(* elements of calculations.

    they are partially held in association lists as ref's for

    switching language levels (meta-string, object-values).

    in order to keep these ref's during re-evaluation of code,

    they are defined here at the beginning of the code.

    Author: Walther Neuper 2003

    (c) copyright due to lincense terms

 *)

 (*

 structure CalcElems =

 struct

 *)

 val linefeed = (curry op^) "\n";

 type authors = string list;

 type cterm' = string;

 val empty_cterm' = "empty_cterm'";

 (* TODO CLEANUP Thm:

 type rule = 

 Thm (string, thm): (a) needs string to identify sym_thmID for handling in front-end;

                    (b) investigate if ""RS sym" attaches a [.]" still occurs: string_of_thmI

 thmID            : type for data from user input + program

 thmDeriv         : type for thy_hierarchy ONLY

 obsolete types   : thm' (SEE "ad thm'"), thm''. 

 revise funs      : id_of_thm, thm_of_thm, rep_thm_G', eq_thmI, eq_thmI', thm'_of_thm thm.

 activate         : thmID_of_derivation_name'

 *)

 type thmID = string;    (* identifier for a thm (the shortest possible identifier)       *)

 type thmDeriv = string; (* WN120524 deprecated

   thyID ^"."^ xxx ^"."^ thmID, see fun thmID_of_derivation_name 

   WN120524: dont use Thm.derivation_name, this is destroyed by num_str;

   Thm.get_name_hint survives num_str and seems perfectly reliable *)

 type thm' = thmID * cterm';(*WN060610 deprecated in favour of thm''*)

 type thm'' = thmID * term;

 type rls' = string;

 (*.a 'guh'='globally unique handle' is a string unique for each element

    of isac's KEStore and persistent over time

    (in particular under shifts within the respective hierarchy);

    specialty for thys:

    # guh NOT resistant agains shifts from one thy to another

    (which is the price for Isabelle's design: thy's overwrite ids of subthy's)

    # requirement for matchTheory: induce guh from tac + current thy

    (see 'fun thy_containing_thm', 'fun thy_containing_rls' etc.)

    TODO: introduce to pbl, met.*)

 type guh = string;

 val e_guh = "e_guh":guh;

 type xml = string;

 (* eval function calling sml code during rewriting.

 Unifying "type cal" and "type calc" would make Lucas-Interpretation more efficient,

   see "fun rule2stac": instead of 

     Calc: calID * eval_fn -> rule

   would be better

     Calc: prog_calcID * (calID * eval_fn)) -> rule*)

 type eval_fn = (string -> term -> theory -> (string * term) option);

 fun e_evalfn (_:'a) (_:term) (_:theory) = NONE:(string * term) option;

 (*. op in isa-term 'Const(op,_)' .*)

 type calID = string;

 (* *)

 type cal = (calID * eval_fn);

 (*. fun calculate_ fetches the evaluation-function via this list. *)

 type prog_calcID = string;

 type calc = (prog_calcID * cal);

 type calc_elem =

   prog_calcID *   (* a simple identifier used in programs *)

   (calID *        (* a long identifier used in Const *)

     eval_fn)      (* an ML function *)

 fun calc_eq ((pi1, (ci1, _)) : calc_elem, (pi2, (ci2, _)) : calc_elem) =

   if pi1 = pi2

   then if ci1 = ci2 then true else error ("calc_eq: " ^ ci1 ^ " <> " ^ ci2)

   else false

 type subs' = (cterm' * cterm') list; (*16.11.00 for FE-KE*)

 type subst = (term * term) list; (*here for ets2str*)

 val e_subst = []:(term * term) list;

 (*TODO.WN060610 make use of "type rew_ord" total*)

 type rew_ord' = string;

 val e_rew_ord' = "e_rew_ord" : rew_ord';

 type rew_ord_ = subst -> Term.term * Term.term -> bool;

 fun dummy_ord (_:subst) (_:term,_:term) = true;

 val e_rew_ord_ = dummy_ord;

 type rew_ord = rew_ord' * rew_ord_;

 val e_rew_ord = dummy_ord; (* TODO.WN071231 clarify identifiers..e_rew_ordX*)

 val e_rew_ordX = (e_rew_ord', e_rew_ord_) : rew_ord;

 (* error patterns and fill patterns *)

 type errpatID = string

 type errpat =

   errpatID    (* one identifier for a list of patterns                       

                  DESIGN ?TODO: errpatID list for hierarchy of errpats ?      *)

   * term list (* error patterns                                              *)

   * thm list  (* thms related to error patterns; note that respective lhs 

                  do not match (which reflects student's error).

                  fillpatterns are stored with these thms.                    *)

 (* for (at least) 2 kinds of access:

   (1) given an errpatID, find the respective fillpats (e.g. in fun find_fill_pats)

   (2) given a thm, find respective fillpats *)

 type fillpatID = string

 type fillpat =

   fillpatID   (* DESIGN ?TODO: give an order w.r.t difficulty ? *)

   * term      (* the pattern with fill-in gaps                  *)

   * errpatID; (* which the fillpat would be a help for          

                  DESIGN ?TODO: list for several patterns ?      *)

 datatype rule =

   Erule                (*.the empty rule                     .*)

 | Thm of (string * Basic_Thm.thm) (* see TODO CLEANUP Thm     *)

 | Calc of string *     (*.sml-code manipulating a (sub)term  .*)

 	  eval_fn

 | Cal1 of string *     (*.sml-code applied only to whole term

                           or left/right-hand-side of eqality .*)

 	  eval_fn

 | Rls_ of rls          (*.ie. rule sets may be nested.*)

 and scr =

     EmptyScr

   | Prog of term (* for met *)

   | Rfuns of     (* for Rrls, usage see rational.sml ----- reverse rewrite -----      *)

     {init_state : (* initialise for reverse rewriting by the Interpreter              *)

       term ->         (* for this the rrlsstate is initialised:                       *)

       term *          (* the current formula: goes locate_gen -> next_tac via istate  *)

       term *          (* the final formula                                            *)

       rule list       (* of reverse rewrite set (#1#)                                 *)

         list *        (*   may be serveral, eg. in norm_rational                      *)

       ( rule *        (* Thm (+ Thm generated from Calc) resulting in ...             *)

         (term *       (*   ... rewrite with ...                                       *)

         term list))   (*   ... assumptions                                            *)

       list,           (* derivation from given term to normalform

                          in reverse order with sym_thm;

                                                 (#1#) could be extracted from here #1 *)  

 	  normal_form:  (* the function which drives the Rrls ##############################*)

 	    term -> (term * term list) option,

 	  locate_rule:  (* checks a rule R for being a cancel-rule, and if it is,

                      then return the list of rules (+ the terms they are rewriting to)

                      which need to be applied before R should be applied.

                      precondition: the rule is applicable to the argument-term.       *)

 	    rule list list -> (* the reverse rule list                                      *)

 	    term ->         (* ... to which the rule shall be applied                       *)

 	    rule ->         (* ... to be applied to term                                    *)

 	    ( rule *        (* value: a rule rewriting to ...                               *)

 	      (term *       (*   ... the resulting term ...                                 *)

 	      term list))   (*   ... with the assumptions ( //#0)                           *)

 	    list,           (*   there may be several such rules; the list is empty,          

                            if the rule has nothing to do with e.g. cancelation        *)

 	  next_rule:    (* for a given term return the next rules to be done for cancelling *)

 	    rule list list->(* the reverse rule list                                        *)

 	    term ->         (* the term for which ...                                       *)

 	    rule option,    (* ... this rule is appropriate for cancellation;

 		                     there may be no such rule (if the term is eg.canceled already*)

 	  attach_form:  (* checks an input term TI, if it may belong to e.g. a current 

                      cancellation, by trying to derive it from the given term TG.     

