{loading}{ConTeXt Math Macros / Math Alignments}
+
+\unprotect
+
+%D The code here has been moved from other files. Beware: the \MKII\ and
+%D \MKIV\ code is not gathered in files with the same name. In the
+%D meantime this code has been adapted to \MKIV\ but mnore is possible.
+
+%D \macros
+%D {definemathalignment, setupmathalignment, startmathalignment}
+%D
+%D Modules may provide additional alignment features. The following
+%D mechanisms are provided by the core.
+
+% n>1 ### needed, strange # interaction in recurse
+
+\newtoks\c_math_align_a
+\newtoks\c_math_align_b
+\newtoks\c_math_align_c
+
+\def\displayopenupvalue{.25\bodyfontsize}
+
+\def\math_build_eqalign
+ {\scratchtoks\emptytoks
+ \dorecurse{\mathalignmentparameter\c!m}\math_build_eqalign_step
+ \normalexpanded{\scratchtoks{\the\scratchtoks\the\c_math_align_c}}}
+
+\def\math_build_eqalign_step
+ {\ifnum\recurselevel>\plusone
+ \scratchtoks\expandafter{\the\scratchtoks\tabskip\mathalignmentparameter\c!distance\aligntab\tabskip\zeropoint}%
+ \fi
+ \normalexpanded{\scratchtoks{\the\scratchtoks\the\c_math_align_a}}%
+ \dorecurse{\numexpr\mathalignmentparameter\c!n-\plusone\relax}
+ {\normalexpanded{\scratchtoks{\the\scratchtoks\the\c_math_align_b}}}}
+
+\def\math_math_in_eqalign#1%
+ {\startforceddisplaymath
+ \tabskip\zeropoint
+ \everycr\emptytoks
+ {{}#1{}}%
+ \stopforceddisplaymath}
+
+\def\math_text_in_eqalign#1%
+ {\startimath
+ \tabskip\zeropoint
+ \everycr\emptytoks
+ #1%
+ \stopimath}
+
+\def\eqalign#1% why no halign here, probably because of displaywidth
+ {\emptyhbox
+ \mskip\thinmuskip
+ \vcenter
+ {\math_openup\displayopenupvalue % was: \openup\jot
+ \mathsurround\zeropoint
+ \ialign{%
+ \strut
+ \hfil
+ \startforceddisplaymath{\alignmark\alignmark}\stopforceddisplaymath
+ \aligntab
+ \startforceddisplaymath{{}\alignmark\alignmark{}}\stopforceddisplaymath
+ \hfil\crcr
+ #1\crcr}%
+ }%
+ \mskip\thinmuskip}
+
+% preamble is scanned for tabskips so we need the span to prevent an error message
+
+\setnewconstant\eqalignmode\plusone
+
+% use zeroskipplusfill
+
+% i really need to redo this eqno mess ... in lua
+
+\def\math_prepare_r_eqalign_no
+ {\c_math_align_a{\strut\math_first_in_eqalign\hfil\math_left_of_equalign\span\math_math_in_eqalign{\alignmark\alignmark}\math_right_of_eqalign\tabskip\zeropoint}%
+ \c_math_align_b{\aligntab\math_next_in_eqalign\math_left_of_equalign\span\math_math_in_eqalign{\alignmark\alignmark}\math_right_of_eqalign\tabskip\zeropoint}%
+ \ifnum\mathraggedstatus=\plusone
+ \c_math_align_c{\hfil\aligntab\span\math_text_in_eqalign{\alignmark\alignmark}\tabskip\zeropoint}%
+ \else\ifnum\mathraggedstatus=\plusthree
+ \c_math_align_c{\hfil\tabskip\zeropoint\s!plus 1\s!fill\aligntab\span\math_text_in_eqalign{\alignmark\alignmark}\tabskip\zeropoint}%
+ \else
+ \c_math_align_c{\hfil\tabskip\centering\aligntab\llap{\span\math_text_in_eqalign{\alignmark\alignmark}}\tabskip\zeropoint}%
+ \fi\fi
+ \global\mathnumberstatus\zerocount
+ \math_build_eqalign
+ \the\mathdisplayaligntweaks
+ \tabskip\centering}
+
+\def\math_prepare_l_eqalign_no % \checkeddisplaymath
+ {\c_math_align_a{\strut\math_first_in_eqalign\hfil\math_left_of_equalign\span\math_math_in_eqalign{\alignmark\alignmark}\math_right_of_eqalign\tabskip\zeropoint}%
+ \c_math_align_b{\aligntab\math_next_in_eqalign\math_left_of_equalign\span\math_math_in_eqalign{\alignmark\alignmark}\math_right_of_eqalign\tabskip\zeropoint}%
+ % problem: number is handled after rest and so ends up in the margin
+ \ifnum\mathraggedstatus=\plusone
+ \c_math_align_c{\hfil\aligntab\kern-\displaywidth\rlap{\span\math_text_in_eqalign{\alignmark\alignmark}}\tabskip\displaywidth}%
+ \else\ifnum\mathraggedstatus=\plusthree
+ \c_math_align_c{\hfil\tabskip\zeropoint\s!plus 1\s!fill\aligntab\kern-\displaywidth\span\math_rlap{\span\math_text_in_eqalign{\alignmark\alignmark}}\tabskip\displaywidth}%
+ \else
+ \c_math_align_c{\hfil\tabskip\centering\aligntab\kern-\displaywidth\rlap{\span\math_text_in_eqalign{\alignmark\alignmark}}\tabskip\displaywidth}%
+ \fi\fi
+ \global\mathnumberstatus\zerocount
+ \math_build_eqalign
+ \the\mathdisplayaligntweaks
+ \tabskip\centering}
+
+\def\math_both_eqalign_no_normal#1#2%
+ {\ifmmode
+ \the\mathdisplayaligntweaks % \let\strc_formulas_place_number\relax % strange hack
+ \vcenter\bgroup
