perm filename TMP.TEX[TEX,DEK]11 blob
sn#710196 filedate 1983-05-18 generic text, type T, neo UTF8
\newcount\letcount
\setcount\letcount=0
\def\Let{\ifnum\count\letcount>0 \else\letit\fi\advcount\letcount by 1 }
\def\letit{\let\\=\cr}
\def\align{\Let\vbox\lb\halign\lb$##$&$##$\cr}
\def\endalign{\cr\rb\rb\advcount\letcount by -1 }
$$ \align a&=\align x&y\\z&w\endalign\\c&d\endalign$$
\endinput
\def\Let{\relax\iffalse{\fi\let\\=\cr\iffalse}\fi}
$$ \align a&\align x&y\\z&w\endalign\\c&d\endalign$$
$$ \align a&=\align x&y\\z&w\endalign\\c&d\endalign$$