From 90b275219d518d1c851c71c87484c1a3385f3b70 Mon Sep 17 00:00:00 2001
From: Michael Orlitzky <michael@orlitzky.com>
Date: Tue, 20 Sep 2016 17:46:56 -0400
Subject: [PATCH] Add two- and three-argument commands for union and
 intersection.

---
 mjo-common.tex | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/mjo-common.tex b/mjo-common.tex
index efa10a2..b269417 100644
--- a/mjo-common.tex
+++ b/mjo-common.tex
@@ -71,3 +71,20 @@
 \providecommand*{\Cn}[1][n]{
   \mathbb{C}\if\detokenize{#1}\detokenize{1}{}\else^{#1}\fi
 }
+
+
+%
+% Basic set operations
+%
+
+% The union of its two arguments.
+\providecommand*{\union}[2]{ {#1} \cup {#2} }
+
+% A three-argument union.
+\providecommand*{\unionthree}[3]{ \union{\union{#1}{#2}}{#3} }
+
+% The intersection of its two arguments.
+\providecommand*{\intersect}[2]{ {#1} \cap {#2} }
+
+% A three-argument intersection.
+\providecommand*{\intersectthree}[3]{ \intersect{\intersect{#1}{#2}}{#3} }
-- 
2.43.2