+ \let\math_finish_eqalign_no\egroup
+ \else
+ \let\math_finish_eqalign_no\relax
+ \fi
+ #1%
+ \halign \ifcase\eqalignmode \or to \checkeddisplaywidth \fi \expandafter {\the\scratchtoks\crcr#2\crcr}%
+ \math_finish_eqalign_no}
+
+\def\math_both_eqalign_no_aligned#1%
+ {\ifmmode
+ \the\mathdisplayaligntweaks
+ \global\mathnumberstatus\plusone
+ \ifcase\mathraggedstatus
+ \def\math_finish_eqalign_no{\crcr\egroup}%
+ \else
+ % we're in a mathbox
+ \vcenter\bgroup
+ \def\math_finish_eqalign_no{\crcr\egroup\egroup}%
+ \fi
+ \fi
+ #1%
+ \halign \ifcase\eqalignmode \or to \checkeddisplaywidth \fi \expandafter \bgroup\the\scratchtoks\crcr}
+
+\def\math_rlap#1%
+ {\setbox\scratchbox\hbox{#1}%
+ \ifdim\wd\scratchbox>\mathnumbercorrection
+ \xdef\mathnumbercorrection{\the\wd\scratchbox}%
+ \fi
+ \box\scratchbox
+ \global\mathnumberstatus\plustwo}
+
+\def\math_handle_eqalign_no_r_normal {\math_both_eqalign_no_normal \math_prepare_r_eqalign_no}
+\def\math_handle_eqalign_no_l_normal {\math_both_eqalign_no_normal \math_prepare_l_eqalign_no}
+\def\math_handle_eqalign_no_r_aligned{\math_both_eqalign_no_aligned\math_prepare_r_eqalign_no}
+\def\math_handle_eqalign_no_l_aligned{\math_both_eqalign_no_aligned\math_prepare_l_eqalign_no}
+\def\math_finish_eqalign_no {\crcr\egroup}
+
+\let \reqalignno \math_handle_eqalign_no_r_normal
+\let \leqalignno \math_handle_eqalign_no_l_normal
+\let\alignreqalignno \math_handle_eqalign_no_r_aligned
+\let\alignleqalignno \math_handle_eqalign_no_l_aligned
+\let \eqalignno \math_handle_eqalign_no_r_normal
+\let \aligneqalignno \math_handle_eqalign_no_r_aligned
+
+%D Here we implement the user interface part. We start with basic math alignments:
+
+\newcount\c_math_eqalign_column
+
+\newtoks \everymathalignment
+
+\def\math_alignment_NR_indeed[#1][#2]%
+ {\strc_formulas_place_number_nested{#1}{#2}% to be tagged (better an attribute)
+ \crcr
+ \dostoptagged % finish row
+ \noalign{\glet\math_alignment_NC\math_alignment_NC_first}} % noalign used for change state, conditional does not work here
+
+\def\math_alignment_NC_first
+ {\glet\math_alignment_NC\math_alignment_NC_rest}
+
+\def\math_alignment_NC_rest
+ {\aligntab}
+
+\def\math_alignment_EQ
+ {\NC=}
+
+\def\math_alignment_NR
+ {\aligntab
+ \dostoptagged % finish cell
+ \dodoubleempty\math_alignment_NR_indeed} % use xx from tabulate
+
+\appendtoks
+ \glet\math_alignment_NC\math_alignment_NC_first
+ \unexpanded\def\NC{\math_alignment_NC}% messy, due to lookahead (we cannot use a flag)
+ \let\EQ\math_alignment_EQ
+ \let\NR\math_alignment_NR
+\to \everymathalignment
+
+\let\math_alignment_snap_start\relax
+\let\math_alignment_snap_stop \relax
+
+% experimental
+
+\def\math_alignment_snap_start
+ {\ifgridsnapping
+ \snaptogrid[\v!both]\vbox\bgroup
+ \fi}
+
+\def\math_alignment_snap_stop
+ {\ifgridsnapping
+ \egroup
+ \fi}
+
+% end of experimental
+
+\unexpanded\def\math_alignment_start#1%
+ {\edef\currentmathalignment{#1}%
+ \dosingleempty\math_alignment_start_indeed}
+
+\def\math_alignment_start_indeed[#1]%
+ {% \begingroup not permitted ($$...assignments...\halign... )
+ \math_alignment_snap_start
+ \iffirstargument
+ \setupmathalignment[\currentmathalignment][#1]% bad! ungrouped
+ \fi
+ \the\everymathalignment
+ \c_math_eqalign_column\zerocount
+ \processcommacommand
+ [\mathalignmentparameter\c!align]
+ {\advance\c_math_eqalign_column\plusone\math_eqalign_set_column}% takes argument
+ \global\c_math_eqalign_column\plusone
+ \dostarttagged\t!math\empty
+ \dostarttagged\t!mathtable\currentmathalignment
+ \numberedeqalign}
+
+\def\math_alignment_stop
+ {\math_finish_eqalign_no
+ \dostoptagged
+ \dostoptagged
+ \math_alignment_snap_stop}
+
+\installcorenamespace{mathalignment}
+\installcorenamespace{mathalignmentvariant}
+
+\installcommandhandler \??mathalignment {mathalignment} \??mathalignment
+
+\appendtoks
+ \setuevalue{\e!start\currentmathalignment}{\math_alignment_start{\currentmathalignment}}%
+ \setvalue {\e!stop \currentmathalignment}{\math_alignment_stop}%
+\to \everydefinemathalignment
+
+\setupmathalignment
+ [\c!n=2,
+ \c!m=1,
+ \c!distance=\emwidth]
+
+\definemathalignment[align] % default case (this is what amstex users expect)
+\definemathalignment[\v!mathalignment] % prefered case (this is cleaner, less clashing)
+
+% special case.. in case one mistypes ..
