| `Previous_sibling
| `Stay ]
+module Move =
+struct
+ type t = move
+ type 'a table = 'a array
+ let idx = function
+ | `First_child -> 0
+ | `Next_sibling -> 1
+ | `Parent -> 2
+ | `Previous_sibling -> 3
+ | `Stay -> 4
+ let ridx = function
+ | 0 -> `First_child
+ | 1 -> `Next_sibling
+ | 2 -> `Parent
+ | 3 -> `Previous_sibling
+ | 4 -> `Stay
+ | _ -> assert false
+
+ let create_table a = Array.make 5 a
+ let get m k = m.(idx k)
+ let set m k v = m.(idx k) <- v
+ let iter f m = Array.iteri (fun i v -> f (ridx i) v) m
+ let fold f m acc =
+ let acc = ref acc in
+ iter (fun i v -> acc := f i v !acc) m;
+ !acc
+ let for_all p m =
+ try
+ iter (fun i v -> if not (p i v) then raise Exit) m;
+ true
+ with
+ Exit -> false
+ let for_all2 p m1 m2 =
+ try
+ for i = 0 to 4 do
+ let v1 = m1.(i)
+ and v2 = m2.(i) in
+ if not (p (ridx i) v1 v2) then raise Exit
+ done;
+ true
+ with
+ Exit -> false
+
+ let exists p m =
+ try
+ iter (fun i v -> if p i v then raise Exit) m;
+ false
+ with
+ Exit -> true
+ let print ppf m =
+ match m with
+ `First_child -> fprintf ppf "%s" Pretty.down_arrow
+ | `Next_sibling -> fprintf ppf "%s" Pretty.right_arrow
+ | `Parent -> fprintf ppf "%s" Pretty.up_arrow
+ | `Previous_sibling -> fprintf ppf "%s" Pretty.left_arrow
+ | `Stay -> fprintf ppf "%s" Pretty.bullet
+
+ let print_table pr_e ppf m =
+ iter (fun i v -> fprintf ppf "%a: %a" print i pr_e v;
+ if (idx i) < 4 then fprintf ppf ", ") m
+end
+
type predicate = Move of move * State.t
| Is_first_child
| Is_next_sibling
let print ppf a =
match a.node with
- | Move (m, q) -> begin
- match m with
- `First_child -> fprintf ppf "%s" Pretty.down_arrow
- | `Next_sibling -> fprintf ppf "%s" Pretty.right_arrow
- | `Parent -> fprintf ppf "%s" Pretty.up_arrow
- | `Previous_sibling -> fprintf ppf "%s" Pretty.left_arrow
- | `Stay -> fprintf ppf "%s" Pretty.bullet
- end;
- fprintf ppf "%a" State.print q
+ | Move (m, q) ->
+ fprintf ppf "%a%a" Move.print m State.print q
| Is_first_child -> fprintf ppf "%s?" Pretty.up_arrow
| Is_next_sibling -> fprintf ppf "%s?" Pretty.left_arrow
| Is k -> fprintf ppf "is-%a?" Tree.NodeKind.print k
has_first_child
let next_sibling q =
- and_
- (mk_move `Next_sibling q)
- has_next_sibling
+ and_
+ (mk_move `Next_sibling q)
+ has_next_sibling
let parent q =
- and_
- (mk_move `Parent q)
- is_first_child
+ and_
+ (mk_move `Parent q)
+ is_first_child
let previous_sibling q =
- and_
- (mk_move `Previous_sibling q)
- is_next_sibling
+ and_
+ (mk_move `Previous_sibling q)
+ is_next_sibling
let stay q = mk_move `Stay q
- let get_states phi =
- fold (fun phi acc ->
+ let get_states_by_move phi =
+ let table = Move.create_table StateSet.empty in
+ iter (fun phi ->
match expr phi with
- | Boolean.Atom ({ Atom.node = Move(_,q) ; _ }, _) -> StateSet.add q acc
- | _ -> acc
- ) phi StateSet.empty
+ | Boolean.Atom ({ Atom.node = Move(v,q) ; _ }, _) ->
+ let s = Move.get table v in
+ Move.set table v (StateSet.add q s)
+ | _ -> ()
+ ) phi;
+ table
+ let get_states phi =
+ let table = get_states_by_move phi in
+ Move.fold (fun _ s acc -> StateSet.union s acc) table StateSet.empty
end
module Transition =
- struct
- include Hcons.Make (struct
- type t = State.t * QNameSet.t * Formula.t
- let equal (a, b, c) (d, e, f) =
- a == d && b == e && c == f
- let hash (a, b, c) =
- HASHINT4 (PRIME1, a, ((QNameSet.uid b) :> int), ((Formula.uid c) :> int))
-end)
- let print ppf t =
- let q, l, f = t.node in
- fprintf ppf "%a, %a %s %a"
- State.print q
- QNameSet.print l
- Pretty.double_right_arrow
- Formula.print f
- end
+struct
+ include Hcons.Make (struct
