Experimental: cycles in proofs generated by paramodulation are now detected

[helm.git] / helm / software / components / tactics / paramodulation / utils.ml

diff --git a/helm/software/components/tactics/paramodulation/utils.ml b/helm/software/components/tactics/paramodulation/utils.ml
index 8b67ddb05a6a0b05ecee68300a69d29a142e9295..00d745fd906fb1ec2ac0aa6fa88a11faa17b7515 100644 (file)
--- a/helm/software/components/tactics/paramodulation/utils.ml
+++ b/helm/software/components/tactics/paramodulation/utils.ml
@@ -98,11 +98,24 @@ let metas_of_term term =
     | C.Meta _ as t -> TermSet.singleton t
     | C.Appl l ->
         List.fold_left (fun res t -> TermSet.union res (aux t)) TermSet.empty l
+    | C.Lambda(n,s,t) ->
+       TermSet.union (aux s) (aux t)
+    | C.Prod(n,s,t) ->
+       TermSet.union (aux s) (aux t)
+    | C.LetIn(n,s,t) ->
+       TermSet.union (aux s) (aux t)
     | t -> TermSet.empty (* TODO: maybe add other cases? *)
   in
   aux term
 ;;
 
+let rec remove_local_context =
+  function
+    | Cic.Meta (i,_) -> Cic.Meta (i,[])
+    | Cic.Appl l ->
+       Cic.Appl(List.map remove_local_context l)
+    | t -> t 
+
 
 (************************* rpo ********************************)
 let number = [
@@ -292,6 +305,29 @@ end
 
 module IntSet = Set.Make(OrderedInt)
 
+let goal_symbols = ref TermSet.empty
+
+let set_of_map m = 
+  TermMap.fold (fun k _ s -> TermSet.add k s) m TermSet.empty
+;;
+
+let set_goal_symbols term = 
+  let m = symbols_of_term term in
+  goal_symbols := (set_of_map m)
+;;
+
+let symbols_of_eq (ty,left,right,_) = 
+  let sty = set_of_map (symbols_of_term ty) in
+  let sl = set_of_map (symbols_of_term left) in
+  let sr = set_of_map (symbols_of_term right) in
+  TermSet.union sty (TermSet.union sl sr)
+;;
+
+let distance sgoal seq =
+  let s = TermSet.diff seq sgoal in
+  TermSet.cardinal s
+;;
+
 let compute_equality_weight (ty,left,right,o) =
   let factor = 2 in
   match o with
@@ -314,6 +350,21 @@ let compute_equality_weight (ty,left,right,o) =
       w1 + w2 + (factor * (List.length m1)) + (factor * (List.length m2))
 ;;
 
+let compute_equality_weight e =
+  let w = compute_equality_weight e in
+  let d = 0 in (* distance !goal_symbols (symbols_of_eq e) in *)
+(*
+  prerr_endline (Printf.sprintf "dist %s --- %s === %d" 
+   (String.concat ", " (List.map (CicPp.ppterm) (TermSet.elements
+     !goal_symbols)))
+   (String.concat ", " (List.map (CicPp.ppterm) (TermSet.elements
+     (symbols_of_eq e))))
+   d
+  );
+*)
+  w + d 
+;;
+
 (* old
 let compute_equality_weight (ty,left,right,o) =
   let metasw = ref 0 in
@@ -709,14 +760,6 @@ let guarded_simpl ?(debug=false) context t =
       end
 ;;
 
-type equality_sign = Negative | Positive;;
-
-let string_of_sign = function
-  | Negative -> "Negative"
-  | Positive -> "Positive"
-;;
-
-
 type pos = Left | Right 
 
 let string_of_pos = function