                      NOT IMPLEMENTED                                                 *)

 	    rule list list->(**)

 	    term ->         (* TG, the last one agreed upon by user + math-eng              *)

 	    term ->         (* TI, the next one input by the user                           *)

 	    ( rule *        (* the rule to be applied in order to reach TI                  *) 

 	      (term *       (* ... obtained by applying the rule ...                        *)

 	      term list))   (* ... and the respective assumptions                           *) 

 	    list}           (* there may be several such rules; the list is empty, if the 

                          users term does not belong to e.g. a cancellation of the term 

                          last agreed upon.                                            *)

 and rls =

     Erls                          (*for init e_rls*)

   | Rls of (*a confluent and terminating ruleset, in general         *)

     {id : string,          (*for trace_rewrite:=true                 *)

      preconds : term list, (*unused WN020820                         *)

      (*WN060616 for efficiency...

       bdvs    : false,       (*set in prep_rls' for get_bdvs *)*)

      rew_ord  : rew_ord,   (*for rules*)

      erls     : rls,       (*for the conditions in rules             *)

      srls     : rls,       (*for evaluation of list_fns in script    *)

      calc     : calc list, (*for Calculate in scr, set by prep_rls'   *)

      rules    : rule list,

      errpatts : errpatID list,(*dialog-authoring in Build_Thydata.thy*)

      scr      : scr}       (*Prog term: generating intermed.steps  *)

   | Seq of (*a sequence of rules to be tried only once               *)

     {id : string,          (*for trace_rewrite:=true                 *)

      preconds : term list, (*unused 20.8.02                          *)

      (*WN060616 for efficiency...

       bdvs    : false,       (*set in prep_rls' for get_bdvs *)*)

      rew_ord  : rew_ord,   (*for rules                               *)

      erls     : rls,       (*for the conditions in rules             *)

      srls     : rls,       (*for evaluation of list_fns in script    *)

      calc     : calc list, (*for Calculate in scr, set by prep_rls'   *)

      rules    : rule list,

      errpatts : errpatID list,(*dialog-authoring in Build_Thydata.thy*)

      scr      : scr}  (*Prog term  (how to restrict type ???)*)

   (*Rrls call SML-code and simulate an rls

     difference: there is always _ONE_ redex rewritten in 1 call,

     thus wrap Rrls by: Rls (Rls_ ...)*)

   | Rrls of (* SML-functions within rewriting; step-wise execution provided;   

                Rrls simulate an rls

                difference: there is always _ONE_ redex rewritten in 1 call,

                thus wrap Rrls by: Rls (Rls_ ...)                              *)

     {id : string,          (* for trace_rewrite := true                       *)

      prepat  : (term list *(* preconds, eval with subst from pattern;

                               if [@{term True}], match decides alone          *)

 		            term )     (* pattern matched with current (sub)term          *)

 		   list,               (* meta-conjunction is or                          *)

      rew_ord  : rew_ord,   (* for rules                                       *)

      erls     : rls,       (* for the conditions in rules and preconds        *)

      calc     : calc list, (* for Calculate in scr, set automatic.in prep_rls' *)

      errpatts : errpatID list,(*dialog-authoring in Build_Thydata.thy*)

      scr      : scr};      (* Rfuns {...}  (how to restrict type ???)         *)

 (*ad thm':

    there are two kinds of theorems ...

    (1) known by isabelle

    (2) not known, eg. calc_thm, instantiated rls

        the latter have a thmid "#..."

    and thus outside isa we ALWAYS transport both (thmID, string_of_thmI)

    and have a special assoc_thm / assoc_rls in this interface      *)

 type theory' = string; (* = domID ^".thy" WN.101011 ABOLISH !*)

 type domID = string;   (* domID ^".thy" = theory' WN.101011 replace by thyID*)

 type thyID = string;    (*WN.3.11.03 TODO: replace domID with thyID*)

 fun term_to_string' ctxt t =

   let

     val ctxt' = Config.put show_markup false ctxt

   in Print_Mode.setmp [] (Syntax.string_of_term ctxt') t end;

 fun term_to_string'' (thyID : thyID) t =

   let

     val ctxt' = Config.put show_markup false (Proof_Context.init_global (Thy_Info.get_theory thyID))

   in Print_Mode.setmp [] (Syntax.string_of_term ctxt') t end;

 fun term_to_string''' thy t =

   let

     val ctxt' = Config.put show_markup false (Proof_Context.init_global thy)

   in Print_Mode.setmp [] (Syntax.string_of_term ctxt') t end;

 fun thy2ctxt' thy' = Proof_Context.init_global (Thy_Info.get_theory thy');(*FIXXXME thy-ctxt*)

 fun thy2ctxt thy = Proof_Context.init_global thy;(*FIXXXME thy-ctxt*)

 fun term2str t = term_to_string' (thy2ctxt' "Isac") t;

 fun terms2strs ts = map term2str ts;

 (*terms2strs [t1,t2] = ["1 + 2", "abc"];*)

 val terms2str = strs2str o terms2strs;

 (*terms2str [t1,t2] = "[\"1 + 2\",\"abc\"]";*)

 val terms2str' = strs2str' o terms2strs;

 (*terms2str' [t1,t2] = "[1 + 2,abc]";*)

 fun termopt2str (SOME t) = "(SOME " ^ term2str t ^ ")"

   | termopt2str NONE = "NONE";

 fun type_to_string' ctxt t =

   let

     val ctxt' = Config.put show_markup false ctxt

   in Print_Mode.setmp [] (Syntax.string_of_typ ctxt') t end;

 fun type_to_string'' (thyID : thyID) t =

   let

     val ctxt' = Config.put show_markup false (Proof_Context.init_global (Thy_Info.get_theory thyID))

   in Print_Mode.setmp [] (Syntax.string_of_typ ctxt') t end;

 fun type_to_string''' thy t =

   let

     val ctxt' = Config.put show_markup false (Proof_Context.init_global thy)

   in Print_Mode.setmp [] (Syntax.string_of_typ ctxt') t end;

 fun type2str typ = type_to_string'' "Isac" typ; (*legacy*)

 val string_of_typ = type2str; (*legacy*)

 fun string_of_typ_thy thy typ = type_to_string'' thy typ; (*legacy*)

 fun Isac _ = Proof_Context.theory_of (thy2ctxt' "Isac"); (*@{theory "Isac"}*)

 val e_rule = Thm ("refl", @{thm refl});

 fun id_of_thm (Thm (id, _)) = id

   | id_of_thm _ = error "error id_of_thm";

 fun thm_of_thm (Thm (_, thm)) = thm

   | thm_of_thm _ = error "error thm_of_thm";

 fun rep_thm_G' (Thm (thmid, thm)) = (thmid, thm);

 fun thmID_of_derivation_name dn = last_elem (space_explode "." dn);

 fun thmID_of_derivation_name' thm = (thmID_of_derivation_name o Thm.get_name_hint) thm

 fun thyID_of_derivation_name dn = hd (space_explode "." dn);

 fun eq_thmI ((thmid1 : thmID, _ : thm), (thmid2 : thmID, _ : thm)) =

     (strip_thy thmid1) = (strip_thy thmid2);

 (*WN120201 weakened*)

 fun eq_thmI ((thmid1 : thmID, _ : thm), (thmid2 : thmID, _)) = thmid1 = thmid2;

