(forall b . PGArrow g (GArrowTensor g b b) b) ->
-}
--foo con mer = <[ ~~mer ~~con ~~con ]>
-foo const merge = <[ ~~merge ~~const (~~merge ~~const ~~const) ]>
+--foo const merge = <[ ~~merge ~~const (~~merge ~~const ~~const) ]>
+foo const merge = <[ ~~merge ~~const ~~const ]>
--tester2 f = <[ \x -> ~~f x x ]>