4.22 amsmath.sty

<..configure html32-math amsmath..>+
 \Configure{equation}
   {\Configure{gather}
      {\HCode{<\tbl:XV{equation}><tr><td><center>}\IgnorePar}
      {\end:TTT\IgnorePar\par}
      {}{}
      {\ifnum\HCol=2 \IgnorePar\HCode{</center></td><td width="5\%">}\fi}
      {}
   }{}{}
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<..configure html32-math amsmath..>+
 \Configure{equation}
   {\NoHtmlEnv \Configure{gather}
      {\HCode{<\tbl:XV{equation}><tr><td><center>}\IgnorePar}
      {\end:TTT\IgnorePar\par}
      {\Configure{$}{\PicMath}{\EndPicMath}{}}
      {}
      {\ifnum\HCol=2 \IgnorePar\HCode{</center></td><td width="5\%">}\fi}
      {}
   }{}{}
-_-_-

Equations in amsmath.sty are defined in term of gather, and gather is a one parameter macro. Unlike laktex where the body is read within the environment, in gather it is read at the \begin{equation} point under the conditions that exist there.

<..32,4 pic amsmath..>
 \Configure{substack}{\Picture+{}}{\EndPicture}
-_-_-