mtl has been around for a while now and using any the monads from the mtl transformers library is very inferrable, although like any inference it returns the mo

mtl has been around for a while now and using any the monads from the mtl transformers library is very inferrable, although like any inference it returns the most general type possible and it's generally just good practice to forward declare the type. example = do a <- ask modify (+ a) b <- get tell [b] GHC correctly infers: example :: (Num s, MonadState s m, MonadReader s m, MonadWriter [s] m) => m ()