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
* 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 =