(* Title:  todo's for isac core

    Author: Walther Neuper 111013

    (c) copyright due to lincense terms.

 *)

 theory TODO

 imports "~~/src/Doc/Prog_Prove/LaTeXsugar"

 begin

 section \<open>TODOs from current changesets\<close>

 text\<open>

   Shift more complicated issues from the next subsection to the next but one!

 \<close>

 subsection \<open>Current changeset\<close>

 text \<open>

   \begin{itemize}

   \item xxx

   \item + test/..

     rename Env.upd_env -> Env.update  & Co.

   \item xxx

   \item finalise changes in istate, scan_dn2, scan_dn1 & Co

     \begin{itemize}

     \item remove remaining src/ which opens structure "(E," "(_,"

       + Test_Isac

     \item cleanup arguments of scan_dn2, scan_dn1 & Co

       + Test_Isac/../lucas-interpreter.sml, Minisubpbl/

     \item draw changes into remaining tests

     \item xxx

     \end{itemize}

   \end{itemize}

   \item xxx

   \item fun handle_leaf: trace_prog .. separate message

   \item xxx

   \item rm test/..--- check Scripts ---

   \item xxx

   \item reformat + rename "fun subst_stacexpr"+"fun get_stac"

         (*1*)(*2*)

         ?consistency with subst term?

   \item Tactic.Rewrite*: drop "bool"

   \item xxx

   \item Prog_Tac.contain + Tactical.contain   using contains_Const

   \item exception PROG analogous to TERM

   \item xxx

   \item xxx

   \item xxx

   \item Prog_Tac: fun get_stac takes both Prog_Tac + Program --- wait for separate Taciical

     then shift into common descendant

     rename get_stac --> ?ptac?

   \item xxx

   \item xxx

   \item xxx

   \item separate code required in both, ProgLang & Interpret

   \item xxx

   \item /-------------------------------------------------------------------

   \item check occurences of KEStore_Elems.add_rlss [("list_rls",

   \item rename list_rls accordingly

   \item ------------------------------------------------------------------/

   \item xxx

     \item lucas-interpreter.sml         ----- vvvvvvvvv etc.

       val (p'',_,_,pt'') = Generate.generate1 @ {theory} tac' (Istate.Pstate is, ctxt) (po', p_) pt

   \item xxx

   \item rm Float

   \item xxx

     \item signature LIBRARY_C

     \item Program.thy  (*=========== record these ^^^ in 'tacs' in program.ML =========*)

     \item sig/struc ..elems --> elem

     \item xxx

     \item xxx

     \end{itemize}

   \item xxx

   \item xxx

   \item distribute test/../scrtools.sml

   \item xxx

   \item xxx

   \item simplify calls of scan_dn1, scan_dn2 etc

   \item open Istate in LucinNEW

   \end{itemize}

 \<close>

 subsection \<open>Differences between code and paper\<close>

 text \<open>

 * Prog_Tac.consts

   Rewrite'_Inst:: "[(char list * real) list, char list, bool, 'a] => 'a"

 ->Rewrite'_Inst:: "[(char list *   'a) list, char list,       'a] => 'a"

 * Tactical.consts

   Seq      :: "['a => 'a, 'a => 'a, 'a] => 'a" (infixr "@@" 10)

 ->Seq      :: "['a => 'a, 'a => 'a, 'a] => 'a" (infixr "#>" 10)

 + If       :: "[bool, 'a => 'a, 'a => 'a, 'a] => 'a"

 \<close>

 subsection \<open>Postponed from current changeset\<close>

 text \<open>

   \begin{itemize}

   \item xxx

   \item xxx

   \item shift tests into NEW model.sml (upd, upds_envv, ..)