+
+\ifdefined \startalignment
+
+ \let\align_math_normal_start\startalign
+ \let\align_math_normal_stop \stopalign
+
+ \let\align_text_normal_start\startalignment
+ \let\align_text_normal_stop \stopalignment
+
+ \unexpanded\def\startalign
+ {\ifmmode
+ \let\stopalign\align_math_normal_stop % cannot be an unexpanded def ... lookahead in align
+ \expandafter\align_math_normal_start
+ \else
+ \let\stopalign\align_text_normal_stop
+ \expandafter\align_text_normal_start
+ \fi}
+
+ \let\stopalign\relax
+
+ \unexpanded\def\startalignment
+ {\ifmmode
+ \let\stopalignment\align_math_normal_stop % cannot be an unexpanded def ... lookahead in align
+ \expandafter\align_math_normal_start
+ \else
+ \let\stopalignment\align_text_normal_stop
+ \expandafter\align_text_normal_start
+ \fi}
+
+ \let\stopalignment\relax
+
+\fi
+
+%
+
+\unexpanded\def\numberedeqalign
+ {\doifelse{\formulaparameter\c!location}\v!left
+ \math_handle_eqalign_no_l_aligned
+ \math_handle_eqalign_no_r_aligned}
+
+\def\math_first_in_eqalign
+ {\global\c_math_eqalign_column\plusone
+ \dostarttagged\t!mathtablerow \empty
+ \dostarttagged\t!mathtablecell\empty}
+
+\def\math_next_in_eqalign
+ {\global\advance\c_math_eqalign_column\plusone
+ \dostoptagged % finish cell
+ \dostarttagged\t!mathtablecell\empty}
+
+\def\math_left_of_equalign
+ {\ifcsname\??mathalignmentvariant\number\c_math_eqalign_column\endcsname
+ \ifcase\csname\??mathalignmentvariant\number\c_math_eqalign_column\endcsname\or
+ \relax \or \hfill \or \hfill
+ \fi
+ \fi}
+
+\def\math_right_of_eqalign
+ {\ifcsname\??mathalignmentvariant\number\c_math_eqalign_column\endcsname
+ \ifcase\csname\??mathalignmentvariant\number\c_math_eqalign_column\endcsname\or
+ \hfill \or \relax \or \hfill
+ \fi
+ \fi}
+
+\def\math_eqalign_set_column#1% we could just add to the preamble (as with other alignments)
+ {\expandafter\let\csname\??mathalignmentvariant\number\c_math_eqalign_column\expandafter\endcsname
+ \csname\??mathalignmentvariant\ifcsname\??mathalignmentvariant#1\endcsname#1\else\v!normal\fi\endcsname}
+
+\letvalue{\??mathalignmentvariant\v!normal}\zerocount
+\letvalue{\??mathalignmentvariant\v!left }\plusone
+\letvalue{\??mathalignmentvariant\v!right }\plustwo
+\letvalue{\??mathalignmentvariant\v!middle}\plusthree
+
+\def\math_align_NR_generic[#1][#2]%
+ {\strc_formulas_place_number_nested{#1}{#2}\crcr}
+
+%D \starttyping
+%D \placeformula[eqn0]\startformula \startalign[n=1] a\NR \stopalign \stopformula See \in[eqn0]
+%D \placeformula[eqn1]\startformula \startalign[n=1] a\NR \stopalign \stopformula See \in[eqn1]
+%D \placeformula \startformula \startalign[n=1] a\NR[eqn2] \stopalign \stopformula See \in[eqn2]
+%D \placeformula[eqn3]\startformula \startalign[n=1] a\NR[+] \stopalign \stopformula See \in[eqn3]
+%D \stoptyping
+
+%D \startbuffer
+%D \placeformula \startformula \eqalignno {
+%D a &= b & \formulanumber \cr
+%D c &= d \cr
+%D &= e \cr
+%D &= f & \formulanumber
+%D } \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula \startformula \startalign
+%D \NC a \EQ b \NR[+]
+%D \NC c \EQ d \NR
+%D \NC \EQ f \NR[for:demo-a-1]
+%D \NC \EQ g \NR[for:demo-a-2][a]
+%D \NC \EQ h \NR[for:demo-a-3][b]
+%D \NC \EQ i \NR
+%D \stopalign \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula \startformula \startalign
+%D \NC a \EQ b \NR[+]
+%D \NC c \EQ d \NR
+%D \NC \EQ f \NR
+%D \NC \EQ g \NR
+%D \NC \EQ h \NR
+%D \NC \EQ i \NR[+]
+%D \stopalign \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula \startformula \startalign
+%D \NC a \NC \eq b \NR[+]
+%D \NC c \NC \neq d \NR
+%D \NC \NC \neq f \NR[for:demo-b-1]
+%D \NC \NC \geq g \NR[for:demo-b-2][a]
+%D \NC \NC \leq h \NR[for:demo-b-3][b]
+%D \NC \NC \neq i \NR
+%D \stopalign \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula \startformula \startalign[n=3,align={left,middle,right}]
+%D \NC l \NC = \NC r \NR
+%D \NC left \NC = \NC right \NR
+%D \stopalign \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula \startformula \startalign[n=3,align={right,middle,left}]
+%D \NC l \NC = \NC r \NR
+%D \NC left \NC = \NC right \NR
+%D \stopalign \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula \startformula \startalign[n=3,align={middle,middle,middle}]
+%D \NC l \NC = \NC r \NR
+%D \NC left \NC = \NC right \NR
+%D \stopalign \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula
+%D \startformula
+%D \startalign[n=3,align={middle,middle,middle}]
+%D \NC a \NC = \NC b \NR[+]
+%D \NC 2a \NC = \NC 2b \NR
+%D \stopalign
+%D \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula
+%D \startformulas
+%D \setupmathalignment[n=3,align={middle,middle,middle}]%
+%D \startformula
+%D \startalign
+%D \NC a \NC = \NC b \NR[+]
+%D \NC 2a \NC = \NC 2b \NR
+%D \stopalign