+ type t = State.t * QNameSet.t * Formula.t
+ let equal (a, b, c) (d, e, f) =
+ a == d && b == e && c == f
+ let hash (a, b, c) =
+ HASHINT4 (PRIME1, a, ((QNameSet.uid b) :> int), ((Formula.uid c) :> int))
+ end)
+ let print ppf t =
+ let q, l, f = t.node in
+ fprintf ppf "%a, %a %s %a"
+ State.print q
+ QNameSet.print l
+ Pretty.double_right_arrow
+ Formula.print f
+end
module TransList : sig
include Hlist.S with type elt = Transition.t
val print : Format.formatter -> ?sep:string -> t -> unit
end =
- struct
- include Hlist.Make(Transition)
- let print ppf ?(sep="\n") l =
- iter (fun t ->
- let q, lab, f = Transition.node t in
- fprintf ppf "%a, %a -> %a%s" State.print q QNameSet.print lab Formula.print f sep) l
- end
+struct
+ include Hlist.Make(Transition)
+ let print ppf ?(sep="\n") l =
+ iter (fun t ->
+ let q, lab, f = Transition.node t in
+ fprintf ppf "%a, %a → %a%s"
+ State.print q
+ QNameSet.print lab
+ Formula.print f sep) l
+end
+type rank = { td : StateSet.t;
+ bu : StateSet.t;
+ exit : StateSet.t }
type t = {
mutable starting_states : StateSet.t;
mutable selecting_states: StateSet.t;
transitions: (State.t, (QNameSet.t*Formula.t) list) Hashtbl.t;
+ mutable ranked_states : rank array
}
let uid t = t.id
let get_states a = a.states
let get_starting_states a = a.starting_states
let get_selecting_states a = a.selecting_states
-
+let get_states_by_rank a = a.ranked_states
+let get_max_rank a = Array.length a.ranked_states - 1
let _pr_buff = Buffer.create 50
let _str_fmt = formatter_of_buffer _pr_buff
fprintf fmt
"Internal UID: %i@\n\
States: %a@\n\
+ Number of states: %i@\n\
Starting states: %a@\n\
Selection states: %a@\n\
+ Ranked states: %a@\n\
Alternating transitions:@\n"
(a.id :> int)
StateSet.print a.states
+ (StateSet.cardinal a.states)
StateSet.print a.starting_states
- StateSet.print a.selecting_states;
+ StateSet.print a.selecting_states
+ (let r = ref 0 in Pretty.print_array ~sep:", " (fun ppf s ->
+ fprintf ppf "(%i:{td=%a,bu=%a,exit=%a)" !r
+ StateSet.print s.td StateSet.print s.bu StateSet.print s.exit;
+ incr r)) a.ranked_states;
let trs =
Hashtbl.fold
(fun q t acc -> List.fold_left (fun acc (s , f) -> (q,s,f)::acc) acc t)
[]
in
let sorted_trs = List.stable_sort (fun (q1, s1, _) (q2, s2, _) ->
- let c = State.compare q1 q2 in - (if c == 0 then QNameSet.compare s1 s2 else c))
+ let c = State.compare q2 q1 in if c == 0 then QNameSet.compare s2 s1 else c)
trs
in
let _ = _flush_str_fmt () in
- let strs_strings, max_pre, max_all = List.fold_left (fun (accl, accp, acca) (q, s, f) ->
- let s1 = State.print _str_fmt q; _flush_str_fmt () in
- let s2 = QNameSet.print _str_fmt s; _flush_str_fmt () in
- let s3 = Formula.print _str_fmt f; _flush_str_fmt () in
- let pre = Pretty.length s1 + Pretty.length s2 in
- let all = Pretty.length s3 in
- ( (q, s1, s2, s3) :: accl, max accp pre, max acca all)
- ) ([], 0, 0) sorted_trs
+ let strs_strings, max_pre, max_all =
+ List.fold_left (fun (accl, accp, acca) (q, s, f) ->
+ let s1 = State.print _str_fmt q; _flush_str_fmt () in
+ let s2 = QNameSet.print _str_fmt s; _flush_str_fmt () in
+ let s3 = Formula.print _str_fmt f; _flush_str_fmt () in
+ let pre = Pretty.length s1 + Pretty.length s2 in
+ let all = Pretty.length s3 in
+ ( (q, s1, s2, s3) :: accl, max accp pre, max acca all)
+ ) ([], 0, 0) sorted_trs
in
let line = Pretty.line (max_all + max_pre + 6) in
let prev_q = ref State.dummy in
if !prev_q != q && !prev_q != State.dummy then fprintf fmt "%s@\n" line;
prev_q := q;
fprintf fmt "%s, %s" s1 s2;
- fprintf fmt "%s" (Pretty.padding (max_pre - Pretty.length s1 - Pretty.length s2));
