X-Git-Url: http://gitweb.michael.orlitzky.com/?p=mjotex.git;a=blobdiff_plain;f=mjo-convex.tex;h=5ac7dcb974ebaf1282c3506cc7e5840bc9777871;hp=823f1f46cd5cf4023b89f2462c559a3060a70f8c;hb=HEAD;hpb=af7e58d88448fa6726d8e6df22b280390e0a5a34

diff --git a/mjo-convex.tex b/mjo-convex.tex
index 823f1f4..5ac7dcb 100644
--- a/mjo-convex.tex
+++ b/mjo-convex.tex
@@ -1,11 +1,15 @@
 %
 % Operations that usually appear in convex optimization.
 %
+\ifx\havemjoconvex\undefined
+\def\havemjoconvex{1}
 
-% Needed for \operatorname.
-\usepackage{amsopn}
 
-\input{mjo-common}
+\ifx\operatorname\undefined
+  \usepackage{amsopn}
+\fi
+
+\input{mjo-common} % for \of, at least
 
 % The ``conic combination'' operator.
 \newcommand*{\cone}[1]{ \operatorname{cone} \of{{#1}} }
@@ -22,5 +26,12 @@
 % The ``lineality'' operator.
 \newcommand*{\lin}[1]{ \operatorname{lin} \of{{#1}} }
 
-% The ``Exteme vectors'' operator.
+% 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