+%D \stopformula
+%D \startformula
+%D \startalign
+%D \NC a \NC = \NC b \NR[+]
+%D \NC 2a \NC = \NC 2b \NR
+%D \stopalign
+%D \stopformula
+%D \stopformulas
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula
+%D \startformulas
+%D \dorecurse{5}{\startformula
+%D \startalign[n=3,align={middle,middle,middle}]
+%D \NC a \NC = \NC b \NR[+]
+%D \NC 2a \NC = \NC 2b \NR
+%D \stopalign
+%D \stopformula}
+%D \stopformulas
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+
+%D \macros
+%D {definemathcases, setupmathcases, startmathcases}
+%D
+%D Another wish \unknown
+
+\installcorenamespace{mathcases}
+
+\installcommandhandler \??mathcases {mathcases} \??mathcases
+
+\setupmathcases
+ [\c!distance=\emwidth,
+ \c!strut=\v!yes, % new
+ \c!numberdistance=2.5\emwidth,
+ \c!left={\left\{\mskip\thinmuskip},
+ \c!right={\right.}]
+
+\appendtoks
+ \setuevalue{\e!start\currentmathcases}{\math_cases_start{\currentmathcases}}%
+ \setvalue {\e!stop \currentmathcases}{\math_cases_stop}%
+\to \everydefinemathcases
+
+\unexpanded\def\math_cases_start#1%
+ {\begingroup
+ \edef\currentmathcases{#1}%
+ \dosingleempty\math_cases_start_indeed}
+
+\def\math_cases_NC_zero
+ {\math_cases_NC}
+
+\def\math_cases_MC_zero
+ {\math_cases_NC
+ \ifmmode\else
+ \startimath
+ \let\math_cases_end_math\stopimath
+ \fi}
+
+\let\math_cases_end_math\relax
+
+\def\math_cases_NR_zero
+ {\unskip
+ \math_cases_end_math
+ \aligntab
+ \global\let\math_cases_NC\math_cases_NC_first
+ \dodirectdoubleempty\math_cases_NR}
+
+\def\math_cases_NC_first
+ {\global\let\math_cases_NC\math_cases_NC_second}
+
+\def\math_cases_NC_second
+ {\math_cases_end_math\aligntab}
+
+\let\math_cases_NR\math_align_NR_generic
+
+\unexpanded\def\math_cases_start_indeed[#1]%
+ {\iffirstargument
+ \setupcurrentmathcases[#1]%
+ \fi
+ \edef\p_strut{\mathcasesparameter\c!strut}%
+ \ifx\p_strut\v!yes
+ \let\math_cases_strut\strut
+ \else
+ \let\math_cases_strut\relax
+ \fi
+ \mathcasesparameter\c!left
+ \vcenter\bgroup
+ \pushmacro\math_cases_NC
+ \let\endmath\relax
+ \let\NC\math_cases_NC_zero
+ \let\MC\math_cases_MC_zero
+ \let\NR\math_cases_NR_zero
+ \global\let\math_cases_NC\math_cases_NC_first
+ \normalbaselines
+ \mathsurround\zeropoint
+ \everycr\emptytoks
+ \tabskip\zeropoint
+ \global\c_math_eqalign_column\plusone
+ \halign\bgroup
+ \startimath
+ \mathcasesparameter\c!style
+ \alignmark\alignmark
+ \stopimath
+ \hfil
+ \aligntab
+ \hskip\mathcasesparameter\c!distance\relax
+ \popmacro\math_cases_NC
+ \math_cases_strut % looks better
+ \alignmark\alignmark
+ \hfil
+ \aligntab
+ \hskip\mathcasesparameter\c!numberdistance\relax
+ \let\formuladistance\!!zeropoint
+ \span\math_text_in_eqalign{\alignmark\alignmark}%
+ \crcr} % todo: number
+
+\def\math_cases_stop
+ {\crcr
+ \egroup
+ \popmacro\math_cases_NC
+ \egroup
+ \mathcasesparameter\c!right
+ \endgroup}
+
+\definemathcases[cases]
+\definemathcases[\v!mathcases]
+
+%D \startbuffer
+%D \placeformula \startformula \startcases
+%D \NC 2 \NC $ y > 0 $ \NR
+%D \NC 7 \NC $ x = 7 $ \NR[+]
+%D \NC 4 \NC otherwise \NR
+%D \stopcases \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula \startformula x \startcases
+%D \NC 2 \NC $ y > 0 $ \NR[+]
+%D \NC 7 \NC $ x = 7 $ \NR
+%D \NC 4 \NC otherwise \NR
+%D \stopcases \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula \startformula \startcases
+%D \NC 2 \NC $ y > 0 $ \NR
+%D \NC 7 \NC $ x = 7 $ \NR
+%D \NC 4 \NC otherwise \NR
+%D \stopcases \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \placeformula \startformula x \startcases
+%D \NC 2 \NC $ y > 0 $ \NR
+%D \NC 7 \NC $ x = 7 $ \NR
+%D \NC 4 \NC otherwise \NR
+%D \stopcases \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+
+%D \macros
+%D {definemathmatrix, setupmathmatrix, startmathmatrix}
+%D
+%D Yet another one \unknown
+
+\installcorenamespace{mathmatrix}
+
+\installcommandhandler \??mathmatrix {mathmatrix} \??mathmatrix
+
+\setupmathmatrix
+ [\c!distance=\emwidth,
+ \c!left=,
+ \c!right=,
+ \c!align=\v!middle]
+
+\appendtoks
+ \setuevalue{\e!start\currentmathmatrix}{\math_matrix_start{\currentmathmatrix}}%
+ \setvalue {\e!stop \currentmathmatrix}{\math_matrix_stop}% no u else lookahead problem
+\to \everydefinemathmatrix
+
+\let\math_matrix_NC\relax
+
+\unexpanded\def\math_matrix_start#1%
+ {\begingroup
+ \edef\currentmathmatrix{#1}%
+ \dosingleempty\math_matrix_start_indeed}
+
+\unexpanded\def\math_matrix_start_indeed[#1]%
+ {\iffirstargument
+ \setupcurrentmathmatrix[#1]%
+ \fi
+ % \emptyhbox % noted at 25-05-2014: what was that one doing here? it messed up spacing
+ \math_matrix_align_method_analyze
+ \mathmatrixleft
+ % new per 13-10-2014
+ \edef\p_strut{\mathmatrixparameter\c!strut}%
+ \ifx\p_strut\v!no
+ \let\m_matrix_strut\relax
