fact: Definition plusStateT `(l : Lens' s nat) (n : nat) `{Monad m} : StateT s m unit := modifyT (l %~ plus n).
imports: Hask.Prelude Hask.Control.Monad Hask.Data.Functor.Contravariant Hask.Data.Functor.Identity Hask.Control.Monad.Trans.State