(* Title:  solve an example by interpreting a method's script

   Author: Walther Neuper 1999

   (c) copyright due to lincense terms.

*)

signature SOLVE =

sig

  datatype auto = CompleteCalc | CompleteCalcHead | CompleteModel | CompleteSubpbl 

  | CompleteToSubpbl | Step of int

  val autoord : auto -> int

  type tac'_

  val mk_tac'_ : Tac.tac -> string * Tac.tac

  val specsteps : string list

  val nxt_solve_ : Ctree.ctree * Ctree.pos' ->

    (Tac.tac * Tac.tac_ * (Ctree.pos' * (Selem.istate * Proof.context))) list *

      Ctree.pos' list * Ctree.state

  val all_solve : auto -> Ctree.pos' list -> Ctree.state ->

    string * Ctree.pos' list * (Ctree.ctree * (int list * Ctree.pos_))

  val complete_solve :

     auto -> Ctree.pos' list -> Ctree.state -> string * Ctree.pos' list * Ctree.state

  val nxt_solv : Tac.tac_ -> Selem.istate * Proof.context -> Ctree.state -> Chead.calcstate'

  val solve : string * Tac.tac_ -> Ctree.state -> string * Chead.calcstate'

  val detailrls : Ctree.ctree -> Ctree.pos' -> string * Ctree.ctree * Ctree.pos'

(* ---- for tests only: shifted from below to remove the Warning "unused" at fun.def. --------- *)

  val get_form : tac'_ -> Ctree.pos' -> Ctree.ctree -> Generate.mout

(*/-------------------------------------------------------- ! aktivate for Test_Isac BEGIN ---\* )

  (* NONE *)

( *\--- ! aktivate for Test_Isac END ----------------------------------------------------------/*)

(*----- unused code, kept as hints to design ideas ---------------------------------------------*)

  (* NONE *)

end

(**)

structure Solve(**): SOLVE(**) =

struct

(**)

open Ctree;

type mstID = string;

type tac'_ = mstID * Tac.tac; (*DG <-> ME*)

fun mk_tac'_   m = case m of (* scr not cleaned -- will disappear eventually *)

  Tac.Init_Proof (ppc, spec)    => ("Init_Proof", Tac.Init_Proof (ppc, spec )) 

| Tac.Model_Problem             => ("Model_Problem", Tac.Model_Problem)

| Tac.Refine_Tacitly pblID      => ("Refine_Tacitly", Tac.Refine_Tacitly pblID)

| Tac.Refine_Problem pblID      => ("Refine_Problem", Tac.Refine_Problem pblID)

| Tac.Add_Given cterm'          => ("Add_Given", Tac.Add_Given cterm') 

| Tac.Del_Given cterm'          => ("Del_Given", Tac.Del_Given cterm') 

| Tac.Add_Find cterm'           => ("Add_Find", Tac.Add_Find cterm') 

| Tac.Del_Find cterm'           => ("Del_Find", Tac.Del_Find cterm') 

| Tac.Add_Relation cterm'       => ("Add_Relation", Tac.Add_Relation cterm') 

| Tac.Del_Relation cterm'       => ("Del_Relation", Tac.Del_Relation cterm') 

| Tac.Specify_Theory domID	    => ("Specify_Theory", Tac.Specify_Theory domID) 

| Tac.Specify_Problem pblID     => ("Specify_Problem", Tac.Specify_Problem pblID)

| Tac.Specify_Method metID	    => ("Specify_Method", Tac.Specify_Method metID) 

| Tac.Apply_Method metID	    => ("Apply_Method", Tac.Apply_Method metID) 

| Tac.Check_Postcond pblID	    => ("Check_Postcond", Tac.Check_Postcond pblID)

| Tac.Free_Solve                => ("Free_Solve", Tac.Free_Solve)

| Tac.Rewrite_Inst (subs, thm') => ("Rewrite_Inst", Tac.Rewrite_Inst (subs, thm')) 

| Tac.Rewrite thm'		    => ("Rewrite", Tac.Rewrite thm') 

| Tac.Rewrite_Asm thm'	    => ("Rewrite_Asm", Tac.Rewrite_Asm thm') 

| Tac.Rewrite_Set_Inst (subs, rls')