+ fprintf fmt "%s"
+ (Pretty.padding (max_pre - Pretty.length s1 - Pretty.length s2));
fprintf fmt " %s %s@\n" Pretty.right_arrow s3;
) strs_strings;
fprintf fmt "%s@\n" line
let rec flip b f =
match Formula.expr f with
Boolean.True | Boolean.False -> if b then f else Formula.not_ f
- | Boolean.Or(f1, f2) -> (if b then Formula.or_ else Formula.and_)(flip b f1) (flip b f2)
- | Boolean.And(f1, f2) -> (if b then Formula.and_ else Formula.or_)(flip b f1) (flip b f2)
+ | Boolean.Or(f1, f2) ->
+ (if b then Formula.or_ else Formula.and_)(flip b f1) (flip b f2)
+ | Boolean.And(f1, f2) ->
+ (if b then Formula.and_ else Formula.or_)(flip b f1) (flip b f2)
| Boolean.Atom(a, b') -> begin
match a.Atom.node with
| Move (m, q) ->
- if b == b' then begin
- (* a appears positively, either no negation or double negation *)
- if not (Hashtbl.mem memo_state (q,b)) then Queue.add (q,true) todo;
- Formula.mk_atom (Move(m, q))
- end else begin
- (* need to reverse the atom
- either we have a positive state deep below a negation
- or we have a negative state in a positive formula
- b' = sign of the state
- b = sign of the enclosing formula
- *)
- let not_q =
- try
- (* does the inverted state of q exist ? *)
- Hashtbl.find memo_state (q, false)
- with
- Not_found ->
- (* create a new state and add it to the todo queue *)
- let nq = State.make () in
- auto.states <- StateSet.add nq auto.states;
- Hashtbl.add memo_state (q, false) nq;
- Queue.add (q, false) todo; nq
- in
- Formula.mk_atom (Move (m,not_q))
- end
+ if b == b' then begin
+ (* a appears positively, either no negation or double negation *)
+ if not (Hashtbl.mem memo_state (q,b)) then Queue.add (q,true) todo;
+ Formula.mk_atom (Move(m, q))
+ end else begin
+ (* need to reverse the atom
+ either we have a positive state deep below a negation
+ or we have a negative state in a positive formula
+ b' = sign of the state
+ b = sign of the enclosing formula
+ *)
+ let not_q =
+ try
+ (* does the inverted state of q exist ? *)
+ Hashtbl.find memo_state (q, false)
+ with
+ Not_found ->
+ (* create a new state and add it to the todo queue *)
+ let nq = State.make () in
+ auto.states <- StateSet.add nq auto.states;
+ Hashtbl.add memo_state (q, false) nq;
+ Queue.add (q, false) todo; nq
+ in
+ Formula.mk_atom (Move (m,not_q))
+ end
| _ -> if b then f else Formula.not_ f
end
in
while not (Queue.is_empty todo) do
let (q, b) as key = Queue.pop todo in
- let q' =
- try
- Hashtbl.find memo_state key
- with
- Not_found ->
- let nq = if b then q else
- let nq = State.make () in
- auto.states <- StateSet.add nq auto.states;
- nq
- in
- Hashtbl.add memo_state key nq; nq
- in
- let trans = try Hashtbl.find auto.transitions q with Not_found -> [] in
- let trans' = List.map (fun (lab, f) -> lab, flip b f) trans in
- Hashtbl.replace auto.transitions q' trans';
+ if not (StateSet.mem q auto.starting_states) then
+ let q' =
+ try
+ Hashtbl.find memo_state key
+ with
+ Not_found ->
+ let nq = if b then q else
+ let nq = State.make () in
+ auto.states <- StateSet.add nq auto.states;
+ nq
+ in
+ Hashtbl.add memo_state key nq; nq
+ in
+ let trans = try Hashtbl.find auto.transitions q with Not_found -> [] in
+ let trans' = List.map (fun (lab, f) -> lab, flip b f) trans in
+ Hashtbl.replace auto.transitions q' trans';
done;
cleanup_states auto
+(* [compute_dependencies auto] returns a hash table storing for each
+ states [q] a Move.table containing the set of states on which [q]
+ depends (loosely). [q] depends on [q'] if there is a transition
+ [q, {...} -> phi], where [q'] occurs in [phi].
