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-rw-r--r--pretyping/unification.ml30
1 files changed, 27 insertions, 3 deletions
diff --git a/pretyping/unification.ml b/pretyping/unification.ml
index 55210d067..31fd711bf 100644
--- a/pretyping/unification.ml
+++ b/pretyping/unification.ml
@@ -356,6 +356,22 @@ let set_no_delta_flags flags = {
resolve_evars = flags.resolve_evars
}
+(* For the first phase of keyed unification, restrict
+ to conversion (including beta-iota) only on closed terms *)
+let set_no_delta_open_core_flags flags = { flags with
+ modulo_delta = empty_transparent_state;
+ modulo_betaiota = false;
+}
+
+let set_no_delta_open_flags flags = {
+ core_unify_flags = set_no_delta_open_core_flags flags.core_unify_flags;
+ merge_unify_flags = set_no_delta_open_core_flags flags.merge_unify_flags;
+ subterm_unify_flags = set_no_delta_open_core_flags flags.subterm_unify_flags;
+ allow_K_in_toplevel_higher_order_unification =
+ flags.allow_K_in_toplevel_higher_order_unification;
+ resolve_evars = flags.resolve_evars
+}
+
(* Default flag for the "simple apply" version of unification of a *)
(* type against a type (e.g. apply) *)
(* We set only the flags available at the time the new "apply" extended *)
@@ -1790,17 +1806,25 @@ let w_unify_to_subterm_list env evd flags hdmeta oplist t =
let allow_K = flags.allow_K_in_toplevel_higher_order_unification in
let flags =
if occur_meta_or_existential op || !keyed_unification then
+ (* This is up to delta for subterms w/o metas ... *)
flags
else
(* up to Nov 2014, unification was bypassed on evar/meta-free terms;
now it is called in a minimalistic way, at least to possibly
unify pre-existing non frozen evars of the goal or of the
pattern *)
- set_no_delta_flags flags in
+ set_no_delta_flags flags in
+ let t' = (strip_outer_cast op,t) in
let (evd',cl) =
try
- (* This is up to delta for subterms w/o metas ... *)
- w_unify_to_subterm env evd ~flags (strip_outer_cast op,t)
+ if is_keyed_unification () then
+ try (* First try finding a subterm w/o conversion on open terms *)
+ let flags = set_no_delta_open_flags flags in
+ w_unify_to_subterm env evd ~flags t'
+ with e ->
+ (* If this fails, try with full conversion *)
+ w_unify_to_subterm env evd ~flags t'
+ else w_unify_to_subterm env evd ~flags t'
with PretypeError (env,_,NoOccurrenceFound _) when
allow_K ||
(* w_unify_to_subterm does not go through evars, so