               => ("Rewrite_Set_Inst", Tac.Rewrite_Set_Inst (subs, rls')) 

| Tac.Rewrite_Set rls'          => ("Rewrite_Set", Tac.Rewrite_Set rls') 

| Tac.End_Ruleset		    => ("End_Ruleset", Tac.End_Ruleset)

| Tac.End_Detail                => ("End_Detail", Tac.End_Detail)

| Tac.Detail_Set rls'           => ("Detail_Set", Tac.Detail_Set rls')

| Tac.Detail_Set_Inst (s, rls') => ("Detail_Set_Inst", Tac.Detail_Set_Inst (s, rls'))

| Tac.Calculate op_             => ("Calculate", Tac.Calculate op_)

| Tac.Substitute sube           => ("Substitute", Tac.Substitute sube) 

| Tac.Apply_Assumption cts'	    => ("Apply_Assumption", Tac.Apply_Assumption cts')

| Tac.Take cterm'               => ("Take", Tac.Take cterm') 

| Tac.Take_Inst cterm'          => ("Take_Inst", Tac.Take_Inst cterm') 

| Tac.Subproblem (domID, pblID) => ("Subproblem", Tac.Subproblem (domID, pblID)) 

(*

| Tac.Subproblem_Full(spec,cts')=> ("Subproblem_Full", Tac.Subproblem_Full(spec,cts')) 

*)

| Tac.End_Subproblem            => ("End_Subproblem", Tac.End_Subproblem)

| Tac.CAScmd cterm'		    => ("CAScmd", Tac.CAScmd cterm')

| Tac.Split_And                 => ("Split_And", Tac.Split_And) 

| Tac.Conclude_And		    => ("Conclude_And", Tac.Conclude_And) 

| Tac.Split_Or                  => ("Split_Or", Tac.Split_Or) 

| Tac.Conclude_Or		    => ("Conclude_Or", Tac.Conclude_Or) 

| Tac.Begin_Trans               => ("Begin_Trans", Tac.Begin_Trans) 

| Tac.End_Trans		    => ("End_Trans", Tac.End_Trans) 

| Tac.Begin_Sequ                => ("Begin_Sequ", Tac.Begin_Sequ) 

| Tac.End_Sequ                  => ("End_Sequ", Tac.Begin_Sequ) 

| Tac.Split_Intersect           => ("Split_Intersect", Tac.Split_Intersect) 

| Tac.End_Intersect		    => ("End_Intersect", Tac.End_Intersect) 

| Tac.Check_elementwise cterm'  => ("Check_elementwise", Tac.Check_elementwise cterm')

| Tac.Or_to_List                => ("Or_to_List", Tac.Or_to_List) 

| Tac.Collect_Trues	            => ("Collect_Results", Tac.Collect_Trues) 

| Tac.Empty_Tac               => ("Empty_Tac", Tac.Empty_Tac)

| Tac.Tac string              => ("Tac", Tac.Tac string)

| Tac.End_Proof'                => ("End_Proof'", Tac.End_Proof')

| _ => error "mk_tac'_: uncovered case"; 

type squ = ctree; (* TODO: safe etc. *)

val specsteps = ["Init_Proof", "Refine_Tacitly", "Refine_Problem", "Model_Problem",

  "Add_Given", "Del_Given", "Add_Find", "Del_Find", "Add_Relation", "Del_Relation",

  "Specify_Theory", "Specify_Problem", "Specify_Method"];

fun step2taci ((tac_, _, pt, p, _) : Lucin.step) = (*FIXXME.040312: redesign step*)

