Module S2

type ('a, 'b, 'c) writer = 'a writer0 -> ('b, 'c) S1.writer

type ('a, 'b, 'c) reader = 'a reader0 -> ('b, 'c) S1.reader

type ('a, 'b, 'c) t = 'a t0 -> ('b, 'c) S1.t