(* Todo refactor and remove this alias *)
INCLUDE "debug.ml"
let gen_id =
  let id = ref (-1) in
    fun () -> incr id;!id

  module TS = 
  struct
    type t = Nil | Cons of Tree.t * t | Concat of t*t
    let empty = Nil
      
    let cons e t = Cons(e,t)
    let concat t1 t2 =  Concat (t1,t2)
    let append e t = Concat(t,Cons(e,Nil))
      
    let fold f l acc = 
      let rec loop acc = function
	| Nil -> acc
	| Cons(e,t) -> loop (f e acc) t
	| Concat(t1,t2) -> loop (loop acc t1) t2
      in
	loop acc l

    let length l = fold (fun _ x -> x+1) l 0
      

    let iter f l =
      let rec loop = function
	| Nil -> ()
	| Cons(e,t) -> let _ = f e in loop t
	| Concat(t1,t2) -> let _ = loop t1 in loop t2
      in loop l

  end



let h_union = Hashtbl.create 4097

let pt_cup s1 s2 = 
  let h = (Ptset.hash s1)*(Ptset.hash s2) - ((Ptset.hash s2)+(Ptset.hash s1)) in
    try
      Hashtbl.find h_union h
    with
	| Not_found -> let s = Ptset.union s1 s2
	  in
	    Hashtbl.add h_union h s;s


module State = struct

  type t = int
  let mk = gen_id

end
let mk_state = State.mk

type state = State.t


	
type formula_expr = 
  | False | True
  | Or of formula * formula 
  | And of formula * formula 
  | Atom of ([ `Left | `Right  | `LLeft | `RRight  ]*bool*state)
and formula = { fid: int;
		fkey : int;
		pos : formula_expr;
		neg : formula;
		st : (Ptset.t*Ptset.t*Ptset.t)*(Ptset.t*Ptset.t*Ptset.t);
		size: int;
	      }
    
external hash_const_variant : [> ] -> int = "%identity" 
external int_bool : bool -> int = "%identity"

let hash_node_form t = match t with 
  | False -> 0
  | True -> 1
  | And(f1,f2) -> (2+17*f1.fkey + 37*f2.fkey) (*land max_int *)
  | Or(f1,f2) -> (3+101*f1.fkey + 253*f2.fkey) (*land max_int *)
  | Atom(v,b,s) -> ((hash_const_variant v) + (3846*(int_bool b) +257) + (s lsl 13 - s)) (*land max_int *)
	

module FormNode = 
struct
  type t = formula
      
  let hash t = t.fkey
  let equal f1 f2 = 
    if f1.fid == f2.fid || f1.fkey == f2.fkey || f1.pos == f2.pos then true
    else
    match f1.pos,f2.pos with
      | False,False | True,True -> true
      | Atom(d1,b1,s1), Atom(d2,b2,s2) when (b1==b2) &&  (s1==s2) && (d1 = d2) -> true
      | Or(g1,g2),Or(h1,h2) 
      | And(g1,g2),And(h1,h2)  -> g1.fid == h1.fid && g2.fid == h2.fid
      | _ -> false

end
module WH = Weak.Make(FormNode)

let f_pool = WH.create 107

let empty_triple = Ptset.empty,Ptset.empty,Ptset.empty
let empty_hex = empty_triple,empty_triple

let true_,false_ = 
  let rec t = { fid = 1; pos = True; fkey=1; neg = f ; st = empty_hex; size =1; }
  and f = { fid = 0; pos = False; fkey=0; neg = t; st = empty_hex; size = 1; }
  in 
    WH.add f_pool f;
    WH.add f_pool t;
    t,f

let is_true f = f.fid == 1
let is_false f = f.fid == 0


let cons pos neg s1 s2 size1 size2 = 
  let rec pnode = 
    { fid = gen_id ();
      fkey = hash_node_form pos;
      pos = pos;
      neg = nnode;
      st = s1; 
      size = size1;}
  and nnode = { 
    fid = gen_id ();
    pos = neg;
    fkey = hash_node_form neg;
    neg = pnode;
    st = s2;
    size = size2;
  }
  in
    (WH.merge f_pool pnode),(WH.merge f_pool nnode)