 (*version typed weaker WN100910*)

 fun eq_thmI' ((thmid1, _), (thmid2, _)) =

     (thmID_of_derivation_name thmid1) = (thmID_of_derivation_name thmid2);

 (*check for [.] as caused by "fun assoc_thm'"*)

 fun string_of_thm thm = term_to_string' (thy2ctxt' "Isac") (prop_of thm)

 fun string_of_thmI thm =

   let 

     val str = (de_quote o string_of_thm) thm

     val (a, b) = split_nlast (5, Symbol.explode str)

   in 

     case b of

       [" ", " ","[", ".", "]"] => implode a

     | _ => str

   end

 fun thm'_of_thm thm =

   ((thmID_of_derivation_name o Thm.get_name_hint) thm, string_of_thmI thm): thm'

 (*.id requested for all, Rls,Seq,Rrls.*)

 fun id_rls Erls = "e_rls" (*WN060714 quick and dirty: recursive defs!*)

   | id_rls (Rls {id,...}) = id

   | id_rls (Seq {id,...}) = id

   | id_rls (Rrls {id,...}) = id;

 val rls2str = id_rls;

 fun id_rule (Thm (id, _)) = id

   | id_rule (Calc (id, _)) = id

   | id_rule (Rls_ rls) = id_rls rls;

 fun get_rules (Rls {rules,...}) = rules

   | get_rules (Seq {rules,...}) = rules

   | get_rules (Rrls _) = [];

 fun rule2str Erule = "Erule"

   | rule2str (Thm (str, thm)) = "Thm (\""^str^"\","^(string_of_thmI thm)^")"

   | rule2str (Calc (str,f))  = "Calc (\""^str^"\",fn)"

   | rule2str (Cal1 (str,f))  = "Cal1 (\""^str^"\",fn)"

   | rule2str (Rls_ rls) = "Rls_ (\""^id_rls rls^"\")";

 fun rule2str' Erule = "Erule"

   | rule2str' (Thm (str, thm)) = "Thm (\""^str^"\",\"\")"

   | rule2str' (Calc (str,f))  = "Calc (\""^str^"\",fn)"

   | rule2str' (Cal1 (str,f))  = "Cal1 (\""^str^"\",fn)"

   | rule2str' (Rls_ rls) = "Rls_ (\""^id_rls rls^"\")";

 (*WN080102 compare eq_rule ?!?*)

 fun eqrule (Thm (id1,_), Thm (id2,_)) = id1 = id2

   | eqrule (Calc (id1,_), Calc (id2,_)) = id1 = id2

   | eqrule (Cal1 (id1,_), Cal1 (id2,_)) = id1 = id2

   | eqrule (Rls_ _, Rls_ _) = false (*{id=id1}{id=id2} = id1 = id2 FIXXME*)

   | eqrule _ = false;

 type rrlsstate =  (* state for reverse rewriting, comments see type rule and scr | Rfuns *)

   (term * term * rule list list * (rule * (term * term list)) list);

 val e_type = Type("empty",[]);

 val a_type = TFree("'a",[]);

 val e_term = Const("empty",e_type);

 val a_term = Free("empty",a_type);

 val e_rrlsstate = (e_term,e_term,[[e_rule]],[(e_rule,(e_term,[]))]):rrlsstate;

 val e_term = Const("empty", Type("'a", []));

 val e_scr = Prog e_term;

 fun string_of_thy thy = Context.theory_name thy: theory';

 val theory2domID = string_of_thy;

 val theory2thyID = (get_thy o string_of_thy) : theory -> thyID;

 val theory2theory' = string_of_thy;

 val theory2str = string_of_thy; (*WN050903 ..most consistent naming*)

 val theory2str' = implode o (drop_last_n 4) o Symbol.explode o string_of_thy;

 (* fun theory'2theory = fun thyID2thy ... see fun assoc_thy (...Thy_Info.get_theory string);

 al it = "Isac" : string

 *)

 fun thyID2theory' (thyID:thyID) = thyID;

 (*

     let val ss = Symbol.explode thyID

 	val ext = implode (takelast (4, ss))

     in if ext = ".thy" then thyID : theory' (*disarm abuse of thyID*)

        else thyID ^ ".thy"

     end;

 *)

 (* thyID2theory' "Isac" (*ok*);

 val it = "Isac" : theory'

  > thyID2theory' "Isac" (*abuse, goes ok...*);

 val it = "Isac" : theory'

 *)

 fun theory'2thyID (theory':theory') = theory';

 (*

     let val ss = Symbol.explode theory'

 	val ext = implode (takelast (4, ss))

     in if ext = ".thy" then ((implode o (drop_last_n 4)) ss) : thyID

        else theory' (*disarm abuse of theory'*)

     end;

 *)

 (* theory'2thyID "Isac";

 val it = "Isac" : thyID

 > theory'2thyID "Isac";

 val it = "Isac" : thyID*)

 (*. WN0509 discussion:

 #############################################################################

 #   How to manage theorys in subproblems wrt. the requirement,              #

 #   that scripts should be re-usable ?                                      #

 #############################################################################

     eg. 'Script Solve_rat_equation' calls 'SubProblem (RatEq',..'

     which would not allow to 'solve (y'' = -M_b / EI, M_b)' by this script

     because Biegelinie.thy is subthy of RatEq.thy and thus Biegelinie.M_b

     is unknown in RatEq.thy and M_b cannot be parsed into the scripts guard

     (see match_ags).

     Preliminary solution:

     # the thy in 'SubProblem (thy', pbl, arglist)' is not taken automatically,

     # instead the 'maxthy (rootthy pt) thy' is taken for each subpbl

     # however, a thy specified by the user in the rootpbl may lead to

       errors in far-off subpbls (which are not yet reported properly !!!)

       and interactively specifiying thys in subpbl is not very relevant.

     Other solutions possible:

     # always parse and type-check with Thy_Info.get_theory "Isac"

       (rejected tue to the vague idea eg. to re-use equations for R in C etc.)

     # regard the subthy-relation in specifying thys of subpbls

     # specifically handle 'SubProblem (undefined, pbl, arglist)'

     # ???

 .*)

 (*WN0509 TODO "ProtoPure" ... would be more consistent

   with assoc_thy <--> theory2theory' +FIXME assoc_thy "e_domID" -> Script.thy*)

 val e_domID = "e_domID":domID;

 (*the key into the hierarchy ob theory elements*)

 type theID = string list;

 val e_theID = ["e_theID"];

 val theID2str = strs2str;

 (*theID eg. is ["IsacKnowledge", "Test", "Rulesets", "ac_plus_times"]*)

 fun theID2thyID (theID:theID) =

     if length theID >= 3 then (last_elem o (drop_last_n 2)) theID : thyID

     else error ("theID2thyID called with "^ theID2str theID);

 (*the key into the hierarchy ob problems*)

 type pblID = string list; (* domID::...*)

 val e_pblID = ["e_pblID"]:pblID;

 val pblID2str = strs2str;

 (*the key into the hierarchy ob methods*)

 type metID = string list;

 val e_metID = ["e_metID"]:metID;

 val metID2str = strs2str;

 type spec = 

      domID * (*WN.12.03: is replaced by thy from get_met ?FIXME? in:

 	      specify (Init_Proof..), nxt_specify_init_calc,

 	      assod (.SubProblem...), stac2tac (.SubProblem...)*)

      pblID * 

      metID;

 fun spec2str ((dom,pbl,met)(*:spec*)) = 

   "(" ^ (quote dom) ^ ", " ^ (strs2str pbl) ^ 

   ", " ^ (strs2str met) ^ ")";

