Bi_mappable.Fix2_rightFix2_right (S) (Left) fixes the right type of S to Right, making it an S1_left.
module I : Bi_mappable_types.Basic2include Generic_types.Bi_left
with type 'l t = ('l, Right.t) I.t
with type right = Right.ttype 'l t = ('l, Right.t) I.tPartially fixed type of containers.