    (Lucin.tac_2tac tac_, tac_, (p, Ctree.get_loc pt p)): Generate.taci;

(*FIXME.WN050821 compare solve ... nxt_solv*)

fun solve ("Apply_Method", m as Tac.Apply_Method' (mI, _, _, _)) (pt, (pos as (p, _))) =

    let val {srls, ...} = Specify.get_met mI;

      val itms = case get_obj I pt p of

        PblObj {meth=itms, ...} => itms

      | _ => error "solve Apply_Method: uncovered case get_obj"

      val thy' = get_obj g_domID pt p;

      val thy = Celem.assoc_thy thy';

      val (is, env, ctxt, sc) = case Lucin.init_scrstate thy itms mI of

        (is as Selem.ScrState (env,_,_,_,_,_), ctxt, sc) =>  (is, env, ctxt, sc)

      | _ => error "solve Apply_Method: uncovered case init_scrstate"

      val ini = Lucin.init_form thy sc env;

      val p = lev_dn p;

    in 

      case ini of

	      SOME t =>

          let val (pos,c,_, pt) = 

		        Generate.generate1 thy (Tac.Apply_Method' (mI, SOME t, is, ctxt))

		        (is, ctxt) (lev_on p, Frm)(*implicit Take*) pt;

	        in ("ok",([(Tac.Apply_Method mI, Tac.Apply_Method' (mI, SOME t, is, ctxt), 

		        ((lev_on p, Frm), (is, ctxt)))], c, (pt, pos))) 

	        end	      

	    | NONE => (*execute the first tac in the Script, compare solve m*)

	        let

            val (m', (is', ctxt'), _) = Lucin.next_tac (thy', srls) (pt, (p, Res)) sc (is, ctxt);

	          val d = Celem.e_rls (*FIXME: get simplifier from domID*);

	        in 

	          case Lucin.locate_gen (thy',srls) m' (pt,(p, Res)) (sc,d) (is', ctxt') of 

		          Lucin.Steps (_, ss as (_, _, pt', p', c') :: _) =>

		            ("ok", (map step2taci ss, c', (pt', p')))

		        | _ => (* NotLocatable *)

		            let val (p, ps, _, pt) = Generate.generate_hard (Celem.assoc_thy "Isac") m (p, Frm) pt;

		            in 

		              ("not-found-in-script",([(Lucin.tac_2tac m, m, (pos, (is, ctxt)))], ps, (pt, p))) 

		            end

	        end

    end

  | solve ("Free_Solve", Tac.Free_Solve')  (pt, po as (p, _)) =

    let

      val p' = lev_dn_ (p, Res);

      val pt = update_metID pt (par_pblobj pt p) Celem.e_metID;

    in

      ("ok", ([(Tac.Empty_Tac, Tac.Empty_Tac_, (po, (Selem.Uistate, Selem.e_ctxt)))], [], (pt,p')))

    end

  | solve ("Check_Postcond", Tac.Check_Postcond' (pI, _)) (pt, (p, p_)) =

    let

      val pp = par_pblobj pt p

      val asm = 

        (case get_obj g_tac pt p of

		       Tac.Check_elementwise _ => (*collects and instantiates asms*)

		         (snd o (get_obj g_result pt)) p

		     | _ => get_assumptions_ pt (p,p_))

	      handle _ => [] (*WN.27.5.03 asms in subpbls not completely clear*)

      val metID = get_obj g_metID pt pp;

      val {srls = srls, scr = sc, ...} = Specify.get_met metID;

      val (loc, E, l, a, b, ctxt) = case get_loc pt (p, p_) of

        loc as (Selem.ScrState (E, l, a, _, _, b), ctxt) => (loc, E, l, a, b, ctxt)

      | _ => error "solve Check_Postcond: uncovered case get_loc"

      val thy' = get_obj g_domID pt pp;

      val thy = Celem.assoc_thy thy';

      val (_, _, (scval, scsaf)) = Lucin.next_tac (thy', srls) (pt, (p, p_)) sc loc;

