+infixr 1 <=<, >=>
+
+-- | Left-to-right Kleisli composition of monads.
+(>=>) :: Monad m => (a -> m b) -> (b -> m c) -> (a -> m c)
+f >=> g = \x -> f x >>= g
+
+-- | Right-to-left Kleisli composition of monads. '(>=>)', with the arguments flipped
+(<=<) :: Monad m => (b -> m c) -> (a -> m b) -> (a -> m c)
+(<=<) = flip (>=>)
+
+-- | @'forever' act@ repeats the action infinitely.
+forever :: (Monad m) => m a -> m b
+forever a = a >> forever a
+