 (*> spec2str empty_spec;

 val it = "(\"\", [], (\"\", \"\"))" : string *)

 val empty_spec = (e_domID,e_pblID,e_metID):spec;

 val e_spec = empty_spec;

 (*.association list with cas-commands, for generating a complete calc-head.*)

 type generate_fn = 

   (term list ->    (* the arguments of the cas-command, eg. (x+1=2, x) *)

     (term *        (* description of an element                        *)

       term list)   (* value of the element (always put into a list)    *)

   list)            (* of elements in the formalization                 *)

 type cas_elem = 

   (term *          (* cas-command, eg. 'solve'                         *)

     (spec *        (* theory, problem, method                          *)

     generate_fn))

 fun cas_eq ((t1, (_, _)) : cas_elem, (t2, (_, _)) : cas_elem) = t1 = t2

 (*either theID or pblID or metID*)

 type kestoreID = string list;

 val e_kestoreID = ["e_kestoreID"];

 val kestoreID2str = strs2str;

 (*for distinction of contexts WN130621: disambiguate with Isabelle's Context !*)

 datatype ketype = Exp_ | Thy_ | Pbl_ | Met_;

 fun ketype2str Exp_ = "Exp_"

   | ketype2str Thy_ = "Thy_"

   | ketype2str Pbl_ = "Pbl_"

   | ketype2str Met_ = "Met_";

 fun ketype2str' Exp_ = "Example"

   | ketype2str' Thy_ = "Theory"

   | ketype2str' Pbl_ = "Problem"

   | ketype2str' Met_ = "Method";

 (*rewrite orders, also stored in 'type met' and type 'and rls'

   The association list is required for 'rewrite.."rew_ord"..'

   WN0509 tests not well-organized: see smltest/Knowledge/termorder.sml*)

 val rew_ord' = Unsynchronized.ref

         ([]:(rew_ord' *        (*the key for the association list         *)

 	     (subst 	       (*the bound variables - they get high order*)

 	      -> (term * term) (*(t1, t2) to be compared                  *)

 	      -> bool))        (*if t1 <= t2 then true else false         *)

 		list);         (*association list                         *)

 rew_ord' := overwritel (!rew_ord', [("e_rew_ord", e_rew_ord),

 				    ("dummy_ord", dummy_ord)]);

 (* A tree for storing data defined in different theories 

   for access from the Interpreter and from dialogue authoring 

   using a string list as key.

   'a is for pbt | met | thydata; after WN030424 naming became inappropriate *)

 datatype 'a ptyp =

 	Ptyp of string * (* element of the key *)

 		'a list *      (* several pbts with different domIDs/thy TODO: select by subthy (isaref.p.69)

 			                presently only _ONE_ elem FOR ALL KINDS OF CONTENT pbt | met | thydata *)

 		('a ptyp) list;(* the children nodes *)

 (*.datatype for collecting thydata for hierarchy.*)

 (*WN060720 more consistent naming would be 'type thyelem' or 'thelem'*)

 (*WN0606 Htxt contains html which does not belong to the sml-kernel*)

 datatype thydata = Html of {guh: guh,

 			    coursedesign: authors,

 			    mathauthors: authors,

 			    html: string} (*html; for demos before database*)

 		 | Hthm of {guh: guh,

 			    coursedesign: authors,

 			    mathauthors: authors,

 			    fillpats: fillpat list,

 			    thm: thm}

 		 | Hrls of {guh: guh,

 			    coursedesign: authors,

 			    mathauthors: authors,

 			    thy_rls: (thyID * rls)}

 		 | Hcal of {guh: guh,

 			    coursedesign: authors,

 			    mathauthors: authors,

 			    calc: calc}

 		 | Hord of {guh: guh,

 			    coursedesign: authors,

 			    mathauthors: authors,

 			    ord: (subst -> (term * term) -> bool)};

 val e_thydata = Html {guh="e_guh", coursedesign=[], mathauthors=[], html=""};

 fun the2str (Html {guh, coursedesign, mathauthors, html}) = guh : string

   | the2str (Hthm {guh, coursedesign, mathauthors, fillpats, thm}) = guh

   | the2str (Hrls {guh, coursedesign, mathauthors, thy_rls}) = guh

   | the2str (Hcal {guh, coursedesign, mathauthors, calc}) = guh

   | the2str (Hord {guh, coursedesign, mathauthors, ord}) = guh

 fun thes2str thes = map the2str thes |> list2str;

 (* notes on thehier concerning sym_thmID theorems (created in derivations, reverse rewriting)

      (a): thehier does not contain sym_thmID theorems

      (b): lookup for sym_thmID directly from Isabelle using sym_thm

           (within math-engine NO lookup in thehier -- within java in *.xml only!)

 TODO (c): export from thehier to xml

 TODO (c1)   creates one entry for "thmID" (and NONE for "sym_thmID") in the hierarchy

 TODO (c2)   creates 2 files "thy_*-thm-thmID.xml" and "thy_*-thm-sym_thmID.xml"

 TODO (d): 1 entry in the MiniBrowser's hierarchy (generated from xml)

           stands for both, "thmID" and "sym_thmID" 

 TODO (d1)   lookup from calctxt          

 TODO (d1)   lookup from from rule set in MiniBrowser *)

 type thehier = (thydata ptyp) list;

 (* required to determine sequence of main nodes of thehier in KEStore.thy *)

 fun part2guh ([str]:theID) =

     (case str of

 	"Isabelle" => "thy_isab_" ^ str ^ "-part" : guh

       | "IsacScripts" => "thy_scri_" ^ str ^ "-part"

       | "IsacKnowledge" => "thy_isac_" ^ str ^ "-part"

       | str => error ("thy2guh: called with '"^str^"'"))

   | part2guh theID = error ("part2guh called with theID = " ^ theID2str theID);

 fun thy2guh ([part, thyID] : theID) = (case part of

       "Isabelle" => "thy_isab_" ^ thyID : guh

     | "IsacScripts" => "thy_scri_" ^ thyID

     | "IsacKnowledge" => "thy_isac_" ^ thyID

     | str => error ("thy2guh: called with '" ^ str ^ "'"))

   | thy2guh theID = error ("thy2guh called with '" ^ strs2str' theID ^ "'");

 fun thypart2guh ([part, thyID, thypart] : theID) = case part of

     "Isabelle" => "thy_isab_" ^ thyID ^ "-" ^ thypart : guh

   | "IsacScripts" => "thy_scri_" ^ thyID ^ "-" ^ thypart

   | "IsacKnowledge" => "thy_isac_" ^ thyID ^ "-" ^ thypart

   | str => error ("thypart2guh: called with '" ^ str ^ "'");

