add suchthat macro

src/math/mathop.pysty

@@ -163,6 +163,10 @@ __END_OPTIONS_X__
 \newcommand*{\cfun}{\ensuremath{\mathbbm{1}}}
 \newcommand*{\One}{\cfun}
 
+%% such that in set declarations
+\newcommand{\suchthat}{\;\middle|\;}
+
+
 %Paired Delimiters
 \DeclarePairedDelimiter\ceil{\lceil}{\rceil}
 \DeclarePairedDelimiter\floor{\lfloor}{\rfloor}