Derived2.1-M
type ('a, 'b) t
val compare : ('a -> 'a -> int) -> ('b -> 'b -> int) -> ('a, 'b) t -> ('a, 'b) t -> int
val sexp_of_t : ('a -> Sexp.t) -> ('b -> Sexp.t) -> ('a, 'b) t -> Sexp.t