X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fng_paramodulation%2Fterms.ml;h=a7173b1b96989be4cdee817a5169f3a895ba4ac9;hb=39a2078b0e835d39895a5b6c0862d668ece544f3;hp=9a225fd27b2807f3a3ea37d57276eb93332e384a;hpb=016f069da6221053873b4d505716ef1bd80f08b6;p=helm.git

diff --git a/helm/software/components/ng_paramodulation/terms.ml b/helm/software/components/ng_paramodulation/terms.ml
index 9a225fd27..a7173b1b9 100644
--- a/helm/software/components/ng_paramodulation/terms.ml
+++ b/helm/software/components/ng_paramodulation/terms.ml
@@ -18,7 +18,7 @@ type 'a foterm =
 
 type 'a substitution = (int * 'a foterm) list
 
-type comparison = Lt | Eq | Gt | Incomparable
+type comparison = Lt | Eq | Gt | Incomparable | Invertible
 
 type rule = Superposition | Demodulation
 type direction = Left2Right | Right2Left | Nodir
@@ -44,15 +44,24 @@ type 'a unit_clause =
  * varlist       (* variable list *)
  * 'a proof      (* proof *)
 
-type 'a passive_clause = int * 'a unit_clause (* weight * equation *)
+type 'a clause =
+    int
+    * ('a literal * bool) list (* left hand side of the arrow,
+				  with flag for selection *)
+    * ('a literal * bool) list (* right hand side of the arrow,
+				  with flag for selection *)
+    * varlist
+    * 'a proof
 
+type 'a passive_clause = int * 'a clause (* weight * equation *)
 
-let vars_of_term t =
+
+let vars_of_term ?(start_acc=[]) t =
   let rec aux acc = function
     | Leaf _ -> acc
     | Var i -> if (List.mem i acc) then acc else i::acc
     | Node l -> List.fold_left aux acc l
-  in aux [] t
+  in aux start_acc t
 ;;
 
 module OT =