Module Univ.VarianceSource

Sourcetype t =
  1. | Irrelevant
  2. | Covariant
  3. | Invariant

A universe position in the instance given to a cumulative inductive can be the following. Note there is no Contravariant case because forall x : A, B <= forall x : A', B' requires A = A' as opposed to A' <= A.

Sourceval check_subtype : t -> t -> bool

check_subtype x y holds if variance y is also an instance of x

Sourceval sup : t -> t -> t
Sourceval pr : t -> Pp.t
Sourceval equal : t -> t -> bool