   \item xxx

   \item xxx

   \item xxx

   \item clarify handling of contexts

     \begin{itemize}

     \item Check_Elementwise "Assumptions": prerequisite for ^^goal

       rm tactic Check_elementwise "Assumptions" in a way, which keeps it for Minisubpbl

       rm Assumptions  :: bool  (* TODO: remove with making ^^^ idle *)

     \item xxx

     \item cleanup fun me:

       fun me (*(_, Empty_Tac) p _ _ = raise ERROR ("me:  Empty_Tac at " ^ pos'2str p)

         | me*) (_, tac) p _(*NEW remove*) pt =

       + -------------------------^^^^^^

     \item xxx

     \item Tactic.Apply_Method' (mI, _, _, _(*ctxt ?!?*))) .. remove ctxt

     \item rm ctxt from Subproblem' (is separated in associate!))

     \item check Tactic.Subproblem': are 2 terms required?

     \item xxx

     \item Test_Some.--- rat-equ: remove x = 0 from [x = 0, x = 6 / 5] due to contexts --

       --: wait for deleting Check_Elementwise Assumptions

     \item xxx

     \item lucas-intrpreter.scan_dn1: Generate.generate1 (Celem.assoc_thy "Isac_Knowledge") 

     \end{itemize}

   \item xxx

   \item reconsider "fun subst_stacexpr"

      CAUTION: (1) currying with @@ requires 2 patterns for each tactic

               (2) the non-curried version must return NONE for a 

      	      (3) non-matching patterns become an Celem.Expr by fall-through.

        (a, (*in these cases we hope, that a = SOME _*) --> exn ?PROGRAM?

      rename ?ptac?, prog_tac

   \item xxx

   \item complete mstools.sml (* survey on handling contexts:

   \item xxx

   \item dest_spec (Const ("Product_Type.Pair", _) $ d $ (Const ("Product_Type.Pair", _) FORALL occur.

   \item introduce simple type names to LUCAS_INTERPRETER <-?-> readable paper

   \item xxx

   \item check in states: length ?? > 1 with tracing these cases

   \item xxx

   \item xxx

   \item Lucin.Ass_Weak etc \<longrightarrow> NEW structutre ? LItool ?

   \item xxx

   \item istate

     \begin{itemize}

     \item datatype L,R,D --> Istate

     \item xxx

     \item xxx

     \item xxx

     \item in locate_input_tactic .. ?scan_dn1?; Program.is_eval_expr   .use  Term.exists_Const

     \item xxx

     \item change Lucin.handle_leaf "locate" "Isac_Knowledge" sr E a v t

         to     Lucin.handle_leaf "locate"  ctxt ( pstate )        !!srls in pstate!!^^

         and redesign handle_leaf .. subst_stacexpr .. associate

         to Tactic.from_code : 

         + keep ! trace_script

         + scrstate2str --> pstate2str

     \item xxx

     \item after review of Rrls, detail ?-->? istate

     \item locate_input_tactic: get_simplifier cstate (*TODO: shift to init_istate*)

     \item xxx

     \item push srls into pstate

     \item lucas-intrpreter.locate_input_tactic: scan_to_tactic1 srls tac cstate (progr, Rule.e_rls)

                                                                                         ^^^^^^^^^^

     \item xxx

     \item xxx

     \end{itemize}

   \item xxx

   \item ctxt context

     \begin{itemize}

     \item xxx

     \item xxx

     \item xxx

     \end{itemize}

   \item trace_script: replace ' by " in writeln

   \item xxx

   \item librarys.ml --> libraryC.sml + text from termC.sml

   \item xxx

   \item xxx

   \item xxx

   \item xxx

   \item xxx

   \item xxx

   \item pull update of Ctree.state out of 2 Lucin funs (locate_input_formula is different))

     \begin{itemize}

     \item 1. check if Ctree.state can be updated OUTSIDE determine_next_step

     \item 2. fun locate_input_tactic: pull generate1 out (because it stores ctxt also in cstate)

     \item 

     \item xxx

     \end{itemize}

   \item concentrate "insert_assumptions" in "associate" ?for determine_next_tactic ?where?

     \begin{itemize}

     \item rm from "generate1" ("Detail_Set_Inst'", Tactic.Detail_Set' ?)