 (* convert the data got via contextToThy to a globally unique handle

    there is another way to get the guh out of the 'theID' in the hierarchy *)

 fun thm2guh (isa, thyID:thyID) (thmID:thmID) = case isa of

     "Isabelle" => "thy_isab_" ^ theory'2thyID thyID ^ "-thm-" ^ strip_thy thmID : guh

   | "IsacKnowledge" => "thy_isac_" ^ theory'2thyID thyID ^ "-thm-" ^ strip_thy thmID

   | "IsacScripts" => "thy_scri_" ^ theory'2thyID thyID ^ "-thm-" ^ strip_thy thmID

   | str => error ("thm2guh called with isa = '" ^ isa ^ "' for thm = " ^ thmID ^ "'");

 fun rls2guh (isa, thyID:thyID) (rls':rls') = case isa of

     "Isabelle" => "thy_isab_" ^ theory'2thyID thyID ^ "-rls-" ^ rls' : guh

   | "IsacKnowledge" => "thy_isac_" ^ theory'2thyID thyID ^ "-rls-" ^ rls'

   | "IsacScripts" => "thy_scri_" ^ theory'2thyID thyID ^ "-rls-" ^ rls'

   | str => error ("rls2guh called with isa = '" ^ isa ^ "' for rls = '" ^ rls' ^ "'");

 fun cal2guh (isa, thyID:thyID) calID = case isa of

     "Isabelle" => "thy_isab_" ^ theory'2thyID thyID ^ "-cal-" ^ calID : guh

   | "IsacKnowledge" => "thy_isac_" ^ theory'2thyID thyID ^ "-cal-" ^ calID

   | "IsacScripts" => "thy_scri_" ^ theory'2thyID thyID ^ "-cal-" ^ calID

   | str => error ("cal2guh called with isa = '" ^ isa ^ "' for cal = '" ^ calID ^ "'");

 fun ord2guh (isa, thyID:thyID) (rew_ord':rew_ord') = case isa of

     "Isabelle" => "thy_isab_" ^ theory'2thyID thyID ^ "-ord-" ^ rew_ord' : guh

   | "IsacKnowledge" => "thy_isac_" ^ theory'2thyID thyID ^ "-ord-" ^ rew_ord'

   | "IsacScripts" => "thy_scri_" ^ theory'2thyID thyID ^ "-ord-" ^ rew_ord'

   | str => error ("ord2guh called with isa = '" ^ isa ^ "' for ord = '" ^ rew_ord' ^ "'");

 (* not only for thydata, but also for thy's etc *)

 fun theID2guh (theID : theID) = case length theID of

     0 => error ("theID2guh: called with theID = " ^ strs2str' theID)

   | 1 => part2guh theID

   | 2 => thy2guh theID

   | 3 => thypart2guh theID

   | 4 => 

     let val [isa, thyID, typ, elemID] = theID

     in case typ of

         "Theorems" => thm2guh (isa, thyID) elemID

       | "Rulesets" => rls2guh (isa, thyID) elemID

       | "Calculations" => cal2guh (isa, thyID) elemID

       | "Orders" => ord2guh (isa, thyID) elemID

       | "Theorems" => thy2guh [isa, thyID]

       | str => error ("theID2guh: called with theID = " ^ strs2str' theID)

     end

   | n => error ("theID2guh called with theID = " ^ strs2str' theID);

 type path = string;

 type filename = string;

 (*val xxx = fn: a b => (a,b);   ??? fun-definition ???*)

 local

     fun ii (_:term) = e_rrlsstate;

     fun no (_:term) = SOME (e_term,[e_term]);

     fun lo (_:rule list list) (_:term) (_:rule) = [(e_rule,(e_term,[e_term]))];

     fun ne (_:rule list list) (_:term) = SOME e_rule;

     fun fo (_:rule list list) (_:term) (_:term) = [(e_rule,(e_term,[e_term]))];

 in

 val e_rfuns = Rfuns {init_state=ii,normal_form=no,locate_rule=lo,

 		     next_rule=ne,attach_form=fo};

 end;

 val e_rls =

   Rls {id = "e_rls", preconds = [], rew_ord = ("dummy_ord", dummy_ord), erls = Erls,

     srls = Erls, calc = [], rules = [], errpatts = [], scr = EmptyScr}: rls;

 val e_rrls =

   Rrls {id = "e_rrls", prepat = [], rew_ord = ("dummy_ord", dummy_ord), erls = Erls,

     calc = [], errpatts = [], scr=e_rfuns}:rls;

 fun rep_rls (Rls {id,preconds,rew_ord,erls,srls,calc,errpatts,rules,scr}) =

   {id=id,preconds=preconds,rew_ord=rew_ord,erls=erls,srls=srls,calc=calc,

    (*asm_thm=asm_thm,*)rules=rules,scr=scr}

   | rep_rls (Seq {id,preconds,rew_ord,erls,srls,calc,errpatts,rules,scr}) =

   {id=id,preconds=preconds,rew_ord=rew_ord,erls=erls,srls=srls,calc=calc,

    (*asm_thm=asm_thm,*)rules=rules,scr=scr}

   | rep_rls Erls = rep_rls e_rls

   | rep_rls (Rrls {id,...})  = rep_rls e_rls

     (*error("rep_rls doesn't take apart reverse-rewrite-rule-sets: "^id)*);

 (*| rep_rls (Seq {id,...})  =

     error("rep_rls doesn't take apart reverse-rewrite-rule-sets: "^id);

 --1.7.03*)

 fun rep_rrls (Rrls {id, calc, erls, prepat, rew_ord, errpatts,

 	      scr = Rfuns {attach_form, init_state, locate_rule, next_rule, normal_form}}) =

   {id=id, calc=calc, erls=erls, prepat=prepat,

      rew_ord=rew_ord, errpatts=errpatts, attach_form=attach_form, init_state=init_state,

      locate_rule=locate_rule, next_rule=next_rule, normal_form=normal_form}

   | rep_rrls (Rls {id,...}) =

     error ("rep_rrls doesn't take apart (normal) rule-sets: "^id)

   | rep_rrls (Seq {id,...}) =

     error ("rep_rrls doesn't take apart (normal) rule-sets: "^id);

 fun append_rls id (Rls {id=_,preconds=pc,rew_ord=ro,erls=er,srls=sr,calc=ca,

 			rules =rs, errpatts=errpatts, scr=sc}) r =

     (Rls{id=id,preconds=pc,rew_ord=ro,erls=er,srls=sr,calc=ca,

 	 rules = rs @ r, errpatts=errpatts, scr=sc}:rls)

   | append_rls id (Seq {id=_,preconds=pc,rew_ord=ro,erls=er,srls=sr,calc=ca,

 			rules =rs, errpatts=errpatts, scr=sc}) r =

     (Seq{id=id,preconds=pc,rew_ord=ro,erls=er,srls=sr,calc=ca,

 	 rules = rs @ r, errpatts=errpatts, scr=sc}:rls)

   | append_rls id (Rrls _) _ =

     error ("append_rls: not for reverse-rewrite-rule-set "^id);

 (*. are _atomic_ rules equal ?.*)

 (*WN080102 compare eqrule ?!?*)

 fun eq_rule (Thm (thm1,_), Thm (thm2,_)) = thm1 = thm2

   | eq_rule (Calc (id1,_), Calc (id2,_)) = id1 = id2

   | eq_rule (Rls_ rls1, Rls_ rls2) = id_rls rls1 = id_rls rls2

   (*id_rls checks for Rls, Seq, Rrls*)

   | eq_rule _ = false;

 fun merge_ids rls1 rls2 =

   let 

     val id1 = (#id o rep_rls) rls1

     val id2 = (#id o rep_rls) rls2

   in

     if id1 = id2 then id1

     else "merged_" ^ id1 ^ "_" ^ id2

   end

 fun merge_rls _ Erls rls = rls

   | merge_rls _ rls Erls = rls

   | merge_rls _ (Rrls x) _ = Rrls x (* required for merging Theory_Data *)

   | merge_rls _ _ (Rrls x) = Rrls x

   | merge_rls id

 	  (Rls {preconds = pc1, rew_ord = ro1, erls = er1, srls = sr1, calc = ca1,

 	    rules = rs1, errpatts = eps1, scr = sc1, ...})

 	  (Rls {preconds = pc2, erls = er2, srls = sr2, calc = ca2,

 	    rules = rs2, errpatts = eps2, ...})

