mjo-linear_algebra: add the \rank{} of a matrix (or EJA, or...).

[mjotex.git] / examples.tex

diff --git a/examples.tex b/examples.tex
index af125a726265dbfd53b150bc42cca2cfeb5c3c6f..dde74d0f6997418a8ab283ee1f6fb53452f6a6bf 100644 (file)
--- a/examples.tex
+++ b/examples.tex
@@ -30,8 +30,12 @@
     is a multivariate polynomial ring with indeterminates $X$, $Y$,
     and $Z$, and coefficients in $R$. If $R$ is a moreover an integral
     domain, then its fraction field is $\Frac{R}$. If $x,y,z \in R$,
-    then $\ideal{\set{x,y,z}}$ is the ideal generated by $\set{x,y,z}$,
-    which is defined to be the smallest ideal in $R$ containing that set.
+    then $\ideal{\set{x,y,z}}$ is the ideal generated by
+    $\set{x,y,z}$, which is defined to be the smallest ideal in $R$
+    containing that set. Likewise, if we are in an algebra
+    $\mathcal{A}$ and if $x,y,z \in \mathcal{A}$, then
+    $\alg{\set{x,y,z}}$ is the smallest subalgebra of $\mathcal{A}$
+    containing the set $\set{x,y,z}$.
   \end{section}
 
   \begin{section}{Algorithm}
@@ -178,7 +182,8 @@
     $L$ is $\adjoint{L}$, or if it's a matrix, then its transpose is
     $\transpose{L}$. Its trace is $\trace{L}$. Another matrix-specific
     concept is the Moore-Penrose pseudoinverse of $L$, denoted by
-    $\pseudoinverse{L}$.
+    $\pseudoinverse{L}$. Finally, the rank of a matrix $L$ is
+    $\rank{L}$.
 
     The span of a set $X$ is $\spanof{X}$, and its codimension is
     $\codim{X}$. The projection of $X$ onto $V$ is $\proj{V}{X}$. The