[css-grid-2] Define resolved value to only represent line names assigned by the subgrid. w3c#4362

Author: fantasai

css-grid-2/Overview.bs

@@ -480,12 +480,12 @@ Resolved Value of a Track Listing</h3>
 
 	When an element generates a [=grid container=] box that is a [=subgrid=],
 	the [=resolved value=]
-	of the 'grid-template-rows' and 'grid-template-columns' properties is the <a>used value</a>,
+	of the 'grid-template-rows' and 'grid-template-columns' properties
+	represents the [=used value|used=] number of columns,
 	serialized as the ''subgrid'' keyword
 	followed by a list representing each of its lines
-	as a [=line name set=] of all the line's names,
-	whether the names were explicitly created for the subgrid
-	or adopted from the parent grid,
+	as a [=line name set=] of all the line's names
+	excluding those adopted from the parent grid,
 	without using the ''repeat()'' notation.
 
 	<div class="example">
@@ -839,6 +839,7 @@ Changes</h2>
 	CSS Grid Layout Level 2 Working Draft</a></h3>
 
 	<ul>
+		<li>Defined [=resolved value=] of 'grid-template-rows' and 'grid-template-columns' for [=subgrids=].
 		<li>Renamed ''ar'' unit to ''tr''.
 	</ul>