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| author |  Gaëtan Gilbert <gaetan.gilbert@skyskimmer.net> | 2018-02-16 15:44:44 +0100 |
|---|---|---|
| committer | Gaëtan Gilbert <gaetan.gilbert@skyskimmer.net> | 2018-03-09 16:29:06 +0100 |
| commit | 17a0dccfe91d6f837ce285e62b8d843720f8c1a1 (patch) | |
| tree | 605a2dae6692cec6503ab5fcdce7c90421db26f0 /tactics | |
| parent | 3d86afb36517c9ba4200289e169239f7fa54fca1 (diff) | |
Allow using cumulativity without forcing strict constraints.
Previously [fun x : Ind@{i} => x : Ind@{j}] with Ind some cumulative
inductive would try to generate a constraint [i = j] and use
cumulativity only if this resulted in an inconsistency. This is
confusingly different from the behaviour with [Type] and means
cumulativity can only be used to lift between universes related by
strict inequalities. (This isn't a kernel restriction so there might
be some workaround to send the kernel the right constraints, but
not in a nice way.)
See modified test for more details of what is now possible.
Technical notes:
When universe constraints were inferred by comparing the shape of
terms without reduction, cumulativity was not used and so too-strict
equality constraints were generated. Then in order to use cumulativity
we had to make this comparison fail to fall back to full conversion.
When unifiying 2 instances of a cumulative inductive type, if there
are any Irrelevant universes we try to unify them if they are
flexible.
Diffstat (limited to 'tactics')
| -rw-r--r-- | tactics/tactics.ml | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/tactics/tactics.ml b/tactics/tactics.ml index 12aef852d..b111fd1ef 100644 --- a/tactics/tactics.ml +++ b/tactics/tactics.ml @@ -4824,9 +4824,9 @@ let intros_transitivity n = Tacticals.New.tclTHEN intros (transitivity_gen n) is solved by tac *) (** d1 is the section variable in the global context, d2 in the goal context *) -let interpretable_as_section_decl evd d1 d2 = +let interpretable_as_section_decl env evd d1 d2 = let open Context.Named.Declaration in - let e_eq_constr_univs sigma c1 c2 = match eq_constr_universes !sigma c1 c2 with + let e_eq_constr_univs sigma c1 c2 = match eq_constr_universes env !sigma c1 c2 with | None -> false | Some cstr -> try ignore (Evd.add_universe_constraints !sigma cstr); true @@ -4890,6 +4890,7 @@ let cache_term_by_tactic_then ~opaque ?(goal_type=None) id gk tac tacK = let open Tacmach.New in let open Proofview.Notations in Proofview.Goal.enter begin fun gl -> + let env = Proofview.Goal.env gl in let sigma = Proofview.Goal.sigma gl in let current_sign = Global.named_context_val () and global_sign = Proofview.Goal.hyps gl in @@ -4899,7 +4900,7 @@ let cache_term_by_tactic_then ~opaque ?(goal_type=None) id gk tac tacK = (fun d (s1,s2) -> let id = NamedDecl.get_id d in if mem_named_context_val id current_sign && - interpretable_as_section_decl evdref (lookup_named_val id current_sign) d + interpretable_as_section_decl env evdref (lookup_named_val id current_sign) d then (s1,push_named_context_val d s2) else (Context.Named.add d s1,s2)) global_sign (Context.Named.empty, empty_named_context_val) in |