X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Fparamodulation%2Fsaturation.ml;h=6d5ecee159a8ba72f0d39b4351af16a044d837eb;hb=162a34842afbb574f89e3a358a79a310e7ec8b16;hp=793e48423b1d999d97a342fa8affe2048d2f3399;hpb=c9d7e6a946744890def5b5471c93b4dbd78c4ac9;p=helm.git

diff --git a/helm/ocaml/paramodulation/saturation.ml b/helm/ocaml/paramodulation/saturation.ml
index 793e48423..6d5ecee15 100644
--- a/helm/ocaml/paramodulation/saturation.ml
+++ b/helm/ocaml/paramodulation/saturation.ml
@@ -2,6 +2,10 @@ open Inference;;
 open Utils;;
 
 
+(* set to false to disable paramodulation inside auto_tac *)
+let connect_to_auto = true;;
+
+
 (* profiling statistics... *)
 let infer_time = ref 0.;;
 let forward_simpl_time = ref 0.;;
@@ -18,12 +22,15 @@ let elapsed_time = ref 0.;;
 let maximal_retained_equality = ref None;;
 
 (* equality-selection related globals *)
-let use_fullred = ref false;;
-let weight_age_ratio = ref 0;; (* settable by the user from the command line *)
+let use_fullred = ref true;;
+let weight_age_ratio = ref (* 5 *) 4;; (* settable by the user *)
 let weight_age_counter = ref !weight_age_ratio;;
-let symbols_ratio = ref 0;;
+let symbols_ratio = ref (* 0 *) 3;;
 let symbols_counter = ref 0;;
 
+(* non-recursive Knuth-Bendix term ordering by default *)
+Utils.compare_terms := Utils.nonrec_kbo;; 
+
 (* statistics... *)
 let derived_clauses = ref 0;;
 let kept_clauses = ref 0;;
@@ -33,8 +40,8 @@ let maxmeta = ref 0;;
 
 
 type result =
-  | Failure
-  | Success of Inference.equality option * environment
+  | ParamodulationFailure
+  | ParamodulationSuccess of Inference.equality option * environment
 ;;
 
 
@@ -44,7 +51,7 @@ let symbols_of_equality (_, (_, left, right), _, _) =
 ;;
 *)
 
-let symbols_of_equality ((_, (_, left, right, _), _, _) as equality) =
+let symbols_of_equality ((_, _, (_, left, right, _), _, _) as equality) =
   let m1 = symbols_of_term left in
   let m = 
     TermMap.fold
@@ -64,17 +71,6 @@ let symbols_of_equality ((_, (_, left, right, _), _, _) as equality) =
 ;;
 
 
-let weight_of_equality (_, (ty, left, right, _), _, _) =
-  let meta_number = ref 0 in
-  let weight_of t =
-    let weight, ml =  weight_of_term t in
-    meta_number := !meta_number + (List.fold_left (fun r (_, n) -> r+n) 0 ml);
-    weight
-  in
-  (weight_of ty) + (weight_of left) + (weight_of right), meta_number
-;;
-
-
 module OrderedEquality = struct
   type t = Inference.equality
 
@@ -82,17 +78,25 @@ module OrderedEquality = struct
     match meta_convertibility_eq eq1 eq2 with
     | true -> 0
     | false ->
-        let _, (ty, left, right, _), _, _ = eq1
-        and _, (ty', left', right', _), _, _ = eq2 in
-(*         let w1, m1 = weight_of_equality eq1 *)
-(*         and w2, m2 = weight_of_equality eq2 in        *)
-        let weight_of t = fst (weight_of_term ~consider_metas:false t) in
-        let w1 = (weight_of ty) + (weight_of left) + (weight_of right)
-        and w2 = (weight_of ty') + (weight_of left') + (weight_of right') in
+        let w1, _, (ty, left, right, _), _, a = eq1
+        and w2, _, (ty', left', right', _), _, a' = eq2 in
+(*         let weight_of t = fst (weight_of_term ~consider_metas:false t) in *)
+(*         let w1 = (weight_of ty) + (weight_of left) + (weight_of right) *)
+(*         and w2 = (weight_of ty') + (weight_of left') + (weight_of right') in *)
         match Pervasives.compare w1 w2 with
-        | 0 -> Pervasives.compare eq1 eq2
-(*             let res = Pervasives.compare m1 m2 in *)
-(*             if res = 0 then Pervasives.compare eq1 eq2 else res *)
+        | 0 ->
+            let res = (List.length a) - (List.length a') in
+            if res <> 0 then res else (
+              try
+                let res = Pervasives.compare (List.hd a) (List.hd a') in
+                if res <> 0 then res else Pervasives.compare eq1 eq2
+              with Failure "hd" -> Pervasives.compare eq1 eq2
+(*               match a, a' with *)
+(*               | (Cic.Meta (i, _)::_), (Cic.Meta (j, _)::_) -> *)
+(*                   let res = Pervasives.compare i j in *)
+(*                   if res <> 0 then res else Pervasives.compare eq1 eq2 *)
+(*               | _, _ -> Pervasives.compare eq1 eq2 *)
+            )
         | res -> res
 end
 