    in 

      if pp = [] 

      then

	      let 

          val is = Selem.ScrState (E,l,a,scval,scsaf,b)

	        val tac_ = Tac.Check_Postcond' (pI, (scval, asm))

	        val (pos, ps, _, pt) = Generate.generate1 thy tac_ (is, ctxt) (pp, Res) pt;

	      in ("ok", ([(Tac.Check_Postcond pI, tac_, ((pp, Res), (is, ctxt)))], ps, (pt, pos))) end

      else

        let (*resume script of parpbl, transfer value of subpbl-script*)

          val ppp = par_pblobj pt (lev_up p);

	        val thy' = get_obj g_domID pt ppp;

          val thy = Celem.assoc_thy thy';

          val (E, l, a, b, ctxt') = case get_loc pt (pp, Frm) of

            (Selem.ScrState (E, l, a, _, _, b), ctxt') => (E, l, a, b, ctxt')

          | _ => error "solve Check_Postcond resume script of parpbl: uncovered case get_loc"

	        val ctxt'' = Stool.from_subpbl_to_caller ctxt scval ctxt'

          val ((p, p_), ps, _, pt) = Generate.generate1 thy (Tac.Check_Postcond' (pI, (scval, asm)))

		        (Selem.ScrState (E,l,a,scval,scsaf,b), ctxt'') (pp,Res) pt;

       in ("ok", ([(Tac.Check_Postcond pI, Tac.Check_Postcond'(pI, (scval, asm)),

  	      ((pp, Res), (Selem.ScrState (E, l, a, scval, scsaf, b), ctxt'')))], ps, (pt, (p, p_)))) end

     end

  | solve (_, Tac.End_Proof'') (pt, (p, p_)) =

    ("end-proof", ([(Tac.Empty_Tac, Tac.Empty_Tac_, (([], Res), (Selem.Uistate, Selem.e_ctxt)))], [], (pt, (p, p_))))

  | solve (_, Tac.End_Detail' t) (pt, (p, p_)) = (* could be done by generate1 ?!? *)

    let (*Rewrite_Set* done at Detail_Set*: this result is already in ctree*)

      val pr = (lev_up p, Res)

    in

      ("ok", ([(Tac.End_Detail, Tac.End_Detail' t , ((p, p_), get_loc pt (p, p_)))], [], (pt, pr)))

    end

  | solve (_, m) (pt, po as (p, p_)) =

    if Celem.e_metID = get_obj g_metID pt (par_pblobj pt p) (*29.8.02: could be detail, too !!*)

    then

      let

        val ctxt = get_ctxt pt po

        val ((p,p_),ps,_,pt) = Generate.generate1 (Celem.assoc_thy (get_obj g_domID pt (par_pblobj pt p))) 

		      m (Selem.e_istate, ctxt) (p, p_) pt;

	    in ("no-method-specified", (*Free_Solve*)

	      ([(Tac.Empty_Tac, Tac.Empty_Tac_, ((p, p_), (Selem.Uistate, ctxt)))], ps, (pt, (p, p_))))

      end

    else

	    let 

	      val thy' = get_obj g_domID pt (par_pblobj pt p);

	      val (srls, is, sc) = Lucin.from_pblobj_or_detail' thy' (p,p_) pt;

		    val d = Celem.e_rls; (*FIXME.WN0108: canon.simplifier for domain is missing: generate from domID?*)

	    in

        case Lucin.locate_gen (thy',srls) m  (pt,(p, p_)) (sc,d) is of 

	        Lucin.Steps (_, ss as (_, _, pt', p', c') :: _) =>

	          ("ok", (map step2taci ss, c', (pt', p')))

            (*27.8.02:next_tac may change to other branches in pt FIXXXXME*)

	      | _ => (* NotLocatable *)

	        let 

	          val (p,ps, _, pt) = Generate.generate_hard (Celem.assoc_thy "Isac") m (p, p_) pt;

	        in

	          ("not-found-in-script", ([(Lucin.tac_2tac m, m, (po, is))], ps, (pt, p)))

          end

	    end;