+*)
+let compute_dependencies auto =
+ let edges = Hashtbl.create 17 in
+ StateSet.iter
+ (fun q -> Hashtbl.add edges q (Move.create_table StateSet.empty))
+ auto.starting_states;
+ Hashtbl.iter (fun q trans ->
+ let moves = try Hashtbl.find edges q with Not_found ->
+ let m = Move.create_table StateSet.empty in
+ Hashtbl.add edges q m;
+ m
+ in
+ List.iter (fun (_, phi) ->
+ let m_phi = Formula.get_states_by_move phi in
+ Move.iter (fun m set ->
+ Move.set moves m (StateSet.union set (Move.get moves m)))
+ m_phi) trans) auto.transitions;
+
+ edges
+
+let state_prerequisites dir auto q =
+ let trans = Hashtbl.find auto.transitions q in
+ List.fold_left (fun acc (_, phi) ->
+ let m_phi = Formula.get_states_by_move phi in
+ let prereq = Move.get m_phi dir in
+ StateSet.union prereq acc)
+ StateSet.empty trans
+
+
+let compute_rank auto =
+ let dependencies = compute_dependencies auto in
+ let upward = [ `Stay ; `Parent ; `Previous_sibling ] in
+ let downward = [ `Stay; `First_child; `Next_sibling ] in
+ let swap dir = if dir == upward then downward else upward in
+ let is_satisfied dir q t =
+ Move.for_all (fun d set ->
+ if List.mem d dir then
+ StateSet.(is_empty (remove q set))
+ else StateSet.is_empty set) t
+ in
+ let update_dependencies dir initacc =
+ let rec loop acc =
+ let new_acc =
+ Hashtbl.fold (fun q deps acc ->
+ let to_remove = StateSet.union acc initacc in
+ List.iter
+ (fun m ->
+ Move.set deps m (StateSet.diff (Move.get deps m) to_remove)
+ )
+ dir;
+ if is_satisfied dir q deps then StateSet.add q acc else acc
+ ) dependencies acc
+ in
+ if acc == new_acc then new_acc else loop new_acc
+ in
+ let satisfied = loop StateSet.empty in
+ StateSet.iter (fun q ->
+ Hashtbl.remove dependencies q) satisfied;
+ satisfied
+ in
+ let current_states = ref StateSet.empty in
+ let rank_list = ref [] in
+ let rank = ref 0 in
+ let current_dir = ref upward in
+ let detect_cycle = ref 0 in
+ while Hashtbl.length dependencies != 0 do
+ let new_sat = update_dependencies !current_dir !current_states in
+ if StateSet.is_empty new_sat then incr detect_cycle;
+ if !detect_cycle > 2 then assert false;
+ rank_list := (!rank, new_sat) :: !rank_list;
+ rank := !rank + 1;
+ current_dir := swap !current_dir;
+ current_states := StateSet.union new_sat !current_states;
+ done;
+ let by_rank = Hashtbl.create 17 in
+ List.iter (fun (r,s) ->
+ let set = try Hashtbl.find by_rank r with Not_found -> StateSet.empty in
+ Hashtbl.replace by_rank r (StateSet.union s set)) !rank_list;
+ let rank = Hashtbl.length by_rank in
+ if rank mod 2 == 1 then Hashtbl.replace by_rank rank StateSet.empty;
+ let rank = Hashtbl.length by_rank in
+ assert (rank mod 2 == 0);
+ let rank_array =
+ Array.init (rank / 2)
+ (fun i ->
+ let td_set = Hashtbl.find by_rank (2 * i) in
+ let bu_set = Hashtbl.find by_rank (2 * i + 1) in
+ { td = td_set; bu = bu_set ; exit = StateSet.empty }
+ )
+ in
+ let max_rank = Array.length rank_array - 1 in
+ for i = 0 to max_rank do
+ let this_rank = rank_array.(i) in
+ let exit = if i == max_rank then auto.selecting_states else
+ let next = rank_array.(i+1) in
+ let res =
+ StateSet.fold (fun q acc ->
+ List.fold_left (fun acc m ->