@@ -278,9 +282,13 @@ let prune_passive howmany (active, _) passive =
   let (nl, ns), (pl, ps), tbl = passive in
   let howmany = float_of_int howmany
   and ratio = float_of_int !weight_age_ratio in
-  let in_weight = int_of_float (howmany *. ratio /. (ratio +. 1.))
-  and in_age = int_of_float (howmany /. (ratio +. 1.)) in 
-  Printf.printf "in_weight: %d, in_age: %d\n" in_weight in_age;
+  let round v =
+    let t = ceil v in 
+    int_of_float (if t -. v < 0.5 then t else v)
+  in
+  let in_weight = round (howmany *. ratio /. (ratio +. 1.))
+  and in_age = round (howmany /. (ratio +. 1.)) in 
+  debug_print (Printf.sprintf "in_weight: %d, in_age: %d\n" in_weight in_age);
   let symbols, card =
     match active with
     | (Negative, e)::_ ->
@@ -361,7 +369,7 @@ let prune_passive howmany (active, _) passive =
   let _, ps, pl = picka in_age ps pl in
   if not (EqualitySet.is_empty ps) then
 (*     maximal_weight := Some (weight_of_equality (EqualitySet.max_elt ps)); *)
-    maximal_retained_equality := Some (EqualitySet.max_elt ps);
+    maximal_retained_equality := Some (EqualitySet.max_elt ps); 
   let tbl =
     EqualitySet.fold
       (fun e tbl -> Indexing.index tbl e) ps (Indexing.empty_table ())
@@ -379,7 +387,10 @@ let infer env sign current (active_list, active_table) =
   let new_neg, new_pos = 
     match sign with
     | Negative ->
-        Indexing.superposition_left env active_table current, []
+        let maxm, res = 
+          Indexing.superposition_left !maxmeta env active_table current in
+        maxmeta := maxm;
+        res, [] 
     | Positive ->
         let maxm, res =
           Indexing.superposition_right !maxmeta env active_table current in
@@ -387,7 +398,9 @@ let infer env sign current (active_list, active_table) =
         let rec infer_positive table = function
           | [] -> [], []
           | (Negative, equality)::tl ->
-              let res = Indexing.superposition_left env table equality in
+              let maxm, res =
+                Indexing.superposition_left !maxmeta env table equality in
+              maxmeta := maxm;
               let neg, pos = infer_positive table tl in
               res @ neg, pos
           | (Positive, equality)::tl ->
@@ -403,11 +416,52 @@ let infer env sign current (active_list, active_table) =
   in
   derived_clauses := !derived_clauses + (List.length new_neg) +
     (List.length new_pos);
-  match (* !maximal_weight *)!maximal_retained_equality with
+  match !maximal_retained_equality with
   | None -> new_neg, new_pos
-  | Some (* w *) eq ->
-      let new_pos =
-        List.filter (fun e -> (* (weight_of_equality e) <= w *) OrderedEquality.compare e eq <= 0) new_pos in
+  | Some eq ->
+      (* if we have a maximal_retained_equality, we can discard all equalities
+         "greater" than it, as they will never be reached...  An equality is
+         greater than maximal_retained_equality if it is bigger
+         wrt. OrderedEquality.compare and it is less similar than
+         maximal_retained_equality to the current goal *)
+      let symbols, card =
+        match active_list with
+        | (Negative, e)::_ ->
+            let symbols = symbols_of_equality e in
+            let card = TermMap.fold (fun k v res -> res + v) symbols 0 in
+            Some symbols, card
+        | _ -> None, 0
+      in
+      let new_pos = 
+        match symbols with
+        | None ->
+            List.filter (fun e -> OrderedEquality.compare e eq <= 0) new_pos
+        | Some symbols ->
+            let filterfun e =
+              if OrderedEquality.compare e eq <= 0 then
+                true
+              else
+                let foldfun k v (r1, r2) =
+                  if TermMap.mem k symbols then
+                    let c = TermMap.find k symbols in
+                    let c1 = abs (c - v) in
+                    let c2 = v - c1 in
+                    r1 + c2, r2 + c1
+                  else
+                    r1, r2 + v
+                in
+                let initial =
+                  let common, others =
+                    TermMap.fold foldfun (symbols_of_equality eq) (0, 0) in
+                  others + (abs (common - card))
+                in
+                let common, others =
+                  TermMap.fold foldfun (symbols_of_equality e) (0, 0) in
+                let c = others + (abs (common - card)) in
+                if c < initial then true else false 
+            in
+            List.filter filterfun new_pos
+      in
       new_neg, new_pos
 ;;
 
@@ -417,7 +471,7 @@ let contains_empty env (negative, positive) =
   try
     let found =
       List.find
-        (fun (proof, (ty, left, right, ordering), m, a) ->
+        (fun (w, proof, (ty, left, right, ordering), m, a) ->
            fst (CicReduction.are_convertible context left right ugraph))
         negative
     in
@@ -438,7 +492,7 @@ let forward_simplify env (sign, current) ?passive (active_list, active_table) =
   in
   let all = if pl = [] then active_list else active_list @ pl in
 
-(*   let rec find_duplicate sign current = function *)
+  (*   let rec find_duplicate sign current = function *)
 (*     | [] -> false *)
 (*     | (s, eq)::tl when s = sign -> *)
 (*         if meta_convertibility_eq current eq then true *)
@@ -458,11 +512,11 @@ let forward_simplify env (sign, current) ?passive (active_list, active_table) =
   
   let demodulate table current = 
     let newmeta, newcurrent =
-      Indexing.demodulation !maxmeta env table current in
+      Indexing.demodulation !maxmeta env table sign current in
     maxmeta := newmeta;
     if is_identity env newcurrent then
       if sign = Negative then Some (sign, newcurrent)
-      else (Inference.delete_proof newcurrent; None)
+      else None
     else
       Some (sign, newcurrent)
   in
@@ -486,13 +540,12 @@ let forward_simplify env (sign, current) ?passive (active_list, active_table) =
       if ok then res else None
   | Some (Positive, c) ->
       if Indexing.in_index active_table c then
-        (Inference.delete_proof c; None)
+        None
       else
         match passive_table with
         | None -> res
         | Some passive_table ->
-            if Indexing.in_index passive_table c then
-              (Inference.delete_proof c; None)
+            if Indexing.in_index passive_table c then None
             else res
 
