X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=examples.tex;h=2d05431e2ceb2fcdcdf3314980f3348929a69ea8;hb=07b10e9bcd59b16af1cd6b143f07f0a3cd56d33d;hp=7646b66183ec3ce967677147959b6ef195cb1470;hpb=390a27bedd90d549cefe80c0a973575b8a636978;p=mjotex.git

diff --git a/examples.tex b/examples.tex
index 7646b66..2d05431 100644
--- a/examples.tex
+++ b/examples.tex
@@ -38,7 +38,8 @@
     containing the set $\set{x,y,z}$.
 
     If $R$ has a multiplicative identity (that is, a unit) element,
-    then that element is denoted by $\unit{R}$.
+    then that element is denoted by $\unit{R}$. Its additive identity
+    element is $\zero{R}$.
   \end{section}
 
   \begin{section}{Algorithm}
@@ -171,6 +172,11 @@
     \end{itemize}
   \end{section}
 
+  \begin{section}{Hurwitz}
+    Here lies the Hurwitz algebras, like the quaternions
+    $\quaternions$ and octonions $\octonions$.
+  \end{section}
+
   \begin{section}{Linear algebra}
     The absolute value of $x$ is $\abs{x}$, or its norm is
     $\norm{x}$. The inner product of $x$ and $y$ is $\ip{x}{y}$ and
@@ -202,7 +208,8 @@
     instead.
 
     If you want to solve a system of equations, try Cramer's
-    rule~\cite{ehrenborg}.
+    rule~\cite{ehrenborg}. Or at least the reduced row-echelon form of
+    the matrix, $\rref{A}$.
 
     The direct sum of $V$ and $W$ is $\directsum{V}{W}$, of course,
     but what if $W = V^{\perp}$? Then we wish to indicate that fact by