mjo-algebra: add \Stab command for stabilizer subgroups.

[mjotex.git] / mjo-algebra.tex

diff --git a/mjo-algebra.tex b/mjo-algebra.tex
index 36ad4bd64888c1b2926ff2d454c989e3a561a6aa..1ab88806c2cdad1caa64bfb62ea860496e820db9 100644 (file)
--- a/mjo-algebra.tex
+++ b/mjo-algebra.tex
@@ -12,6 +12,18 @@
 \input{mjo-common} % for \of, and \binopmany
 
 
+% The additive identity element of its argument, which should be
+% an algebraic structure.
+\newcommand*{\zero}[1]{ 0_{{#1}} }
+
+\ifdefined\newglossaryentry
+  \newglossaryentry{zero}{
+    name={\ensuremath{\zero{R}}},
+    description={the additive identity element of $R$},
+    sort=z
+  }
+\fi
+
 % The multiplicative identity element of its argument, which should be
 % an algebraic structure.
 \newcommand*{\unit}[1]{ 1_{{#1}} }
@@ -78,4 +90,8 @@
 \fi
 
 
+% The stabilizer subgroup of its first argument that fixes the point
+% given by its second argument.
+\newcommand*{\Stab}[2]{ #1_{#2} }
+
 \fi