Implemented LPO

[helm.git] / helm / software / components / ng_paramodulation / terms.mli

diff --git a/helm/software/components/ng_paramodulation/terms.mli b/helm/software/components/ng_paramodulation/terms.mli
index f5aaa619f2dc01dfac4c13d661f7cc29b65597bd..47295035ca47e7196beb616887c4d98cccbb7a5c 100644 (file)
--- a/helm/software/components/ng_paramodulation/terms.mli
+++ b/helm/software/components/ng_paramodulation/terms.mli
@@ -18,14 +18,20 @@ type 'a foterm =
 
 type 'a substitution = (int * 'a foterm) list
 
-type comparison = Lt | Le | Eq | Ge | Gt | Incomparable
+type comparison = Lt | Eq | Gt | Incomparable
 
-type rule = SuperpositionRight | SuperpositionLeft | Demodulation
+type rule = Superposition | Demodulation
+
+(* A Discrimination tree is a map: foterm |-> (dir, clause) *)
 type direction = Left2Right | Right2Left | Nodir
+
 type position = int list
 
 type 'a proof =
-  | Exact of 'a
+  | Exact of 'a foterm
+         (* for theorems like T : \forall x. C[x] = D[x] the proof is 
+          * a foterm like (Node [ Leaf T ; Var i ]), while for the Goal
+          * it is just (Var g), i.e. the identity proof *)
   | Step of rule * int * int * direction * position * 'a substitution
          (* rule, eq1, eq2, direction of eq2, position, substitution *)
 
@@ -46,9 +52,26 @@ type 'a unit_clause =
 
 type 'a passive_clause = int * 'a unit_clause (* weight * equation *)
 
+val vars_of_term : 'a foterm -> int list
+
 module M : Map.S with type key = int 
 
-type 'a bag = 'a unit_clause M.t
+type 'a bag = int (* max ID  *)
+              * (('a unit_clause * bool * int) M.t)
+
+(* also gives a fresh ID to the clause *)
+    val add_to_bag : 
+          'a unit_clause -> 'a bag ->
+            'a bag * 'a unit_clause
+
+    val replace_in_bag : 
+          'a unit_clause * bool * int -> 'a bag ->
+            'a bag
+
+    val get_from_bag : 
+          int -> 'a bag -> 'a unit_clause * bool * int
+
+    val empty_bag : 'a bag
 
 module type Blob =
   sig
@@ -59,20 +82,16 @@ module type Blob =
     type t
     val eq : t -> t -> bool
     val compare : t -> t -> int
+    val eqP : t
     (* TODO: consider taking in input an imperative buffer for Format 
      *  val pp : Format.formatter -> t -> unit
      * *)
-    val pp : t -> string 
-  end
+    val pp : t -> string
 
-module Utils (B : Blob) :
-  sig
-    val eq_foterm : B.t foterm -> B.t foterm -> bool
-    val compare_foterm : B.t foterm -> B.t foterm -> int
+    type input
+    val embed : input -> t foterm
+    (* saturate [proof] [type] -> [proof] * [type] *)
+    val saturate : input -> input -> t foterm * t foterm
 
-    val eq_literal : B.t literal -> B.t literal -> bool
-    val compare_literal : B.t literal -> B.t literal -> int
-
-    val eq_unit_clause : B.t unit_clause -> B.t unit_clause -> bool
-    val compare_unit_clause : B.t unit_clause -> B.t unit_clause -> int
   end
+