60.6 Matrix

<..amstex.tex matrix..>
                                     \catcode‘\#=13 \catcode‘\!=6
 \def\reg:matrix{\vcenter\bgroup
    \SaveMkHalignConf:g{matrix}%
    \Let@
    \MkHalign#{$\m@th#$&&$\m@th#$}}
                                     \catcode‘\#=6 \catcode‘\!=12
 \def\:tempc{\crcr\EndMkHalign \RecallMkHalignConfig \egroup\b:matrix}
 \HLet\endmatrix=\:tempc
 \def\:temp{\pic:MkHalign{matrix}}
 \HLet\matrix=\:temp
 \NewConfigure{matrix}{6}
 -_-_-

<..equations of amstex.texNO..>
 \def\:temp{\a:smallmatrix \o:smallmatrix:}
 \HLet\smallmatrix=\:temp
 \let\:tempc=\endsmallmatrix
 \append:def\:tempc{\b:smallmatrix}
 \HLet\endsmallmatrix=\:tempc
 \NewConfigure{smallmatrix}{2}
 -_-_-

<..equations of amstex.tex..>+
                                     \catcode‘\#=13 \catcode‘\!=6
 \def\reg:smallmatrix{\vcenter\bgroup
    \SaveMkHalignConf:g{smallmatrix}%
    \Let@
    \MkHalign#{$\m@th\scriptstyle{#}$&&$\m@th
                     \scriptstyle{#}$}}
                                     \catcode‘\#=6 \catcode‘\!=12
 \def\:tempc{\crcr\EndMkHalign
     \RecallMkHalignConfig \egroup\b:smallmatrix}
 \HLet\endsmallmatrix=\:tempc
 \def\:temp{\pic:MkHalign{smallmatrix}}
 \HLet\smallmatrix=\:temp
 \NewConfigure{smallmatrix}{6}
 -_-_-

<..plain,latex utilities..>+
 \def\pic:MkHalign#1{%
   \csname a:#1\endcsname
   \ifx \EndPicture\:Undef
      \expandafter\expandafter\csname reg:#1\endcsname
   \else
      \vtop\bgroup$$
      \expandafter\def\csname #1\endcsname{\bgroup
          \expandafter\def\csname end#1\endcsname{\csname
               o:#1:\endcsname\egroup}%
          \csname o:#1:\endcsname}%
       \expandafter\def\csname end#1\endcsname{\csname
           o:end#1:\endcsname$$\egroup
          \csname b:#1\endcsname}\expandafter
                                \expandafter\csname o:#1:\endcsname
   \fi}
 -_-_-

<..plain,latex utilities..>+
 \def\SaveMkHalignConf:g#1{\SaveMkHalignConfig
    \edef\:temp{\noexpand\Configure{MkHalign} {} {}
      {\expandafter\noexpand\csname c:#1\endcsname}
      {\expandafter\noexpand\csname d:#1\endcsname }
      {\expandafter\noexpand\csname e:#1\endcsname
         \noexpand\RecallMkHalignConfig}
      {\expandafter\noexpand\csname f:#1\endcsname }}\:temp}
 -_-_-

<..amstex.tex matrix..>+
 \let\:tempc=\pmatrix
 \pend:def\:tempc{\a:pmatrix}
 \HLet\pmatrix=\:tempc
 \let\:tempc=\endpmatrix
 \append:def\:tempc{\b:pmatrix}
 \HLet\endpmatrix=\:tempc
 \NewConfigure{pmatrix}{2}
 -_-_-