# File proof_kernel.ML

    (*  Title:      HOL/Import/proof_kernel.ML
        ID:         $Id: proof_kernel.ML,v 1.35 2005/09/26 17:19:14 wenzelm Exp $
        Author:     Sebastian Skalberg (TU Muenchen), Steven Obua
    *)

    signature ProofKernel =
    sig
        type hol_type
        type tag
        type term
        type thm
        type ('a,'b) subst

        type proof_info
        datatype proof = Proof of proof_info * proof_content
    	 and proof_content
    	   = PRefl of term
    	   | PInstT of proof * (hol_type,hol_type) subst
    	   | PSubst of proof list * term * proof
    	   | PAbs of proof * term
    	   | PDisch of proof * term
    	   | PMp of proof * proof
    	   | PHyp of term
    	   | PAxm of string * term
    	   | PDef of string * string * term
    	   | PTmSpec of string * string list * proof
    	   | PTyDef of string * string * proof
    	   | PTyIntro of string * string * string * string * term * term * proof
    	   | POracle of tag * term list * term
    	   | PDisk
    	   | PSpec of proof * term
    	   | PInst of proof * (term,term) subst
    	   | PGen of proof * term
    	   | PGenAbs of proof * term option * term list
    	   | PImpAS of proof * proof
    	   | PSym of proof
    	   | PTrans of proof * proof
    	   | PComb of proof * proof
    	   | PEqMp of proof * proof
    	   | PEqImp of proof
    	   | PExists of proof * term * term
    	   | PChoose of term * proof * proof
    	   | PConj of proof * proof
    	   | PConjunct1 of proof
    	   | PConjunct2 of proof
    	   | PDisj1 of proof * term
    	   | PDisj2 of proof * term
    	   | PDisjCases of proof * proof * proof
    	   | PNotI of proof
    	   | PNotE of proof
    	   | PContr of proof * term

        exception PK of string * string

        val get_proof_dir: string -> theory -> string option
        val disambiguate_frees : Thm.thm -> Thm.thm
        val debug : bool ref
        val disk_info_of : proof -> (string * string) option
        val set_disk_info_of : proof -> string -> string -> unit
        val mk_proof : proof_content -> proof
        val content_of : proof -> proof_content
        val import_proof : string -> string -> theory -> (theory -> term) option * (theory -> proof)

        val rewrite_hol4_term: Term.term -> theory -> Thm.thm

        val type_of : term -> hol_type

        val get_thm  : string -> string         -> theory -> (theory * thm option)
        val get_def  : string -> string -> term -> theory -> (theory * thm option)
        val get_axiom: string -> string         -> theory -> (theory * thm option)

        val store_thm : string -> string -> thm -> theory -> theory * thm

        val to_isa_thm : thm -> (term * term) list * Thm.thm
        val to_isa_term: term -> Term.term

        val REFL : term -> theory -> theory * thm
        val ASSUME : term -> theory -> theory * thm
        val INST_TYPE : (hol_type,hol_type) subst -> thm -> theory -> theory * thm
        val INST : (term,term)subst -> thm -> theory -> theory * thm
        val EQ_MP : thm -> thm -> theory -> theory * thm
        val EQ_IMP_RULE : thm -> theory -> theory * thm
        val SUBST : thm list -> term -> thm -> theory -> theory * thm
        val DISJ_CASES : thm -> thm -> thm -> theory -> theory * thm
        val DISJ1: thm -> term -> theory -> theory * thm
        val DISJ2: term -> thm -> theory -> theory * thm
        val IMP_ANTISYM: thm -> thm -> theory -> theory * thm
        val SYM : thm -> theory -> theory * thm
        val MP : thm -> thm -> theory -> theory * thm
        val GEN : term -> thm -> theory -> theory * thm
        val CHOOSE : term -> thm -> thm -> theory -> theory * thm
        val EXISTS : term -> term -> thm -> theory -> theory * thm
        val ABS : term -> thm -> theory -> theory * thm
        val GEN_ABS : term option -> term list -> thm -> theory -> theory * thm
        val TRANS : thm -> thm -> theory -> theory * thm
        val CCONTR : term -> thm -> theory -> theory * thm
        val CONJ : thm -> thm -> theory -> theory * thm
        val CONJUNCT1: thm -> theory -> theory * thm
        val CONJUNCT2: thm -> theory -> theory * thm
        val NOT_INTRO: thm -> theory -> theory * thm
        val NOT_ELIM : thm -> theory -> theory * thm
        val SPEC : term -> thm -> theory -> theory * thm
        val COMB : thm -> thm -> theory -> theory * thm
        val DISCH: term -> thm -> theory -> theory * thm

        val type_introduction: string -> string -> string -> string -> string -> term * term -> thm -> theory -> theory * thm

        val new_definition : string -> string -> term -> theory -> theory * thm
        val new_specification : string -> string -> string list -> thm -> theory -> theory * thm
        val new_type_definition : string -> string -> string -> thm -> theory -> theory * thm
        val new_axiom : string -> term -> theory -> theory * thm

        val prin : term -> unit
        val protect_factname : string -> string
    end

    structure ProofKernel :> ProofKernel =
    struct
    type hol_type = Term.typ
    type term = Term.term
    datatype tag = Tag of string list
    type ('a,'b) subst = ('a * 'b) list
    datatype thm = HOLThm of (Term.term * Term.term) list * Thm.thm

    fun hthm2thm (HOLThm (_, th)) = th

    datatype proof_info
      = Info of {disk_info: (string * string) option ref}

    datatype proof = Proof of proof_info * proof_content
         and proof_content
           = PRefl of term
           | PInstT of proof * (hol_type,hol_type) subst
           | PSubst of proof list * term * proof
           | PAbs of proof * term
           | PDisch of proof * term
           | PMp of proof * proof
           | PHyp of term
           | PAxm of string * term
           | PDef of string * string * term
           | PTmSpec of string * string list * proof
           | PTyDef of string * string * proof
           | PTyIntro of string * string * string * string * term * term * proof
           | POracle of tag * term list * term
           | PDisk
           | PSpec of proof * term
           | PInst of proof * (term,term) subst
           | PGen of proof * term
           | PGenAbs of proof * term option * term list
           | PImpAS of proof * proof
           | PSym of proof
           | PTrans of proof * proof
           | PComb of proof * proof
           | PEqMp of proof * proof
           | PEqImp of proof
           | PExists of proof * term * term
           | PChoose of term * proof * proof
           | PConj of proof * proof
           | PConjunct1 of proof
           | PConjunct2 of proof
           | PDisj1 of proof * term
           | PDisj2 of proof * term
           | PDisjCases of proof * proof * proof
           | PNotI of proof
           | PNotE of proof
           | PContr of proof * term

    exception PK of string * string
    fun ERR f mesg = PK (f,mesg)

    fun print_exn e =
        case e of
    	PK (m,s) => (writeln ("PK (" ^ m ^ "): " ^ s); raise e)
          | _ => Goals.print_exn e

