Re: [Haskell-cafe] adjoint of coproduct & diagonal

Derek Elkins wrote:

[id,id] is the counit. [id,id] : C+C -> C Given a function f : A+B -> C there exists a unique function f* : (A,B) -> (C,C) that is a pair of functions h : A -> C and k : B -> C such that [id,id] . h+k = f.

This f is what I have labelled [f,g] (or f+g) in the diagram I linked to, right? In that case h and k are just f and g, respectively, and the unique arrow that goes from A+B to C+C is f+g -- but that would make C+C just the same as C. -- _jsn