val arrow_1 : unit -> (unit, ('a, 'a) t) Law.tval arrow_2 : unit -> ('a -> 'b, ('b -> 'c) -> ('a, 'c) t) Law.tval arrow_3 : unit -> ('a -> 'b, ('a * 'c, 'b * 'c) t) Law.tval arrow_4 : unit -> (('a, 'b) t, ('b, 'c) t -> ('a * 'd, 'c * 'd) t) Law.tval arrow_5 : unit -> (('a, 'b) t, ('a * 'c, 'b) t) Law.tval arrow_6 : unit -> (('a, 'b) t, ('c -> 'd) -> ('a * 'c, 'b * 'd) t) Law.tval arrow_7 : unit -> (('a, 'b) t, (('a * 'c) * 'd, 'b * ('c * 'd)) t) Law.t