+ StateSet.union acc (state_prerequisites m auto q ))
+ acc [`First_child; `Next_sibling; `Parent; `Previous_sibling; `Stay]
+ ) (StateSet.union next.td next.bu) StateSet.empty
+ in
+
+ StateSet.(
+ union auto.selecting_states ( inter res (union this_rank.td this_rank.bu)))
-
+ in
+ rank_array.(i) <- {this_rank with exit = exit };
+ done;
+ auto.ranked_states <- rank_array
module Builder =
- struct
- type auto = t
- type t = auto
- let next = Uid.make_maker ()
-
- let make () =
- let auto =
- {
- id = next ();
- states = StateSet.empty;
- starting_states = StateSet.empty;
- selecting_states = StateSet.empty;
- transitions = Hashtbl.create MED_H_SIZE;
- }
- in
- (*
- at_exit (fun () ->
- let n4 = ref 0 in
- let n2 = ref 0 in
- Cache.N2.iteri (fun _ _ _ b -> if b then incr n2) auto.cache2;
- Cache.N4.iteri (fun _ _ _ _ _ b -> if b then incr n4) auto.cache4;
- Logger.msg `STATS "automaton %i, cache2: %i entries, cache6: %i entries"
- (auto.id :> int) !n2 !n4;
- let c2l, c2u = Cache.N2.stats auto.cache2 in
- let c4l, c4u = Cache.N4.stats auto.cache4 in
- Logger.msg `STATS
- "cache2: length: %i, used: %i, occupation: %f"
- c2l c2u (float c2u /. float c2l);
- Logger.msg `STATS
- "cache4: length: %i, used: %i, occupation: %f"
- c4l c4u (float c4u /. float c4l)
-
- ); *)
- auto
-
- let add_state a ?(starting=false) ?(selecting=false) q =
- a.states <- StateSet.add q a.states;
- if starting then a.starting_states <- StateSet.add q a.starting_states;
- if selecting then a.selecting_states <- StateSet.add q a.selecting_states
-
- let add_trans a q s f =
- if not (StateSet.mem q a.states) then add_state a q;
- let trs = try Hashtbl.find a.transitions q with Not_found -> [] in
- let cup, ntrs =
- List.fold_left (fun (acup, atrs) (labs, phi) ->
- let lab1 = QNameSet.inter labs s in
- let lab2 = QNameSet.diff labs s in
- let tr1 =
- if QNameSet.is_empty lab1 then []
- else [ (lab1, Formula.or_ phi f) ]
- in
- let tr2 =
- if QNameSet.is_empty lab2 then []
- else [ (lab2, Formula.or_ phi f) ]
- in
- (QNameSet.union acup labs, tr1@ tr2 @ atrs)
- ) (QNameSet.empty, []) trs
- in
- let rem = QNameSet.diff s cup in
- let ntrs = if QNameSet.is_empty rem then ntrs
- else (rem, f) :: ntrs
- in
- Hashtbl.replace a.transitions q ntrs
+struct
+ type auto = t
+ type t = auto
+ let next = Uid.make_maker ()
+
+ let make () =
+ let auto =
+ {
+ id = next ();
+ states = StateSet.empty;
+ starting_states = StateSet.empty;
+ selecting_states = StateSet.empty;
+ transitions = Hashtbl.create MED_H_SIZE;
+ ranked_states = [| |]
+ }
+ in
+ auto
+
+ let add_state a ?(starting=false) ?(selecting=false) q =
+ a.states <- StateSet.add q a.states;
+ if starting then a.starting_states <- StateSet.add q a.starting_states;
+ if selecting then a.selecting_states <- StateSet.add q a.selecting_states
+
+ let add_trans a q s f =
+ if not (StateSet.mem q a.states) then add_state a q;
+ let trs = try Hashtbl.find a.transitions q with Not_found -> [] in
+ let cup, ntrs =
+ List.fold_left (fun (acup, atrs) (labs, phi) ->
+ let lab1 = QNameSet.inter labs s in
+ let lab2 = QNameSet.diff labs s in
+ let tr1 =
+ if QNameSet.is_empty lab1 then []
+ else [ (lab1, Formula.or_ phi f) ]
+ in
+ let tr2 =