     \item shift from "applicable_in..Apply_Method" to ? ? ? (is ONLY use-case in appl.sml))

     \item ?"insert_assumptions" necessary in "init_pstate" ?+++? in "applicable_in" ?+++? "associate"

     \item xxx

     \item xxx

     \item DO DELETIONS AFTER analogous concentrations in determine_next_tactic

     \end{itemize}

   \item xxx

   \item ? what is the difference headline <--> cascmd in

     Subproblem' (spec, oris, headline, fmz_, context, cascmd)

   \item xxx

   \item inform: TermC.parse (Celem.assoc_thy "Isac_Knowledge") istr --> parseNEW context istr

   \item extract common code from associate.. stac2tac_

   \end{itemize}

 \<close>

 section \<open>Separated tasks\<close>

 text \<open>

 \<close>

 subsection \<open>Simple\<close>

 text \<open>

   \item xxx

   \item xxx

   \item check location of files:

         test/Tools/isac/Interpret/ptyps.thy

         test/Tools/isac/Specify.ptyps.sml

   \item xxx

   \item check occurences of Atools in src/ test/

   \item xxx

   \item drop  drop_questionmarks_

   \item xxx

   \item Const ("Atools.pow", _) ---> Const ("Base_Tool.pow", _) 

   \item rename   Base_Tool.thy  <---         Base_Tool

   \item xxx

   \item test/..  tools.sml, atools.sml, scrtools.sml ...

   \item xxx

   \item Diff.thy: differentiateX --> differentiate after removal of script-constant

   \item Test.thy: met_test_sqrt2: deleted?!

   \item xxx

   \item Applicable.applicable_in --> Applicable.tactic_at

   \item xxx

   \item adopt naming conventions in Knowledge: EqSystem --> Equation_System, etc

   \item xxx

   \item TermC.vars_of replace by vars (recognises numerals)

   \item xxx

   \item xxx

   \end{itemize}

 \<close>

 subsection \<open>Simple but laborous\<close>

 text \<open>

   \begin{itemize}

   \item prep_met

     \begin{itemize}

     \item rename field scr in meth

     \item xxx

     \item Rule.rew_ord' := overwritel (! Rule.rew_ord', (*<<<---- use KEStore.xxx, too*)

     \item xxx

     \item check match between args of partial_function and model-pattern of meth;

        provide error message.

     \item xxx

     \item automatically extrac rls from program-code 

       ? take ["SignalProcessing", "Z_Transform", "Inverse_sub"] as an example ?

     \item xxx

     \item xxx

     \item xxx

     \end{itemize}

   \item xxx

   \item drop "init_form" and use "Take" in programs (start with latter!)

   \item xxx

   \item deprive Check_elementwise, but keep it for Minisubpl

     (which checks for Check_Postcond separated by another tactic)

     This seems a prerequisite for appropriate handling of contexts at Check_Postcond.

   \item xxx

   \end{itemize}

 \<close>

 subsection \<open>Questionable\<close>

 text \<open>

   \begin{itemize}

   \item finish output of trace_script with Check_Postcond (useful for SubProblem)

   \item unify in signature LANGUAGE_TOOLS =\\

     val pblterm: Rule.domID -> Celem.pblID -> term     vvv        vvv\\

     val subpbl: string -> string list -> term          unify with ^^^

   \item xxx

   \item Telem.safe is questionable: has it been replaced by Safe_Step, Not_Derivable, Helpless, etc?

     Note: replacement of Istate.safe by Istate.appy_ didn't care much about Telem.safe.

     If Telem.safe is kept, consider merge with CTbasic.ostate

   \item xxx

   \item xxx

   \end{itemize}

 \<close>

 section \<open>Complex, related to --> other tasks\<close>

 text \<open>

 \<close>

 subsection \<open>Exception Size raised\<close>

 text \<open>

   During update Isabelle2018 --> Isabelle2019 we noticed, that

   "isabelle build" uses resources more efficiently than "isabelle jedit".

