X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fng_paramodulation%2Fterms.mli;h=e0576d1f3e95dea87cd8d3955b125ac41e4f9588;hb=1eb00eff3c3a5f67c3a200a82098c97f4fbe0c5e;hp=3013ed7d0fb700b7bea4998b89f04571f66e40d2;hpb=6c4056ea40b96039f24eeda9a1e1900c95bad7c8;p=helm.git

diff --git a/helm/software/components/ng_paramodulation/terms.mli b/helm/software/components/ng_paramodulation/terms.mli
index 3013ed7d0..e0576d1f3 100644
--- 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 *)
 
@@ -48,21 +54,27 @@ type 'a passive_clause = int * 'a unit_clause (* weight * equation *)
 
 module M : Map.S with type key = int 
 
-type 'a bag = 'a unit_clause M.t
+type 'a bag = ('a unit_clause * bool) M.t
 
 module type Blob =
   sig
+    (* Blob is the type for opaque leaves: 
+     * - checking equlity should be efficient
+     * - atoms have to be equipped with a total order relation
+     *)
     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
 
-module Utils (B : Blob) :
-  sig
-    val eq_literal : B.t literal -> B.t literal -> bool
-    val compare_literal : B.t literal -> B.t literal -> int
+    type input
+    val embed : input -> t foterm
+    (* saturate [proof] [type] -> [proof] * [type] *)
+    val saturate : input -> input -> t foterm * t foterm
 
-    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
+