[don't bind an usused case default binding when scrutinizing a variable
John Meacham <john@repetae.net>**20070522034342] hunk ./Grin/FromE.hs 492
+            (TVr { tvrIdent = 0 },EVar etvr) -> localEvaled [etvr] v $ do
+                    as <- mapM cp as
+                    def <- createDef d newNodeVar
+                    return $ e :>>= v :-> Case v (as ++ def)