   The former works, but the latter causes 

   \begin{itemize}

   \item "Exception- Size raised"

     in Build_Thydata.thy

   \item "exception Size raised (line 169 of "./basis/LibrarySupport.sml")"

     in test/../biegelinie-*.xml.

   \end{itemize}

   This has been detected after changeset (30cd47104ad7) "lucin: reorganise theories in ProgLang".

   Find tools to investigate the Exception, and find ways around it eventually.

 \<close>

 subsection \<open>Cleanup & review signatures wrt. implementation.pdf canonical argument order\<close>

 text \<open>

   \begin{itemize}

   \item there are comments in several signatures

   \item ML_file "~~/src/Tools/isac/Interpret/specification-elems.sml" can be (almost) deleted

   \item src/../Frontend/: signatures missing

   \item xxx

   \end{itemize}

 \<close>

 subsection \<open>overall structure of code\<close>

 text \<open>

   \begin{itemize}

   \item try to separate Isac_Knowledge from MathEngine

     common base: Knowledge_Author / ..??

   \item xxx

   \item  ML_file "~~/src/Tools/isac/Interpret/ctree.sml" (*shift to base in common with Interpret*)

   \item xxx

   \item xxx

   \item xxx

   \end{itemize}

 \<close>

 subsection \<open>solve, loc_solve_, ...\<close>

 text \<open>

   unify to calcstate, calcstate'

   \begin{itemize}

   \item ?delete Check_Postcond' in begin_end_prog (already done in solve?)

     in case both are needed, unify !

   \item xxx

   \item ? rename begin_end_prog -> check_switch_prog

   \item adopt the same for specification phase

   \item xxx

   \end{itemize}

 \<close>

 subsection \<open>Review modelling- + specification-phase\<close>

 text \<open>

   \begin{itemize}

   \item "--- hack for funpack: generalise handling of meths which extend problem items ---"

     \begin{itemize}

     \item see several locations of hack in code

     \item these locations are NOT sufficient, see

       test/../biegelinie-3.sml --- IntegrierenUndKonstanteBestimmen2: Bsp.7.70. auto ---

     \item "fun associate" "match_ags ..dI" instead "..pI" breaks many tests, however,

       this would be according to survey Notes (3) in src/../calchead.sml.

     \end{itemize}

   \item see "failed trial to generalise handling of meths"98298342fb6d

   \item abstract specify + nxt_specif to common aux-funs;

     see e.g. "--- hack for funpack: generalise handling of meths which extend problem items ---"

   \item xxx

   \item type model = itm list ?

   \item review survey Notes in src/../calchead.sml: they are questionable

   \item review copy-named, probably two issues commingled 

     \begin{itemize}

     \item special handling of "#Find#, because it is not a formal argument of partial_function

     \item special naming for solutions of equation solving: x_1, x_2, ...

     \end{itemize}

   \item xxx

   \item structure Tactic Specify -?-> Proglang (would require Model., Selem.)

   \item xxx

   \item this has been written in one go:

     \begin{itemize}

     \item reconsidering Model.max_vt, use problem with meth ["DiffApp","max_by_calculus"]

     \item reconsider add_field': where is it used for what? Shift into mk_oris

     \item reconsider match_itms_oris: where is it used for what? max_vt ONLY???

     \item in Specify_Method search root-oris for items (e.g. "errorBound"), #1# in survey

     \item Specify_Problem, Specify_Method: check respective identifiers after re-Specify_

       (relevant for pre-condition)

     \item unify match_ags to mk_oris1..N with different args (fmz | pat list, pbl | meth

     \item 

     \end{itemize}

   \end{itemize}

 \<close>

 subsection \<open>taci list, type step\<close>

 text \<open>

   \begin{itemize}

   \item states.sml: check, when "length tacis > 1"

   \item in Test_Isac.thy there is only 1 error in Interpret/inform.sml

   \item (*WN190713 REMOVE: "creating a new node" was never implemented for more than one node?!?

