[css-values-4] Define 0/0 as just *behaving as* 1/0, not computing to. w3c#5084

Author: tabatkins

css-values-4/Overview.bs

@@ -1263,9 +1263,8 @@ Ratios: the <<ratio>> type</h3>
 	defaulting to ''1''.
 	However, <<ratio>> is always serialized with both components.
 
-	The computed value of a <<ratio>> is the pair of numbers provided,
-	unless both numbers are zero,
-	in which case the computed value is the pair (1, 0) (same as ''1 / 0'').
+	The computed value of a <<ratio>> is the pair of numbers provided.
+	However, a ratio of ''0 / 0'' behaves as the ratio ''1 / 0'' instead.
 
 	Note: This makes the behavior of ''calc(0 / 0)''
 	(an ordinary division,
@@ -4084,7 +4083,7 @@ Simplification</h4>
 
 		8. If |root| is a Min or Max node:
 
-			1. [=For each=] node |child| of |root|’s children:
+			1. [=list/For each=] node |child| of |root|’s children:
 
 				If |child| is a numeric value
 				with a unit other than "percent",