+ \else
+ \let\m_matrix_strut\strut
+ \ifx\p_strut\v!yes\else
+ \spacing\p_strut
+ \fi
+ \fi
+ %
+ \mathmatrixbox\bgroup
+ \pushmacro\math_matrix_NC
+ \let\endmath\relax
+ \def\NC{\math_matrix_NC}%
+ \def\MC{\math_matrix_NC\ifmmode\else\startimath\let\endmath\stopimath\fi}%
+ \global\let\math_matrix_NC\math_matrix_NC_indeed
+ \def\NR{\endmath\global\let\math_matrix_NC\math_matrix_NC_indeed\m_matrix_strut \crcr}%
+ \normalbaselines
+ \mathsurround\zeropoint
+ \everycr\emptytoks
+ \tabskip\zeropoint
+ \c_math_eqalign_column\zerocount
+ \processcommacommand
+ [\mathmatrixparameter\c!align]
+ {\advance\c_math_eqalign_column\plusone\math_eqalign_set_column}%
+ \scratchcounter\ifnum\c_math_eqalign_column>\zerocount \c_math_eqalign_column \else \plusone \fi
+ \global\c_math_eqalign_column\plusone
+ \math_matrix_prepare}
+
+\def\math_matrix_stop
+ {\crcr
+ \mathstrut\crcr
+ \noalign{\kern-\baselineskip}%
+ \egroup
+ \popmacro\math_matrix_NC
+ \egroup
+ \mathmatrixright
+ \endgroup}
+
+\definemathmatrix[matrix]
+\definemathmatrix[\v!mathmatrix]
+
+\def\math_matrix_prepare
+ {\c_math_align_a{\strut\math_first_in_eqalign\math_left_of_equalign\span
+ \math_text_in_eqalign{\mathmatrixparameter\c!style\alignmark\alignmark}\math_right_of_eqalign}%
+ \c_math_align_b{\aligntab\hskip\mathmatrixparameter\c!distance
+ \math_next_in_eqalign\math_left_of_equalign\span
+ \math_text_in_eqalign{\mathmatrixparameter\c!style\alignmark\alignmark}\math_right_of_eqalign}%
+ \c_math_align_c{\aligntab\aligntab\hskip\mathmatrixparameter\c!distance
+ \math_left_of_equalign\span
+ \math_text_in_eqalign{\mathmatrixparameter\c!style\alignmark\alignmark}\math_right_of_eqalign}%
+ \scratchtoks\emptytoks
+ \normalexpanded{\scratchtoks{\the\scratchtoks\the\c_math_align_a}}%
+ \dorecurse{\numexpr\scratchcounter-\plusone\relax}
+ {\normalexpanded{\scratchtoks{\the\scratchtoks\the\c_math_align_b}}}%
+ \normalexpanded{\scratchtoks{\the\scratchtoks\the\c_math_align_c}}%
+ \halign \expandafter \bgroup\the\scratchtoks \crcr}
+
+\unexpanded\def\math_matrix_NC_indeed
+ {\gdef\math_matrix_NC{\endmath\aligntab}}
+
+\installcorenamespace{mathmatrixalignmethod}
+
+\let\mathmatrixleft \empty % experimental hook
+\let\mathmatrixright\empty % experimental hook
+
+\def\math_matrix_process#1#2%
+ {\dowithnextbox
+ {\scratchdimen\dimexpr(\nextboxdp-\nextboxht)/2 \ifcase#2\or+\mathaxisheight\textfont2\fi\relax
+ \ifcase#1\relax\or\lower\scratchdimen\or\or\raise\scratchdimen\fi
+ \hbox{$\mathmatrixparameter\c!left
+ \vcenter{\unvbox\nextbox}%
+ \mathmatrixparameter\c!right$}}%
+ \vbox}
+
+\unexpanded\def\installmathmatrixalignmethod#1#2%
+ {\setvalue{\??mathmatrixalignmethod#1}{#2}}
+
+\def\math_matrix_align_method_analyze
+ {\csname\??mathmatrixalignmethod\ifcsname\??mathmatrixalignmethod\mathmatrixparameter\c!location\endcsname
+ \mathmatrixparameter\c!location
+ \else
+ \v!normal
+ \fi\endcsname}
+
+\installmathmatrixalignmethod\v!top {\def\mathmatrixbox{\math_matrix_process\plusthree\plusone }}
+\installmathmatrixalignmethod\v!high {\def\mathmatrixbox{\math_matrix_process\plusthree\zerocount}}
+\installmathmatrixalignmethod\v!lohi {\def\mathmatrixbox{\math_matrix_process\plustwo \zerocount}}
+\installmathmatrixalignmethod\v!low {\def\mathmatrixbox{\math_matrix_process\plusone \zerocount}}
+\installmathmatrixalignmethod\v!bottom{\def\mathmatrixbox{\math_matrix_process\plusone \plusone }}
+\installmathmatrixalignmethod\v!normal{\def\mathmatrixbox{\math_matrix_process\plustwo \zerocount}} % lohi
+
+%D \startbuffer
+%D \placeformula \startformula[-] \startmatrix
+%D \NC 1 \NC x \NC a \NR
+%D \NC 2 \NC y \NC b \NR
+%D \NC 3 \NC z \NC c \NR
+%D \stopmatrix \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \definemathmatrix[bmatrix][left={\left[\mskip\thinmuskip},right={\mskip\thinmuskip\right]},strut=1.25]
+%D
+%D \startbuffer
+%D \placeformula \startformula[-] \startbmatrix
+%D \NC 1 \NC x \NC a \NR
+%D \NC 2 \NC y \NC b \NR
+%D \NC 3 \NC z \NC c \NR
+%D \stopbmatrix \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D Taco added some code (dedicated to Aditya Mahajan) that gives more
+%D control over aligments:
+
+%D \startbuffer
+%D \startformula
+%D \startmatrix
+%D \NC a + x \NC = \NC a + d \NR
+%D \NC y \NC = \NC d \NR
+%D \stopmatrix
+%D \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+
+%D \startbuffer
+%D \startformula
+%D \startmatrix [distance=3pt,align={right,left}]
+%D \NC a + x \NC = a + d \NR
+%D \NC y \NC = d \NR
+%D \stopmatrix
+%D \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+
+%D \startbuffer
+%D \startformula
+%D \startmatrix [left=\left(,right=\right)]
+%D \NC a + x \NR
+%D \NC y \NR
+%D \stopmatrix
+%D \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D A bit more complex code:
