sig
type ('a, 'b) monad
val ( >>= ) :
('a, 'b) Monad.Infix2.monad ->
('a -> ('c, 'b) Monad.Infix2.monad) -> ('c, 'b) Monad.Infix2.monad
val ( >>| ) :
('a, 'b) Monad.Infix2.monad -> ('a -> 'c) -> ('c, 'b) Monad.Infix2.monad
end