Module type Foldable.M3

module type M3 = sig .. end

type '_ t 
type ('_, '_, '_) m 
val foldr_m : ('a -> 'b -> ('u, 'v, 'b) m) ->
'b -> 'a t -> ('u, 'v, 'b) m
val foldl_m : ('b -> 'a -> ('u, 'v, 'b) m) ->
'b -> 'a t -> ('u, 'v, 'b) m