+%D
+%D \startbuffer
+%D \startformula
+%D \text{Let }{\cal R} = \bigcup_{P_{X_1},P_{X_2}}
+%D \left\{ (R_1, R_2) :
+%D \startmatrix[distance=1em,align={left,left,right}]
+%D \NC R_1 \NC < I(X_1 ; Y \mid X_2) \NC R_1 \NR
+%D \NC \hfill Q_2 \NC < I(X_2 ; Y \mid X_1) \NC R_2 \NR
+%D \NC R_1 + R_2 \NC < I(X_1 ; Y) \NC R_1 + R_2 \NR
+%D \stopmatrix
+%D \right\}
+%D \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+
+%D \macros
+%D {startmatrices}
+%D
+%D Just a handy keystroke safer:
+
+\unexpanded\def\startmatrices
+ {\begingroup
+ \setupmathmatrix}
+
+\unexpanded\def\stopmatrices
+ {\endgroup}
+
+%D \startbuffer
+%D \startformula
+%D \startmatrix[left={\left(},right={\right)}]
+%D \NC A \NC B \NR \NC C \NC D \NR
+%D \stopmatrix
+%D =
+%D \startmatrix[left={\left(},right={\right)},location=low]
+%D \NC A \NC B \NR \NC C \NC D \NR
+%D \stopmatrix
+%D =
+%D \startmatrix[left={\left(},right={\right)},location=high]
+%D \NC A \NC B \NR \NC C \NC D \NR
+%D \stopmatrix
+%D \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer \getbuffer
+%D
+%D \startbuffer
+%D \startformula
+%D \startmatrices[left={\left(},right={\right)}]
+%D \startmatrix
+%D \NC A \NC B \NR \NC C \NC D \NR
+%D \stopmatrix
+%D =
+%D \startmatrix[location=bottom]
+%D \NC A \NC B \NR \NC C \NC D \NR
+%D \stopmatrix
+%D =
+%D \startmatrix[location=top]
+%D \NC A \NC B \NR \NC C \NC D \NR
+%D \stopmatrix
+%D \stopmatrices
+%D \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer % does not run well: \getbuffer
+
+%D \macros
+%D {startintertext}
+%D
+%D Preliminary feature:
+%D
+%D {\em example code}
+%D
+%D The intertext commands have to be expandable (in aligment lookahead) so
+%D we cannot use \type {\unexpanded}.
+
+\def\startintertext#1\stopintertext
+ {\noalign{\math_intertext{#1}}}
+
+\let\stopintertext\relax
+
+\def\intertext#1%
+ {\noalign{\math_intertext{#1}}}
+
+\unexpanded\def\math_intertext#1%
+ {\penalty\postdisplaypenalty
+ \afterdisplayspace
+ \vbox{\forgetall\noindent#1\par}%
+ \penalty\predisplaypenalty
+ \beforedisplayspace}
+
+%D \macros
+%D {substack}
+%D
+%D Preliminary code:
+%D
+%D \startbuffer
+%D \startformula
+%D \sum_{%
+%D \startsubstack
+%D i = 1 \NR
+%D i \neq n \NR
+%D i \neq m
+%D \stopsubstack
+%D }a_i
+%D \stopformula
+%D \stopbuffer
+%D
+%D \getbuffer which was typed as \typebuffer
+%D
+%D Notice that these macros give the correct spacing for
+%D subscripts. Compare for example
+%D
+%D \startbuffer
+%D \startformula
+%D \sum_{\startsubstack a \NR b \NR \stopsubstack}
+%D \text{ and }
+%D \sum_{\scriptstyle a \atop \scriptstyle}
+%D \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer which gives \getbuffer
+
+\unexpanded\def\startsubstack
+ {\begingroup
+ \vcenter\bgroup
+ \baselineskip\mathstacktotal
+ \lineskip\mathstackvgap
+ \lineskiplimit\lineskip
+ \let\stopmathmode\relax
+ \def\NC{\math_matrix_NC}%
+ \def\MC{\math_matrix_NC\startmathmode}%
+ \global\let\math_matrix_NC\math_matrix_NC_indeed
+ \def\NR
+ {\stopmathmode
+ \global\let\math_matrix_NC\math_matrix_NC_indeed
+ \crcr}%
+ \mathsurround\zeropoint
+ \everycr\emptytoks
+ \halign\bgroup\hfil$\scriptstyle\alignmark\alignmark$\hfil\crcr}
+
+\def\stopsubstack
+ {\crcr
+ \egroup
+ \egroup
+ \endgroup}
+
+%D \macros
+%D {bordermatrix}
+%D
+%D In \PLAIN\ \TEX\ the width of a parenthesis is stored in
+%D the \DIMENSION\ \type{\mathparentwd}. This value is derived from
+%D the width of \type{\tenrm B}, so let's take care of it now:
+
+\ifx\mathparentwd\undefined \newdimen\mathparentwd \fi
+
+\let\normalbordermatrix\bordermatrix % move that code to here instead
+
+\def\bordermatrix
+ {\begingroup
+ \setbox\scratchbox\hbox{\mr\char"239C}%
+ \global\mathparentwd\wd\scratchbox
+ \endgroup
+ \normalbordermatrix}
+
+% to be tested
+%
+% \def\bordermatrix
+% {\begingroup\mr\global\mathparentwd\fontcharwd\font"239C\relax\endgroup
+% \normalbordermatrix}
+
+%D \macros{overset, underset}
+%D
+%D The macros \type{\overset} and \type{\underset} are provided by
+%D \AMS\ packages in \LATEX. These macro allows you to place a symbol
+%D above or below another symbol, irrespective of whether the other
+%D symbol is a relation or something else, and without influencing the
+%D spacing. For most cases there is a better way to do such things
+%D (declaring a math command with limop option, or using accents), but
+%D occasionally these macros can be useful, for example:
+%D
+%D \startbuffer
+%D \startformula
+%D \overset{*}{X} \underset{*}{X}
+%D \stopformula
+%D \stopbuffer
+%D \typebuffer \getbuffer
+%D
+%D Use these macros sparingly. Remember, \TEX\ was designed for
+%D mathematics, so there is usually a proper method for typesetting
+%D common math notation.
