Ashley Yakeley wrote:
If you remember your category theory, you'll recall that two morphisms are not necessarily the same just because they're between the same two objects. For instance, the objects may be sets, and the morphisms may be functions between sets: morphisms from A to B are the same only if they map each element in A to the same element in B.
Yes, but I though the 'objects' in this case are endofunctors from a type to itself... the the morphisms operate on these endofunctors, the morphisms are unit and join.... such that joining 'unit' to the endofuntor retults in the endofunctor. But I think that as the endofunctor is from the type to itself, the value does not come into it. A -> A `join` unit => A -> A Keean.