   \item xxx

   \end{itemize}

 \<close>

 subsection \<open>Ctree\<close>

 text \<open>

   \begin{itemize}

   \item review get_ctxt, update_ctxt, get_istate, upd_istate, upd_ctxt,

     <---> update_loc', repl_loc (remove the latter)

   \item delete field ctxt in PblObj in favour of loc

   \item xxx

   \item xxx

   \end{itemize}

 \<close>

 subsection \<open>replace theory/thy by context/ctxt\<close>

 text \<open>

   \begin{itemize}

   \item xxx

   \item ??? can theory be retrieved from ctxt --- YES --- see Proof_Context.theory_of below

   \item xxx

   \item cleaup the many conversions string -- theory

   \item make dest_spec --> (theory, pblID, metID) ?+ common_subthy ?

   \item 1. Rewrite.eval_true_, then

     Lucin.handle_leaf, Rewrite.eval_listexpr_, Generate.generate1, Lucin.stac2tac.

   \item fun associate

     let val thy = Celem.assoc_thy "Isac_Knowledge";(*TODO*)

   \item xxx

   \item xxx

   \item xxx

   \item !!! Tactic.Refine_Problem uses Pattern.match, which takes a theory, NOT a ctxt

     but there is Proof_Context.theory_of !!!

   \end{itemize}

 \<close>

 subsection \<open>Rfuns, Begin_/End_Detail', Rrls, Istate\<close>

 text \<open>

   \begin{itemize}

   \item removing from_pblobj_or_detail' causes many strange errors

   \item ^^^+ see from_pblobj_or_detail_thm, from_pblobj_or_detail_calc, ...

   \item xxx

   \item probably only "normal_form" seems to be needed

   \item deleted Rfuns in NEW "locate_input_tactic": no active test for "locate_rule"

     but that seems desirable

   \item ?how is the relation to reverse-rewriting ???

   \item "Rfuns" markers in test/../rational

   \item xxx

   \item datatype istate (Istate.T): remove RrlsState, pstate: use Rrls only for creating results beyond

     rewriting and/or respective intermediate steps (e.g. cancellation of fractions).

     Thus we get a 1-step-action which does NOT require a state beyond istate/pstate.

     Thus we drastically reduce complexity, also get rid of "fun from_pblobj_or_detail_calc" , etc.

   \item debug ^^^ related: is there an occurence of Steps with more than 1 element?

   \item xxx

   \item and do_solve_step (* WN1907: ?only for Begin_/End_Detail' DEL!!!*)

   \item xxx

   \item shouldn't go Rfuns from Rewrite --> Rewrite_Set; they behave similar to "fun interSteps" ?

   \end{itemize}

 \<close>

 subsection \<open>Inverse_Z_Transform.thy\<close>

 text \<open>

   \begin{itemize}

   \item\label{new-var-rhs} rule1..6, ruleZY introduce new variables on the rhs of the rewrite-rule.

   ? replace rewriting with substitution ?!?

   The problem is related to the decision of typing for "d_d" and making bound variables free (while

   shifting specific handling in equation solving etc. to the meta-logic). 

   \item Find "stepResponse (x[n::real]::bool)" is superfluous, because immediately used by

     rewrite-rules; see \ref{new-var-rhs}.

   \item Reconsider whole problem:

     input only the polynomial as argument of partial_function, in ([1], Frm) compile lhs "X z" ?

   \end{itemize}

 \<close>

 subsection \<open>Adopt Isabelle's numerals for Isac\<close>

 text \<open>

   \begin{itemize}

   \item replace numerals of type "real" by "nat" in some specific functions from ListC.thy

     and have both representations in parallel for "nat".

