From 17a0dccfe91d6f837ce285e62b8d843720f8c1a1 Mon Sep 17 00:00:00 2001 From: Gaëtan Gilbert Date: Fri, 16 Feb 2018 15:44:44 +0100 Subject: 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. --- tactics/tactics.ml | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'tactics') 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 -- cgit v1.2.3