    (* Compatibility. *)

    fun mk_syn thy c =
      if Syntax.is_identifier c andalso not (Syntax.is_keyword (Sign.syn_of thy) c) then NoSyn
      else Syntax.literal c

    fun quotename c =
      if Syntax.is_identifier c andalso not (OuterSyntax.is_keyword c) then c else quote c

    fun simple_smart_string_of_cterm ct =
        let
    	val {sign,t,T,...} = rep_cterm ct
    	(* Hack to avoid parse errors with Trueprop *)
    	val ct  = (cterm_of sign (HOLogic.dest_Trueprop t)
    			   handle TERM _ => ct)
        in
    	quote(
    	Library.setmp print_mode [] (
    	Library.setmp show_brackets false (
    	Library.setmp show_all_types true (
    	Library.setmp Syntax.ambiguity_is_error false (
    	Library.setmp show_sorts true string_of_cterm))))
    	ct)
        end

    fun smart_string_of_cterm ct =
        let
    	val {sign,t,T,...} = rep_cterm ct
            (* Hack to avoid parse errors with Trueprop *)
    	val ct  = (cterm_of sign (HOLogic.dest_Trueprop t)
    		   handle TERM _ => ct)
    	fun match cu = t aconv (term_of cu)
    	fun G 0 = Library.setmp show_types true (Library.setmp show_sorts true)
    	  | G 1 = Library.setmp show_all_types true (G 0)
              | G _ = error ("ProofKernel.smart_string_of_cterm internal error")
    	fun F n =
    	    let
    		val str = Library.setmp show_brackets false (G n string_of_cterm) ct
    		val cu  = transform_error (read_cterm sign) (str,T)
    	    in
    		if match cu
    		then quote str
    		else F (n+1)
    	    end
    	    handle ERROR_MESSAGE mesg => F (n+1)
        in
    	transform_error (Library.setmp print_mode [] (Library.setmp Syntax.ambiguity_is_error true F)) 0
        end
        handle ERROR_MESSAGE mesg => simple_smart_string_of_cterm ct

    val smart_string_of_thm = smart_string_of_cterm o cprop_of

    fun prth th = writeln ((Library.setmp print_mode [] string_of_thm) th)
    fun prc ct = writeln ((Library.setmp print_mode [] string_of_cterm) ct)
    val prin = Library.setmp print_mode [] prin
    fun pth (HOLThm(ren,thm)) =
        let
    	(*val _ = writeln "Renaming:"
    	val _ = app (fn(v,w) => (prin v; writeln " -->"; prin w)) ren*)
    	val _ = prth thm
        in
    	()
        end

    fun disk_info_of (Proof(Info{disk_info,...},_)) = !disk_info
    fun mk_proof p = Proof(Info{disk_info = ref NONE},p)
    fun content_of (Proof(_,p)) = p

    fun set_disk_info_of (Proof(Info{disk_info,...},_)) thyname thmname =
        disk_info := SOME(thyname,thmname)

    structure Lib =
    struct
    fun wrap b e s = String.concat[b,s,e]

    fun assoc x =
        let
    	fun F [] = raise PK("Lib.assoc","Not found")
    	  | F ((x',y)::rest) = if x = x'
    			       then y
    			       else F rest
        in
    	F
        end
    fun i mem L =
        let fun itr [] = false
    	  | itr (a::rst) = i=a orelse itr rst
        in itr L end;

    fun insert i L = if i mem L then L else i::L

    fun mk_set [] = []
      | mk_set (a::rst) = insert a (mk_set rst)

    fun [] union S = S
      | S union [] = S
      | (a::rst) union S2 = rst union (insert a S2)

    fun implode_subst [] = []
      | implode_subst (x::r::rest) = ((x,r)::(implode_subst rest))
      | implode_subst _ = raise ERR "implode_subst" "malformed substitution list"

    fun apboth f (x,y) = (f x,f y)
    end
    open Lib

    structure Tag =
    struct
    val empty_tag = Tag []
    fun read name = Tag [name]
    fun merge (Tag tag1) (Tag tag2) = Tag (Lib.union(tag1,tag2))
    end

    (* Acutal code. *)

    fun get_segment thyname l = (Lib.assoc "s" l
    			     handle PK _ => thyname)
    val get_name : (string * string) list -> string = Lib.assoc "n"

    local
        open LazyScan
        infix 7 |-- --|
        infix 5 :-- -- ^^
        infix 3 >>
        infix 0 ||
    in
    exception XML of string

    datatype xml = Elem of string * (string * string) list * xml list
    datatype XMLtype = XMLty of xml | FullType of hol_type
    datatype XMLterm = XMLtm of xml | FullTerm of term

    fun pair x y = (x,y)

    fun scan_id toks =
        let
            val (x,toks2) = one Char.isAlpha toks
            val (xs,toks3) = any Char.isAlphaNum toks2
        in
            (String.implode (x::xs),toks3)
        end

    fun scan_string str c =
        let
    	fun F [] toks = (c,toks)
    	  | F (c::cs) toks =
    	    case LazySeq.getItem toks of
    		SOME(c',toks') =>
    		if c = c'
    		then F cs toks'
    		else raise SyntaxError
    	      | NONE => raise SyntaxError
        in
    	F (String.explode str)
        end

    local
        val scan_entity =
    	(scan_string "amp;" #"&")
    	    || scan_string "quot;" #"\""
    	    || scan_string "gt;" #">"
    	    || scan_string "lt;" #"<"
                || scan_string "apos;" #"'"
    in
    fun scan_nonquote toks =
        case LazySeq.getItem toks of
    	SOME (c,toks') =>
    	(case c of
    	     #"\"" => raise SyntaxError
    	   | #"&" => scan_entity toks'
    	   | c => (c,toks'))
          | NONE => raise SyntaxError
    end

    val scan_string = $$ #"\"" |-- repeat scan_nonquote --| $$ #"\"" >>
    		     String.implode

    val scan_attribute = scan_id -- $$ #"=" |-- scan_string

    val scan_start_of_tag = $$ #"<" |-- scan_id --
    			   repeat ($$ #" " |-- scan_attribute)

    (* The evaluation delay introduced through the 'toks' argument is needed
    for the sake of the SML/NJ (110.9.1) compiler.  Either that or an explicit
    type :-( *)
    fun scan_end_of_tag toks = ($$ #"/" |-- $$ #">" |-- succeed []) toks

    val scan_end_tag = $$ #"<" |-- $$ #"/" |-- scan_id --| $$ #">"

    fun scan_children id = $$ #">" |-- repeat scan_tag -- scan_end_tag >>
    		       (fn (chldr,id') => if id = id'
    					  then chldr
    					  else raise XML "Tag mismatch")
    and scan_tag toks =
        let
    	val ((id,atts),toks2) = scan_start_of_tag toks
    	val (chldr,toks3) = (scan_children id || scan_end_of_tag) toks2
        in
    	(Elem (id,atts,chldr),toks3)
        end
    end

    val type_of = Term.type_of

    val boolT = Type("bool",[])
    val propT = Type("prop",[])

    fun mk_defeq name rhs thy =
        let
    	val ty = type_of rhs
        in
    	Logic.mk_equals (Const(Sign.intern_const (sign_of thy) name,ty),rhs)
        end

    fun mk_teq name rhs thy =
        let
    	val ty = type_of rhs
        in
    	HOLogic.mk_eq (Const(Sign.intern_const (sign_of thy) name,ty),rhs)
        end

    fun intern_const_name thyname const thy =
        case get_hol4_const_mapping thyname const thy of
    	SOME (_,cname,_) => cname
          | NONE => (case get_hol4_const_renaming thyname const thy of
    		     SOME cname => Sign.intern_const (sign_of thy) (thyname ^ "." ^ cname)
    		   | NONE => Sign.intern_const (sign_of thy) (thyname ^ "." ^ const))

    fun intern_type_name thyname const thy =
        case get_hol4_type_mapping thyname const thy of
    	SOME (_,cname) => cname
          | NONE => Sign.intern_const (sign_of thy) (thyname ^ "." ^ const)

    fun mk_vartype name = TFree(name,["HOL.type"])
    fun mk_thy_type thy Thy Tyop Args = Type(intern_type_name Thy Tyop thy,Args)

    val mk_var = Free

    fun dom_rng (Type("fun",[dom,rng])) = (dom,rng)
      | dom_rng _ = raise ERR "dom_rng" "Not a functional type"