let atom_  d p s = 
  let si = Ptset.singleton s in
  let ss = match d with
    | `Left -> (si,Ptset.empty,si),empty_triple
    | `Right -> empty_triple,(si,Ptset.empty,si)
    | `LLeft -> (Ptset.empty,si,si),empty_triple
    | `RRight -> empty_triple,(Ptset.empty,si,si)
  in fst (cons (Atom(d,p,s)) (Atom(d,not p,s)) ss ss 1 1)
       
let union_hex  ((l1,ll1,lll1),(r1,rr1,rrr1))  ((l2,ll2,lll2),(r2,rr2,rrr2)) =
  (pt_cup l1 l2 ,pt_cup ll1 ll2,pt_cup lll1 lll2),
  (pt_cup r1 r2 ,pt_cup rr1 rr2,pt_cup rrr1 rrr2)

let merge_states f1 f2 =
  let sp = 
    union_hex f1.st f2.st
  and sn = 
    union_hex f1.neg.st f2.neg.st
  in
    sp,sn
      
let full_or_ f1 f2 = 
  let f1,f2 = if f1.fid < f2.fid then f2,f1 else f1,f2 in
  let sp,sn = merge_states f1 f2 in
  let psize = f1.size + f2.size in
  let nsize = f1.neg.size + f2.neg.size in
    fst (cons (Or(f1,f2)) (And(f1.neg,f2.neg)) sp sn psize nsize )

let or_ f1 f2 = 
  let f1,f2 = if f1.fid < f2.fid then f2,f1 else f1,f2 in
  if is_true f1 || is_true f2 then true_
  else if is_false f1 && is_false f2 then false_
  else if is_false f1 then f2
  else if is_false f2 then f1
  else 
    let psize = f1.size + f2.size in
    let nsize = f1.neg.size + f2.neg.size in
    let sp,sn = merge_states f1 f2 in
      fst (cons (Or(f1,f2)) (And(f1.neg,f2.neg)) sp sn psize nsize)



let and_ f1 f2 = 
  let f1,f2 = if f1.fid < f2.fid then f2,f1 else f1,f2 in
  if is_true f1 && is_true f2 then true_
  else if is_false f1 || is_false f2 then false_
  else if is_true f1 then f2 
  else if is_true f2 then f1
  else
    let psize = f1.size + f2.size in
    let nsize = f1.neg.size + f2.neg.size in
    let sp,sn = merge_states f1 f2 in
      fst (cons (And(f1,f2)) (Or(f1.neg,f2.neg)) sp sn psize nsize)
	

let not_ f = f.neg

let k_hash (s,t) = ((Ptset.hash s)) lsl 31  lxor (Tag.hash t) 

module HTagSetKey = 
struct 
  type t = Ptset.t*Tag.t 
  let equal (s1,s2) (t1,t2) =  (s2 == t2) &&  Ptset.equal s1 t1
  let hash = k_hash
end

module HTagSet =
struct
  type key = Ptset.t*Tag.t
  let equal (s1,s2) (t1,t2) =  (s2 == t2) &&  Ptset.equal s1 t1
  let hash (s,t) = ((Ptset.hash s)) lsl 31  lxor (Tag.hash t) 

type 'a t =
  { mutable size: int;                        (* number of elements *)
    mutable data: (key,'a) bucketlist array } (* the buckets *)

and ('a, 'b) bucketlist =
    Empty
  | Cons of 'a * 'b * ('a, 'b) bucketlist

let create initial_size =
  let s = min (max 1 initial_size) Sys.max_array_length in
  { size = 0; data = Array.make s Empty }

let clear h =
  for i = 0 to Array.length h.data - 1 do
    h.data.(i) <- Empty
  done;
  h.size <- 0

