fact: Definition EitherT_apply {E M} `{Applicative M} {X Y} (mf : EitherT E M (X -> Y)) (mx : EitherT E M X) : EitherT E M Y := liftA2 (@ap _ Either_Applicative X Y) mf mx.
imports: Hask.Prelude Hask.Control.Monad Hask.Control.Monad.Trans.Class Hask.Control.Monad.Morph