 (*   | Some (s, c) -> if find_duplicate s c all then None else res *)
@@ -546,8 +599,9 @@ let forward_simplify_new env (new_neg, new_pos) ?passive active =
   let t2 = Unix.gettimeofday () in
   fs_time_info.build_all <- fs_time_info.build_all +. (t2 -. t1);
   
-  let demodulate table target =
-    let newmeta, newtarget = Indexing.demodulation !maxmeta env table target in
+  let demodulate sign table target =
+    let newmeta, newtarget =
+      Indexing.demodulation !maxmeta env table sign target in
     maxmeta := newmeta;
     newtarget
   in
@@ -559,13 +613,13 @@ let forward_simplify_new env (new_neg, new_pos) ?passive active =
   let t1 = Unix.gettimeofday () in
 
   let new_neg, new_pos =
-    let new_neg = List.map (demodulate active_table) new_neg
-    and new_pos = List.map (demodulate active_table) new_pos in
+    let new_neg = List.map (demodulate Negative active_table) new_neg
+    and new_pos = List.map (demodulate Positive active_table) new_pos in
     match passive_table with
     | None -> new_neg, new_pos
     | Some passive_table ->
-        List.map (demodulate passive_table) new_neg,
-        List.map (demodulate passive_table) new_pos
+        List.map (demodulate Negative passive_table) new_neg,
+        List.map (demodulate Positive passive_table) new_pos
   in
 
   let t2 = Unix.gettimeofday () in
@@ -575,12 +629,9 @@ let forward_simplify_new env (new_neg, new_pos) ?passive active =
     List.fold_left
       (fun s e ->
          if not (Inference.is_identity env e) then
-           if EqualitySet.mem e s then
-             (Inference.delete_proof e; s)
-           else
-             EqualitySet.add e s
-         else
-           (Inference.delete_proof e; s))
+           if EqualitySet.mem e s then s
+           else EqualitySet.add e s
+         else s)
       EqualitySet.empty new_pos
   in
   let new_pos = EqualitySet.elements new_pos_set in
@@ -612,16 +663,11 @@ let forward_simplify_new env (new_neg, new_pos) ?passive active =
   let is_duplicate =
     match passive_table with
     | None ->
-        (fun e ->
-           let ok = not (Indexing.in_index active_table e) in
-           if not ok then Inference.delete_proof e;
-           ok)
+        (fun e -> not (Indexing.in_index active_table e))
     | Some passive_table ->
         (fun e ->
-           let ok = not ((Indexing.in_index active_table e) ||
-                           (Indexing.in_index passive_table e)) in
-           if not ok then Inference.delete_proof e;
-           ok)
+           not ((Indexing.in_index active_table e) ||
+                  (Indexing.in_index passive_table e)))
   in
   new_neg, List.filter is_duplicate new_pos
 
@@ -635,18 +681,22 @@ let forward_simplify_new env (new_neg, new_pos) ?passive active =
 ;;
 
 
-let backward_simplify_active env new_pos new_table active =
+let backward_simplify_active env new_pos new_table min_weight active =
   let active_list, active_table = active in
   let active_list, newa = 
     List.fold_right
       (fun (s, equality) (res, newn) ->
-         match forward_simplify env (s, equality) (new_pos, new_table) with
-         | None -> res, newn
-         | Some (s, e) ->
-             if equality = e then
-               (s, e)::res, newn
-             else 
-               res, (s, e)::newn)
+         let ew, _, _, _, _ = equality in
+         if ew < min_weight then
+           (s, equality)::res, newn
+         else
+           match forward_simplify env (s, equality) (new_pos, new_table) with
+           | None -> res, newn
+           | Some (s, e) ->
+               if equality = e then
+                 (s, e)::res, newn
+               else 
+                 res, (s, e)::newn)
       active_list ([], [])
   in
   let find eq1 where =
@@ -658,7 +708,6 @@ let backward_simplify_active env new_pos new_table active =
          if List.mem (s, eq) res then
            res, tbl
          else if (is_identity env eq) || (find eq res) then (
-           Inference.delete_proof eq;
            res, tbl
          ) (* else if (find eq res) then *)
 (*            res, tbl *)
@@ -668,7 +717,6 @@ let backward_simplify_active env new_pos new_table active =
     List.fold_right
       (fun (s, eq) (n, p) ->
          if (s <> Negative) && (is_identity env eq) then (
-           Inference.delete_proof eq;
            (n, p)
          ) else
            if s = Negative then eq::n, p
@@ -681,17 +729,22 @@ let backward_simplify_active env new_pos new_table active =
 ;;
 
