Prevent loosing labels in transformations.

Prevent loosing labels of formulas with f.t_node equal to Tquant in
transformations eliminate_algebraic and introduce_premises.

src/transform/eliminate_algebraic.ml

@@ -171,7 +171,8 @@ and rewriteF kn state av sign f = match f.t_node with
                       (rewriteF kn state Svs.empty sign) tr in
       let av = List.fold_left (fun s v -> Svs.add v s) av vl in
       let f1 = rewriteF kn state av sign f1 in
-      t_quant_simp q (close vl tr f1)
+      (* Preserve labels and location of f *)
+      t_label_copy f (t_quant_simp q (close vl tr f1))
   | Tbinop (o, _, _) when (o = Tand && sign) || (o = Tor && not sign) ->
       TermTF.t_map_sign (Util.const (rewriteT kn state))
         (rewriteF kn state av) sign f

src/transform/introduction.ml

@@ -23,7 +23,7 @@ open Decl
 let rec intros pr f = match f.t_node with
   | Tbinop (Timplies,f1,f2) ->
       (* split f1 *)
-      (* f is going to be removed, preserve its labels (and possibly also location) in f2  *)
+      (* f is going to be removed, preserve its labels and location in f2  *)
       let f2 = t_label_copy f f2 in
       let l = Split_goal.split_pos_intro f1 in
       List.fold_right
@@ -34,14 +34,15 @@ let rec intros pr f = match f.t_node with
         l
         (intros pr f2)
   | Tquant (Tforall,fq) ->
-      let vsl,_trl,f = t_open_quant fq in
+      let vsl,_trl,f_t = t_open_quant fq in
       let intro_var subst vs =
         let ls = create_lsymbol (id_clone vs.vs_name) [] (Some vs.vs_ty) in
         Mvs.add vs (fs_app ls [] vs.vs_ty) subst,
         create_param_decl ls
       in
       let subst, dl = Lists.map_fold_left intro_var Mvs.empty vsl in
-      let f = t_subst subst f in
+      (* preserve labels and location of f  *)
+      let f = t_label_copy f (t_subst subst f_t) in
       dl @ intros pr f
   | Tlet (t,fb) ->
       let vs,f = t_open_bound fb in