    fun mk_thy_const thy Thy Nam Ty = Const(intern_const_name Thy Nam thy,Ty)

    local
        (* fun get_const sg thyname name =
           (case term_of (read_cterm sg (name, TypeInfer.logicT)) of
              c as Const _ => c)
           handle _ => raise ERR "get_type" (name ^ ": No such constant")*)
          fun get_const sg thyname name =
           (case Sign.const_type sg name of
              SOME ty => Const (name, ty)
            | NONE => raise ERR "get_type" (name ^ ": No such constant"))
    in
    fun prim_mk_const thy Thy Nam =
        let
    	val name = intern_const_name Thy Nam thy
    	val cmaps = HOL4ConstMaps.get thy
        in
    	case StringPair.lookup cmaps (Thy,Nam) of
    	    SOME(_,_,SOME ty) => Const(name,ty)
    	  | _ => get_const (sign_of thy) Thy name
        end
    end

    fun mk_comb(f,a) = f $ a

    (* Needed for HOL Light *)
    fun protect_tyvarname s =
        let
    	fun no_quest s =
    	    if Char.contains s #"?"
    	    then String.translate (fn #"?" => "q_" | c => Char.toString c) s
    	    else s
    	fun beg_prime s =
    	    if String.isPrefix "'" s
    	    then s
    	    else "'" ^ s
        in
    	s |> no_quest |> beg_prime
        end

    val protected_varnames = ref (Symtab.empty:string Symtab.table)
    val invented_isavar = ref (IntInf.fromInt 0)

    fun innocent_varname s = Syntax.is_identifier s andalso not (String.isPrefix "u_" s)

    fun handle_error f d = transform_error f () handle ERROR_MESSAGE _ => d

    val check_name_thy = theory "Main"
    fun valid_boundvarname s = handle_error (fn () => (read_cterm check_name_thy ("SOME "^s^". True", TypeInfer.logicT); true)) false
    fun valid_varname s = handle_error (fn () => (read_cterm check_name_thy (s, TypeInfer.logicT); true)) false

    fun protect_varname s =
        if innocent_varname s andalso valid_varname s then s else
        case Symtab.lookup (!protected_varnames) s of
          SOME t => t
        | NONE =>
          let
    	  val _ = invented_isavar := IntInf.+ (!invented_isavar, IntInf.fromInt 1)
    	  val t = "u_"^(IntInf.toString (!invented_isavar))
              val _ = protected_varnames := Symtab.update (s, t) (!protected_varnames)
          in
    	  t
          end

    fun protect_boundvarname s = if innocent_varname s andalso valid_boundvarname s then s else "u"

    fun mk_lambda (v as Free (x, T)) t = Abs (protect_boundvarname x, T, abstract_over (v, t))
      | mk_lambda (v as Var ((x, _), T)) t = Abs (protect_boundvarname x, T, abstract_over (v, t))
      | mk_lambda v t = raise TERM ("lambda", [v, t]);

    fun replacestr x y s =
    let
      val xl = explode x
      val yl = explode y
      fun isprefix [] ys = true
        | isprefix (x::xs) (y::ys) = if x = y then isprefix xs ys else false
        | isprefix _ _ = false
      fun isp s = isprefix xl s
      fun chg s = yl@(List.drop (s, List.length xl))
      fun r [] = []
        | r (S as (s::ss)) = if isp S then r (chg S) else s::(r ss)
    in
      implode(r (explode s))
    end

    fun protect_factname s = replacestr "." "_dot_" s
    fun unprotect_factname s = replacestr "_dot_" "." s

    val ty_num_prefix = "N_"

    fun startsWithDigit s = Char.isDigit (hd (String.explode s))

    fun protect_tyname tyn =
      let
        val tyn' =
          if String.isPrefix ty_num_prefix tyn then raise (ERR "protect_ty_name" ("type name '"^tyn^"' is reserved")) else
          (if startsWithDigit tyn then ty_num_prefix^tyn else tyn)
      in
        tyn'
      end

    fun protect_constname tcn = tcn
     (* if tcn = ".." then "dotdot"
      else if tcn = "==" then "eqeq"
      else tcn*)

    structure TypeNet =
    struct

    fun get_type_from_index thy thyname types is =
        case Int.fromString is of
    	SOME i => (case Array.sub(types,i) of
    		       FullType ty => ty
    		     | XMLty xty =>
    		       let
    			   val ty = get_type_from_xml thy thyname types xty
    			   val _  = Array.update(types,i,FullType ty)
    		       in
    			   ty
    		       end)
          | NONE => raise ERR "get_type_from_index" "Bad index"
    and get_type_from_xml thy thyname types =
        let
    	fun gtfx (Elem("tyi",[("i",iS)],[])) =
    		 get_type_from_index thy thyname types iS
    	  | gtfx (Elem("tyc",atts,[])) =
    	    mk_thy_type thy
    			(get_segment thyname atts)
    			(protect_tyname (get_name atts))
    			[]
    	  | gtfx (Elem("tyv",[("n",s)],[])) = mk_vartype (protect_tyvarname s)
    	  | gtfx (Elem("tya",[],(Elem("tyc",atts,[]))::tys)) =
    	    mk_thy_type thy
    			(get_segment thyname atts)
    			(protect_tyname (get_name atts))
    			(map gtfx tys)
    	  | gtfx _ = raise ERR "get_type" "Bad type"
        in
    	gtfx
        end

    fun input_types thyname (Elem("tylist",[("i",i)],xtys)) =
        let
    	val types = Array.array(valOf (Int.fromString i),XMLty (Elem("",[],[])))
    	fun IT _ [] = ()
    	  | IT n (xty::xtys) =
    	    (Array.update(types,n,XMLty xty);
    	     IT (n+1) xtys)
    	val _ = IT 0 xtys
        in
    	types
        end
      | input_types _ _ = raise ERR "input_types" "Bad type list"
    end

    structure TermNet =
    struct

    fun get_term_from_index thy thyname types terms is =
        case Int.fromString is of
    	SOME i => (case Array.sub(terms,i) of
    		       FullTerm tm => tm
    		     | XMLtm xtm =>
    		       let
    			   val tm = get_term_from_xml thy thyname types terms xtm
    			   val _  = Array.update(terms,i,FullTerm tm)
    		       in
    			   tm
    		       end)
          | NONE => raise ERR "get_term_from_index" "Bad index"
    and get_term_from_xml thy thyname types terms =
        let
    	fun get_type [] = NONE
    	  | get_type [ty] = SOME (TypeNet.get_type_from_xml thy thyname types ty)
    	  | get_type _ = raise ERR "get_term" "Bad type"

    	fun gtfx (Elem("tmv",[("n",name),("t",tyi)],[])) =
    	    mk_var(protect_varname name,TypeNet.get_type_from_index thy thyname types tyi)
    	  | gtfx (Elem("tmc",atts,[])) =
    	    let
    		val segment = get_segment thyname atts
    		val name = protect_constname(get_name atts)
    	    in
    		mk_thy_const thy segment name (TypeNet.get_type_from_index thy thyname types (Lib.assoc "t" atts))
    		handle PK _ => prim_mk_const thy segment name
    	    end
    	  | gtfx (Elem("tma",[("f",tmf),("a",tma)],[])) =
    	    let
    		val f = get_term_from_index thy thyname types terms tmf
    		val a = get_term_from_index thy thyname types terms tma
    	    in
    		mk_comb(f,a)
    	    end
    	  | gtfx (Elem("tml",[("x",tmx),("a",tma)],[])) =
    	    let
                    val x = get_term_from_index thy thyname types terms tmx
                    val a = get_term_from_index thy thyname types terms tma
    	    in
    		mk_lambda x a
    	    end
    	  | gtfx (Elem("tmi",[("i",iS)],[])) =
    	    get_term_from_index thy thyname types terms iS
    	  | gtfx (Elem(tag,_,_)) =
    	    raise ERR "get_term" ("Not a term: "^tag)
        in
    	gtfx
        end