 
-let backward_simplify_passive env new_pos new_table passive =
+let backward_simplify_passive env new_pos new_table min_weight passive =
   let (nl, ns), (pl, ps), passive_table = passive in
   let f sign equality (resl, ress, newn) =
-    match forward_simplify env (sign, equality) (new_pos, new_table) with
-    | None -> resl, EqualitySet.remove equality ress, newn
-    | Some (s, e) ->
-        if equality = e then
-          equality::resl, ress, newn
-        else
-          let ress = EqualitySet.remove equality ress in
-          resl, ress, e::newn
+    let ew, _, _, _, _ = equality in
+    if ew < min_weight then
+(*       let _ = debug_print (Printf.sprintf "OK: %d %d" ew min_weight) in *)
+      equality::resl, ress, newn
+    else
+      match forward_simplify env (sign, equality) (new_pos, new_table) with
+      | None -> resl, EqualitySet.remove equality ress, newn
+      | Some (s, e) ->
+          if equality = e then
+            equality::resl, ress, newn
+          else
+            let ress = EqualitySet.remove equality ress in
+            resl, ress, e::newn
   in
   let nl, ns, newn = List.fold_right (f Negative) nl ([], ns, [])
   and pl, ps, newp = List.fold_right (f Positive) pl ([], ps, []) in
@@ -706,18 +759,21 @@ let backward_simplify_passive env new_pos new_table passive =
 
 
 let backward_simplify env new' ?passive active =
-  let new_pos, new_table =
+  let new_pos, new_table, min_weight =
     List.fold_left
-      (fun (l, t) e -> (Positive, e)::l, Indexing.index t e)
-      ([], Indexing.empty_table ()) (snd new')
-  in    
-  let active, newa = backward_simplify_active env new_pos new_table active in
+      (fun (l, t, w) e ->
+         let ew, _, _, _, _ = e in
+         (Positive, e)::l, Indexing.index t e, min ew w)
+      ([], Indexing.empty_table (), 1000000) (snd new')
+  in
+  let active, newa =
+    backward_simplify_active env new_pos new_table min_weight active in
   match passive with
   | None ->
       active, (make_passive [] []), newa, None
   | Some passive ->
       let passive, newp =
-        backward_simplify_passive env new_pos new_table passive in
+        backward_simplify_passive env new_pos new_table min_weight passive in
       active, passive, newa, newp
 ;;
 
@@ -740,12 +796,13 @@ let rec given_clause env passive active =
     if !time_limit = 0. || !processed_clauses = 0 then
       passive
     else if !elapsed_time > !time_limit then (
-      Printf.printf "Time limit (%.2f) reached: %.2f\n"
-        !time_limit !elapsed_time;
+      debug_print (Printf.sprintf "Time limit (%.2f) reached: %.2f\n"
+                     !time_limit !elapsed_time);
       make_passive [] []
     ) else if kept > selection_estimate then (
-      Printf.printf ("Too many passive equalities: pruning... (kept: %d, " ^^
-                       "selection_estimate: %d)\n") kept selection_estimate;
+      debug_print (Printf.sprintf ("Too many passive equalities: pruning..." ^^
+                                     "(kept: %d, selection_estimate: %d)\n")
+                     kept selection_estimate);
       prune_passive selection_estimate active passive
     ) else
       passive
@@ -757,7 +814,7 @@ let rec given_clause env passive active =
   kept_clauses := (size_of_passive passive) + (size_of_active active);
     
   match passive_is_empty passive with
-  | true -> Failure
+  | true -> ParamodulationFailure
   | false ->
       let (sign, current), passive = select env passive active in
       let time1 = Unix.gettimeofday () in
@@ -769,15 +826,14 @@ let rec given_clause env passive active =
           given_clause env passive active
       | Some (sign, current) ->
           if (sign = Negative) && (is_identity env current) then (
-            Printf.printf "OK!!! %s %s" (string_of_sign sign)
-              (string_of_equality ~env current);
-            print_newline ();
-            Success (Some current, env)
+            debug_print (Printf.sprintf "OK!!! %s %s" (string_of_sign sign)
+                           (string_of_equality ~env current));
+            ParamodulationSuccess (Some current, env)
           ) else (            
-            print_endline "\n================================================";
-            Printf.printf "selected: %s %s"
-              (string_of_sign sign) (string_of_equality ~env current);
-            print_newline ();
+            debug_print "\n================================================";
+            debug_print (Printf.sprintf "selected: %s %s"
+                           (string_of_sign sign)
+                           (string_of_equality ~env current));
 
             let t1 = Unix.gettimeofday () in
             let new' = infer env sign current active in
@@ -786,7 +842,7 @@ let rec given_clause env passive active =
             
             let res, goal = contains_empty env new' in
             if res then
-              Success (goal, env)
+              ParamodulationSuccess (goal, env)
             else 
               let t1 = Unix.gettimeofday () in
               let new' = forward_simplify_new env new' (* ~passive *) active in
@@ -849,7 +905,7 @@ let rec given_clause env passive active =
                         al @ [(sign, current)], Indexing.index tbl current
                   in
                   let passive = add_to_passive passive new' in
-(*                   let (_, ns), (_, ps), _ = passive in *)
+                  let (_, ns), (_, ps), _ = passive in
 (*                   Printf.printf "passive:\n%s\n" *)
 (*                     (String.concat "\n" *)
 (*                        ((List.map (fun e -> "Negative " ^ *)
@@ -861,7 +917,7 @@ let rec given_clause env passive active =
 (*                   print_newline (); *)
                   given_clause env passive active
               | true, goal ->
-                  Success (goal, env)
+                  ParamodulationSuccess (goal, env)
           )
 ;;
 
