Gathered

<..equations of amsmath.sty..>+
                                     \catcode‘\#=13 \catcode‘\!=6
 \def\reg:gathered[!1]{%
   \RIfM@\else
       \nonmatherr@{\begin{gathered}}%
   \fi
   \null  \vcenter\bgroup
     \Let@ \chardef\dspbrk@context\@ne \restore@math@cr
     <.ialign gathered.>}
                                     \catcode‘\#=6 \catcode‘\!=12
 -_-_-

<..ialign gathered..>
 \SaveMkHalignConf:g{gathered}%\HRestore\noalign
 \MkHalign#{$\m@th\displaystyle{\HCode{}}#$}%
 -_-_-

<..equations of amsmath.sty..>+
 \def\:tempc{\crcr\EndMkHalign
     \RecallMkHalignConfig \egroup\b:gathered}
 \HLet\endgathered=\:tempc
 \def\:temp{\pic:MkHalign{gathered}}
 \expandafter\HLet\csname \string\gathered\endcsname=\:temp
 \NewConfigure{gathered}{6}
 -_-_-