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

Derek Elkins wrote:

The notation f+g is the notation for the functorial action of + : CxC -> C on arrows, that is, if f : A -> B and g : C -> D then f+g : A+C -> B+D.

So [f,g] and f+g different. I assumed that the functorial action of + on arrows was to take ((A -> C), (B -> C)) to A+B -> C, which goes a long way to explaining my confusion :) -- _jsn