X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo-arrow.tex;h=2d5095ee327b9866bbd84b8098f8d7a084bd27f7;hb=66a672c6c1657ad96422fcdb4828bc5d9a108ab0;hp=4dd5f88bc6053dd224dd3c7b138ff757c78fe301;hpb=fc7cfa7f3d02715cb09eae2e1c6bc501dc2d8d50;p=mjotex.git

diff --git a/mjo-arrow.tex b/mjo-arrow.tex
index 4dd5f88..2d5095e 100644
--- a/mjo-arrow.tex
+++ b/mjo-arrow.tex
@@ -5,11 +5,35 @@
 \def\havemjoarrow{1}
 
 
-\input{mjo-common}
+\input{mjo-common} % for \of, at least.
 
-% The identity operator/arrow on its argument.
+\ifx\operatorname\undefined
+  \usepackage{amsopn}
+\fi
+
+
+% The constant function that always returns its argument.
+\newcommand*{\const}[1]{\operatorname{const}_{{#1}}}
+
+\ifdefined\newglossaryentry
+  \newglossaryentry{const}{
+    name={\ensuremath{\const{a}}},
+    description={the constant function that always returns $a$},
+    sort=c
+  }
+\fi
+
+% The identity function/arrow on its argument.
 \newcommand*{\identity}[1]{ \operatorname{id}_{{#1}} }
 
+\ifdefined\newglossaryentry
+  \newglossaryentry{identity}{
+    name={\ensuremath{\identity{X}}},
+    description={the identity function or arrow on $X$},
+    sort=i
+  }
+\fi
+
 % The composition of two arrows/functions. For example, the
 % composition of g with f is \compose{g}{f}\of{x} === g\of{f\of{x}}.
 \newcommand*{\compose}[2]{ {#1}\circ{#2} }