@@ -875,12 +931,13 @@ let rec given_clause_fullred env passive active =
     if !time_limit = 0. || !processed_clauses = 0 then
       passive
     else if !elapsed_time > !time_limit then (
-      Printf.printf "Time limit (%.2f) reached: %.2f\n"
-        !time_limit !elapsed_time;
+      debug_print (Printf.sprintf "Time limit (%.2f) reached: %.2f\n"
+                     !time_limit !elapsed_time);
       make_passive [] []
     ) else if kept > selection_estimate then (
-      Printf.printf ("Too many passive equalities: pruning... (kept: %d, " ^^
-                       "selection_estimate: %d)\n") kept selection_estimate;
+      debug_print (Printf.sprintf ("Too many passive equalities: pruning..." ^^
+                                     "(kept: %d, selection_estimate: %d)\n")
+                     kept selection_estimate);
       prune_passive selection_estimate active passive
     ) else
       passive
@@ -892,7 +949,7 @@ let rec given_clause_fullred env passive active =
   kept_clauses := (size_of_passive passive) + (size_of_active active);
 
   match passive_is_empty passive with
-  | true -> Failure
+  | true -> ParamodulationFailure
   | false ->
       let (sign, current), passive = select env passive active in
       let time1 = Unix.gettimeofday () in
@@ -904,15 +961,14 @@ let rec given_clause_fullred env passive active =
           given_clause_fullred env passive active
       | Some (sign, current) ->
           if (sign = Negative) && (is_identity env current) then (
-            Printf.printf "OK!!! %s %s" (string_of_sign sign)
-              (string_of_equality ~env current);
-            print_newline ();
-            Success (Some current, env)
+            debug_print (Printf.sprintf "OK!!! %s %s" (string_of_sign sign)
+                           (string_of_equality ~env current));
+            ParamodulationSuccess (Some current, env)
           ) else (
-            print_endline "\n================================================";
-            Printf.printf "selected: %s %s"
-              (string_of_sign sign) (string_of_equality ~env current);
-            print_newline ();
+            debug_print "\n================================================";
+            debug_print (Printf.sprintf "selected: %s %s"
+                           (string_of_sign sign)
+                           (string_of_equality ~env current));
 
             let t1 = Unix.gettimeofday () in
             let new' = infer env sign current active in
@@ -953,156 +1009,373 @@ let rec given_clause_fullred env passive active =
             if k < (kept - 1) then
               processed_clauses := !processed_clauses + (kept - 1 - k);
             
-(*             let _ = *)
-(*               Printf.printf "active:\n%s\n" *)
-(*                 (String.concat "\n" *)
-(*                    ((List.map *)
-(*                        (fun (s, e) -> (string_of_sign s) ^ " " ^ *)
-(*                           (string_of_equality ~env e)) (fst active)))); *)
-(*               print_newline (); *)
-(*             in *)
-(*             let _ = *)
-(*               match new' with *)
-(*               | neg, pos -> *)
-(*                   Printf.printf "new':\n%s\n" *)
-(*                     (String.concat "\n" *)
-(*                        ((List.map *)
-(*                            (fun e -> "Negative " ^ *)
-(*                               (string_of_equality ~env e)) neg) @ *)
-(*                           (List.map *)
-(*                              (fun e -> "Positive " ^ *)
-(*                                 (string_of_equality ~env e)) pos))); *)
-(*                   print_newline (); *)
-(*             in *)
+            let _ =
+              debug_print (
+                Printf.sprintf "active:\n%s\n"
+                  (String.concat "\n"
+                     ((List.map
+                         (fun (s, e) -> (string_of_sign s) ^ " " ^
+                            (string_of_equality ~env e)) (fst active)))))
+            in
+            let _ =
+              match new' with
+              | neg, pos ->
+                  debug_print (
+                    Printf.sprintf "new':\n%s\n"
+                      (String.concat "\n"
+                         ((List.map
+                             (fun e -> "Negative " ^
+                                (string_of_equality ~env e)) neg) @
+                            (List.map
+                               (fun e -> "Positive " ^
+                                  (string_of_equality ~env e)) pos))))
+            in
             match contains_empty env new' with
             | false, _ -> 
                 let passive = add_to_passive passive new' in
+(*                 let (_, ns), (_, ps), _ = passive in *)
+(*                 Printf.printf "passive:\n%s\n" *)
+(*                   (String.concat "\n" *)
+(*                      ((List.map (fun e -> "Negative " ^ *)
+(*                                    (string_of_equality ~env e)) *)
+(*                          (EqualitySet.elements ns)) @ *)
+(*                         (List.map (fun e -> "Positive " ^ *)
+(*                                      (string_of_equality ~env e)) *)
+(*                            (EqualitySet.elements ps)))); *)
+(*                 print_newline (); *)
                 given_clause_fullred env passive active
             | true, goal ->
-                Success (goal, env)
+                ParamodulationSuccess (goal, env)
           )
 ;;
 
 
-let get_from_user () =
-  let dbd = Mysql.quick_connect
-    ~host:"localhost" ~user:"helm" ~database:"mowgli" () in
-  let rec get () =
-    match read_line () with
-    | "" -> []
-    | t -> t::(get ())
-  in
-  let term_string = String.concat "\n" (get ()) in
-  let env, metasenv, term, ugraph =
-    List.nth (Disambiguate.Trivial.disambiguate_string dbd term_string) 0
-  in
-  term, metasenv, ugraph
-;;
-
-
 let given_clause_ref = ref given_clause;;
 
