-% The space of real symmetric n-by-n matrices.
-\newcommand*{\Sn}[1][n]{
- \mathcal{S}\if\detokenize{#1}\detokenize{1}{}\else^{#1}\fi
-}
-
-% The space of complex Hermitian n-by-n matrices.
-\newcommand*{\Hn}[1][n]{
- \mathcal{H}\if\detokenize{#1}\detokenize{1}{}\else^{#1}\fi
-}
-
-%
-% Basic set operations
-%
-
-% The union of its two arguments.
-\newcommand*{\union}[2]{ {#1}\cup{#2} }
-
-% A three-argument union.
-\newcommand*{\unionthree}[3]{ \union{\union{#1}{#2}}{#3} }
-
-% The intersection of its two arguments.
-\newcommand*{\intersect}[2]{ {#1}\cap{#2} }
+\ifdefined\newglossaryentry
+ \newglossaryentry{C}{
+ name={\ensuremath{\Cn[1]}},
+ description={the field of complex numbers},
+ sort=C
+ }
+\fi