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diff --git a/tex/context/base/supp-ali.tex b/tex/context/base/supp-ali.tex
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+%D \module
+%D   [       file=supp-ali,
+%D        version=2000.4.17,
+%D          title=\CONTEXT\ Support Macros,
+%D       subtitle=Alignment,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for 
+%C details. 
+
+%D Yet undocumented. 
+
+% 0 = centered 
+% 1 = left  in before
+% 2 = right in before 
+% 3 = left  in after 
+% 4 = right in after 
+
+\unprotect 
+
+\chardef\characteralignmentmode=4
+
+\let\afterassignwidth \!!zeropoint
+\let\beforeassignwidth\!!zeropoint
+
+\def\alignmentcharacter{.}
+
+\let\alignmentclass\s!default % can be used to handle multiple mixed ones
+
+\def\setfirstpasscharacteralign%
+  {\popcharacteralign
+   \expanded{\dosetfirstpasscharacteralign{\alignmentcharacter}}}
+
+\def\dosetfirstpasscharacteralign#1%
+  {\def\checkalignment##1%
+     {\popcharacteralign
+      \setbox\scratchbox=\hbox{#1}%
+      \edef\characterassignwidth{\the\wd\scratchbox}%
+      \setbox\scratchbox=\hbox{}%
+      \docheckalignment#1##1#1\relax\relax
+      \scratchdimen=-\wd\scratchbox
+      \setbox\scratchbox=\hbox{##1}%
+      \advance\scratchdimen by \wd\scratchbox
+      \ifdim\scratchdimen>\beforeassignwidth\relax
+        \edef\beforeassignwidth{\the\scratchdimen}%
+      \fi
+      \ifdim\scratchdimen=\!!zeropoint
+        \setbox\scratchbox=\hbox{##1}%
+        \scratchdimen=\wd\scratchbox
+        \ifnum\characteralignmentmode=0
+          % do nothing 
+        \else\ifnum\characteralignmentmode<3
+          \advance\scratchdimen by \characterassignwidth
+          \ifdim\scratchdimen>\beforeassignwidth\relax
+            \edef\beforeassignwidth{\the\scratchdimen}%
+          \fi
+        \else
+          \ifdim\scratchdimen>\afterassignwidth\relax
+            \edef\afterassignwidth{\the\scratchdimen}%
+          \fi
+        \fi\fi
+      \fi
+      \pushcharacteralign}%
+   \def\docheckalignment##1#1##2##3\relax%
+     {\ifx##2\relax
+        \setbox\scratchbox=\hbox{##1}%
+        \ifdim\wd\scratchbox>\afterassignwidth
+          \edef\afterassignwidth{\the\wd\scratchbox}%
+        \fi
+      \else
+        \docheckalignment##2##3\relax
+      \fi}}
+
+\def\setsecondpasscharacteralign%
+  {\popcharacteralign
+   \expanded{\dosetsecondpasscharacteralign{\alignmentcharacter}}}
+
+\def\dosetsecondpasscharacteralign#1%
+  {\def\checkalignment##1%
+     {\popcharacteralign
+      \setbox\scratchbox=\hbox{#1}%
+      \edef\characterassignwidth{\the\wd\scratchbox}%
+      \setbox\scratchbox=\hbox{}%
+      \docheckalignment#1##1#1\relax\relax
+      \scratchdimen=\wd\scratchbox
+      \setbox\scratchbox=\hbox{##1}%
+      \ifdim\scratchdimen=\wd\scratchbox
+        \ifcase\characteralignmentmode
+          \noindent\box\scratchbox
+        \else
+          \noindent\hbox
+            {\dontcomplain
+             \hbox to \beforeassignwidth
+               {\ifcase\characteralignmentmode\or
+                  \box\scratchbox\hss
+                \or
+                  \hss\box\scratchbox\hskip\characterassignwidth
+                \or
+                  \hss\rlap{\box\scratchbox}%
+                \or
+                  \hss\rlap{\hbox to \afterassignwidth{\hss\box\scratchbox}}%
+                \fi}%
+             \hskip\afterassignwidth}%
+        \fi
+      \else
+        \noindent\hbox
+          {\hbox to \beforeassignwidth
+             {\hss\box\scratchbox\hskip-\scratchdimen}%
+           \hskip\afterassignwidth}%
+      \fi}%
+   \def\docheckalignment##1#1##2##3\relax%
+     {\ifx##2\relax
+        \setbox\scratchbox=\hbox{##1}%
+      \else
+        \docheckalignment##2##3\relax
+      \fi}}
+
+% provide a means to use multiple alignments mixed
+
+\def\pushcharacteralign%
+  {\setxvalue{@cac@\alignmentclass}{\noexpand\do
+     {\afterassignwidth}{\beforeassignwidth}{\alignmentcharacter}}}
+
+\def\popcharacteralign%
+  {\def\do##1##2##3%
+     {\def\afterassignwidth  {##1}%
+      \def\beforeassignwidth {##2}%
+      \def\alignmentcharacter{##3}}%
+   \getvalue{@cac@\alignmentclass}}
+
+\long\def\startcharacteralign#1\stopcharacteralign%
+  {\bgroup
+   \setfirstpasscharacteralign #1%
+   \setsecondpasscharacteralign#1%
+   \egroup}
+
+\protect \endinput