     =

 	  (Rls {id = id, rew_ord = ro1, scr = sc1,

 	    preconds = union (op =) pc1 pc2,	    

 	    erls = merge_rls (merge_ids er1 er2) er1 er2,

 	    srls = merge_rls (merge_ids sr1 sr2) sr1 sr2,

 	    calc = union calc_eq ca1 ca2,

 		  rules = union eq_rule rs1 rs2,

       errpatts = union (op =) eps1 eps2} : rls)

   | merge_rls id

 	  (Seq {preconds = pc1, rew_ord = ro1, erls = er1, srls = sr1, calc = ca1,

 	    rules = rs1, errpatts = eps1, scr = sc1, ...})

 	  (Seq {preconds = pc2, erls = er2, srls = sr2, calc = ca2,

 	    rules = rs2, errpatts = eps2, ...})

     =

 	  (Seq {id = id, rew_ord = ro1, scr = sc1,

 	    preconds = union (op =) pc1 pc2,	    

 	    erls = merge_rls (merge_ids er1 er2) er1 er2,

 	    srls = merge_rls (merge_ids sr1 sr2) sr1 sr2,

 	    calc = union calc_eq ca1 ca2,

 		  rules = union eq_rule rs1 rs2,

       errpatts = union (op =) eps1 eps2} : rls)

   | merge_rls id _ _ = error ("merge_rls: \"" ^ id ^ 

     "\"; not for reverse-rewrite-rule-sets and not for mixed Rls -- Seq");

 fun remove_rls id (Rls {id=_,preconds=pc,rew_ord=ro,erls=er,srls=sr,calc=ca,

 		     rules=rs, errpatts=eps, scr=sc}) r =

     (Rls{id=id,preconds=pc,rew_ord=ro,erls=er,srls=sr,calc=ca,

 	   rules = gen_rems eq_rule (rs, r),

 	   errpatts = eps(*gen_rems op= (eps, TODO)*),

 	 scr=sc}:rls)

   | remove_rls id (Seq {id=_,preconds=pc,rew_ord=ro,erls=er,srls=sr,calc=ca,

 		     rules =rs, errpatts=eps, scr=sc}) r =

     (Seq{id=id,preconds=pc,rew_ord=ro,erls=er,srls=sr,calc=ca,

 	   rules = gen_rems eq_rule (rs, r),

 	   errpatts = eps(*gen_rems op= (eps, TODO)*),

 	 scr=sc}:rls)

   | remove_rls id (Rrls _) _ = error

                    ("remove_rls: not for reverse-rewrite-rule-set "^id);

 (* datastructure for KEStore_Elems, intermediate for thehier *)

 type rlss_elem = 

   (rls' *     (* identifier unique within Isac *)

   (theory' *  (* just for assignment in thehier, not appropriate for parsing etc *)

     rls))     (* ((#id o rep_rls) rls) = rls'   by coding discipline *)

 fun rls_eq ((id1, (_, _)), (id2, (_, _))) = id1 = id2

 fun insert_merge_rls (re as (id, (thyID, r1)) : rlss_elem) ys = 

   case get_index (fn y => if curry rls_eq re y then SOME y else NONE) ys of

     NONE => re :: ys

   | SOME (i, (_, (_, r2))) => 

       let

         val r12 = merge_rls id r1 r2

       in list_update ys i (id, (thyID, r12)) end

 fun merge_rlss (s1, s2) = fold insert_merge_rls s1 s2;

 fun memrls r (Rls {rules,...}) = gen_mem eqrule (r, rules)

   | memrls r (Seq {rules,...}) = gen_mem eqrule (r, rules)

   | memrls r _ = error ("memrls: incomplete impl. r= "^(rule2str r));

 fun assoc' ([], key) = error ("ME_Isa: '"^key^"' not known")

   | assoc' ((keyi, xi) :: pairs, key) =

       if key = keyi then SOME xi else assoc' (pairs, key);

 fun assoc_thy (thy:theory') =

     if thy = "e_domID" then (Thy_Info.get_theory "Script") (*lower bound of Knowledge*)

     else (Thy_Info.get_theory thy)

          handle _ => error ("ME_Isa: thy '" ^ thy ^ "' not in system");

 (*.overwrite an element in an association list and pair it with a thyID

    in order to create the thy_hierarchy;

    overwrites existing rls' even if they are defined in a different thy;

    this is related to assoc_rls, TODO.WN060120: assoc_rew_ord, assoc_calc;.*)

 (*WN060120 ...these are NOT compatible to "fun assoc_thm'" in that

    they do NOT handle overlays by re-using an identifier in different thys;

    "thyID.rlsID" would be a good solution, if the "." would be possible

    in scripts...

    actually a hack to get alltogether run again with minimal effort*)

 fun insthy thy' (rls', rls) = (rls', (thy', rls));

 fun overwritelthy thy (al, bl:(rls' * rls) list) =

     let val bl' = map (insthy ((get_thy o theory2theory') thy)) bl

     in overwritel (al, bl') end;

 fun assoc_rew_ord ro = ((the o assoc') (!rew_ord',ro))

   handle _ => error ("ME_Isa: rew_ord '"^ro^"' not in system");

 (*get the string for stac from rule*)

 fun subst2str (s:subst) =

     (strs2str o

      (map (linefeed o pair2str o

 	   (apsnd term2str) o

 	   (apfst term2str)))) s;

 fun subst2str' (s:subst) =

     (strs2str' o

      (map (pair2str o

 	   (apsnd term2str) o

 	   (apfst term2str)))) s;

 (*> subst2str' [(str2term "bdv", str2term "x"),

 		(str2term "bdv_2", str2term "y")];

 val it = "[(bdv, x)]" : string

 *)

 val env2str = subst2str;

 (*recursive defs:*)

 fun scr2str (Prog s) = "Prog " ^ term2str s

   | scr2str (Rfuns _)  = "Rfuns";

 fun maxthy thy1 thy2 = if Theory.subthy (thy1, thy2) then thy2 else thy1;

 (*.trace internal steps of isac's rewriter*)

 val trace_rewrite = Unsynchronized.ref false;

 (*.depth of recursion in traces of the rewriter, if trace_rewrite:=true.*)

 val depth = Unsynchronized.ref 99999;

 (*.no of rewrites exceeding this int -> NO rewrite.*)

 (*WN060829 still unused...*)

 val lim_rewrite = Unsynchronized.ref 99999;

 (*.no of derivation-elements exceeding this int -> SOME derivation-elements.*)

 val lim_deriv = Unsynchronized.ref 100;

 (*.switch for checking guhs unique before storing a pbl or met;

    set true at startup (done at begin of ROOT.ML)

    set false for editing IsacKnowledge (done at end of ROOT.ML).*)

 val check_guhs_unique = Unsynchronized.ref true;

 datatype lrd = (*elements of a path (=loc_) into an Isabelle term*)

 	 L     (*go left at $*)

        | R     (*go right at $*)

        | D;     (*go down at Abs*)

 type loc_ = lrd list;

 fun ldr2str L = "L"

   | ldr2str R = "R"

   | ldr2str D = "D";

 fun loc_2str (k:loc_) = (strs2str' o (map ldr2str)) k;

 (* the pattern for an item of a problems model or a methods guard *)

 type pat =

   (string *     (* field               *)

 	  (term *     (* description         *)

 	     term))   (* id | arbitrary term *);

 fun pat2str ((field, (dsc, id)) : pat) = 

   pair2str (field, pair2str (term2str dsc, term2str id))

 fun pats2str pats = (strs2str o (map pat2str)) pats

 (* types for problems models (TODO rename to specification models) *)

 type pbt_ =

   (string *   (* field "#Given",..*)(*deprecated due to 'type pat'*)

