mjo-linear_algebra: add \GL command for general linear groups.

diff --git a/examples.tex b/examples.tex
index d8e2c3243f85d436f2600267c21475556a75b99f..6b60b00b0fbf4e25fcc1e9dfd96a0f60cd258592 100644 (file)
--- a/examples.tex
+++ b/examples.tex
@@ -214,7 +214,9 @@
 
     The set of all bounded linear operators from $V$ to $W$ is
     $\boundedops[W]{V}$. If $W = V$, then we write $\boundedops{V}$
-    instead.
+    instead. If you have matrices instead, then the general linear
+    group of $n$-by-$n$ matrices with entries in $\mathbb{F}$ is
+    $\GL{n}{\mathbb{F}}$.
 
     If you want to solve a system of equations, try Cramer's
     rule~\cite{ehrenborg}. Or at least the reduced row-echelon form of

diff --git a/mjo-linear_algebra.tex b/mjo-linear_algebra.tex
index 7f2484a546ef750977ca2b4c1ab7ae451a66f122..5f2554484b2b1c28adea2cfb8e594eb01fa8970d 100644 (file)
--- a/mjo-linear_algebra.tex
+++ b/mjo-linear_algebra.tex
@@ -174,4 +174,8 @@
 \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