X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fng_paramodulation%2Fterms.mli;h=d7f4b74e30c99792ce39c936d16d0a279cfe8c09;hb=01b628fc79155f545b283c1d095d8a2ffe00e0a1;hp=c49eaff832727d06f200df5bffce38aacb2f5bf4;hpb=ddd751449e73a22af523ce78ce1d8f0bb211e941;p=helm.git

diff --git a/helm/software/components/ng_paramodulation/terms.mli b/helm/software/components/ng_paramodulation/terms.mli
index c49eaff83..d7f4b74e3 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
+
+(* 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 *)
 
@@ -48,5 +54,25 @@ 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 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
+
+    val embed : t -> t foterm 
+    (* saturate [proof] [type] -> [proof] * [type] *)
+    val saturate : t -> t -> t foterm * t foterm
+  end