 
-let main () =
+let main dbd term metasenv ugraph =
   let module C = Cic in
   let module T = CicTypeChecker in
   let module PET = ProofEngineTypes in
   let module PP = CicPp in
-  let term, metasenv, ugraph = get_from_user () in
   let proof = None, (1, [], term)::metasenv, C.Meta (1, []), term in
-  let proof, goals =
-    PET.apply_tactic (PrimitiveTactics.intros_tac ()) (proof, 1) in
-  let goal = List.nth goals 0 in
+  let status = PET.apply_tactic (PrimitiveTactics.intros_tac ()) (proof, 1) in
+  let proof, goals = status in
+  let goal' = List.nth goals 0 in
   let _, metasenv, meta_proof, _ = proof in
-  let _, context, goal = CicUtil.lookup_meta goal metasenv in
+  let _, context, goal = CicUtil.lookup_meta goal' metasenv in
   let equalities, maxm = find_equalities context proof in
-  maxmeta := maxm; (* TODO ugly!! *)
+  let library_equalities, maxm =
+    find_library_equalities ~dbd context (proof, goal') (maxm+2)
+  in
+  maxmeta := maxm+2; (* TODO ugly!! *)
+  let irl = CicMkImplicit.identity_relocation_list_for_metavariable context in
+  let new_meta_goal, metasenv, type_of_goal =
+    let _, context, ty = CicUtil.lookup_meta goal' metasenv in
+    Printf.printf "\n\nTIPO DEL GOAL: %s\n" (CicPp.ppterm ty);
+    print_newline ();
+    Cic.Meta (maxm+1, irl),
+    (maxm+1, context, ty)::metasenv,
+    ty
+  in
+(*   let new_meta_goal = Cic.Meta (goal', irl) in *)
   let env = (metasenv, context, ugraph) in
   try
-    let term_equality = equality_of_term meta_proof goal in
-    let meta_proof, (eq_ty, left, right, ordering), _, _ = term_equality in
-    let active = make_active () in
-    let passive = make_passive [term_equality] equalities in
-    Printf.printf "\ncurrent goal: %s\n"
-      (string_of_equality ~env term_equality);
-    Printf.printf "\ncontext:\n%s\n" (PP.ppcontext context);
-    Printf.printf "\nmetasenv:\n%s\n" (print_metasenv metasenv);
-    Printf.printf "\nequalities:\n%s\n"
-      (String.concat "\n"
-         (List.map
-            (string_of_equality ~env)
-            equalities));
-    print_endline "--------------------------------------------------";
-    let start = Unix.gettimeofday () in
-    print_endline "GO!";
-    start_time := Unix.gettimeofday ();
-    let res =
-      (if !use_fullred then given_clause_fullred else given_clause)
-        env passive active
-    in
-    let finish = Unix.gettimeofday () in
-    let _ =
-      match res with
-      | Failure ->
-          Printf.printf "NO proof found! :-(\n\n"
-      | Success (Some goal, env) ->
-          Printf.printf "OK, found a proof!\n";
-          let proof = Inference.build_term_proof goal in
-          print_endline (PP.pp proof (names_of_context context));
-          print_endline (string_of_float (finish -. start));
-      | Success (None, env) ->
-          Printf.printf "Success, but no proof?!?\n\n"
-    in
-    Printf.printf ("infer_time: %.9f\nforward_simpl_time: %.9f\n" ^^
-                     "forward_simpl_new_time: %.9f\n" ^^
-                     "backward_simpl_time: %.9f\n")
-      !infer_time !forward_simpl_time !forward_simpl_new_time
-      !backward_simpl_time;
-    Printf.printf "passive_maintainance_time: %.9f\n"
-      !passive_maintainance_time;
-    Printf.printf "    successful unification/matching time: %.9f\n"
-      !Indexing.match_unif_time_ok;
-    Printf.printf "    failed unification/matching time: %.9f\n"
-      !Indexing.match_unif_time_no;
-    Printf.printf "    indexing retrieval time: %.9f\n"
-      !Indexing.indexing_retrieval_time;
-    Printf.printf "    demodulate_term.build_newtarget_time: %.9f\n"
-      !Indexing.build_newtarget_time;
-    Printf.printf "derived %d clauses, kept %d clauses.\n"
-      !derived_clauses !kept_clauses;
+    let term_equality = equality_of_term new_meta_goal goal in
+    let _, meta_proof, (eq_ty, left, right, ordering), _, _ = term_equality in
+    if is_identity env term_equality then
+      let proof =
+        Cic.Appl [Cic.MutConstruct (* reflexivity *)
+                    (HelmLibraryObjects.Logic.eq_URI, 0, 1, []);
+                  eq_ty; left]
+      in
+      let _ = 
+        Printf.printf "OK, found a proof!\n";
+        let names = names_of_context context in
+        print_endline (PP.pp proof names)
+      in
+      ()
+    else
+      let equalities =
+        let equalities = equalities @ library_equalities in
+        debug_print (
+          Printf.sprintf "equalities:\n%s\n"
+            (String.concat "\n"
+               (List.map string_of_equality equalities)));
+        debug_print "SIMPLYFYING EQUALITIES...";
+        let rec simpl e others others_simpl =
+          let active = others @ others_simpl in
