}
\fi
+% The reduced row-echelon form of its argument, a matrix.
+\newcommand*{\rref}[1]{\operatorname{rref}\of{#1}}
+\ifdefined\newglossaryentry
+ \newglossaryentry{rref}{
+ name={\ensuremath{\rref{A}}},
+ description={the reduced row-echelon form of $A$},
+ sort=r
+ }
+\fi
+
% The ``Automorphism group of'' operator.
\newcommand*{\Aut}[1]{ \operatorname{Aut}\of{{#1}} }
\fi
+% The general linear group of square matrices whose size is the first
+% argument and whose entries come from the second argument.
+\newcommand*{\GL}[2]{\operatorname{GL}_{#1}\of{#2}}
+
\fi