    fun input_terms thyname types (Elem("tmlist",[("i",i)],xtms)) =
        let
    	val terms = Array.array(valOf(Int.fromString i),XMLtm (Elem("",[],[])))

    	fun IT _ [] = ()
    	  | IT n (xtm::xtms) =
    	    (Array.update(terms,n,XMLtm xtm);
    	     IT (n+1) xtms)
    	val _ = IT 0 xtms
        in
    	terms
        end
      | input_terms _ _ _ = raise ERR "input_terms" "Bad term list"
    end

    fun get_proof_dir (thyname:string) thy =
        let
    	val import_segment =
    	    case get_segment2 thyname thy of
    		SOME seg => seg
    	      | NONE => get_import_segment thy
    	val path = space_explode ":" (getenv "HOL4_PROOFS")
    	fun find [] = NONE
    	  | find (p::ps) =
    	    (let
    		 val dir = OS.Path.joinDirFile {dir = p,file=import_segment}
    	     in
    		 if OS.FileSys.isDir dir
    		 then SOME dir
    		 else find ps
    	     end) handle OS.SysErr _ => find ps
        in
    	Option.map (fn p => OS.Path.joinDirFile {dir = p, file = thyname}) (find path)
        end

    fun proof_file_name thyname thmname thy =
        let
    	val path = case get_proof_dir thyname thy of
    		       SOME p => p
    		     | NONE => error "Cannot find proof files"
    	val _ = OS.FileSys.mkDir path handle OS.SysErr _ => ()
        in
    	OS.Path.joinDirFile {dir = path, file = OS.Path.joinBaseExt {base = (unprotect_factname thmname), ext = SOME "prf"}}
        end

    fun xml_to_proof thyname types terms prf thy =
        let
    	val xml_to_hol_type = TypeNet.get_type_from_xml thy thyname types
    	val xml_to_term = TermNet.get_term_from_xml thy thyname types terms

    	fun index_to_term is =
    	    TermNet.get_term_from_index thy thyname types terms is

    	fun x2p (Elem("prefl",[("i",is)],[])) = mk_proof (PRefl (index_to_term is))
    	  | x2p (Elem("pinstt",[],p::lambda)) =
    	    let
    		val p = x2p p
    		val lambda = implode_subst (map xml_to_hol_type lambda)
    	    in
    		mk_proof (PInstT(p,lambda))
    	    end
    	  | x2p (Elem("psubst",[("i",is)],prf::prfs)) =
    	    let
    		val tm = index_to_term is
    		val prf = x2p prf
    		val prfs = map x2p prfs
    	    in
    		mk_proof (PSubst(prfs,tm,prf))
    	    end
    	  | x2p (Elem("pabs",[("i",is)],[prf])) =
    	    let
    		val p = x2p prf
    		val t = index_to_term is
    	    in
    		mk_proof (PAbs (p,t))
    	    end
    	  | x2p (Elem("pdisch",[("i",is)],[prf])) =
    	    let
    		val p = x2p prf
    		val t = index_to_term is
    	    in
    		mk_proof (PDisch (p,t))
    	    end
    	  | x2p (Elem("pmp",[],[prf1,prf2])) =
    	    let
    		val p1 = x2p prf1
    		val p2 = x2p prf2
    	    in
    		mk_proof (PMp(p1,p2))
    	    end
    	  | x2p (Elem("phyp",[("i",is)],[])) = mk_proof (PHyp (index_to_term is))
    	  | x2p (Elem("paxiom",[("n",n),("i",is)],[])) =
    	    mk_proof (PAxm(n,index_to_term is))
    	  | x2p (Elem("pfact",atts,[])) =
    	    let
    		val thyname = get_segment thyname atts
    		val thmname = protect_factname (get_name atts)
    		val p = mk_proof PDisk
    		val _  = set_disk_info_of p thyname thmname
    	    in
    		p
    	    end
    	  | x2p (Elem("pdef",[("s",seg),("n",name),("i",is)],[])) =
    	    mk_proof (PDef(seg,protect_constname name,index_to_term is))
    	  | x2p (Elem("ptmspec",[("s",seg)],p::names)) =
    	    let
    		val names = map (fn Elem("name",[("n",name)],[]) => name
    				  | _ => raise ERR "x2p" "Bad proof (ptmspec)") names
    	    in
    		mk_proof (PTmSpec(seg,names,x2p p))
    	    end
    	  | x2p (Elem("ptyintro",[("s",seg),("n",name),("a",abs_name),("r",rep_name)],[xP,xt,p])) =
    	    let
    		val P = xml_to_term xP
    		val t = xml_to_term xt
    	    in
    		mk_proof (PTyIntro(seg,protect_tyname name,protect_constname abs_name,protect_constname rep_name,P,t,x2p p))
    	    end
    	  | x2p (Elem("ptydef",[("s",seg),("n",name)],[p])) =
    	    mk_proof (PTyDef(seg,protect_tyname name,x2p p))
    	  | x2p (xml as Elem("poracle",[],chldr)) =
    	    let
    		val (oracles,terms) = Library.partition (fn (Elem("oracle",_,_)) => true | _ => false) chldr
    		val ors = map (fn (Elem("oracle",[("n",name)],[])) => name | xml => raise ERR "x2p" "bad oracle") oracles
    		val (c,asl) = case terms of
    				  [] => raise ERR "x2p" "Bad oracle description"
    				| (hd::tl) => (hd,tl)
    		val tg = foldr (fn (oracle,tg) => Tag.merge (Tag.read oracle) tg) Tag.empty_tag ors
    	    in
    		mk_proof (POracle(tg,map xml_to_term asl,xml_to_term c))
    	    end
    	  | x2p (Elem("pspec",[("i",is)],[prf])) =
    	    let
    		val p = x2p prf
    		val tm = index_to_term is
    	    in
    		mk_proof (PSpec(p,tm))
    	    end
    	  | x2p (Elem("pinst",[],p::theta)) =
    	    let
    		val p = x2p p
    		val theta = implode_subst (map xml_to_term theta)
    	    in
    		mk_proof (PInst(p,theta))
    	    end
    	  | x2p (Elem("pgen",[("i",is)],[prf])) =
    	    let
    		val p = x2p prf
    		val tm = index_to_term is
    	    in
    		mk_proof (PGen(p,tm))
    	    end
    	  | x2p (Elem("pgenabs",[],prf::tms)) =
    	    let
    		val p = x2p prf
    		val tml = map xml_to_term tms
    	    in
    		mk_proof (PGenAbs(p,NONE,tml))
    	    end
    	  | x2p (Elem("pgenabs",[("i",is)],prf::tms)) =
    	    let
    		val p = x2p prf
    		val tml = map xml_to_term tms
    	    in
    		mk_proof (PGenAbs(p,SOME (index_to_term is),tml))
    	    end
    	  | x2p (Elem("pimpas",[],[prf1,prf2])) =
    	    let
    		val p1 = x2p prf1
    		val p2 = x2p prf2
    	    in
    		mk_proof (PImpAS(p1,p2))
    	    end
    	  | x2p (Elem("psym",[],[prf])) =
    	    let
    		val p = x2p prf
    	    in
    		mk_proof (PSym p)
    	    end
    	  | x2p (Elem("ptrans",[],[prf1,prf2])) =
    	    let
    		val p1 = x2p prf1
    		val p2 = x2p prf2
    	    in
    		mk_proof (PTrans(p1,p2))
    	    end
    	  | x2p (Elem("pcomb",[],[prf1,prf2])) =
    	    let
    		val p1 = x2p prf1
    		val p2 = x2p prf2
    	    in
    		mk_proof (PComb(p1,p2))
    	    end
    	  | x2p (Elem("peqmp",[],[prf1,prf2])) =
    	    let
    		val p1 = x2p prf1
    		val p2 = x2p prf2
    	    in
    		mk_proof (PEqMp(p1,p2))
    	    end
    	  | x2p (Elem("peqimp",[],[prf])) =
    	    let
    		val p = x2p prf
    	    in
    		mk_proof (PEqImp p)
    	    end
    	  | x2p (Elem("pexists",[("e",ise),("w",isw)],[prf])) =
    	    let
    		val p = x2p prf
    		val ex = index_to_term ise
    		val w = index_to_term isw
    	    in
    		mk_proof (PExists(p,ex,w))
    	    end
    	  | x2p (Elem("pchoose",[("i",is)],[prf1,prf2])) =
    	    let
    		val v  = index_to_term is
    		val p1 = x2p prf1
    		val p2 = x2p prf2
    	    in
    		mk_proof (PChoose(v,p1,p2))
    	    end
    	  | x2p (Elem("pconj",[],[prf1,prf2])) =
    	    let
    		val p1 = x2p prf1
    		val p2 = x2p prf2
    	    in
    		mk_proof (PConj(p1,p2))
    	    end
    	  | x2p (Elem("pconjunct1",[],[prf])) =
    	    let
    		val p = x2p prf
    	    in
    		mk_proof (PConjunct1 p)
    	    end
    	  | x2p (Elem("pconjunct2",[],[prf])) =
    	    let
    		val p = x2p prf
    	    in
    		mk_proof (PConjunct2 p)
    	    end
    	  | x2p (Elem("pdisj1",[("i",is)],[prf])) =
    	    let
    		val p = x2p prf
    		val t = index_to_term is
    	    in
    		mk_proof (PDisj1 (p,t))
    	    end
    	  | x2p (Elem("pdisj2",[("i",is)],[prf])) =
    	    let
    		val p = x2p prf
    		val t = index_to_term is
    	    in
    		mk_proof (PDisj2 (p,t))
    	    end
    	  | x2p (Elem("pdisjcases",[],[prf1,prf2,prf3])) =
    	    let
    		val p1 = x2p prf1
    		val p2 = x2p prf2
    		val p3 = x2p prf3
    	    in
    		mk_proof (PDisjCases(p1,p2,p3))
    	    end
    	  | x2p (Elem("pnoti",[],[prf])) =
    	    let
    		val p = x2p prf
    	    in
    		mk_proof (PNotI p)
    	    end
    	  | x2p (Elem("pnote",[],[prf])) =
    	    let
    		val p = x2p prf
    	    in
    		mk_proof (PNotE p)
    	    end
    	  | x2p (Elem("pcontr",[("i",is)],[prf])) =
    	    let
    		val p = x2p prf
    		val t = index_to_term is
    	    in
    		mk_proof (PContr (p,t))
    	    end
    	  | x2p xml = raise ERR "x2p" "Bad proof"
        in
    	x2p prf
        end