(* FIXME.WN050821 compare fun solve ... fun nxt_solv

   nxt_solv (Apply_Method'     vvv FIXME: get args in applicable_in *)

fun nxt_solv (Tac.Apply_Method' (mI, _, _, _)) _ (pt, pos as (p, _)) =

   let

     val {ppc, ...} = Specify.get_met mI;

     val (itms, oris, probl) = case get_obj I pt p of

       PblObj {meth = itms, origin = (oris, _, _), probl, ...} => (itms, oris, probl)

     | _ => error "nxt_solv Apply_Method': uncovered case get_obj"

     val itms = if itms <> [] then itms else Chead.complete_metitms oris probl [] ppc

     val thy' = get_obj g_domID pt p;

     val thy = Celem.assoc_thy thy';

     val (is, env, ctxt, scr) = case Lucin.init_scrstate thy itms mI of

       (is as Selem.ScrState (env,_,_,_,_,_), ctxt, scr) => (is, env, ctxt, scr)

     | _ => error "nxt_solv Apply_Method': uncovered case init_scrstate"

     val ini = Lucin.init_form thy scr env;

   in 

     case ini of

       SOME t =>

       let

         val pos = ((lev_on o lev_dn) p, Frm)

	       val tac_ = Tac.Apply_Method' (mI, SOME t, is, ctxt);

	       val (pos, c, _, pt) = Generate.generate1 thy tac_ (is, ctxt) pos pt (* implicit Take *)

       in

        ([(Tac.Apply_Method mI, tac_, (pos, (is, ctxt)))], c, (pt, pos))

       end

     | NONE =>

       let

         val pt = update_env pt (fst pos) (SOME (is, ctxt))

	       val (tacis, c, ptp) = nxt_solve_ (pt, pos)

       in (tacis @ [(Tac.Apply_Method mI, Tac.Apply_Method' (mI, NONE, Selem.e_istate, ctxt), (pos, (is, ctxt)))],

	       c, ptp)

       end

    end

  | nxt_solv (Tac.Check_Postcond' (pI, _)) _ (pt, (p, p_))  =

    let

      val pp = par_pblobj pt p

      val asm = (case get_obj g_tac pt p of

		    Tac.Check_elementwise _ => (snd o (get_obj g_result pt)) p (*collects and instantiates asms*)

		  | _ => get_assumptions_ pt (p, p_))

	      handle _ => [] (*FIXME.WN030527 asms in subpbls not completely clear*)

      val metID = get_obj g_metID pt pp;

      val {srls = srls, scr = sc, ...} = Specify.get_met metID;

      val (loc, E, l, a, b, ctxt) = case get_loc pt (p, p_) of

        loc as (Selem.ScrState (E,l,a,_,_,b), ctxt) => (loc, E, l, a, b, ctxt)

      | _ => error "nxt_solv Check_Postcond': uncovered case get_loc"

      val thy' = get_obj g_domID pt pp;

      val thy = Celem.assoc_thy thy';

      val (_, _, (scval, scsaf)) = Lucin.next_tac (thy', srls) (pt, (p, p_)) sc loc;

    in

      if pp = []

      then 

	      let

          val is = Selem.ScrState (E, l, a, scval, scsaf, b)

	        val tac_ = Tac.Check_Postcond'(pI,(scval, asm))

	        val ((p, p_), ps, _, pt) = Generate.generate1 thy tac_ (is, ctxt) (pp, Res) pt;

	      in ([(Tac.Check_Postcond pI, tac_, ((pp, Res), (is, ctxt)))], ps, (pt, (p, p_))) end

      else

        let (*resume script of parpbl, transfer value of subpbl-script*)

          val ppp = par_pblobj pt (lev_up p);

	        val thy' = get_obj g_domID pt ppp;