+%D
+%D These macros are a cleaner version of \type {\binrel@} and
+%D \type {\binrel@@} macros in \AMSTEX\ packages.
+
+\def\math_binrel_apply#1%
+ {\begingroup
+ \setbox\scratchbox\hbox
+ {\thinmuskip 0mu
+ \medmuskip -1mu
+ \thickmuskip -1mu
+ \setbox\scratchbox\hbox{$#1\mathsurround\zeropoint$}%
+ \kern-\wd\scratchbox
+ ${}#1{}\mathsurround\zeropoint$}%
+ \ifdim\wd\scratchbox<\zeropoint
+ \endgroup
+ \expandafter\mathbin
+ \else\ifdim\wd\scratchbox>\zeropoint
+ \endgroup
+ \doubleexpandafter\mathrel
+ \else
+ \endgroup
+ \doubleexpandafter\firstofoneargument
+ \fi\fi}
+
+\unexpanded\def\overset#1#2%
+ {\math_binrel_apply{#2}{\mathop{\kern\zeropoint#2}\limits\normalsuperscript{#1}}}
+
+\unexpanded\def\underset#1#2%
+ {\math_binrel_apply{#2}{\mathop{\kern\zeropoint#2}\limits\normalsubscript {#1}}}
+
+%D The following code comes from \type {math-str.mkiv}.
+%D
+%D Here we implement a basic math alignment mechanism. Numbers
+%D are also handled. The macros \type {\startinnermath} and
+%D \type {\stopinnermath} can be overloaded in specialized
+%D modules.
+
+\installcorenamespace{mathinnerstart}
+\installcorenamespace{mathinnerstop}
+
+% \unexpanded\def\startinnermath{\csname\??mathinnerstart\formulaparameter\c!align\endcsname}
+% \unexpanded\def\stopinnermath {\csname\??mathinnerstop \formulaparameter\c!align\endcsname}
+
+\unexpanded\def\startinnermath{\expandnamespaceparameter\??mathinnerstart\formulaparameter\c!align\v!normal}
+\unexpanded\def\stopinnermath {\expandnamespaceparameter\??mathinnerstop \formulaparameter\c!align\v!normal}
+
+\unexpanded\def\mathinnerstrut
+ {\doif{\formulaparameter\c!strut}\v!yes\strut}
+
+\unexpanded\def\defineinnermathhandler#1#2#3%
+ {\setvalue{\??mathinnerstart#1}{#2}%
+ \setvalue{\??mathinnerstop #1}{#3}}
+
+\newif\iftracemath
+
+\def\math_hbox
+ {\iftracemath\ruledhbox\else\hbox\fi}
+
+\newconstant\mathraggedstatus % normal left center right
+\newconstant\mathnumberstatus % nothing normal shift_right
+
+\let\mathnumbercorrection\!!zeropoint
+
+\let\math_the_r_eq_no\empty
+\let\math_the_l_eq_no\empty
+
+\unexpanded\def\startmathbox#1%
+ {\hsize\displaywidth % \checkeddisplaymath
+ \global\mathnumberstatus\plusone
+ \mathraggedstatus#1\relax
+ \let\mathnumbercorrection\!!zeropoint
+ \global\let\math_the_r_eq_no\empty
+ \global\let\math_the_l_eq_no\empty
+ \def\reqno{\gdef\math_the_r_eq_no}%
+ \def\leqno{\gdef\math_the_l_eq_no}%
+ \let\eqno\reqno
+ % added
+ \let\normalreqno\reqno
+ \let\normalleqno\leqno
+ \let\normaleqno \eqno
+ % added
+ \strc_formulas_place_number
+ \setbox\scratchbox\math_hbox to \displaywidth\bgroup % \checkeddisplaymath
+ \mathinnerstrut
+ \startforceddisplaymath
+ \ifcase\mathraggedstatus\or\hfill\or\hfill\fi}
+
+\def\math_box_llapped_math_no
+ {\ifcase\mathraggedstatus\or
+ \math_the_r_eq_no
+ \or
+ \llap{\math_the_r_eq_no}%
+ \or
+ \llap{\math_the_r_eq_no}%
+ \fi}
+
+\def\math_box_rlapped_math_no
+ {\ifcase\mathraggedstatus\or
+ \rlap{\math_the_l_eq_no}%
+ \or
+ \rlap{\math_the_l_eq_no}%
+ \or
+ \math_the_l_eq_no
+ \fi}
+
+\unexpanded\def\stopmathbox
+ {\stopforceddisplaymath
+ \ifcase\mathraggedstatus\or\or\hfill\or\hfill\fi
+ \egroup
+ \setbox0\hbox{\unhcopy\scratchbox}%
+ \scratchdimen\wd0
+ % to be tested: \scratchdimen\naturalwd\scratchbox
+ \ifdim\scratchdimen>\displaywidth % \checkeddisplaymath
+ \donetrue
+ \else
+ \donefalse
+ \fi
+ \hbox to \displaywidth\bgroup
+ \ifcase\mathnumberstatus
+ \box\scratchbox
+ \or
+ \ifx\math_the_l_eq_no\empty
+ \ifx\math_the_r_eq_no\empty
+ \box\scratchbox
+ \else
+ \ifdone
+ \vpack{\box\scratchbox\hpack to \displaywidth{\hss\math_box_llapped_math_no}}% \checkeddisplaymath
+ \else
+ \hss\box\scratchbox\math_box_llapped_math_no % hss makes room for number
+ \fi
+ \fi
+ \else
+ \ifdone
+ \vpack{\hpack to \displaywidth{\math_box_rlapped_math_no\hss}\box\scratchbox}% \checkeddisplaymath
+ \else
+ \math_box_rlapped_math_no\box\scratchbox\hss % hss makes room for number
+ \fi
+ \fi
+ \or
+ \hskip\mathnumbercorrection
+ \box\scratchbox
+ \hss
+ \else
+ \box\scratchbox
+ \fi
+ \egroup}
+
+\defineinnermathhandler\v!left {\startmathbox\plusone }{\stopmathbox}
+\defineinnermathhandler\v!middle {\startmathbox\plustwo }{\stopmathbox}
+\defineinnermathhandler\v!right {\startmathbox\plusthree}{\stopmathbox}
+\defineinnermathhandler\v!flushleft {\startmathbox\plusthree}{\stopmathbox}
+\defineinnermathhandler\v!center {\startmathbox\plustwo }{\stopmathbox}
+\defineinnermathhandler\v!flushright{\startmathbox\plusone }{\stopmathbox}
+\defineinnermathhandler\v!normal {} {}
+
+%defineinnermathhandler\v!normal {\startmathbox\plustwo }{\stopmathbox}
+
+%D [The examples below are in english and don't process in the
+%D documentation style, which will be english some day.]