     (term *   (* description      *)

       term)); (* id | struct-var  *)

 val e_pbt_ = ("#Undef", (e_term, e_term)) : pbt_

 type pbt = 

   {guh : guh,         (* unique within this isac-knowledge *)

   mathauthors : string list, (* copyright *)

   init : pblID,       (* to start refinement with *)

   thy  : theory,      (* which allows to compile that pbt

                       TODO: search generalized for subthy (ref.p.69*)

                       (*^^^ WN050912 NOT used during application of the problem,

                       because applied terms may be from 'subthy' as well as from super;

                       thus we take 'maxthy'; see match_ags !*)

   cas : term option,  (* 'CAS-command'*)

   prls : rls,         (* for preds in where_*)

   where_ : term list, (* where - predicates*)

   ppc : pat list,     (* this is the model-pattern; 

                        it contains "#Given","#Where","#Find","#Relate"-patterns

                        for constraints on identifiers see "fun cpy_nam" *)

   met : metID list}   (* methods solving the pbt*)

 val e_pbt = {guh = "pbl_empty", mathauthors = [], init = e_pblID, thy = Thy_Info.get_theory "Pure",

   cas = NONE, prls = Erls, where_ = [], ppc = [], met = []} : pbt

 fun pbt2str

         ({cas = cas', guh = guh', init = init', mathauthors = ma', met = met', ppc = ppc',

           prls = prls', thy = thy', where_ = w'} : pbt) =

       "{cas = " ^ (termopt2str cas') ^  ", guh = \"" ^ guh'  ^ "\", init = "

         ^ (strs2str init') ^ ", mathauthors = " ^ (strs2str ma' |> quote) ^ ", met = "

         ^ (strslist2strs met') ^ ", ppc = " ^ pats2str ppc' ^ ", prls = "

         ^ (rls2str prls' |> quote) ^ ", thy = {" ^ (theory2str thy') ^ "}, where_ = "

         ^ (terms2str w') ^ "}" |> linefeed;

 fun pbts2str pbts = map pbt2str pbts |> list2str;

 val e_Ptyp = Ptyp ("e_pblID",[e_pbt],[])

 type ptyps = (pbt ptyp) list

 fun coll_pblguhs pbls =

     let fun node coll (Ptyp (_,[n],ns)) =

 	    [(#guh : pbt -> guh) n] @ (nodes coll ns)

 	and nodes coll [] = coll

 	  | nodes coll (n::ns) = (node coll n) @ (nodes coll ns);

     in nodes [] pbls end;

 fun check_pblguh_unique (guh:guh) (pbls: (pbt ptyp) list) =

     if member op = (coll_pblguhs pbls) guh

     then error ("check_guh_unique failed with '"^guh^"';\n"^

 		      "use 'sort_pblguhs()' for a list of guhs;\n"^

 		      "consider setting 'check_guhs_unique := false'")

     else ();

 fun insrt _ pbt [k] [] = [Ptyp (k, [pbt], [])]

   | insrt d pbt [k] ((Ptyp (k', [p], ps)) :: pys) =

       ((*writeln ("### insert 1: ks = " ^ strs2str [k] ^ "    k'= " ^ k');*)

       if k = k'

       then ((Ptyp (k', [pbt], ps)) :: pys)

       else  ((Ptyp (k', [p], ps)) :: (insrt d pbt [k] pys))

       )			 

   | insrt d pbt (k::ks) ((Ptyp (k', [p], ps))::pys) =

       ((*writeln ("### insert 2: ks = "^(strs2str (k::ks))^"    k'= "^k');*)

       if k = k'

       then ((Ptyp (k', [p], insrt d pbt ks ps)) :: pys)

       else 

         if length pys = 0

         then error ("insert: not found " ^ (strs2str (d : pblID)))

         else ((Ptyp (k', [p], ps)) :: (insrt d pbt (k :: ks) pys))

       );

 fun update_ptyps ID _ _ [] =

     error ("update_ptyps: " ^ strs2str' ID ^ " does not exist")

   | update_ptyps ID [i] data ((py as Ptyp (key, _, pys)) :: pyss) =

     if i = key

     then 

       if length pys = 0

       then ((Ptyp (key, [data], [])) :: pyss)

       else error ("update_ptyps: " ^ strs2str' ID ^ " has descendants")

     else py :: update_ptyps ID [i] data pyss

   | update_ptyps ID (i :: is) data ((py as Ptyp (key, d, pys)) :: pyss) =

     if i = key

     then ((Ptyp (key,  d, update_ptyps ID is data pys)) :: pyss)

     else (py :: (update_ptyps ID (i :: is) data pyss))

 (* this function only works wrt. the way Isabelle evaluates Theories and is not a general merge

   function for trees / ptyps *)

 fun merge_ptyps ([], pt) = pt

   | merge_ptyps (pt, []) = pt

   | merge_ptyps ((x' as Ptyp (k, x, ps)) :: xs, (xs' as Ptyp (k', y, ps') :: ys)) =

       if k = k'

       then Ptyp (k, y, merge_ptyps (ps, ps')) :: merge_ptyps (xs, ys)

       else x' :: merge_ptyps (xs, xs');

 fun merge_ptyps' pt1 pt2 = merge_ptyps (pt1, pt2)

 (* data for methods stored in 'methods'-database*)

 type met = 

      {guh        : guh,        (*unique within this isac-knowledge           *)

       mathauthors: string list,(*copyright                                   *)

       init       : pblID,      (*WN060721 introduced mistakenly--TODO.REMOVE!*)

       rew_ord'   : rew_ord',   (*for rules in Detail

 			                           TODO.WN0509 store fun itself, see 'type pbt'*)

       erls       : rls,        (*the eval_rls for cond. in rules FIXME "rls'

 				                         instead erls in "fun prep_met"              *)

       srls       : rls,        (*for evaluating list expressions in scr      *)

       prls       : rls,        (*for evaluating predicates in modelpattern   *)

       crls       : rls,        (*for check_elementwise, ie. formulae in calc.*)

       nrls       : rls,        (*canonical simplifier specific for this met  *)

       errpats    : errpat list,(*error patterns expected in this method      *)

       calc       : calc list,  (*Theory_Data in fun prep_met                 *)

       (*branch   : TransitiveB set in append_problem at generation ob pblobj

           FIXXXME.0308: set branch from met in Apply_Method ?                *)

       ppc        : pat list,   (*.items in given, find, relate;

 	      items (in "#Find") which need not occur in the arg-list of a SubProblem

         are 'copy-named' with an identifier "*'.'".

         copy-named items are 'generating' if they are NOT "*'''" ?WN120516??

         see ME/calchead.sml 'fun is_copy_named'.                              *)

       pre        : term list,  (*preconditions in where                       *)

       scr        : scr         (*prep_met gets progam or string "empty_script"*)