    fun import_proof_concl thyname thmname thy =
        let
    	val is = TextIO.openIn(proof_file_name thyname thmname thy)
    	val (proof_xml,_) = scan_tag (LazySeq.of_instream is)
    	val _ = TextIO.closeIn is
        in
    	case proof_xml of
    	    Elem("proof",[],xtypes::xterms::prf::rest) =>
    	    let
    		val types = TypeNet.input_types thyname xtypes
    		val terms = TermNet.input_terms thyname types xterms
                    fun f xtm thy = TermNet.get_term_from_xml thy thyname types terms xtm
    	    in
    		case rest of
    		    [] => NONE
    		  | [xtm] => SOME (f xtm)
    		  | _ => raise ERR "import_proof" "Bad argument list"
    	    end
    	  | _ => raise ERR "import_proof" "Bad proof"
        end

    fun import_proof thyname thmname thy =
        let
    	val is = TextIO.openIn(proof_file_name thyname thmname thy)
    	val (proof_xml,_) = scan_tag (LazySeq.of_instream is)
    	val _ = TextIO.closeIn is
        in
    	case proof_xml of
    	    Elem("proof",[],xtypes::xterms::prf::rest) =>
    	    let
    		val types = TypeNet.input_types thyname xtypes
    		val terms = TermNet.input_terms thyname types xterms
    	    in
    		(case rest of
    		     [] => NONE
    		   | [xtm] => SOME (fn thy => TermNet.get_term_from_xml thy thyname types terms xtm)
    		   | _ => raise ERR "import_proof" "Bad argument list",
    		 xml_to_proof thyname types terms prf)
    	    end
    	  | _ => raise ERR "import_proof" "Bad proof"
        end

    fun uniq_compose m th i st =
        let
    	val res = bicompose false (false,th,m) i st
        in
    	case Seq.pull res of
    	    SOME (th,rest) => (case Seq.pull rest of
    				   SOME _ => raise ERR "uniq_compose" "Not unique!"
    				 | NONE => th)
    	  | NONE => raise ERR "uniq_compose" "No result"
        end

    val reflexivity_thm = thm "refl"
    val substitution_thm = thm "subst"
    val mp_thm = thm "mp"
    val imp_antisym_thm = thm "light_imp_as"
    val disch_thm = thm "impI"
    val ccontr_thm = thm "ccontr"

    val meta_eq_to_obj_eq_thm = thm "meta_eq_to_obj_eq"

    val gen_thm = thm "HOLallI"
    val choose_thm = thm "exE"
    val exists_thm = thm "exI"
    val conj_thm = thm "conjI"
    val conjunct1_thm = thm "conjunct1"
    val conjunct2_thm = thm "conjunct2"
    val spec_thm = thm "spec"
    val disj_cases_thm = thm "disjE"
    val disj1_thm = thm "disjI1"
    val disj2_thm = thm "disjI2"

    local
        val th = thm "not_def"
        val sg = sign_of_thm th
        val pp = reflexive (cterm_of sg (Const("Trueprop",boolT-->propT)))
    in
    val not_elim_thm = combination pp th
    end

    val not_intro_thm = symmetric not_elim_thm
    val abs_thm = thm "ext"
    val trans_thm = thm "trans"
    val symmetry_thm = thm "sym"
    val transitivity_thm = thm "trans"
    val eqmp_thm = thm "iffD1"
    val eqimp_thm = thm "HOL4Setup.eq_imp"
    val comb_thm = thm "cong"

    (* Beta-eta normalizes a theorem (only the conclusion, not the *
    hypotheses!)  *)

    fun beta_eta_thm th =
        let
    	val th1 = Thm.equal_elim (Thm.beta_conversion true (cprop_of th))  th
    	val th2 = Thm.equal_elim (Thm.eta_conversion       (cprop_of th1)) th1
        in
    	th2
        end

    fun implies_elim_all th =
        Library.foldl (fn (th,p) => implies_elim th (assume p)) (th,cprems_of th)

    fun norm_hyps th =
        th |> beta_eta_thm
           |> implies_elim_all
           |> implies_intr_hyps

    fun mk_GEN v th sg =
        let
    	val c = HOLogic.dest_Trueprop (concl_of th)
    	val cv = cterm_of sg v
    	val lc = Term.lambda v c
    	val clc = Thm.cterm_of sg lc
    	val cvty = ctyp_of_term cv
    	val th1 = implies_elim_all th
    	val th2 = beta_eta_thm (forall_intr cv th1)
    	val th3 = th2 COMP (beta_eta_thm (Drule.instantiate' [SOME cvty] [SOME clc] gen_thm))
    	val c = prop_of th3
    	val vname = fst(dest_Free v)
    	val (cold,cnew) = case c of
    			      tpc $ (Const("All",allT) $ Abs(oldname,ty,body)) =>
    			      (Abs(oldname,dummyT,Bound 0),Abs(vname,dummyT,Bound 0))
    			    | tpc $ (Const("All",allT) $ rest) => (tpc,tpc)
    			    | _ => raise ERR "mk_GEN" "Unknown conclusion"
    	val th4 = Thm.rename_boundvars cold cnew th3
    	val res = implies_intr_hyps th4
        in
    	res
        end