   \item xxx

   \item xxx

   \end{itemize}

 \<close>

 subsection \<open>Auto_Prog\<close>

 text \<open>

 two issues:

 (1) fun prep_rls creates a Program with too general and wrong types.

 (2) generated Programs (huge since strings are coded in ASCII) stored in rls drives

     Build_Thydata towards limits of resources.

   \begin{itemize}

   \item rename Auto_Prog.prep_rls --> Auto_Prog.generate

   \item Auto_Prog.generate : term -> rls -> (*Program*)term

      Ctree.current_formula---^^^^

   \item xxx

   \item xxx

   \item generate Program on demand in from_pblobj_or_detail'

   \item xxx

   \item xxx

   \end{itemize}

 \<close>

 subsection \<open>Redesign specify-phase\<close>

 text \<open>

   \begin{itemize}

   \item xxx

   \item Separate Specify/ Interpret/ MathEngine/

     MathEngine.solve, ...,

     ? or identify "layers" like in Isabelle?

   \item xxx

   \item xxx

   \end{itemize}

 \<close>

 subsection \<open>Redesign thms for equation solver\<close>

 text \<open>

   Existing solver is structured along the WRONG assumption,

   that Poly.thy must be the LAST thy among all thys involved.

   Preliminary solution: all inappropriately located thms are collected in Base_Tools.thy

 \<close>

 subsection \<open>Finetunig required for xmldata\<close>

 text \<open>

   See xmldata https://intra.ist.tugraz.at/hg/isac/rev/5b222a649390

   and in kbase html-representation generated from these xmldata.

   Notes in ~~/xmldata/TODO.txt.

 \<close>

 section \<open>Hints for further development\<close>

 text \<open>

 \<close>

 subsection \<open>Coding standards & some explanations for math-authors\<close>

 text \<open>copy from doc/math-eng.tex WN.28.3.03

 WN071228 extended\<close>

 subsubsection \<open>Identifiers\<close>

 text \<open>Naming is particularily crucial, because Isabelles name space is global, and isac does

   not yet use the novel locale features introduces by Isar. For instance, {\tt probe} sounds

   reasonable as (1) a description in the model of a problem-pattern, (2) as an element of the

   problem hierarchies key, (3) as a socalled CAS-command, (4) as the name of a related script etc.

   However, all the cases (1)..(4) require different typing for one and the same

   identifier {\tt probe} which is impossible, and actually leads to strange errors

   (for instance (1) is used as string, except in a script addressing a Subproblem).

   These are the preliminary rules for naming identifiers>

   \begin{description}

   \item [elements of a key] into the hierarchy of problems or methods must not contain

     capital letters and may contain underscrores, e.g. {\tt probe, for_polynomials}.

   \item [descriptions in problem-patterns] must contain at least 1 capital letter and

     must not contain underscores, e.g. {\tt Probe, forPolynomials}.

   \item [CAS-commands] follow the same rules as descriptions in problem-patterns above, thus

     beware of conflicts~!

   \item [script identifiers] always end with {\tt Program}, e.g. {\tt ProbeScript}.

   \item [???] ???

   \item [???] ???

   \end{description}

 %WN071228 extended\<close>

 subsubsection \<open>Rule sets\<close>

 text \<open>The actual version of the coding standards for rulesets is in {\tt /IsacKnowledge/Atools.ML

   where it can be viewed using the knowledge browsers.

   There are rulesets visible to the student, and there are rulesets visible (in general) only for

   math authors. There are also rulesets which {\em must} exist for {\em each} theory;

   these contain the identifier of the respective theory (including all capital letters) 

   as indicated by {\it Thy} below.

   \begin{description}

   \item [norm\_{\it Thy}] exists for each theory, and {\em efficiently} calculates a

     normalform for all terms which can be expressed by the definitions of the respective theory

     (and the respective parents).

   \item [simplify\_{\it Thy}] exists for each theory, and calculates a normalform for all terms

     which can be expressed by the definitions of the respective theory (and the respective parents)

     such, that the rewrites can be presented to the student.

