X-Git-Url: http://gitweb.michael.orlitzky.com/?p=mjotex.git;a=blobdiff_plain;f=mjo-algebra.tex;h=25b96d9f8a184edc051ed2867bc8fa9b4b0a269b;hp=7ff7b5ae737ac2c14cbe4eda7af0a4f72fde2a5d;hb=HEAD;hpb=3dfec40b7f8df25dad0bcefb2d14d27789960a3e

diff --git a/mjo-algebra.tex b/mjo-algebra.tex
index 7ff7b5a..3bb51c1 100644
--- a/mjo-algebra.tex
+++ b/mjo-algebra.tex
@@ -12,6 +12,30 @@
 \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}} }
+
+\ifdefined\newglossaryentry
+  \newglossaryentry{unit}{
+    name={\ensuremath{\unit{R}}},
+    description={the multiplicative identity (unit) element of $R$},
+    sort=u
+  }
+\fi
+
 % The direct sum of two things.
 \newcommand*{\directsum}[2]{ {#1}\oplus{#2} }
 
@@ -66,4 +90,21 @@
 \fi
 
 
+% The stabilizer subgroup of its first argument that fixes the point
+% given by its second argument.
+\newcommand*{\Stab}[2]{ #1_{#2} }
+
+
+% The affine algebraic variety consisting of the common solutions to
+% every polynomial in its argument, which should be a subset of some
+% polynomial ring.
+\newcommand*{\variety}[1]{ \mathcal{V}\of{{#1}} }
+\ifdefined\newglossaryentry
+  \newglossaryentry{variety}{
+    name={\ensuremath{\variety{I}}},
+    description={variety corresponding to the ideal $I$},
+    sort=v
+  }
+\fi
+
 \fi