From af9f65d664b95a3090d29a109e9efb1d9d08be5b Mon Sep 17 00:00:00 2001
From: Michael Orlitzky <michael@orlitzky.com>
Date: Thu, 30 Mar 2023 17:56:52 -0400
Subject: [PATCH] mjo-linear_algebra: add \GL command for general linear
 groups.

---
 examples.tex           | 4 +++-
 mjo-linear_algebra.tex | 4 ++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/examples.tex b/examples.tex
index d8e2c32..6b60b00 100644
--- 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 7f2484a..5f25544 100644
--- 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
-- 
2.43.2