          val thy = Celem.assoc_thy thy';

          val (E, l, a, b, ctxt') = case get_loc pt (pp, Frm) of

            (Selem.ScrState (E,l,a,_,_,b), ctxt') => (E, l, a, b, ctxt')

          | _ => error "nxt_solv Check_Postcond' script of parpbl: uncovered case get_loc"

	        val ctxt'' = Stool.from_subpbl_to_caller ctxt scval ctxt'

          val tac_ = Tac.Check_Postcond' (pI, (scval, asm))

	        val is = Selem.ScrState (E,l,a,scval,scsaf,b)

          val ((p, p_), ps, _, pt) = Generate.generate1 thy tac_ (is, ctxt'') (pp, Res) pt;

        in ([(Tac.Check_Postcond pI, tac_, ((pp, Res), (is, ctxt'')))], ps, (pt, (p, p_))) end

    end

  | nxt_solv (Tac.End_Proof'') _ ptp = ([], [], ptp)

  | nxt_solv tac_ is (pt, pos) =

    let

      val pos = case pos of

 		   (p, Met) => ((lev_on o lev_dn) p, Frm) (* begin script        *)

 		  | (p, Res) => (lev_on p, Res)            (* somewhere in script *)

 		  | _ => pos

 	    val (pos', c, _, pt) = Generate.generate1 (Celem.assoc_thy "Isac") tac_ is pos pt;

    in

      ([(Lucin.tac_2tac tac_, tac_, (pos, is))], c, (pt, pos'))

    end

(* find the next tac from the script, nxt_solv will update the ctree *)

and nxt_solve_ (ptp as (pt, pos as (p, p_))) =

    if Celem.e_metID = get_obj g_metID pt (par_pblobj pt p)

    then ([], [], (pt, (p, p_)))

    else 

      let 

        val thy' = get_obj g_domID pt (par_pblobj pt p);

	      val (srls, is, sc) = Lucin.from_pblobj_or_detail' thy' (p,p_) pt;

	      val (tac_, is, (t, _)) = Lucin.next_tac (thy', srls) (pt, pos) sc is;

	      (* TODO here  ^^^  return finished/helpless/ok !*)

	    in case tac_ of

		    Tac.End_Detail' _ => ([(Tac.End_Detail, Tac.End_Detail' (t, [(*FIXME.04*)]), (pos, is))], [], (pt, pos))

	    | _ => nxt_solv tac_ is ptp

      end;

(* says how may steps of a calculation should be done by "fun autocalc"

   FIXXXME040624: does NOT match interfaces/ITOCalc.java

   TODO.WN0512 redesign togehter with autocalc ?                     *)

datatype auto = 

  Step of int      (*1 do #int steps (may stop in model/specify)

                       IS VERY INEFFICIENT IN MODEL/SPECIY                    *)

| CompleteModel    (*2 complete modeling

                       if model complete, finish specifying                   *)

| CompleteCalcHead (*3 complete model/specify in one go                       *)

| CompleteToSubpbl (*4 stop at the next begin of a subproblem,

                       if none, complete the actual (sub)problem              *)

| CompleteSubpbl   (*5 complete the actual (sub)problem (incl.ev.subproblems) *)

| CompleteCalc;    (*6 complete the calculation as a whole                    *)

fun autoord (Step _ ) = 1

  | autoord CompleteModel = 2

  | autoord CompleteCalcHead = 3

  | autoord CompleteToSubpbl = 4

  | autoord CompleteSubpbl = 5

  | autoord CompleteCalc = 6;

fun complete_solve auto c (ptp as (_, p as (_, p_))) =

    if p = ([], Res)

    then ("end-of-calculation", [], ptp)

    else

      if member op = [Pbl,Met] p_

      then

        let

          val ptp = Chead.all_modspec ptp

	        val (_, c', ptp) = all_solve auto c ptp

	      in complete_solve auto (c @ c') ptp end

      else

        case nxt_solve_ ptp of

	        ((Tac.Subproblem _, _, _) :: _, c', ptp') =>

	          if autoord auto < 5

            then ("ok", c @ c', ptp)

