+ (* 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))
+ | NCic.Meta (n, _), _ when is_locked n subst && swap ->
+ unify rdb test_eq_only metasenv subst context t2 t1 false
+
+ | 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 swap
+ | C.Meta (n,_), _ when List.mem_assoc n subst ->
+ unify rdb test_eq_only metasenv subst context t2 t1 (not swap)
+
+ | _, NCic.Appl (NCic.Meta (i,l)::args) when List.mem_assoc i subst ->
+ let _,_,term,_ = NCicUtils.lookup_subst i subst in
+ let term = NCicSubstitution.subst_meta l term in
+ unify rdb test_eq_only metasenv subst context t1
+ (mk_appl ~upto:(List.length args) term args) swap
+ | NCic.Appl (NCic.Meta (i,_)::_), _ when List.mem_assoc i subst ->
+ unify rdb test_eq_only metasenv subst context t2 t1 (not swap)
+
+ | C.Meta (n,_), C.Meta (m,lc') when
+ let _,cc1,_ = NCicUtils.lookup_meta n metasenv in
+ let _,cc2,_ = NCicUtils.lookup_meta m metasenv in
+ (n < m && cc1 = cc2) ||
+ let len1 = List.length cc1 in
+ let len2 = List.length cc2 in
+ len2 < len1 && cc2 = fst (HExtlib.split_nth len2 cc1) ->
+ instantiate rdb test_eq_only metasenv subst context m lc'
+ (NCicReduction.head_beta_reduce ~subst t1) (not swap)
+ | C.Meta (n,lc), t ->
+ instantiate rdb test_eq_only metasenv subst context n lc
+ (NCicReduction.head_beta_reduce ~subst t) swap
+ | t, C.Meta (n,lc) ->
+ instantiate rdb test_eq_only metasenv subst context n lc
+ (NCicReduction.head_beta_reduce ~subst t) (not swap)
+
+ | NCic.Appl (NCic.Meta (i,l) as meta :: args), _ ->
+ let metasenv, lambda_Mj =
+ lambda_intros rdb metasenv subst context (List.length args)
+ (NCicTypeChecker.typeof ~metasenv ~subst context meta)
+ in
+ let metasenv, subst =
+ try
+ unify rdb test_eq_only metasenv subst context
+ (C.Meta (i,l)) lambda_Mj swap
+ with UnificationFailure msg | Uncertain msg when not norm2->
+ (* failure: let's try again argument vs argument *)
+ raise (KeepReducing msg)
+ in
+ let metasenv, subst =
+ unify rdb test_eq_only metasenv subst context t1 t2 swap
+ 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)
+ | _, NCic.Appl (NCic.Meta (_,_) :: _) ->
+ unify rdb test_eq_only metasenv subst context t2 t1 (not swap)