let copy h =
  { size = h.size;
    data = Array.copy h.data }

let length h = h.size

let resize tbl =
  let odata = tbl.data in
  let osize = Array.length odata in
  let nsize = min (2 * osize + 1) Sys.max_array_length in
  if nsize <> osize then begin
    let ndata = Array.create nsize Empty in
    let rec insert_bucket = function
        Empty -> ()
      | Cons(key, data, rest) ->
          insert_bucket rest; (* preserve original order of elements *)
          let nidx = (hash key) mod nsize in
          ndata.(nidx) <- Cons(key, data, ndata.(nidx)) in
    for i = 0 to osize - 1 do
      insert_bucket odata.(i)
    done;
    tbl.data <- ndata;
  end

let add h key info =
  let i = (hash key) mod (Array.length h.data) in
  let bucket = Cons(key, info, h.data.(i)) in
  h.data.(i) <- bucket;
  h.size <- succ h.size;
  if h.size > Array.length h.data lsl 1 then resize h

let remove h key =
  let rec remove_bucket = function
      Empty ->
        Empty
    | Cons(k, i, next) ->
        if equal k key 
        then begin h.size <- pred h.size; next end
        else Cons(k, i, remove_bucket next) in
  let i = (hash key) mod (Array.length h.data) in
  h.data.(i) <- remove_bucket h.data.(i)

let rec find_rec key = function
    Empty ->
      raise Not_found
  | Cons(k, d, rest) ->
      if equal key k  then d else find_rec key rest

let find h key =
  match h.data.((hash key) mod (Array.length h.data)) with
    Empty -> raise Not_found
  | Cons(k1, d1, rest1) ->
      if equal key k1  then d1 else
      match rest1 with
        Empty -> raise Not_found
      | Cons(k2, d2, rest2) ->
          if equal key k2  then d2 else
          match rest2 with
            Empty -> raise Not_found
          | Cons(k3, d3, rest3) ->
              if equal key k3 then d3 else find_rec key rest3

let find_all h key =
  let rec find_in_bucket = function
    Empty ->
      []
  | Cons(k, d, rest) ->
      if equal k key
      then d :: find_in_bucket rest
      else find_in_bucket rest in
  find_in_bucket h.data.((hash key) mod (Array.length h.data))

let replace h key info =
  let rec replace_bucket = function
      Empty ->
        raise Not_found
    | Cons(k, i, next) ->
        if equal k key
        then Cons(k, info, next)
        else Cons(k, i, replace_bucket next) in
  let i = (hash key) mod (Array.length h.data) in
  let l = h.data.(i) in
  try
    h.data.(i) <- replace_bucket l
  with Not_found ->
    h.data.(i) <- Cons(key, info, l);
    h.size <- succ h.size;
    if h.size > Array.length h.data lsl 1 then resize h

let mem h key =
  let rec mem_in_bucket = function
  | Empty ->
      false
  | Cons(k, d, rest) ->
      equal k key || mem_in_bucket rest in
  mem_in_bucket h.data.((hash key) mod (Array.length h.data))

let iter f h =
  let rec do_bucket = function
      Empty ->
        ()
    | Cons(k, d, rest) ->
        f k d; do_bucket rest in
  let d = h.data in
  for i = 0 to Array.length d - 1 do
    do_bucket d.(i)
  done

let fold f h init =
  let rec do_bucket b accu =
    match b with
      Empty ->
        accu
    | Cons(k, d, rest) ->
        do_bucket rest (f k d accu) in
  let d = h.data in
  let accu = ref init in
  for i = 0 to Array.length d - 1 do
    accu := do_bucket d.(i) !accu
  done;
  !accu


end













type dispatch = { first : Tree.t -> Tree.t;
		  flabel : string;
		  next : Tree.t -> Tree.t -> Tree.t;
		  nlabel : string;
		}
type t = { 
    id : int;
    mutable states : Ptset.t;
    init : Ptset.t;
    mutable final : Ptset.t;
    universal : Ptset.t;
    (* Transitions of the Alternating automaton *)
    phi : (state,(TagSet.t*(bool*formula*bool)) list) Hashtbl.t;
    sigma : (dispatch*bool*formula) HTagSet.t;
}
	   
  module Pair (X : Set.OrderedType) (Y : Set.OrderedType) =
  struct
    type t = X.t*Y.t
    let compare (x1,y1) (x2,y2) =
      let r = X.compare x1 x2 in
	if r == 0 then Y.compare y1 y2
	else r
  end

