<..captions in amsppt.sty..>
\append:def\@ins{\def\vspace##1{\vskip##1\relax}%
\def\captionwidth##1{\captionwidth@##1\relax}}
\let\:topcaption=\topcaption
\let\:botcaption=\botcaption
\def\:caption#1#2\endcaption{\a:caption
{\captionfont@#1}\if\notempty{#2}.\fi\b:caption
\if\notempty{#2}{\rm#2}\fi \c:caption}
\def\botcaption{\ifx \EndPicture\:UnDef \expandafter\:caption
\else \expandafter\:botcaption \fi}
\def\topcaption{\ifx \EndPicture\:UnDef \expandafter\:caption
\else \expandafter\:topcaption \fi}
\NewConfigure{caption}{3}
-_-_-