	          else

              let

                val ptp = Chead.all_modspec ptp'

	             val (_, c'', ptp) = all_solve auto (c @ c') ptp

	           in complete_solve auto (c @ c'@ c'') ptp end

	      | ((Tac.Check_Postcond _, _, _) :: _, c', ptp' as (_, p')) =>

	        if autoord auto < 6 orelse p' = ([], Res)

          then ("ok", c @ c', ptp')

	        else complete_solve auto (c @ c') ptp'

	      | ((Tac.End_Detail, _, _) :: _, c', ptp') => 

	        if autoord auto < 6

          then ("ok", c @ c', ptp')

	        else complete_solve auto (c @ c') ptp'

	      | (_, c', ptp') => complete_solve auto (c @ c') ptp'

and all_solve auto c (ptp as (pt, pos as (p,_)): ctree * pos') = 

    let

      val (_, _, mI) = get_obj g_spec pt p

      val ctxt = get_ctxt pt pos

      val (_, c', ptp) = nxt_solv (Tac.Apply_Method' (mI, NONE, Selem.e_istate, ctxt)) (Selem.e_istate, ctxt) ptp

    in

      complete_solve auto (c @ c') ptp

    end;

(* aux.fun for detailrls with Rrls, reverse rewriting *)

fun rul_terms_2nds _ nds _ [] = nds

  | rul_terms_2nds thy nds t ((rule, res as (t', _)) :: rts) =

    (append_atomic [] (Selem.e_istate, Selem.e_ctxt) t (Tac.rule2tac thy [] rule) res Complete EmptyPtree) ::

      (rul_terms_2nds thy nds t' rts);

(* detail steps done internally by Rewrite_Set* into ctree by use of a script *)

fun detailrls pt (pos as (p, _)) = 

  let

    val t = get_obj g_form pt p

	  val tac = get_obj g_tac pt p

	  val rls = (assoc_rls o Tac.rls_of) tac

    val ctxt = get_ctxt pt pos

  in

    case rls of

	    Celem.Rrls {scr = Celem.Rfuns {init_state,...},...} => 

	    let

        val (_, _, _, rul_terms) = init_state t

	      val newnds = rul_terms_2nds (Proof_Context.theory_of ctxt) [] t rul_terms

	      val pt''' = ins_chn newnds pt p 

	    in ("detailrls", pt''', (p @ [length newnds], Res)) end

	  | _ =>

	    let

        val is = Generate.init_istate tac t

	      (*TODO.WN060602 ScrState (["(t_, Problem (Isac,[equation,univar]))"]

			    is wrong for simpl, but working ?!? *)

	      val tac_ = Tac.Apply_Method' (Celem.e_metID(*WN0402: see generate1 !?!*), SOME t, is, ctxt)

	      val pos' = ((lev_on o lev_dn) p, Frm)

	      val thy = Celem.assoc_thy "Isac"

	      val (_, _, _, pt') = Generate.generate1 thy tac_ (is, ctxt) pos' pt (* implicit Take *)

	      val (_,_, (pt'', _)) = complete_solve CompleteSubpbl [] (pt', pos')

	      val newnds = children (get_nd pt'' p)

	      val pt''' = ins_chn newnds pt p (*complete_solve cuts branches after*)

	    in ("detailrls", pt''', (p @ [length newnds], Res):pos') end

  end;

fun get_form (mI, m) (p,p_) pt = 

  case Applicable.applicable_in (p, p_) pt m of

    Chead.Notappl e => Generate.Error' e

  | Chead.Appl m => 

      if member op = specsteps mI

      then

        let val (_, _, f, _, _, _) = Chead.specify m (p, p_) [] pt

        in f end

      else Generate.EmptyMout;

end