+          let tbl =
+            List.fold_left
+              (fun t (_, e) -> Indexing.index t e)
+              (Indexing.empty_table ()) active
+          in
+          let res = forward_simplify env e (active, tbl) in
+          match others with
+          | hd::tl -> (
+              match res with
+              | None -> simpl hd tl others_simpl
+              | Some e -> simpl hd tl (e::others_simpl)
+            )
+          | [] -> (
+              match res with
+              | None -> others_simpl
+              | Some e -> e::others_simpl
+            )
+        in
+        match equalities with
+        | [] -> []
+        | hd::tl ->
+            let others = List.map (fun e -> (Positive, e)) tl in
+            let res =
+              List.rev (List.map snd (simpl (Positive, hd) others []))
+            in
+            debug_print (
+              Printf.sprintf "equalities AFTER:\n%s\n"
+                (String.concat "\n"
+                   (List.map string_of_equality res)));
+            res
+      in
+      let active = make_active () in
+      let passive = make_passive [term_equality] equalities in
+      Printf.printf "\ncurrent goal: %s\n"
+        (string_of_equality ~env term_equality);
+      Printf.printf "\ncontext:\n%s\n" (PP.ppcontext context);
+      Printf.printf "\nmetasenv:\n%s\n" (print_metasenv metasenv);
+      Printf.printf "\nequalities:\n%s\n"
+        (String.concat "\n"
+           (List.map
+              (string_of_equality ~env)
+              (equalities @ library_equalities)));
+      print_endline "--------------------------------------------------";
+      let start = Unix.gettimeofday () in
+      print_endline "GO!";
+      start_time := Unix.gettimeofday ();
+      let res =
+        (if !use_fullred then given_clause_fullred else given_clause)
+          env passive active
+      in
+      let finish = Unix.gettimeofday () in
+      let _ =
+        match res with
+        | ParamodulationFailure ->
+            Printf.printf "NO proof found! :-(\n\n"
+        | ParamodulationSuccess (Some goal, env) ->
+            let proof = Inference.build_proof_term goal in         
+            let newmetasenv =
+              List.fold_left
+                (fun m (_, _, _, menv, _) -> m @ menv) metasenv equalities
+            in
+            let _ =
+              try
+                let ty, ug =
+                  CicTypeChecker.type_of_aux' newmetasenv context proof ugraph
+                in
+                Printf.printf "OK, found a proof!\n";
+                (* REMEMBER: we have to instantiate meta_proof, we should use
+                   apply  the "apply" tactic to proof and status 
+                *)
+                let names = names_of_context context in
+                print_endline (PP.pp proof names);
+                (*           print_endline (PP.ppterm proof); *)
+                
+                print_endline (string_of_float (finish -. start));
+                Printf.printf
+                  "\nGOAL was: %s\nPROOF has type: %s\nconvertible?: %s\n\n"
+                  (CicPp.pp type_of_goal names) (CicPp.pp ty names)
+                  (string_of_bool
+                     (fst (CicReduction.are_convertible
+                             context type_of_goal ty ug)));
+              with e ->
+                Printf.printf "\nEXCEPTION!!! %s\n" (Printexc.to_string e);
+                Printf.printf "MAXMETA USED: %d\n" !maxmeta;
+                print_endline (string_of_float (finish -. start));
+            in
+            ()
+              
+        | ParamodulationSuccess (None, env) ->
+            Printf.printf "Success, but no proof?!?\n\n"
+      in
+      Printf.printf ("infer_time: %.9f\nforward_simpl_time: %.9f\n" ^^
+                       "forward_simpl_new_time: %.9f\n" ^^
+                       "backward_simpl_time: %.9f\n")
+        !infer_time !forward_simpl_time !forward_simpl_new_time
+        !backward_simpl_time;
+      Printf.printf "passive_maintainance_time: %.9f\n"
+        !passive_maintainance_time;
+      Printf.printf "    successful unification/matching time: %.9f\n"
+        !Indexing.match_unif_time_ok;
+      Printf.printf "    failed unification/matching time: %.9f\n"
+        !Indexing.match_unif_time_no;
+      Printf.printf "    indexing retrieval time: %.9f\n"
+        !Indexing.indexing_retrieval_time;
+      Printf.printf "    demodulate_term.build_newtarget_time: %.9f\n"
+        !Indexing.build_newtarget_time;
+      Printf.printf "derived %d clauses, kept %d clauses.\n"
+        !derived_clauses !kept_clauses;
   with exc ->
     print_endline ("EXCEPTION: " ^ (Printexc.to_string exc));
     raise exc
 ;;
 