+%D
+%D Normally a formula is centered, but in case you want to
+%D align it left or right, you can set up formulas to behave
+%D that way. Normally a formula will adapt is left indentation
+%D to the environment:
+%D
+%D \startbuffer
+%D \fakewords{20}{40}\epar
+%D \startitemize
+%D \item \fakewords{20}{40}\epar
+%D \placeformula \startformula \fakeformula \stopformula
+%D \item \fakewords{20}{40}\epar
+%D \stopitemize
+%D \fakewords{20}{40}\epar
+%D \stopbuffer
+%D
+%D % \getbuffer
+%D
+%D In the next examples we explicitly align formulas to the
+%D left (\type {\raggedleft}), center and right (\type
+%D {\raggedright}):
+%D
+%D \startbuffer
+%D \setupformulas[align=left]
+%D \startformula\fakeformula\stopformula
+%D \setupformulas[align=middle]
+%D \startformula\fakeformula\stopformula
+%D \setupformulas[align=right]
+%D \startformula\fakeformula\stopformula
+%D \stopbuffer
+%D
+%D \typebuffer
+%D
+%D Or in print:
+%D
+%D % {\getbuffer}
+%D
+%D With formula numbers these formulas look as follows:
+%D
+%D \startbuffer
+%D \setupformulas[align=left]
+%D \placeformula \startformula\fakeformula\stopformula
+%D \setupformulas[align=middle]
+%D \placeformula \startformula\fakeformula\stopformula
+%D \setupformulas[align=right]
+%D \placeformula \startformula\fakeformula\stopformula
+%D \stopbuffer
+%D
+%D % {\getbuffer}
+%D
+%D This was keyed in as:
+%D
+%D \typebuffer
+%D
+%D When tracing is turned on (\type {\tracemathtrue}) you can
+%D visualize the bounding box of the formula,
+%D
+%D % {\tracemathtrue\getbuffer}
+%D
+%D As you can see, the dimensions are the natural ones, but if
+%D needed you can force a normalized line:
+%D
+%D \startbuffer
+%D \setupformulas[strut=yes]
+%D \placeformula \startformula \fakeformula \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer
+%D
+%D This time we get a more spacy result.
+%D
+%D % {\tracemathtrue\getbuffer}
+%D
+%D We will now show a couple of more settings and combinations
+%D of settings. In centered formulas, the number takes no space
+%D
+%D \startbuffer
+%D \setupformulas[align=middle]
+%D \startformula \fakeformula \stopformula
+%D \placeformula \startformula \fakeformula \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer % {\tracemathtrue\getbuffer}
+%D
+%D You can influence the placement of the whole box with the
+%D parameters \type {leftmargin} and \type {rightmargin}.
+%D
+%D \startbuffer
+%D \setupformulas[align=right,leftmargin=3em]
+%D \startformula \fakeformula \stopformula
+%D \placeformula \startformula \fakeformula \stopformula
+%D
+%D \setupformulas[align=left,rightmargin=1em]
+%D \startformula \fakeformula \stopformula
+%D \placeformula \startformula \fakeformula \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer % {\tracemathtrue\getbuffer}
+%D
+%D You can also inherit the margin from the environment.
+%D
+%D \startbuffer
+%D \setupformulas[align=right,margin=standard]
+%D \startformula \fakeformula \stopformula
+%D \placeformula \startformula \fakeformula \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer % {\tracemathtrue\getbuffer}
+%D
+%D The distance between the formula and the number is only
+%D applied when the formula is left or right aligned.
+%D
+%D \startbuffer
+%D \setupformulas[align=left,distance=2em]
+%D \startformula \fakeformula \stopformula
+%D \placeformula \startformula \fakeformula \stopformula
+%D \stopbuffer
+%D
+%D \typebuffer % {\tracemathtrue\getbuffer}
+
+\protect \endinput
+
+% \placeformula \startformula[-] \startmatrix
+% \NC 1 \NC x \NC a \NR
+% \NC 2 \NC y \NC b \NR
+% \NC 3 \NC z \NC c \NR
+% \stopmatrix \stopformula
+
+% \definemathmatrix[bordermatrix][left={\left[\mskip\thinmuskip},right={\mskip\thinmuskip\right]}]
+
+% \placeformula \startformula[-] \startbordermatrix
+% \NC 1 \NC x \NC a \NR
+% \NC 2 \NC y \NC b \NR
+% \NC 3 \NC z \NC c \NR
+% \stopbordermatrix \stopformula
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-23 14:49:33 +0000