[css-values-4][editorial] typo

Author: tabatkins

css-values-4/Overview.bs

@@ -4342,7 +4342,7 @@ Type Checking</h3>
 
 	<div algorithm>
 		A value <dfn export for=CSS lt="contain a percentage|percentage-containing">contains a percentage</dfn>
-		if its type is [=CSSNumericValue/type=] is «[ "percent" → 1 ]»,
+		if its [=CSSNumericValue/type=] is «[ "percent" → 1 ]»,
 		or its type's [=percent hint=] is non-null.
 	</div>