    (* rotate left k places, leaving the first j and last l premises alone
    *)

    fun permute_prems j k 0 th = Thm.permute_prems j k th
      | permute_prems j k l th =
        th |> Thm.permute_prems 0 (~l)
           |> Thm.permute_prems (j+l) k
           |> Thm.permute_prems 0 l

    fun rearrange sg tm th =
        let
    	val tm' = Pattern.beta_eta_contract tm
    	fun find []      n = permute_prems 0 1 0 (implies_intr (Thm.cterm_of sg tm) th)
    	  | find (p::ps) n = if tm' aconv (Pattern.beta_eta_contract p)
    			     then permute_prems n 1 0 th
    			     else find ps (n+1)
        in
    	find (prems_of th) 0
        end

    fun zip (x::xs) (y::ys) = (x,y)::(zip xs ys)
      | zip [] [] = []
      | zip _ _ = raise ERR "zip" "arguments not of same length"

    fun mk_INST dom rng th =
        th |> forall_intr_list dom
           |> forall_elim_list rng

    val collect_vars =
        let
    	fun F vars (Bound _) = vars
    	  | F vars (tm as Free _) =
    	    if tm mem vars
    	    then vars
    	    else (tm::vars)
    	  | F vars (Const _) = vars
    	  | F vars (tm1 $ tm2) = F (F vars tm1) tm2
    	  | F vars (Abs(_,_,body)) = F vars body
    	  | F vars (Var _) = raise ERR "collect_vars" "Schematic variable found"
        in
    	F []
        end

    (* Code for disambiguating variablenames (wrt. types) *)

    val disamb_info_empty = {vars=[],rens=[]}

    fun rens_of {vars,rens} = rens

    fun name_of_var (Free(vname,_)) = vname
      | name_of_var _ = raise ERR "name_of_var" "Not a variable"

    fun disamb_term_from info tm = (info, tm)

    fun swap (x,y) = (y,x)

    fun has_ren (HOLThm _) = false

    fun prinfo {vars,rens} = (writeln "Vars:";
    			  app prin vars;
    			  writeln "Renaming:";
    			  app (fn(x,y)=>(prin x; writeln " -->"; prin y)) rens)

    fun disamb_thm_from info (HOLThm (_,thm)) = (info, thm)

    fun disamb_terms_from info tms = (info, tms)

    fun disamb_thms_from info hthms = (info, map hthm2thm hthms)

    fun disamb_term tm   = disamb_term_from disamb_info_empty tm
    fun disamb_terms tms = disamb_terms_from disamb_info_empty tms
    fun disamb_thm thm   = disamb_thm_from disamb_info_empty thm
    fun disamb_thms thms = disamb_thms_from disamb_info_empty thms

    fun norm_hthm sg (hth as HOLThm _) = hth

    (* End of disambiguating code *)

    fun disambiguate_frees thm =
        let
          fun ERR s = error ("Drule.disambiguate_frees: "^s)
          val ct = cprop_of thm
          val t = term_of ct
          val thy = theory_of_cterm ct
          val frees = term_frees t
          val freenames = add_term_free_names (t, [])
          fun is_old_name n = n mem_string freenames
          fun name_of (Free (n, _)) = n
            | name_of _ = ERR "name_of"
          fun new_name' bump map n =
              let val n' = n^bump in
                if is_old_name n' orelse Symtab.lookup map n' <> NONE then
                  new_name' (Symbol.bump_string bump) map n
                else
                  n'
              end
          val new_name = new_name' "a"
          fun replace_name n' (Free (n, t)) = Free (n', t)
            | replace_name n' _ = ERR "replace_name"
          (* map: old oder fresh name -> old free,
             invmap: old free which has fresh name assigned to it -> fresh name *)
          fun dis (v, mapping as (map,invmap)) =
              let val n = name_of v in
                case Symtab.lookup map n of
                  NONE => (Symtab.update (n, v) map, invmap)
                | SOME v' =>
                  if v=v' then
                    mapping
                  else
                    let val n' = new_name map n in
                      (Symtab.update (n', v) map,
                       Termtab.update (v, n') invmap)
                    end
              end
        in
          if (length freenames = length frees) then
            thm
          else
            let
              val (_, invmap) =
                  List.foldl dis (Symtab.empty, Termtab.empty) frees
              fun make_subst ((oldfree, newname), (intros, elims)) =
                  (cterm_of thy oldfree :: intros,
                   cterm_of thy (replace_name newname oldfree) :: elims)
              val (intros, elims) = List.foldl make_subst ([], []) (Termtab.dest invmap)
            in
              forall_elim_list elims (forall_intr_list intros thm)
            end
        end

    val debug = ref false

    fun if_debug f x = if !debug then f x else ()
    val message = if_debug writeln

    val conjE_helper = Thm.permute_prems 0 1 conjE

    fun get_hol4_thm thyname thmname thy =
        case get_hol4_theorem thyname thmname thy of
    	SOME hth => SOME (HOLThm hth)
          | NONE =>
    	let
    	    val pending = HOL4Pending.get thy
    	in
    	    case StringPair.lookup pending (thyname,thmname) of
    		SOME hth => SOME (HOLThm hth)
    	      | NONE => NONE
    	end

    fun non_trivial_term_consts tm =
        List.filter (fn c => not (c = "Trueprop" orelse
    			 c = "All" orelse
    			 c = "op -->" orelse
    			 c = "op &" orelse
    			 c = "op =")) (Term.term_consts tm)

    fun match_consts t (* th *) =
        let
    	fun add_consts (Const (c, _), cs) =
    	    (case c of
    		 "op =" => "==" ins_string cs
    	       | "op -->" => "==>" ins_string cs
    	       | "All" => cs
    	       | "all" => cs
    	       | "op &" => cs
    	       | "Trueprop" => cs
    	       | _ => c ins_string cs)
    	  | add_consts (t $ u, cs) = add_consts (t, add_consts (u, cs))
    	  | add_consts (Abs (_, _, t), cs) = add_consts (t, cs)
    	  | add_consts (_, cs) = cs
    	val t_consts = add_consts(t,[])
        in
    	fn th => eq_set(t_consts,add_consts(prop_of th,[]))
        end

    fun split_name str =
        let
    	val sub = Substring.all str
    	val (f,idx) = apsnd Substring.string (Substring.splitr Char.isDigit sub)
    	val (newstr,u) = apboth Substring.string (Substring.splitr (fn c => c = #"_") f)
        in
    	if not (idx = "") andalso u = "_"
    	then SOME (newstr,valOf(Int.fromString idx))
    	else NONE
        end
        handle _ => NONE

    fun rewrite_hol4_term t thy =
        let
    	val sg = sign_of thy

    	val hol4rews1 = map (Thm.transfer sg) (HOL4Rewrites.get thy)
    	val hol4ss = empty_ss setmksimps single addsimps hol4rews1
        in
    	Thm.transfer sg (Simplifier.full_rewrite hol4ss (cterm_of sg t))
        end

