mjo-hurwitz.tex: new file for Hurwitz algebras (quaternions and octonions).

[mjotex.git] / examples.tex

diff --git a/examples.tex b/examples.tex
index 015c5fd67df5aa3e5d4c272c60480694d20ba1ba..2d05431e2ceb2fcdcdf3314980f3348929a69ea8 100644 (file)
--- a/examples.tex
+++ b/examples.tex
@@ -172,6 +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
@@ -203,7 +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