- | C.Meta (n,lc), t ->
- (try
- let _,_,term,_ = NCicUtils.lookup_subst n subst in
- let term = NCicSubstitution.subst_meta lc term in
- unify hdb test_eq_only metasenv subst context term t
- with NCicUtils.Subst_not_found _->
- instantiate hdb test_eq_only metasenv subst context n lc
- (NCicReduction.head_beta_reduce ~subst t) false)
-
- | t, C.Meta (n,lc) ->
- (try
- let _,_,term,_ = NCicUtils.lookup_subst n subst in
- let term = NCicSubstitution.subst_meta lc term in
- unify hdb test_eq_only metasenv subst context t term
- with NCicUtils.Subst_not_found _->
- instantiate hdb test_eq_only metasenv subst context n lc
- (NCicReduction.head_beta_reduce ~subst t) true)
+ | NCic.Appl (NCic.Meta (i,_)::_ as l1),
+ NCic.Appl (NCic.Meta (j,_)::_ as l2) when i=j ->
+ (try
+ List.fold_left2
+ (fun (metasenv, subst) t1 t2 ->
+ unify rdb test_eq_only metasenv subst context t1 t2)
+ (metasenv,subst) l1 l2
+ with Invalid_argument _ ->
+ raise (UnificationFailure (mk_msg metasenv subst context t1 t2)))
+
+ | _, NCic.Meta (n, _) when is_locked n subst ->
+ (let (metasenv, subst), i =
+ match NCicReduction.whd ~subst context t1 with
+ | NCic.Appl (NCic.Meta (i,l)::args) ->
+ let metasenv, subst, lambda_Mj =
+ lambda_intros rdb metasenv subst context t1 args
+ in
+ unify rdb test_eq_only metasenv subst context
+ (C.Meta (i,l)) lambda_Mj,
+ i
+ | NCic.Meta (i,_) -> (metasenv, subst), i
+ | _ ->
+ raise (UnificationFailure (lazy "Locked term vs non
+ flexible term; probably not saturated enough yet!"))
+ in
+ let t1 = NCicReduction.whd ~subst context t1 in
+ let j, lj =
+ match t1 with NCic.Meta (j,l) -> j, l | _ -> assert false
+ in
+ let metasenv, subst =
+ instantiate rdb test_eq_only metasenv subst context j lj t2 true
+ in
+ (* We need to remove the out_scope_tags to avoid propagation of
+ them that triggers again the ad-hoc case *)
+ let subst =
+ List.map (fun (i,(tag,ctx,bo,ty)) ->
+ let tag =
+ List.filter
+ (function `InScope | `OutScope _ -> false | _ -> true) tag
+ in
+ i,(tag,ctx,bo,ty)
+ ) subst
+ in
+ (try
+ let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
+ let term = eta_reduce subst term in
+ let subst = List.filter (fun (j,_) -> j <> i) subst in
+ metasenv, ((i, (name, ctx, term, ty)) :: subst)
+ with Not_found -> assert false))
+
+ | C.Meta (n,lc), t when List.mem_assoc n subst ->
+ let _,_,term,_ = NCicUtils.lookup_subst n subst in
+ let term = NCicSubstitution.subst_meta lc term in
+ unify rdb test_eq_only metasenv subst context term t
+
+ | t, C.Meta (n,lc) when List.mem_assoc n subst ->
+ let _,_,term,_ = NCicUtils.lookup_subst n subst in
+ let term = NCicSubstitution.subst_meta lc term in
+ unify rdb test_eq_only metasenv subst context t term