  module PL = Set.Make (Pair (Ptset) (Ptset))


  let pr_st ppf l = Format.fprintf ppf "{";
    begin
      match l with
	|	[] -> ()
	| [s] -> Format.fprintf ppf " %i" s
	| p::r -> Format.fprintf ppf " %i" p;
	    List.iter (fun i -> Format.fprintf ppf "; %i" i) r
    end;
    Format.fprintf ppf " }"
  let rec pr_frm ppf f = match f.pos with
    | True -> Format.fprintf ppf "⊤"
    | False -> Format.fprintf ppf "⊥"
    | And(f1,f2) -> 
	Format.fprintf ppf "(";
	(pr_frm ppf f1);
	Format.fprintf ppf ") ∧ (";
	(pr_frm ppf f2);
	Format.fprintf ppf ")"
    | Or(f1,f2) -> 
	(pr_frm ppf f1);
	Format.fprintf ppf " ∨ ";
	(pr_frm ppf f2);
    | Atom(dir,b,s) -> Format.fprintf ppf "%s%s[%i]"
	(if b then "" else "¬")
	(match  dir with 
	   | `Left ->  "↓₁" 
	   | `Right -> "↓₂"
	   | `LLeft ->  "⇓₁" 
	   | `RRight -> "⇓₂") s 	  

  let dnf_hash = Hashtbl.create 17

  let rec dnf_aux f = match f.pos with
    | False -> PL.empty
    | True -> PL.singleton (Ptset.empty,Ptset.empty)
    | Atom((`Left|`LLeft),_,s) -> PL.singleton (Ptset.singleton s,Ptset.empty)
    | Atom((`Right|`RRight),_,s) -> PL.singleton (Ptset.empty,Ptset.singleton s)
    | Or(f1,f2) -> PL.union (dnf f1) (dnf f2)
    | And(f1,f2) ->
  	  let pl1 = dnf f1
  	  and pl2 = dnf f2
  	  in
  	    PL.fold (fun (s1,s2) acc ->
  		       PL.fold ( fun (s1', s2') acc' ->
  				   (PL.add
  				      ((Ptset.union s1 s1'),
  				       (Ptset.union s2 s2')) acc') )
  			  pl2 acc )
  	      pl1 PL.empty


  and dnf f =
    try
      Hashtbl.find dnf_hash f.fid
    with
  	Not_found ->
  	  let d = dnf_aux f in
  	    Hashtbl.add dnf_hash f.fid d;d


  let can_top_down f =
    let nf = dnf f in
      if (PL.cardinal nf > 3)then None
      else match PL.elements nf with
  	| [(s1,s2); (t1,t2); (u1,u2)] when
  	    Ptset.is_empty s1 && Ptset.is_empty s2 && Ptset.is_empty t1 && Ptset.is_empty u2
  	      -> Some(true,t2,u1)
  	| [(t1,t2); (u1,u2)] when Ptset.is_empty t1 && Ptset.is_empty u2
  	    -> Some(false,t2,u1)
  	| _ -> None

     
  let equal_form f1 f2 = 
    (f1.fid == f2.fid) || (FormNode.equal f1 f2) || (PL.equal (dnf f1) (dnf f2))
      
  let dump ppf a = 
    Format.fprintf ppf "Automaton (%i) :\n" a.id;
    Format.fprintf ppf "States : "; pr_st ppf (Ptset.elements a.states);
    Format.fprintf ppf "\nInitial states : "; pr_st ppf (Ptset.elements a.init);
    Format.fprintf ppf "\nFinal states : "; pr_st ppf (Ptset.elements a.final);
    Format.fprintf ppf "\nUniversal states : "; pr_st ppf (Ptset.elements a.universal);
    Format.fprintf ppf "\nAlternating transitions :\n------------------------------\n";
    let l = Hashtbl.fold (fun k t acc -> 
			    (List.map (fun (t,(m,f,p)) -> (t,k),(m,f,p)) t)@ acc) a.phi [] in
    let l = List.sort (fun ((tsx,x),_) ((tsy,y),_) -> if x-y == 0 then TagSet.compare tsx tsy else x-y) l in
    List.iter (fun ((ts,q),(b,f,_)) ->
		    