 
-let configuration_file = ref "../../gTopLevel/gTopLevel.conf.xml";;
-
-let _ =
-  let set_ratio v = weight_age_ratio := (v+1); weight_age_counter := (v+1)
-  and set_sel v = symbols_ratio := v; symbols_counter := v;
-  and set_conf f = configuration_file := f
-  and set_lpo () = Utils.compare_terms := lpo
-  and set_kbo () = Utils.compare_terms := nonrec_kbo
-  and set_fullred () = use_fullred := true
-  and set_time_limit v = time_limit := float_of_int v
+let saturate dbd (proof, goal) =
+  let module C = Cic in
+  maxmeta := 0;
+  let goal' = goal in
+  let uri, metasenv, meta_proof, term_to_prove = proof in
+  let _, context, goal = CicUtil.lookup_meta goal' metasenv in
+  let equalities, maxm = find_equalities context proof in
+  let new_meta_goal, metasenv, type_of_goal =
+    let irl =
+      CicMkImplicit.identity_relocation_list_for_metavariable context in
+    let _, context, ty = CicUtil.lookup_meta goal' metasenv in
+    debug_print (Printf.sprintf "\n\nTIPO DEL GOAL: %s\n" (CicPp.ppterm ty));
+    Cic.Meta (maxm+1, irl),
+    (maxm+1, context, ty)::metasenv,
+    ty
   in
-  Arg.parse [
-    "-f", Arg.Unit set_fullred, "Use full-reduction strategy";
-    
-    "-r", Arg.Int set_ratio, "Weight-Age equality selection ratio (default: 0)";
-
-    "-s", Arg.Int set_sel,
-    "symbols-based selection ratio (relative to the weight ratio)";
+  let ugraph = CicUniv.empty_ugraph in
+  let env = (metasenv, context, ugraph) in
+(*   try *)
+  let term_equality = equality_of_term new_meta_goal goal in
+  let res, time = 
+    if is_identity env term_equality then
+      let w, _, (eq_ty, left, right, o), m, a = term_equality in
+      let proof =
+        Cic.Appl [Cic.MutConstruct (* reflexivity *)
+                    (HelmLibraryObjects.Logic.eq_URI, 0, 1, []);
+                  eq_ty; left]
+      in
+      (ParamodulationSuccess
+         (Some (0, Inference.BasicProof proof,
+                (eq_ty, left, right, o), m, a), env), 0.)
+    else
+      let library_equalities, maxm =
+        find_library_equalities ~dbd context (proof, goal') (maxm+2)
+      in
+      maxmeta := maxm+2;
+      let equalities =
+        let equalities = equalities @ library_equalities in
+        debug_print (
+          Printf.sprintf "equalities:\n%s\n"
+            (String.concat "\n"
+               (List.map string_of_equality equalities)));
+        debug_print "SIMPLYFYING EQUALITIES...";
+        let rec simpl e others others_simpl =
+          let active = others @ others_simpl in
+          let tbl =
+            List.fold_left
+              (fun t (_, e) -> Indexing.index t e)
+              (Indexing.empty_table ()) active
+          in
+          let res = forward_simplify env e (active, tbl) in
+          match others with
+          | hd::tl -> (
+              match res with
+              | None -> simpl hd tl others_simpl
+              | Some e -> simpl hd tl (e::others_simpl)
+            )
+          | [] -> (
+              match res with
+              | None -> others_simpl
+              | Some e -> e::others_simpl
+            )
+        in
+        match equalities with
+        | [] -> []
+        | hd::tl ->
+            let others = List.map (fun e -> (Positive, e)) tl in
+            let res =
+              List.rev (List.map snd (simpl (Positive, hd) others []))
+            in
+            debug_print (
+              Printf.sprintf "equalities AFTER:\n%s\n"
+                (String.concat "\n"
+                   (List.map string_of_equality res)));
+            res
+      in      
+      let active = make_active () in
+      let passive = make_passive [term_equality] equalities in
+      let start = Unix.gettimeofday () in
+      let res = given_clause_fullred env passive active in
+      let finish = Unix.gettimeofday () in
+      (res, finish -. start)
+  in
+  match res with
+  | ParamodulationSuccess (Some goal, env) ->
+      debug_print "OK, found a proof!";
+      let proof = Inference.build_proof_term goal in         
+      let names = names_of_context context in
+      let newmetasenv =
+        let i1 =
+          match new_meta_goal with
+          | C.Meta (i, _) -> i | _ -> assert false
+        in
+(*           let i2 = *)
+(*             match meta_proof with *)
+(*             | C.Meta (i, _) -> i *)
+(*             | t -> *)
+(*                 Printf.printf "\nHMMM!!! meta_proof: %s\ngoal': %s" *)
+(*                   (CicPp.pp meta_proof names) (string_of_int goal'); *)
+(*                 print_newline (); *)
+(*                 assert false *)
+(*           in *)
+        List.filter (fun (i, _, _) -> i <> i1 && i <> goal') metasenv
+      in
+      let newstatus =
+        try
+          let ty, ug =
+            CicTypeChecker.type_of_aux' newmetasenv context proof ugraph
+          in
+          debug_print (CicPp.pp proof [](* names *));
+          debug_print
+            (Printf.sprintf
+               "\nGOAL was: %s\nPROOF has type: %s\nconvertible?: %s\n"
+               (CicPp.pp type_of_goal names) (CicPp.pp ty names)
+               (string_of_bool
+                  (fst (CicReduction.are_convertible
+                          context type_of_goal ty ug))));
+          let equality_for_replace i t1 =
+            match t1 with
+            | C.Meta (n, _) -> n = i
+            | _ -> false
+          in
+          let real_proof =
+            ProofEngineReduction.replace
+              ~equality:equality_for_replace
+              ~what:[goal'] ~with_what:[proof]
+              ~where:meta_proof
+          in
+          debug_print (
+            Printf.sprintf "status:\n%s\n%s\n%s\n%s\n"
+              (match uri with Some uri -> UriManager.string_of_uri uri
+               | None -> "")
+              (print_metasenv newmetasenv)
+              (CicPp.pp real_proof [](* names *))
+              (CicPp.pp term_to_prove names));
+          ((uri, newmetasenv, real_proof, term_to_prove), [])
+        with CicTypeChecker.TypeCheckerFailure _ ->
+          debug_print "THE PROOF DOESN'T TYPECHECK!!!";
+          debug_print (CicPp.pp proof names);
+          raise (ProofEngineTypes.Fail
+                   "Found a proof, but it doesn't typecheck")
+      in
+      debug_print (Printf.sprintf "\nTIME NEEDED: %.9f" time);
+      newstatus          
+  | _ ->
+      raise (ProofEngineTypes.Fail "NO proof found")
+(*   with e -> *)
+(*     raise (Failure "saturation failed") *)
+;;
 
-    "-c", Arg.String set_conf, "Configuration file (for the db connection)";
 
-    "-lpo", Arg.Unit set_lpo, "Use lpo term ordering";
+(* dummy function called within matita to trigger linkage *)
+let init () = ();;
 
-    "-kbo", Arg.Unit set_kbo, "Use (non-recursive) kbo term ordering (default)";
 
-    "-l", Arg.Int set_time_limit, "Time limit (in seconds)";
-  ] (fun a -> ()) "Usage:"
-in
-Helm_registry.load_from !configuration_file;
-main ()
+(* UGLY SIDE EFFECT... *)
+if connect_to_auto then ( 
+  AutoTactic.paramodulation_tactic := saturate;
+  AutoTactic.term_is_equality := Inference.term_is_equality;
+);;