    fun get_isabelle_thm thyname thmname hol4conc thy =
        let
    	val sg = sign_of thy

    	val (info,hol4conc') = disamb_term hol4conc
    	val i2h_conc = symmetric (rewrite_hol4_term (HOLogic.mk_Trueprop hol4conc') thy)
    	val isaconc =
    	    case concl_of i2h_conc of
    		Const("==",_) $ lhs $ _ => lhs
    	      | _ => error "get_isabelle_thm" "Bad rewrite rule"
    	val _ = (message "Original conclusion:";
    		 if_debug prin hol4conc';
    		 message "Modified conclusion:";
    		 if_debug prin isaconc)

    	fun mk_res th = HOLThm(rens_of info,equal_elim i2h_conc th)
        in
    	case get_hol4_mapping thyname thmname thy of
    	    SOME (SOME thmname) =>
    	    let
    		val th1 = (SOME (transform_error (PureThy.get_thm thy) (Name thmname))
    			   handle ERROR_MESSAGE _ =>
    				  (case split_name thmname of
    				       SOME (listname,idx) => (SOME (List.nth(PureThy.get_thms thy (Name listname),idx-1))
    							       handle _ => NONE)
    				     | NONE => NONE))
    	    in
    		case th1 of
    		    SOME th2 =>
    		    (case Shuffler.set_prop thy isaconc [(thmname,th2)] of
    			 SOME (_,th) => (message "YES";(thy, SOME (mk_res th)))
    		       | NONE => (message "NO2";error "get_isabelle_thm" "Bad mapping"))
    		  | NONE => (message "NO1";error "get_isabelle_thm" "Bad mapping")
    	    end
    	  | SOME NONE => error ("Trying to access ignored theorem " ^ thmname)
    	  | NONE =>
    	    let
    		val _ = (message "Looking for conclusion:";
    			 if_debug prin isaconc)
    		val cs = non_trivial_term_consts isaconc
    		val _ = (message "Looking for consts:";
    			 message (commas cs))
    		val pot_thms = Shuffler.find_potential thy isaconc
    		val _ = message ((Int.toString (length pot_thms)) ^ " potential theorems")
    	    in
    		case Shuffler.set_prop thy isaconc pot_thms of
    		    SOME (isaname,th) =>
    		    let
    			val hth as HOLThm args = mk_res th
    			val thy' =  thy |> add_hol4_theorem thyname thmname args
    					|> add_hol4_mapping thyname thmname isaname
    		    in
    			(thy',SOME hth)
    		    end
    		  | NONE => (thy,NONE)
    	    end
        end
        handle e => (message "Exception in get_isabelle_thm"; if_debug print_exn e handle _ => (); (thy,NONE))

    fun get_isabelle_thm_and_warn thyname thmname hol4conc thy =
      let
        val (a, b) = get_isabelle_thm thyname thmname hol4conc thy
        fun warn () =
            let
                val sg = sign_of thy
    	    val (info,hol4conc') = disamb_term hol4conc
    	    val i2h_conc = symmetric (rewrite_hol4_term (HOLogic.mk_Trueprop hol4conc') thy)
    	in
    	    case concl_of i2h_conc of
    		Const("==",_) $ lhs $ _ =>
    		(warning ("Failed lookup of theorem '"^thmname^"':");
    	         writeln "Original conclusion:";
    		 prin hol4conc';
    		 writeln "Modified conclusion:";
    		 prin lhs)
    	      | _ => ()
    	end
      in
          case b of
    	  NONE => (warn () handle _ => (); (a,b))
    	| _ => (a, b)
      end

    fun get_thm thyname thmname thy =
        case get_hol4_thm thyname thmname thy of
    	SOME hth => (thy,SOME hth)
          | NONE => ((case import_proof_concl thyname thmname thy of
    		      SOME f => get_isabelle_thm_and_warn thyname thmname (f thy) thy
    		    | NONE => (message "No conclusion"; (thy,NONE)))
    		 handle e as IO.Io _ => (message "IO exception"; (thy,NONE))
    		      | e as PK _ => (message "PK exception"; (thy,NONE)))

    fun rename_const thyname thy name =
        case get_hol4_const_renaming thyname name thy of
    	SOME cname => cname
          | NONE => name

    fun get_def thyname constname rhs thy =
        let
    	val constname = rename_const thyname thy constname
    	val (thmname,thy') = get_defname thyname constname thy
    	val _ = message ("Looking for definition " ^ thyname ^ "." ^ thmname)
        in
    	get_isabelle_thm_and_warn thyname thmname (mk_teq (thyname ^ "." ^ constname) rhs thy') thy'
        end

    fun get_axiom thyname axname thy =
        case get_thm thyname axname thy of
    	arg as (_,SOME _) => arg
          | _ => raise ERR "get_axiom" ("Trying to retrieve axiom (" ^ axname ^ ")")

    fun intern_store_thm gen_output thyname thmname hth thy =
        let
    	val sg = sign_of thy
    	val (hth' as HOLThm (args as (_,th))) = norm_hthm sg hth
    	val rew = rewrite_hol4_term (concl_of th) thy
    	val th  = equal_elim rew th
    	val thy' = add_hol4_pending thyname thmname args thy
            val th = disambiguate_frees th
    	val thy2 = if gen_output
    		   then add_dump ("lemma " ^ (quotename thmname) ^ ": " ^
                                      (smart_string_of_thm th) ^ "\n  by (import " ^
                                      thyname ^ " " ^ (quotename thmname) ^ ")") thy'
    		   else thy'
        in
    	(thy2,hth')
        end

    val store_thm = intern_store_thm true

    fun mk_REFL ctm =
        let
    	val cty = Thm.ctyp_of_term ctm
        in
    	Drule.instantiate' [SOME cty] [SOME ctm] reflexivity_thm
        end

    fun REFL tm thy =
        let
    	val _ = message "REFL:"
    	val (info,tm') = disamb_term tm
    	val sg = sign_of thy
    	val ctm = Thm.cterm_of sg tm'
    	val res = HOLThm(rens_of info,mk_REFL ctm)
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun ASSUME tm thy =
        let
    	val _ = message "ASSUME:"
    	val (info,tm') = disamb_term tm
    	val sg = sign_of thy
    	val ctm = Thm.cterm_of sg (HOLogic.mk_Trueprop tm')
    	val th = Thm.trivial ctm
    	val res = HOLThm(rens_of info,th)
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun INST_TYPE lambda (hth as HOLThm(rens,th)) thy =
        let
    	val _ = message "INST_TYPE:"
    	val _ = if_debug pth hth
    	val sg = sign_of thy
    	val tys_before = add_term_tfrees (prop_of th,[])
    	val th1 = varifyT th
    	val tys_after = add_term_tvars (prop_of th1,[])
    	val tyinst = map (fn (bef, iS) =>
    			     (case try (Lib.assoc (TFree bef)) lambda of
    				  SOME ty => (ctyp_of sg (TVar iS), ctyp_of sg ty)
    				| NONE => (ctyp_of sg (TVar iS), ctyp_of sg (TFree bef))
    			     ))
    			 (zip tys_before tys_after)
    	val res = Drule.instantiate (tyinst,[]) th1
    	val hth = HOLThm([],res)
    	val res = norm_hthm sg hth
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun INST sigma hth thy =
        let
    	val _ = message "INST:"
    	val _ = if_debug (app (fn (x,y) => (prin x; prin y))) sigma
    	val _ = if_debug pth hth
    	val sg = sign_of thy
    	val (sdom,srng) = ListPair.unzip (rev sigma)
    	val th = hthm2thm hth
    	val th1 = mk_INST (map (cterm_of sg) sdom) (map (cterm_of sg) srng) th
    	val res = HOLThm([],th1)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun EQ_IMP_RULE (hth as HOLThm(rens,th)) thy =
        let
    	val _ = message "EQ_IMP_RULE:"
    	val _ = if_debug pth hth
    	val res = HOLThm(rens,th RS eqimp_thm)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun mk_EQ_MP th1 th2 = [beta_eta_thm th1, beta_eta_thm th2] MRS eqmp_thm