   \item [calculate\_{\it Thy}] exists for each theory, and evaluates terms with 

     numerical constants only (i.e. all terms which can be expressed by the definitions of

     the respective theory and the respective parent theories). In particular, this ruleset includes

     evaluating in/equalities with numerical constants only.

     WN.3.7.03: may be dropped due to more generality: numericals and non-numericals

     are logically equivalent, where the latter often add to the assumptions

     (e.g. in Check_elementwise).

   \end{description}

   The above rulesets are all visible to the user, and also may be input; 

   thus they must be contained in {\tt Theory_Data} (KEStore_Elems.add_rlss,

   KEStore_Elems.get_rlss). All these rulesets must undergo a preparation

   using the function {\tt prep_rls'}, which generates a script for stepwise rewriting etc.

   The following rulesets are used for internal purposes and usually invisible to the (naive) user:

   \begin{description}

   \item [*\_erls] TODO

   \item [*\_prls] 

   \item [*\_srls] 

   \end{description}

 {\tt Rule.append_rls, Rule.merge_rls, remove_rls} TODO

 \<close>

 subsection \<open>get proof-state\<close>

 text \<open>

   Re: [isabelle] Programatically get "this"

   ----------------------------------------------------

   So here is my (Makarius') version of your initial example, following these principles:

   begin{verbatim}

     notepad

     begin

       assume a: A

       ML_val \<open>

         val ctxt = @{context};

         val this_name =

           Name_Space.full_name (Proof_Context.naming_of ctxt) (Binding.name

     Auto_Bind.thisN);

         val this = #thms (the (Proof_Context.lookup_fact ctxt this_name));

       \<close>

     end

   end{verbatim}

 \<close>

 subsection \<open>write Specification to jEdit\<close>

 text \<open>

   Re: [isabelle] Printing terms with type annotations

   ----------------------------------------------------

   On 06/02/2019 17:52, Moa Johansson wrote:

   >

   > I’m writing some code that should create a snippet of Isar script.

   This is how Sledgehammer approximates this:

   http://isabelle.in.tum.de/repos/isabelle/file/Isabelle2018/src/HOL/Tools/Sledgehammer/sledgehammer_isar_proof.ML#l299

   (The module name already shows that the proper terminology is "Isar

   proof" (or "Isar proof text").  Proof scripts are a thing from the past,

   before Isar. You can emulate old-style proof scripts via a sequence of

   'apply' commands, but this is improper Isar.)

   Note that there is no standard function in Isabelle/Pure, because the

   problem to print just the right amount of type information is very

   complex and not fully solved. One day, after 1 or 2 rounds of

   refinements over the above approach, it might become generally available.

 \<close>

 subsection \<open>follow Isabelle conventions (*Does not yet work in Isabelle2018\<close>

 text \<open>

   isabelle update -u path_cartouches

   isabelle update -u inner_syntax_cartouches

 \<close>

 section \<open>Questions to Isabelle experts\<close>

 text \<open>

 \begin{itemize}

 \item what is the actual replacement of "hg log --follow" ?

 \item xxx

 \item how HANDLE these exceptions, e.g.:

     Syntax.read_term ctxt "Randbedingungen y 0 = (0::real), y L = 0, M_b 0 = 0, M_b L = 0]"

   GIVES

     "Inner syntax error

      Failed to parse term"

 \item xxx

 \item xxx

 \item xxx

 \item xxx

 \end{itemize}

 \<close>

 section \<open>For copy & paste\<close>

 text \<open>

 \begin{itemize}

   \begin{itemize}

   \item xxx

     \begin{itemize}

     \item xxx

       \begin{itemize}

       \item xxx

         \begin{itemize}

         \item xxx

         \end{itemize}

       \end{itemize}

     \end{itemize}

   \end{itemize}

 \end{itemize}

 \<close>

 subsection \<open>xxx\<close>

 subsubsection \<open>xxx\<close>

 end