[css-mixins-1] Parameters act a local registrations within the function

Author: andruud

css-mixins-1/Overview.bs

@@ -593,9 +593,7 @@ with its [=function parameters=] overriding "inherited" custom properties of the
 	11. For each [=custom property registration=] of |registrations|
 		except the registration with the name "result",
 		set its initial value
-		to the corresponding value in |argument styles|,
-		set its syntax
-		to the [=universal syntax definition=],
+		to the corresponding value in |argument styles|
 		and prepend a [=custom property=] to |body rule|
 		with the property name and value in |argument styles|.
 	12. [=Resolve function styles=] using |custom function|, |body rule|, |registrations|, and |calling context|.