Module Set_intf.Elt_bin_io
module type S = sig ... endtype ('t, 'c) t= (module S with type comparator_witness = 'c and type t = 't)
Set_intf.Elt_bin_iomodule type S = sig ... endtype ('t, 'c) t = (module S with type comparator_witness = 'c and type t = 't)