5 Feb
1992
5 Feb
'92
11:24 a.m.
I believe Street defined both kinds of morphism, calling them "monad functors" and "monad opfunctors". The Eilenberg-Moore (category of algebras) construction is functorial with respect to the functors (this is touched on in MacLane's Categories for the Working Mathematician, exercise VI.2.3). The Kleisli construction is functorial with respect to the opfunctors. Steve Vickers. =========================================================================