		    let s = 
		      if TagSet.is_finite ts 
		      then "{" ^ (TagSet.fold (fun t a -> a ^ " '" ^ (Tag.to_string t)^"'") ts "") ^" }"
		      else let cts = TagSet.neg ts in
			if TagSet.is_empty cts then "*" else
			  (TagSet.fold (fun t a -> a ^ " " ^ (Tag.to_string t)) cts "*\\{"
			  )^ "}"
		    in
		      Format.fprintf ppf "(%s,%i) %s " s q (if b then "=>" else "->");
		      pr_frm ppf f;
		      Format.fprintf ppf "\n")l;
    
    Format.fprintf ppf "NFA transitions :\n------------------------------\n";
    HTagSet.iter (fun (qs,t) (disp,b,f) ->
		    pr_st ppf (Ptset.elements qs);
		    Format.fprintf ppf ",%s  %s " (Tag.to_string t) (if b then "=>" else "->");
		    pr_frm ppf f;
		    Format.fprintf ppf "(fid=%i) left=" f.fid;
		    let (l,ll,_),(r,rr,_) = f.st in 
		      pr_st ppf (Ptset.elements l);
		      Format.fprintf ppf ", ";
		      pr_st ppf (Ptset.elements ll);
		      Format.fprintf ppf ", right=";
		      pr_st ppf (Ptset.elements r);
		      Format.fprintf ppf ", ";
		      pr_st ppf (Ptset.elements rr);
		      Format.fprintf ppf ", first=%s, next=%s\n" disp.flabel disp.nlabel;
		 ) a.sigma;    
    Format.fprintf ppf "=======================================\n%!"
    
  module Transitions = struct
    type t = state*TagSet.t*bool*formula*bool
    let ( ?< ) x = x
    let ( >< ) state (l,b) = state,(l,b,false)
    let ( ><@ ) state (l,b) = state,(l,b,true)
    let ( >=> ) (state,(label,mark,pred)) form = (state,label,mark,form,pred)
    let ( +| ) f1 f2 = or_ f1 f2
    let ( *& ) f1 f2 = and_ f1 f2
    let ( ** ) d s = atom_ d true s


  end
  type transition = Transitions.t

  let equal_trans (q1,t1,m1,f1,_) (q2,t2,m2,f2,_) =
    (q1 == q2) && (TagSet.equal t1 t2) && (m1 == m2) && (equal_form f1 f2)
      

  module HFEval = Hashtbl.Make(
    struct
      type t = int*Ptset.t*Ptset.t
      let equal (a,b,c) (d,e,f) =
	a==d && (Ptset.equal b e) && (Ptset.equal c f)
      let hash (a,b,c) = 
	a+17*(Ptset.hash b) + 31*(Ptset.hash c)
    end)
    
  let hfeval = HFEval.create 4097
    

    let eval_form_bool f s1 s2 =      
      let rec eval f = match f.pos with
	  (* test some inlining *)
	| True -> true,true,true
	| False -> false,false,false
	| Atom((`Left|`LLeft),b,q) -> if b == (Ptset.mem q s1) then (true,true,false) else false,false,false
	| Atom(_,b,q) -> if b == (Ptset.mem q s2) then (true,false,true) else false,false,false
	| _ ->
	    try	  
	       HFEval.find hfeval (f.fid,s1,s2) 
	    with
	      |	Not_found -> let r = 
		  match f.pos with
		    | Or(f1,f2) ->	    
			let b1,rl1,rr1 = eval f1 
			in
			  if b1 && rl1 && rr1 then (true,true,true)
			  else
			    let b2,rl2,rr2 = eval f2
			    in
			    let rl1,rr1 = if b1 then rl1,rr1 else false,false
			    and rl2,rr2 = if b2 then rl2,rr2 else false,false
			    in (b1 || b2, rl1||rl2,rr1||rr2)				 
		    | And(f1,f2) -> 
			let b1,rl1,rr1 = eval f1 in
			  if b1 && rl1 && rr1 then (true,true,true)
			  else if b1 
			  then let b2,rl2,rr2 = eval f2 in
			    if b2 then (true,rl1||rl2,rr1||rr2)
			    else (false,false,false)
			  else (false,false,false) 
		    | _ -> assert false
		in
		  HFEval.add hfeval (f.fid,s1,s2) r;
		  r
      in eval f


