Add \zero{R} for the additive identity element in R.

[mjotex.git] / examples.tex

diff --git a/examples.tex b/examples.tex
index c3e22e7d96e4660356020cb9d66aeac0074304a5..015c5fd67df5aa3e5d4c272c60480694d20ba1ba 100644 (file)
--- 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}
@@ -118,8 +119,10 @@
     superscript when that superscript would be one: $\Nn[1]$,
     $\Zn[1]$, $\Qn[1]$, $\Rn[1]$, $\Cn[1]$. However, if the
     superscript is (say) two, then it appears: $\Nn[2]$, $\Zn[2]$,
-    $\Qn[2]$, $\Rn[2]$, $\Cn[2]$. Finally, we have the four standard
-    types of intervals in $\Rn[1]$,
+    $\Qn[2]$, $\Rn[2]$, $\Cn[2]$. The symbols $\Fn[1]$, $\Fn[2]$,
+    et cetera, are available for use with a generic field.
+
+    Finally, we have the four standard types of intervals in $\Rn[1]$,
     %
     \begin{align*}
       \intervaloo{a}{b} &= \setc{ x \in \Rn[1]}{ a < x < b },\\