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Diffstat (limited to 'engine/evarutil.ml')
| -rw-r--r-- | engine/evarutil.ml | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/engine/evarutil.ml b/engine/evarutil.ml index 6b3ce048f7..9cf81eccea 100644 --- a/engine/evarutil.ml +++ b/engine/evarutil.ml @@ -813,6 +813,33 @@ let subterm_source evk (loc,k) = | _ -> evk in (loc,Evar_kinds.SubEvar evk) +(* Add equality constraints for covariant/invariant positions. For + irrelevant positions, unify universes when flexible. *) +let compare_cumulative_instances cv_pb variances u u' sigma = + let open Universes in + let cstrs = Univ.Constraint.empty in + let soft = Constraints.empty in + let cstrs, soft = Array.fold_left3 (fun (cstrs, soft) v u u' -> + let open Univ.Variance in + match v with + | Irrelevant -> cstrs, Constraints.add (UWeak (u,u')) soft + | Covariant when cv_pb == Reduction.CUMUL -> + Univ.Constraint.add (u,Univ.Le,u') cstrs, soft + | Covariant | Invariant -> Univ.Constraint.add (u,Univ.Eq,u') cstrs, soft) + (cstrs,soft) variances (Univ.Instance.to_array u) (Univ.Instance.to_array u') + in + match Evd.add_constraints sigma cstrs with + | sigma -> + Inl (Evd.add_universe_constraints sigma soft) + | exception Univ.UniverseInconsistency p -> Inr p + +let compare_constructor_instances evd u u' = + let open Universes in + let soft = + Array.fold_left2 (fun cs u u' -> Constraints.add (UWeak (u,u')) cs) + Constraints.empty (Univ.Instance.to_array u) (Univ.Instance.to_array u') + in + Evd.add_universe_constraints evd soft (** [eq_constr_univs_test sigma1 sigma2 t u] tests equality of [t] and [u] up to existential variable instantiation and equalisable |