Module type Datatype.Polymorphic3

module type Polymorphic3 = sig .. end
Output signature of Datatype.Polymorphic3.
Since Oxygen-20120901

include Type.Polymorphic3
module Make: 
functor (T1 : Datatype.S) ->
functor (T2 : Datatype.S) ->
functor (T3 : Datatype.S) -> Datatype.S with type t = (T1.t, T2.t, T3.t) poly