diff options
| author |  Matthieu Sozeau <mattam@mattam.org> | 2016-11-18 13:25:05 +0100 |
|---|---|---|
| committer | Matthieu Sozeau <mattam@mattam.org> | 2016-11-30 11:29:02 +0100 |
| commit | 25c82d55497db43bf2cd131f10d2ef366758bbe1 (patch) | |
| tree | fdc509d76371e210aa292b49c2bf22537424b3fb /engine/evd.ml | |
| parent | 17559d528cf7ff92a089d1b966c500424ba45099 (diff) | |
Fix UGraph.check_eq!
Universes are kept in normal form w.r.t. equality but not the <=
relation, so the previous check worked almost always but was actually
too strict! In cases like (max(Set,u) = u) when u is declared >= Set it
was failing to find an equality. Applying the KISS principle:
u = v <-> u <= v /\ v <= u.
Fix invariant breakage that triggered the discovery of the check_eq bug as well. No algebraic universes should appear in a term position (on the left of
a colon in a typing judgment), this was not the case when an algebraic
universe instantiated an evar that appeared in the term. We force their
universe variable status to change in refresh_universes to avoid this.
Fix ind sort inference: Use syntactic universe equality for inductive
sort inference instead of check_leq (which now correctly takes
constraints into account) and simplify code
Diffstat (limited to 'engine/evd.ml')
| -rw-r--r-- | engine/evd.ml | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/engine/evd.ml b/engine/evd.ml index aa91fc522..a6b6f742b 100644 --- a/engine/evd.ml +++ b/engine/evd.ml @@ -854,6 +854,13 @@ let is_eq_sort s1 s2 = if Univ.Universe.equal u1 u2 then None else Some (u1, u2) +(* Precondition: l is not defined in the substitution *) +let universe_rigidity evd l = + let uctx = evd.universes in + if Univ.LSet.mem l (Univ.ContextSet.levels (UState.context_set uctx)) then + UnivFlexible (Univ.LSet.mem l (UState.algebraics uctx)) + else UnivRigid + let normalize_universe evd = let vars = ref (UState.subst evd.universes) in let normalize = Universes.normalize_universe_opt_subst vars in |