closed-classes.md

@@ -5,15 +5,24 @@ closed classes are ones for which no more instances may be defined. these can be
 
 ## proposal
 
-```wiki
 
 allow the closed keyword right after class.
 
+```wiki
 class closed ... where
     ...
+```
+
 
 this will mean that even if the class is exported no one may declare more instances for it
 
+## alternate
+
+
+specify it in the export list
+
+```wiki
+module Foo(closed Foo(..)) where
 ```
 
 ## pro