Specify the computed value of calc()

Author: tabatkins

css3-values/Overview.html

@@ -1353,11 +1353,19 @@ <h3 id=calc><span class=secno>8.1. </span> Mathematical Expressions:
    href="#frequency-value"><code>&lt;frequency&gt;</code></a>, <a
    href="#angle-value"><code>&lt;angle&gt;</code></a>, <a
    href="#time-value"><code>&lt;time&gt;</code></a>, or <a
-   href="#number-value"><code>&lt;number&gt;</code></a> values are allowed.</p>
-  <!-- http://lists.w3.org/Archives/Public/www-style/2010May/0001.html
+   href="#number-value"><code>&lt;number&gt;</code></a> values are allowed.
+
+  <p> The computed value of a calc() expression is the expression with all
+   components computed, with all multiplication/division subexpressions
+   resolved, and with all addition/subtraction subexpressions resolved where
+   both sides are the same type. <span class=note> Thus, the computed value
+   of a calc() expression can be represented as a tuple of a number, a
+   dimension, and a percentage. </span>
+   <!-- http://lists.w3.org/Archives/Public/www-style/2010May/0001.html
 	This has notes on how we should handle things when calc() is extended to 
 	handle unit mult/div. Related to this is <unit>mod<unit>, which can return
 	0 and thus introduce computed-time division-by-zero. -->
+   
 
   <div class=example>
    <pre>

css3-values/Overview.src.html

@@ -889,6 +889,19 @@ <h3 id="calc">
 	<code>&lt;number&gt;</code>
 	values are allowed.</p>
 
+	<p>
+		The computed value of a calc() expression is the expression
+		with all components computed,
+		with all multiplication/division subexpressions resolved,
+		and with all addition/subtraction subexpressions resolved where both sides are the same type.
+		<span class='note'>
+			Thus, the computed value of a calc() expression can be represented
+			as a tuple of
+			a number,
+			a dimension,
+			and a percentage.
+		</span>
+
 	<!-- http://lists.w3.org/Archives/Public/www-style/2010May/0001.html
 	This has notes on how we should handle things when calc() is extended to 
 	handle unit mult/div. Related to this is <unit>mod<unit>, which can return