\mathbb{C}\if\detokenize{#1}\detokenize{1}{}\else^{#1}\fi
}
+% The space of symmetric n-by-n matrices.
+\providecommand*{\Sn}[1][n]{
+ \mathcal{S}\if\detokenize{#1}\detokenize{1}{}\else^{#1}\fi
+}
%
% Basic set operations
{ {#1}_{#2}^{#3}{#4} }
}
-\providecommand*{\unionmany}[3]{ \binopmany{\cup}{#1}{#2}{#3} }
\providecommand*{\intersectmany}[3]{ \binopmany{\cap}{#1}{#2}{#3} }
+\providecommand*{\cartprodmany}[3]{ \binopmany{\times}{#1}{#2}{#3} }
+\providecommand*{\directsummany}[3]{ \binopmany{\oplus}{#1}{#2}{#3} }
+\providecommand*{\unionmany}[3]{ \binopmany{\cup}{#1}{#2}{#3} }