X-Git-Url: http://gitweb.michael.orlitzky.com/?p=mjotex.git;a=blobdiff_plain;f=mjo-arrow.tex;fp=mjo-arrow.tex;h=4dd5f88bc6053dd224dd3c7b138ff757c78fe301;hp=8b44ded1753eb175124ed71fa73ad4e5ec9b35e5;hb=fc7cfa7f3d02715cb09eae2e1c6bc501dc2d8d50;hpb=d4712abb88a2f342f31bbd60426d1a983df05ac2

diff --git a/mjo-arrow.tex b/mjo-arrow.tex
index 8b44ded..4dd5f88 100644
--- a/mjo-arrow.tex
+++ b/mjo-arrow.tex
@@ -1,6 +1,9 @@
 %
 % Things dealing with arrows in a category. Or functions, basically.
 %
+\ifx\havemjoarrow\undefined
+\def\havemjoarrow{1}
+
 
 \input{mjo-common}
 
@@ -16,3 +19,6 @@
 
 % The preimage of the second argument (a set) under the first (a function).
 \newcommand*{\preimage}[2]{ #1^{-1}\of{#2} }
+
+
+\fi