X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo-convex.tex;h=5a930fcf34ec9531f9d5b7af792d75b1c3be055c;hb=93c8209c75f02b41fe26c7d58dd7b8f8814051f0;hp=985731e68db59a8baacbbdd432b920d564daf1a0;hpb=10971bbd4f9e00f481f7d8f442e235b6b538ace9;p=mjotex.git

diff --git a/mjo-convex.tex b/mjo-convex.tex
index 985731e..5a930fc 100644
--- a/mjo-convex.tex
+++ b/mjo-convex.tex
@@ -1,9 +1,13 @@
 %
 % Operations that usually appear in convex optimization.
 %
+\ifx\havemjoconvex\undefined
+\def\havemjoconvex{1}
 
-% Needed for \operatorname.
-\usepackage{amsopn}
+
+\ifx\operatorname\undefined
+  \usepackage{amsopn}
+\fi
 
 \input{mjo-common}
 
@@ -24,3 +28,10 @@
 
 % The ``Extreme vectors'' (or ``Extreme directions'') operator.
 \newcommand*{\Ext}[1]{ \operatorname{Ext} \of{{#1}} }
+
+% The "is a face of" and "is a proper face of" relations.
+\newcommand*{\faceof}{ \trianglelefteq }
+\newcommand*{\properfaceof}{ \triangleleft }
+
+
+\fi