+ if QNameSet.is_empty lab2 then []
+ else [ (lab2, Formula.or_ phi f) ]
+ in
+ (QNameSet.union acup labs, tr1@ tr2 @ atrs)
+ ) (QNameSet.empty, []) trs
+ in
+ let rem = QNameSet.diff s cup in
+ let ntrs = if QNameSet.is_empty rem then ntrs
+ else (rem, f) :: ntrs
+ in
+ Hashtbl.replace a.transitions q ntrs
- let finalize a =
- complete_transitions a;
- normalize_negations a;
- a
- end
+ let finalize a =
+ complete_transitions a;
+ normalize_negations a;
+ compute_rank a;
+ a
+end
let map_set f s =
| Boolean.Or(phi1, phi2) -> Formula.or_ (map_form f phi1) (map_form f phi2)
| Boolean.And(phi1, phi2) -> Formula.and_ (map_form f phi1) (map_form f phi2)
| Boolean.Atom({ Atom.node = Move(m,q); _}, b) ->
- let a = Formula.mk_atom (Move (m,f q)) in
- if b then a else Formula.not_ a
+ let a = Formula.mk_atom (Move (m,f q)) in
+ if b then a else Formula.not_ a
| _ -> phi
let rename_states mapper a =
(fun l ->
(List.map (fun (labels, form) -> (labels, map_form rename form)) l))
a.transitions;
+ ranked_states = Array.map (fun s ->
+ { td = map_set rename s.td;
+ bu = map_set rename s.bu;
+ exit = map_set rename s.exit;
+ }) a.ranked_states
}
let copy a =
(fun q ->
Hashtbl.replace a1.transitions q [(QNameSet.any, link_phi)])
a2.starting_states;
- { a1 with
+ let a = { a1 with
states = StateSet.union a1.states a2.states;
selecting_states = a2.selecting_states;
transitions = a1.transitions;
}
+ in compute_rank a; a
let merge a1 a2 =
let a1 = copy a1 in
let a2 = copy a2 in
- { a1 with
+ let a = { a1 with
states = StateSet.union a1.states a2.states;
selecting_states = StateSet.union a1.selecting_states a2.selecting_states;
starting_states = StateSet.union a1.starting_states a2.starting_states;
Hashtbl.iter (fun k v -> Hashtbl.add a1.transitions k v) a2.transitions
in
a1.transitions
+ } in
+ compute_rank a ; a
+
+
+let link a1 a2 q link_phi =
+ let a = { a1 with
+ states = StateSet.union a1.states a2.states;
+ selecting_states = StateSet.singleton q;
+ starting_states = StateSet.union a1.starting_states a2.starting_states;
+ transitions =
+ let () =
+ Hashtbl.iter (fun k v -> Hashtbl.add a1.transitions k v) a2.transitions
+ in
+ Hashtbl.add a1.transitions q [(QNameSet.any, link_phi)];
+ a1.transitions
}
+ in
+ compute_rank a; a
+
+let union a1 a2 =
+ let a1 = copy a1 in
+ let a2 = copy a2 in
+ let q = State.make () in
+ let link_phi =
+ StateSet.fold
+ (fun q phi -> Formula.(or_ (stay q) phi))
+ (StateSet.union a1.selecting_states a2.selecting_states)
+ Formula.false_
+ in
+ link a1 a2 q link_phi
+
+let inter a1 a2 =
+ let a1 = copy a1 in
+ let a2 = copy a2 in
+ let q = State.make () in
+ let link_phi =
+ StateSet.fold
+ (fun q phi -> Formula.(and_ (stay q) phi))
+ (StateSet.union a1.selecting_states a2.selecting_states)
+ Formula.true_
+ in
+ link a1 a2 q link_phi
+
+let neg a =
+ let a = copy a in
+ let q = State.make () in
+ let link_phi =
+ StateSet.fold
+ (fun q phi -> Formula.(and_ (not_(stay q)) phi))
+ a.selecting_states
+ Formula.true_
+ in
+ let () = Hashtbl.add a.transitions q [(QNameSet.any, link_phi)] in
+ let a =
+ { a with
+ selecting_states = StateSet.singleton q;
+ }
+ in
+ normalize_negations a; compute_rank a; a
+
+let diff a1 a2 = inter a1 (neg a2)