COVARIANT_1 (preface.Preface_qcheck.Model.COVARIANT

type 'a t

val generator : 'a QCheck2.Gen.t -> 'a t QCheck2.Gen.t

val observable : 'a QCheck2.Observable.t -> 'a t QCheck2.Observable.t

val pp : 
  (Stdlib.Format.formatter -> 'a -> unit) ->
  Stdlib.Format.formatter ->
  'a t ->
  unit

val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool