+type config = {
+ sat : StateSet.t;
+ unsat : StateSet.t;
+ todo : TransList.t;
+}
+
+let eq_config c1 c2 =
+ c1.sat == c2.sat && c1.unsat == c2.unsat && c1.todo == c2.todo
+
+let simplify_atom atom pos q config =
+ if (pos && StateSet.mem q config.sat)
+ || ((not pos) && StateSet.mem q config.unsat) then SFormula.true_
+ else if (pos && StateSet.mem q config.unsat)
+ || ((not pos) && StateSet.mem q config.sat) then SFormula.false_
+ else atom
+
+
+let eval_form2 phi fcs nss ps ss is_left is_right has_left has_right kind =
+ let rec loop phi =
+ begin match SFormula.expr phi with
+ Formula.True | Formula.False -> phi
+ | Formula.Atom a ->
+ let p, b, q = Atom.node a in begin
+ match p with
+ | First_child -> simplify_atom phi b q fcs
+ | Next_sibling -> simplify_atom phi b q nss
+ | Parent | Previous_sibling -> simplify_atom phi b q ps
+ | Stay -> simplify_atom phi b q ss
+ | Is_first_child -> SFormula.of_bool (b == is_left)
+ | Is_next_sibling -> SFormula.of_bool (b == is_right)
+ | Is k -> SFormula.of_bool (b == (k == kind))
+ | Has_first_child -> SFormula.of_bool (b == has_left)
+ | Has_next_sibling -> SFormula.of_bool (b == has_right)
+ end
+ | Formula.And(phi1, phi2) -> SFormula.and_ (loop phi1) (loop phi2)
+ | Formula.Or (phi1, phi2) -> SFormula.or_ (loop phi1) (loop phi2)
+ end
+ in
+ loop phi
+
+
+
+let eval_trans2 auto fcs nss ps ss is_left is_right has_left has_right kind =
+ let rec loop old_config =
+ let { sat = old_sat; unsat = old_unsat; todo = old_todo } = old_config in
+ let sat, unsat, removed, kept, todo =
+ TransList.fold
+ (fun trs acc ->
+ let q, lab, phi = Transition.node trs in
+ let a_sat, a_unsat, a_rem, a_kept, a_todo = acc in
+ if StateSet.mem q a_sat || StateSet.mem q a_unsat then acc else
+ let new_phi =
+ eval_form2
+ phi fcs nss ps old_config
+ is_left is_right has_left has_right kind
+ in
+ if SFormula.is_true new_phi then
+ StateSet.add q a_sat, a_unsat, StateSet.add q a_rem, a_kept, a_todo
+ else if SFormula.is_false new_phi then
+ a_sat, StateSet.add q a_unsat, StateSet.add q a_rem, a_kept, a_todo
+ else
+ let new_tr = Transition.make (q, lab, new_phi) in
+ (a_sat, a_unsat, a_rem, StateSet.add q a_kept, (TransList.cons new_tr a_todo))
+ ) old_todo (old_sat, old_unsat, StateSet.empty, StateSet.empty, TransList.nil)
+ in
+ (* States that have been removed from the todo list and not kept are now
+ unsatisfiable *)
+ let unsat = StateSet.union unsat (StateSet.diff removed kept) in
+ (* States that were found once to be satisfiable remain so *)
+ let unsat = StateSet.diff unsat sat in
+ let new_config = { sat; unsat; todo } in
+ if sat == old_sat && unsat == old_unsat && todo == old_todo then new_config
+ else loop new_config
+ in
+ loop ss