Fixed math error in the repeating algorithm.

Author: tabatkins

css3-lists/Overview.html

@@ -2053,7 +2053,7 @@ <h4 id=repeating><span class=secno>10.1.1. </span> repeating</h4>
   <p>In general, if there are <var>length</var> <i>counter symbols</i> and a
    representation is being constructed for the value <var>value</var>, the
    representation is the <a href="#counter-symbol"><i>counter symbol</i></a>
-   at index (<var>value</var> mod <var>length</var>) of the list of <a
+   at index ( (<var>value</var>-1) mod <var>length</var>) of the list of <a
    href="#counter-symbol"><i>counter symbol</i></a>s (0-indexed).
 
   <div class=example>

css3-lists/Overview.src.html

@@ -1256,7 +1256,7 @@ <h4>
 	<p>In general, if there are <var>length</var> <i>counter symbols</i> and
 	a representation is being constructed for the value <var>value</var>, 
 	the representation is the <i>counter symbol</i> at index 
-	(<var>value</var> mod <var>length</var>) of the list of <i>counter symbol</i>s
+	( (<var>value</var>-1) mod <var>length</var>) of the list of <i>counter symbol</i>s
 	(0-indexed).</p>
 
 	<div class=example>