+module NodeHash = Hashtbl.Make (Node)
+
+type t = (StateSet.t*StateSet.t) NodeHash.t
+(** Map from nodes to query and recognizing states *)
+(* Note that we do not consider the nil nodes *)
+
+exception Oracle_fail
+exception Over_max_fail
+exception Max_fail
+
+(* Mapped sets for leaves *)
+let map_leaf asta = (Asta.bot_states_s asta, StateSet.empty)
+
+(* Build the Oracle *)
+let rec bu_oracle asta run tree tnode =
+ let node = Tree.preorder tree tnode in
+ if Tree.is_leaf tree tnode
+ then
+ if tnode == Tree.nil
+ then ()
+ else NodeHash.add run node (map_leaf asta)
+ else
+ let tfnode = Tree.first_child tree tnode (* first child *)
+ and tnnode = Tree.next_sibling tree tnode in (* next-sibling *)
+ let fnode,nnode = (* their preorders *)
+ (Tree.preorder tree tfnode, Tree.preorder tree tnnode) in
+ begin
+ bu_oracle asta run tree tfnode;
+ bu_oracle asta run tree tnnode;
+ let q_rec n = (* compute the set for child/sibling *)
+ try NodeHash.find run n
+ with Not_found -> map_leaf asta in
+ let (_,qfr),(_,qnr) = q_rec fnode,q_rec nnode (* computed in rec call *)
+ and lab = Tree.tag tree tnode in
+ let _,list_tr = Asta.transitions_lab asta lab in (* only reco. tran.*)
+ let rec result set = function
+ | [] -> set
+ | (q,form) :: tl ->
+ if Formula.eval_form (qfr,qnr) form (* evaluates the formula *)
+ then result (StateSet.add q set) tl
+ else result set tl in
+ let result_set = result StateSet.empty list_tr in
+ NodeHash.add run node (StateSet.empty, result_set)
+ end
+
+(* Build the over-approx. of the maximal run *)
+let rec bu_over_max asta run tree tnode =
+ if (Tree.is_leaf tree tnode) (* BU_oracle has already created the map *)
+ then
+ ()
+ else
+ let tfnode = Tree.first_child tree tnode
+ and tnnode = Tree.next_sibling tree tnode in
+ begin
+ bu_over_max asta run tree tfnode;
+ bu_over_max asta run tree tnnode;
+ let (fnode,nnode) =
+ (Tree.preorder tree tfnode, Tree.preorder tree tnnode)
+ and node = Tree.preorder tree tnode in
+ let q_rec n =
+ try NodeHash.find run n
+ with Not_found -> map_leaf asta in
+ let (qfq,qfr),(qnq,qnr) = q_rec fnode,q_rec nnode in
+ let lab = Tree.tag tree tnode in
+ let list_tr,_ = Asta.transitions_lab asta lab in (* only take query st. *)
+ let rec result set = function
+ | [] -> set
+ | (q,form) :: tl ->
+ if Formula.infer_form (qfq,qnq) (qfr,qnr) form (* infers the formula*)
+ then result (StateSet.add q set) tl
+ else result set tl in
+ let _,resultr = try NodeHash.find run node
+ with _ -> raise Over_max_fail in
+ let result_set = result StateSet.empty list_tr in
+ (* we keep the old recognizing states set *)
+ NodeHash.replace run node (result_set, resultr)
+ end
+