Module UnivMinimSource

Unordered pairs of universe levels (ie (u,v) = (v,u))

Sourcetype extra = {
  1. weak_constraints : UPairSet.t;
  2. above_prop : Univ.Level.Set.t;
}
Sourceval empty_extra : extra
Sourceval extra_union : extra -> extra -> extra

Simplification and pruning of constraints: normalize_context_set ctx us