    let fstate_pool = Hashtbl.create 11

    let merge_pred a b = match a,b with
      | Some(f1), Some(f2) -> Some(fun x -> f1 x || f2 x)
      | None,None -> None
      | None,Some(_) -> b
      | Some(_),None -> a

    let acc_pred p l1 l2 = match p with
      | `Left _ -> p::l1,l2
      | `Right _ -> l1,p::l2
      | _ -> l1,l2

	      
	      
	      
    let tags_of_state a q = Hashtbl.fold 
      (fun p l acc -> 
	 if p == q then
	   List.fold_left 
	     (fun acc (ts,(_,_,aux)) -> 
		if aux then acc else
		  TagSet.cup ts acc) acc l
	 else acc) a.phi TagSet.empty
    
      

    let tags a qs = 
      let ts = Ptset.fold (fun q acc -> TagSet.cup acc (tags_of_state a q)) qs TagSet.empty
      in
	if TagSet.is_finite ts 
	then `Positive(TagSet.positive ts)
	else `Negative(TagSet.negative ts)
      

	
	
    let merge_trans t a tag q acc = 
      List.fold_left (fun (accf,accm,acchtrue) (ts,(m,f,pred)) ->
			if TagSet.mem tag ts 
			then
			  let tmpf,hastrue = 
			    if is_true f then
			      let newfinal =
				try Hashtbl.find fstate_pool f.fid with
				  | Not_found -> let s = mk_state() in 
				      a.states <- Ptset.add s a.states;
				      a.final <- Ptset.add s a.final;
				      Hashtbl.add fstate_pool f.fid s;s
			      in
				(atom_ `Left true newfinal),true
			    else f,false in
			    (or_ tmpf accf,accm||m,acchtrue||hastrue)
			else (accf,accm,acchtrue)
		     ) acc (try Hashtbl.find a.phi q with Not_found -> [])
	
    let inter_text a b =
      match b with
	| `Positive s -> let r = Ptset.inter a s in (r,Ptset.mem Tag.pcdata r, true)
	| `Negative s -> (Ptset.empty, not (Ptset.mem Tag.pcdata s), false)

    let mk_nil_ctx x _ = Tree.mk_nil x
    let next_sibling_ctx x _ = Tree.next_sibling x 
    let r_ignore _ x = x

 

    let get_trans t a tag r = 
      try	
	let dispatch,mark,f = 
	  HTagSet.find a.sigma (r,tag)
	in  f.st,dispatch,f,mark,r
      with
	  Not_found ->  
	    let f,mark,_,accq = 
	      Ptset.fold (fun q (accf,accm,acchtrue,accq) ->
			    let naccf,naccm,nacctrue =
			      merge_trans t a tag q (accf,accm,acchtrue )
			    in
			      if is_false naccf then (naccf,naccm,nacctrue,accq)
			      else (naccf,naccm,nacctrue,Ptset.add q accq)
			 )
		r (false_,false,false,Ptset.empty)
	    in 
	    let (ls,lls,_),(rs,rrs,_) = f.st    in
	    let tb,ta = 
	      Tree.tags t tag 
	    in 
	    let tl,htlt,lfin = inter_text tb (tags a ls)
	    and tll,htllt,llfin = inter_text tb (tags a lls)
	    and tr,htrt,rfin = inter_text ta (tags a rs)
	    and trr,htrrt,rrfin = inter_text ta  (tags a rrs)
	    in
	    let first,flabel =
	      if (llfin && lfin) then (* no stars *)
		(if htlt || htllt then (Tree.text_below, "#text_below")
		 else
		   let etl = Ptset.is_empty tl
		   and etll = Ptset.is_empty tll
		   in
		     if (etl && etll)
			 then (Tree.mk_nil, "#mk_nil")
			 else
			   if etl then 
			     if Ptset.is_singleton tll 
			     then (Tree.tagged_desc (Ptset.choose tll), "#tagged_desc")
			     else (Tree.select_desc_only tll, "#select_desc_only")
			   else if etll then (Tree.node_child,"#node_child")
			   else (Tree.select_below tl tll,"#select_below"))
		  else (* stars or node() *)
		    if htlt||htllt then (Tree.first_child,"#first_child")
		    else (Tree.node_child,"#node_child")
	    and next,nlabel =
	      if (rrfin && rfin) then (* no stars *)
		( if htrt || htrrt
		  then (Tree.text_next, "#text_next")
		    else
		      let etr = Ptset.is_empty tr
		      and etrr = Ptset.is_empty trr
		      in
			if etr && etrr 
			then (mk_nil_ctx, "#mk_nil_ctx")
			else
			  if etr then
			    if Ptset.is_singleton trr 
			    then (Tree.tagged_foll_below (Ptset.choose trr),"#tagged_foll_below")
			    else (Tree.select_foll_only trr,"#select_foll_only")
			  else if etrr then (Tree.node_sibling_ctx,"#node_sibling_ctx")
			  else 	
			    (Tree.select_next tr trr,"#select_next") )