 	   };

 val e_met = {guh="met_empty",mathauthors=[],init=e_metID,

 	     rew_ord' = "e_rew_ord'": rew_ord',

 	      erls = e_rls, srls = e_rls, prls = e_rls,

 	      calc = [], crls = e_rls, errpats = [], nrls= e_rls,

 	      ppc = []: (string * (term * term)) list,

 	      pre = []: term list,

 	      scr = EmptyScr: scr}:met;

 val e_Mets = Ptyp ("e_metID",[e_met],[]);

 type mets = (met ptyp) list;

 fun coll_metguhs mets =

     let fun node coll (Ptyp (_,[n],ns)) =

 	    [(#guh : met -> guh) n] @ (nodes coll ns)

 	and nodes coll [] = coll

 	  | nodes coll (n::ns) = (node coll n) @ (nodes coll ns);

     in nodes [] mets end;

 fun check_metguh_unique (guh:guh) (mets: (met ptyp) list) =

     if member op = (coll_metguhs mets) guh

     then error ("check_guh_unique failed with '"^guh^"';\n"^

 		      "use 'sort_metguhs()' for a list of guhs;\n"^

 		      "consider setting 'check_guhs_unique := false'")

     else ();

 fun Html_default exist = (Html {guh = theID2guh exist, 

   coursedesign = ["isac team 2006"], mathauthors = [], html = ""})

 fun fill_parents (exist, [i]) thydata = Ptyp (i, [thydata], [])

   | fill_parents (exist, i :: is) thydata =

     Ptyp (i, [Html_default (exist @ [i])], [fill_parents (exist @ [i], is) thydata])

   | fill_parents _ _ = error "Html_default: avoid ML warning: Matches are not exhaustive"

 fun add_thydata (exist, is) thydata [] = [fill_parents (exist, is) thydata]

   | add_thydata (exist, [i]) data (pys as (py as Ptyp (key, _, _)) :: pyss) = 

     if i = key

     then pys (* preserve existing thydata *) 

     else py :: add_thydata (exist, [i]) data pyss

   | add_thydata (exist, iss as (i :: is)) data ((py as Ptyp (key, d, pys)) :: pyss) = 

     if i = key

     then       

       if length pys = 0

       then Ptyp (key, d, [fill_parents (exist @ [i], is) data]) :: pyss

       else Ptyp (key, d, add_thydata (exist @ [i], is) data pys) :: pyss

     else py :: add_thydata (exist, iss) data pyss

   | add_thydata _ _ _ = error "add_thydata: avoid ML warning: Matches are not exhaustive"

 fun update_hthm (Hthm {guh, coursedesign, mathauthors, thm, ...}) fillpats' =

   Hthm {guh = guh, coursedesign = coursedesign, mathauthors = mathauthors,

     fillpats = fillpats', thm = thm}

   | update_hthm _ _ = raise ERROR "wrong data";

 (* for interface for dialog-authoring *)

 fun update_hrls (Hrls {guh, coursedesign, mathauthors, thy_rls = (thyID, rls)}) errpatIDs =

   let

     val rls' = 

       case rls of

         Rls {id, preconds, rew_ord, erls, srls, calc, rules, scr, ...} =>

           Rls {id = id, preconds = preconds, rew_ord = rew_ord, erls = erls, srls = srls,

             calc = calc, rules = rules, scr = scr, errpatts = errpatIDs}

       | Seq {id, preconds, rew_ord, erls, srls, calc, rules, scr, ...} =>

             Seq {id = id, preconds = preconds, rew_ord = rew_ord, erls = erls, srls = srls,

               calc = calc, rules = rules, scr = scr, errpatts = errpatIDs}

       | Rrls {id, prepat, rew_ord, erls, calc, scr, ...} =>

             Rrls {id = id, prepat = prepat, rew_ord = rew_ord, erls = erls, calc = calc,

               scr = scr, errpatts = errpatIDs}

       | Erls => Erls

   in

     Hrls {guh = guh, coursedesign = coursedesign, mathauthors = mathauthors,

       thy_rls = (thyID, rls')}

   end

   | update_hrls _ _ = raise ERROR "wrong data";

 fun app_py p f (d:pblID) (k(*:pblRD*)) = let

     fun py_err _ =

           error ("app_py: not found: " ^ (strs2str d));

     fun app_py' _ [] = py_err ()

       | app_py' [] _ = py_err ()

       | app_py' [k0] ((p' as Ptyp (k', _, _  ))::ps) =

           if k0 = k' then f p' else app_py' [k0] ps

       | app_py' (k' as (k0::ks)) (Ptyp (k'', _, ps)::ps') =

           if k0 = k'' then app_py' ks ps else app_py' k' ps';

   in app_py' k p end;

 fun get_py p = let

         fun extract_py (Ptyp (_, [py], _)) = py

           | extract_py _ = error ("extract_py: Ptyp has wrong format.");

       in app_py p extract_py end;

 fun (*KEStore_Elems.*)insert_fillpats th fis = (* for tests bypassing setup KEStore_Elems *)

   let

     fun update_elem th (theID, fillpats) =

       let

         val hthm = get_py th theID theID

         val hthm' = update_hthm hthm fillpats

           handle ERROR _ => error ("insert_fillpats: " ^ strs2str theID ^ "must address a theorem")

       in update_ptyps theID theID hthm' end

   in fold (update_elem th) fis end

 (* group the theories defined in Isac, compare Build_Thydata:

   section "Get and group the theories defined in Isac" *) 

 fun isabthys () = (*["Complex_Main", "Taylor", .., "Pure"]*)

   let

     val allthys = Theory.ancestors_of (Thy_Info.get_theory "Build_Thydata")

   in

     drop ((find_index (curry Theory.eq_thy (Thy_Info.get_theory "Complex_Main")) allthys), allthys)

   end

 fun knowthys () = (*["Isac", .., "Descript", "Delete"]*)

   let

     fun isacthys () = (* ["Isac", .., "KEStore"] without Build_Isac thys: "Interpret" etc *)

       let

         val allthys = filter_out (member Theory.eq_thy

           [(*Thy_Info.get_theory "ProgLang",*) Thy_Info.get_theory "Interpret", 

             Thy_Info.get_theory "xmlsrc", Thy_Info.get_theory "Frontend"]) 

           (Theory.ancestors_of (Thy_Info.get_theory "Build_Thydata"))

       in

         take ((find_index (curry Theory.eq_thy (Thy_Info.get_theory "Complex_Main")) allthys), 

         allthys)

       end

     val isacthys' = isacthys ()

     val proglang_parent = Thy_Info.get_theory "ProgLang"

   in

     take ((find_index (curry Theory.eq_thy proglang_parent) isacthys'), isacthys')

   end

 fun progthys () = (*["Isac", .., "Descript", "Delete"]*)

   let

     fun isacthys () = (* ["Isac", .., "KEStore"] without Build_Isac thys: "Interpret" etc *)

       let

         val allthys = filter_out (member Theory.eq_thy

           [(*Thy_Info.get_theory "ProgLang",*) Thy_Info.get_theory "Interpret", 

             Thy_Info.get_theory "xmlsrc", Thy_Info.get_theory "Frontend"]) 

           (Theory.ancestors_of (Thy_Info.get_theory "Build_Thydata"))

       in

         take ((find_index (curry Theory.eq_thy (Thy_Info.get_theory "Complex_Main")) allthys), 

         allthys)

       end

     val isacthys' = isacthys ()

     val proglang_parent = Thy_Info.get_theory "ProgLang"

   in

     drop ((find_index (curry Theory.eq_thy proglang_parent) isacthys') + 1(*ProgLang*), isacthys')

   end

 fun partID thy = 

   if member Theory.eq_thy (knowthys ()) thy then "IsacKnowledge"

   else if member Theory.eq_thy (progthys ()) thy then "IsacScripts"

   else if member Theory.eq_thy (isabthys ()) thy then "Isabelle"

   else error ("closure of thys in Isac is broken by " ^ string_of_thy thy)

 fun partID' (thy' : theory') = partID (Thy_Info.get_theory thy')

 (*

 end (*struct*)

 *)