60.11 Aligned

<..equations of amstex.tex..>+
                                     \catcode‘\#=13 \catcode‘\!=6
 \def\reg:aligned@{\bgroup
    \SaveMkHalignConf:g{aligned@}%
    \Let@
    \MkHalign#{$\m@th\displaystyle{#}$&%
               $\m@th\displaystyle{{}#}$}}
                                     \catcode‘\#=6 \catcode‘\!=12
 \def\al:gned#1{%
    \Configure{aligned@}{\csname a:#1\endcsname}%
        {\csname b:#1\endcsname}{\csname c:#1\endcsname}%
        {\csname d:#1\endcsname}{\csname e:#1\endcsname}%
        {\csname f:#1\endcsname}\pic:MkHalign{#1}}
 \NewConfigure{aligned@}{6}
 -_-_-

<..equations of amstex.tex..>+
 \def\:tempc{\crcr\EndMkHalign
     \RecallMkHalignConfig \egroup\b:aligned@}
 \HLet\endaligned=\:tempc
 \def\:temp{\al:gned{aligned}}
 \HLet\aligned=\:temp
 \def\reg:aligned{\vcenter\reg:aligned@}
 \NewConfigure{aligned}{6}
 \HLet\endtopaligned=\endaligned
 \def\:tempc{\al:gned{topaligned}}
 \HLet\topaligned=\:tempc
 \def\reg:topaligned{\null\vtop\reg:aligned@}
 \NewConfigure{topaligned}{6}
 \HLet\endbotaligned=\endaligned
 \def\:tempc{\al:gned{botaligned}}
 \HLet\botaligned=\:tempc
 \def\reg:botaligned{\null\vtop\reg:aligned@}
 \NewConfigure{botaligned}{6}
 -_-_-

<..equations of amstex.tex..>+
 \def\:tempc{\crcr\EndMkHalign
     \RecallMkHalignConfig \egroup\b:alignedat}
 \HLet\endalignedat=\:tempc
 \def\:tempc{\al:gned{alignedat}}
 \HLet\alignedat=\:tempc
 \NewConfigure{alignedat}{6}
                                     \catcode‘\#=13 \catcode‘\!=6
 \def\reg:alignedat!1{\null\vcenter\bgroup
    \SaveMkHalignConf:g{alignedat}%
    \hashtoks@{#}{\let\@lign=\empty \doat@{!1}}\Let@
    \pend:def\preamble@@{\:span}%
    <.expand amstex.tex ...alignat pattern.>\MkHalign#{\preamble@@}}
                                     \catcode‘\#=6 \catcode‘\!=12
 -_-_-