please confirm that this is a feature

I am finishing up revisions on a paper that has been accepted to JFP, on type-checking with multi-parameter type classes. With the following definitions: | class Foo a b | a -> b where foo :: a -> b -> Int | | instance Foo Int Float where foo x y = 0 | | instance Foo a b => Foo [a] [b] where foo [x] [y] = foo x y | | g x y = (foo [x] y) + (foo [y] x) In our system type-checking fails to terminate when type-checking "g", but Hugs 98 (Feb 2001) returns a type. I assume that this is because of a depth bound in the type-checker, can you confirm this before I submit the final version of the paper? Thanks --dd