Yeah, but type foo :: M a p f b c => (a -> p) -> b -> c -> a foo f b c = ... would look something like A foo<M<a>,p,f,b,c>(AP f, B b, C c) { ... in Java (I

Yeah, but type foo :: M a p f b c => (a -> p) -> b -> c -> a foo f b c = ... would look something like A foo<M<a>,p,f,b,c>(AP f, B b, C c) { ... in Java (I don't know Java, but I hope you gen an idea). I mean, this is a really complex example you've shown. And most of the times, you can (just like everywhere else) write simple type synonyms to express what you want.