<..equations of amstex.tex..>
\catcode‘\#=13 \catcode‘\!=6
\def\format:!1\\{\def\preamble@{!1}%
\hashtoks@{#}%
\def\l{$\m@th\the\hashtoks@$\hfil}%
\def\c{\hfil$\m@th\the\hashtoks@$\hfil}%
\def\r{\hfil$\m@th\the\hashtoks@$}%
\SaveMkHalignConf:g{format}%
\edef\preamble@@{\:span\preamble@}%
<.expand amstex.tex ...alignat pattern.>\MkHalign#{\preamble@@}}
\catcode‘\#=6 \catcode‘\!=12
\def\:tempc{\crcr\EndMkHalign\RecallMkHalignConfig
\iffalse{\fi\ifnum‘}=0 \fi\format:}
\HLet\format=\:tempc
\let\:format=\format
\let\format=\o:format:
\let\MkHformat=\empty
\def\:tempc{\def\format{\global\let\format=\o:format: \:format}}
\HLet\MkHformat=\:tempc
\NewConfigure{format}{6}
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