diff --git a/src/plugins/alias/abstract_state.ml b/src/plugins/alias/abstract_state.ml
index 2c82946b31441d8bf26ac37b51f641908f8f99b7..9af3dced6b0a54a8e0e16085da453522d8e46193 100644
--- a/src/plugins/alias/abstract_state.ml
+++ b/src/plugins/alias/abstract_state.ml
@@ -112,7 +112,7 @@ let pretty ?(debug=false) =
 
 (** invariants of type t must be true before and after each functon call *)
 let assert_invariants (x:t) : unit =
-  Format.printf "Checking invariants@.%a@." (pretty ~debug:true) x;
+  (* Format.printf "Checking invariants@.%a@." (pretty ~debug:true) x; *)
   (* check that all vertex of the graph have entries in pending and vmap, and are integer between 0 and cmpt *)
   let assert_vertex (v:V.t) =
     assert (v >= 0);
diff --git a/src/plugins/alias/abstract_state.mli b/src/plugins/alias/abstract_state.mli
index 35f2a6f063335e6d8d64b54fe7ab863520d854ab..2ad7d6c10f4e71d23139156e44c0971828253203 100644
--- a/src/plugins/alias/abstract_state.mli
+++ b/src/plugins/alias/abstract_state.mli
@@ -36,10 +36,11 @@ module LMap = Lval.Map
 type t
 
 (** check all the invariants that must be true on an abstract value
-    before and after each function call *)
+    before and after each function call or transformation of the graph)  *)
 val assert_invariants : t -> unit
 
-(** pretty printer *)
+(** pretty printer; debug=true prints the graph, debug = false only
+    prints aliased variables *)
 val pretty : ?debug:bool -> Format.formatter -> t -> unit
 
 (** dot printer *)
@@ -48,13 +49,19 @@ val print_dot : string -> t -> unit
 (** finds the vertex corresponding to a lval *)
 val find_vertex : lval -> t -> G.V.t
 
-(** Functions for the analysis *)
+(** finds the vertex corresponding to a lval; if not present creates
+    the corresponding node in the graph; the (maybe modifed) graph is
+    returned as well *)
+val find_or_create_vertex : lval -> t -> G.V.t * G.t
+
+(** Functions for Steensgaard's algorithm *)
 val join : t -> G.V.t -> G.V.t -> t
 
 val cjoin : t -> G.V.t -> G.V.t -> t
 
 val set_type : t -> G.V.t -> G.V.t -> t
 
+(** transfert functions for different kinds of assignments *)
 val assignment_x_y : t -> lval -> lval -> t
 
 val assignment_x_addr_y : t -> lval -> lval -> t
@@ -67,6 +74,7 @@ val assignment_ptr_x_y : t -> lval -> lval -> t
 
 val assignment_ptr_x_cst : t -> lval -> t
 
+(** equality test *)
 val equal : t -> t -> bool
 
 (** union of two abstract values ; ensures that if 2 lval are aliased
@@ -74,7 +82,7 @@ val equal : t -> t -> bool
     then they will also be aliased/points-to in the result *)
 val union : t -> t -> t
 
-(* empty graph *)
+(** empty graph *)
 val initial_value : t
 
 (** Type denoting summaries of functions *)
diff --git a/src/plugins/alias/analysis.ml b/src/plugins/alias/analysis.ml
index 8126810ccd64e5b23c8f2dd5401b3f63ca50c870..28a681c7dac1437ba77bc75413084bf0a228f5b8 100644
--- a/src/plugins/alias/analysis.ml
+++ b/src/plugins/alias/analysis.ml
@@ -79,10 +79,10 @@ struct
     | None -> Format.fprintf fmt "None"
     | Some s -> Format.fprintf fmt "%a" (Abstract_state.pretty ~debug:false) s
 
-  let pretty_debug fmt state =
-    match state with
-    | None -> Format.fprintf fmt "None"
-    | Some s -> Format.fprintf fmt "%a" (Abstract_state.pretty ~debug:true) s
+  (* let pretty_debug fmt state =
+   *   match state with
+   *   | None -> Format.fprintf fmt "None"
+   *   | Some s -> Format.fprintf fmt "%a" (Abstract_state.pretty ~debug:true) s *)
 
   let  computeFirstPredecessor _ a = a
 
@@ -97,7 +97,7 @@ struct
         Some (Some (Abstract_state.union old new_))
 
   let do_assignment (a:t) (lv:lval) (exp:exp) : t =
-    Format.printf "State before do_assignment %a = %a : @[%a@]@." Lval.pretty lv Exp.pretty exp pretty_debug a;
+    (* Format.printf "State before do_assignment %a = %a : @[%a@]@." Lval.pretty lv Exp.pretty exp pretty_debug a; *)
     match (a,lv,exp.enode) with
       (Some a, (Var v1, NoOffset), Lval (Var v2,NoOffset)) ->
       (* case x = y *)
diff --git a/src/plugins/alias/tests/basic/oracle/test.res.oracle b/src/plugins/alias/tests/basic/oracle/test.res.oracle
index eff48a5c96ac71e58f3f303650392270a718c35b..a1861b053e48fc30dbdc6db5ca79abe63b59a263 100644
--- a/src/plugins/alias/tests/basic/oracle/test.res.oracle
+++ b/src/plugins/alias/tests/basic/oracle/test.res.oracle
@@ -2,4 +2,4 @@
 [alias] Parsing done
 [alias] Functions done
 [alias] Analysis complete
-[]
\ No newline at end of file
+[]
diff --git a/src/plugins/alias/tests/real_world/oracle/example1.res.oracle b/src/plugins/alias/tests/real_world/oracle/example1.res.oracle
index 11a6a2ae06d49c8146f5bfd2d768e5ef0d5332c2..ef70b78f374f8c9e4632daf45526fac603ae5065 100644
--- a/src/plugins/alias/tests/real_world/oracle/example1.res.oracle
+++ b/src/plugins/alias/tests/real_world/oracle/example1.res.oracle
@@ -1597,4 +1597,4 @@ VMap:
 <end of list>
 )
 [alias] Analysis complete
-]
\ No newline at end of file
+]