		  else if htrt || htrrt then (Tree.next_sibling_ctx,"#next_sibling_ctx")
		  else (Tree.node_sibling_ctx,"#node_sibling_ctx")
	    in
	    let dispatch = { first = first; flabel = flabel; next = next; nlabel = nlabel}	      
	    in 
	      HTagSet.add a.sigma (accq,tag) (dispatch,mark,f);
	      f.st,dispatch,f,mark,accq
		
    let rec accepting_among a t orig ctx =     
      let rest = Ptset.inter orig a.universal in
      let r = Ptset.diff orig rest in
	if Ptset.is_empty r then rest,0,TS.empty else 
	  if Tree.is_nil t
	  then orig,0,TS.empty
	  else 
	    let ((_,_,llls),(_,_,rrrs)),dispatch,formula,mark,r' =
	      get_trans t a (Tree.tag t) r
	    in
	    let s1,n1,res1 = accepting_among a (dispatch.first t) llls t in
	    let s2,n2,res2 = accepting_among a (dispatch.next t ctx) rrrs ctx in
	    let rb,rb1,rb2 = eval_form_bool formula s1 s2 in
	      if rb
	      then 
		let n1,res1 = if rb1 then n1,res1 else 0,TS.empty
		and n2,res2 = if rb2 then n2,res2 else 0,TS.empty
		in 
		  if mark 
		  then r',1+n1+n2,TS.Cons(t,(TS.Concat(res1,res2)))
		  else r',n1+n2,TS.Concat(res1,res2)
	      else Ptset.empty,0,TS.empty	

	
    let rec accepting_among_count a t orig ctx =     
      let rest = Ptset.inter orig a.universal in
      let r = Ptset.diff orig rest in
	if Ptset.is_empty r then rest,0 else 
	  if Tree.is_node t
	  then 
	    let ((_,_,llls),(_,_,rrrs)),dispatch,formula,mark,r' =
	      get_trans t a (Tree.tag t) r
	    in
	    let s1,res1 = accepting_among_count a (dispatch.first t) llls t
	    and s2,res2 = accepting_among_count a (dispatch.next t ctx) rrrs ctx
	    in
	    let rb,rb1,rb2 = eval_form_bool formula s1 s2 in
	      if rb
	      then 
		let res1 = if rb1 then res1 else 0
		and res2 = if rb2 then res2 else 0
		in r', if mark then 1+res1+res2 else res1+res2 
	      else Ptset.empty,0	
	  else orig,0

 
    let run a t = 
      let st,n,res = accepting_among a t a.init t in
        if Ptset.is_empty (st) then TS.empty,0 else res,n

	  

    let run_count a t = 
      let st,res = accepting_among_count a t a.init t in
        if Ptset.is_empty (st) then 0 else  res

	  
    let run_time _ _ = failwith "blah"




(*
  end
*)