[css-values-4] Math functions can have non-calculation children. #6506

Author: tabatkins

css-values-4/Overview.bs

@@ -4470,11 +4470,11 @@ Simplification</h4>
 			2. Otherwise, return |root|.
 
 		3. At this point, |root| is an [=operator node=].
-			[=Simplify=] all the children of |root|.
+			[=Simplify=] all the [=calculation=] children of |root|.
 
 		4. If |root| is an [=operator node=]
 			that's not one of the [=calc-operator nodes=],
-			and all of its children are numeric values
+			and all of its [=calculation=] children are numeric values
 			with enough information to compute the operation |root| represents,
 			return the result of running |root|'s operation
 			using its children,