X (base.Base.Applicative.Make3_using

type ('a, 'd, 'e) t

val return : 'a -> ( 'a, _, _ ) t

val map2 : 
  ( 'a, 'd, 'e ) t ->
  ( 'b, 'd, 'e ) t ->
  f:( 'a -> 'b -> 'c ) ->
  ( 'c, 'd, 'e ) t

val map : 
  [ `Define_using_map2
  | `Custom of ( 'a, 'd, 'e ) t -> f:( 'a -> 'b ) -> ( 'b, 'd, 'e ) t ]