+let eval_form2 phi fcs nss ps ss summary =
+ 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 summary))
+ | Is_next_sibling -> SFormula.of_bool (b == (is_right summary))
+ | Is k -> SFormula.of_bool (b == (k == (kind summary)))
+ | Has_first_child -> SFormula.of_bool (b == (has_left summary))
+ | Has_next_sibling -> SFormula.of_bool (b == (has_right summary))
+ 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_trans auto fcs nss ps ss =
+ let rec loop old_config =
+ let { sat = old_sat;
+ unsat = old_unsat;
+ todo = old_todo;
+ summary = old_summary } = old_config.Config.node
+ 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 old_summary
+ 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 = Config.make { sat; unsat; todo ; summary = old_summary } in
+ if sat == old_sat && unsat == old_unsat && todo == old_todo then new_config
+ else loop new_config
+ in
+ loop ss