    fun EQ_MP hth1 hth2 thy =
        let
    	val _ = message "EQ_MP:"
    	val _ = if_debug pth hth1
    	val _ = if_debug pth hth2
    	val (info,[th1,th2]) = disamb_thms [hth1,hth2]
    	val res = HOLThm(rens_of info,mk_EQ_MP th1 th2)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun mk_COMB th1 th2 sg =
        let
    	val (f,g) = case concl_of th1 of
    			_ $ (Const("op =",_) $ f $ g) => (f,g)
    		      | _ => raise ERR "mk_COMB" "First theorem not an equality"
    	val (x,y) = case concl_of th2 of
    			_ $ (Const("op =",_) $ x $ y) => (x,y)
    		      | _ => raise ERR "mk_COMB" "Second theorem not an equality"
    	val fty = type_of f
    	val (fd,fr) = dom_rng fty
    	val comb_thm' = Drule.instantiate'
    			    [SOME (ctyp_of sg fd),SOME (ctyp_of sg fr)]
    			    [SOME (cterm_of sg f),SOME (cterm_of sg g),
    			     SOME (cterm_of sg x),SOME (cterm_of sg y)] comb_thm
        in
    	[th1,th2] MRS comb_thm'
        end

    fun SUBST rews ctxt hth thy =
        let
    	val _ = message "SUBST:"
    	val _ = if_debug (app pth) rews
    	val _ = if_debug prin ctxt
    	val _ = if_debug pth hth
    	val (info,th) = disamb_thm hth
    	val (info1,ctxt') = disamb_term_from info ctxt
    	val (info2,rews') = disamb_thms_from info1 rews

    	val sg = sign_of thy
    	val cctxt = cterm_of sg ctxt'
    	fun subst th [] = th
    	  | subst th (rew::rews) = subst (mk_COMB th rew sg) rews
    	val res = HOLThm(rens_of info2,mk_EQ_MP (subst (mk_REFL cctxt) rews') th)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun DISJ_CASES hth hth1 hth2 thy =
        let
    	val _ = message "DISJ_CASES:"
    	val _ = if_debug (app pth) [hth,hth1,hth2]
    	val (info,th) = disamb_thm hth
    	val (info1,th1) = disamb_thm_from info hth1
    	val (info2,th2) = disamb_thm_from info1 hth2
    	val sg = sign_of thy
    	val th1 = norm_hyps th1
    	val th2 = norm_hyps th2
    	val (l,r) = case concl_of th of
    			_ $ (Const("op |",_) $ l $ r) => (l,r)
    		      | _ => raise ERR "DISJ_CASES" "Conclusion not a disjunction"
    	val th1' = rearrange sg (HOLogic.mk_Trueprop l) th1
    	val th2' = rearrange sg (HOLogic.mk_Trueprop r) th2
    	val res1 = th RS disj_cases_thm
    	val res2 = uniq_compose ((nprems_of th1')-1) th1' ((nprems_of th)+1) res1
    	val res3 = uniq_compose ((nprems_of th2')-1) th2' (nprems_of res2) res2
    	val res  = HOLThm(rens_of info2,res3)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun DISJ1 hth tm thy =
        let
    	val _ = message "DISJ1:"
    	val _ = if_debug pth hth
    	val _ = if_debug prin tm
    	val (info,th) = disamb_thm hth
    	val (info',tm') = disamb_term_from info tm
    	val sg = sign_of thy
    	val ct = Thm.cterm_of sg tm'
    	val disj1_thm' = Drule.instantiate' [] [NONE,SOME ct] disj1_thm
    	val res = HOLThm(rens_of info',th RS disj1_thm')
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun DISJ2 tm hth thy =
        let
    	val _ = message "DISJ1:"
    	val _ = if_debug prin tm
    	val _ = if_debug pth hth
    	val (info,th) = disamb_thm hth
    	val (info',tm') = disamb_term_from info tm
    	val sg = sign_of thy
    	val ct = Thm.cterm_of sg tm'
    	val disj2_thm' = Drule.instantiate' [] [NONE,SOME ct] disj2_thm
    	val res = HOLThm(rens_of info',th RS disj2_thm')
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun IMP_ANTISYM hth1 hth2 thy =
        let
    	val _ = message "IMP_ANTISYM:"
    	val _ = if_debug pth hth1
    	val _ = if_debug pth hth2
    	val (info,[th1,th2]) = disamb_thms [hth1,hth2]
    	val th = [beta_eta_thm th1,beta_eta_thm th2] MRS imp_antisym_thm
    	val res = HOLThm(rens_of info,th)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun SYM (hth as HOLThm(rens,th)) thy =
        let
    	val _ = message "SYM:"
    	val _ = if_debug pth hth
    	val th = th RS symmetry_thm
    	val res = HOLThm(rens,th)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun MP hth1 hth2 thy =
        let
    	val _ = message "MP:"
    	val _ = if_debug pth hth1
    	val _ = if_debug pth hth2
    	val (info,[th1,th2]) = disamb_thms [hth1,hth2]
    	val th = [beta_eta_thm th1,beta_eta_thm th2] MRS mp_thm
    	val res = HOLThm(rens_of info,th)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun CONJ hth1 hth2 thy =
        let
    	val _ = message "CONJ:"
    	val _ = if_debug pth hth1
    	val _ = if_debug pth hth2
    	val (info,[th1,th2]) = disamb_thms [hth1,hth2]
    	val th = [th1,th2] MRS conj_thm
    	val res = HOLThm(rens_of info,th)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun CONJUNCT1 (hth as HOLThm(rens,th)) thy =
        let
    	val _ = message "CONJUNCT1:"
    	val _ = if_debug pth hth
    	val res = HOLThm(rens,th RS conjunct1_thm)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun CONJUNCT2 (hth as HOLThm(rens,th)) thy =
        let
    	val _ = message "CONJUNCT1:"
    	val _ = if_debug pth hth
    	val res = HOLThm(rens,th RS conjunct2_thm)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun EXISTS ex wit hth thy =
        let
    	val _ = message "EXISTS:"
    	val _ = if_debug prin ex
    	val _ = if_debug prin wit
    	val _ = if_debug pth hth
    	val (info,th) = disamb_thm hth
    	val (info',[ex',wit']) = disamb_terms_from info [ex,wit]
    	val sg = sign_of thy
    	val cwit = cterm_of sg wit'
    	val cty = ctyp_of_term cwit
    	val a = case ex' of
    		    (Const("Ex",_) $ a) => a
    		  | _ => raise ERR "EXISTS" "Argument not existential"
    	val ca = cterm_of sg a
    	val exists_thm' = beta_eta_thm (Drule.instantiate' [SOME cty] [SOME ca,SOME cwit] exists_thm)
    	val th1 = beta_eta_thm th
    	val th2 = implies_elim_all th1
    	val th3 = th2 COMP exists_thm'
    	val th  = implies_intr_hyps th3
    	val res = HOLThm(rens_of info',th)
    	val _   = message "RESULT:"
    	val _   = if_debug pth res
        in
    	(thy,res)
        end

    fun CHOOSE v hth1 hth2 thy =
        let
    	val _ = message "CHOOSE:"
    	val _ = if_debug prin v
    	val _ = if_debug pth hth1
    	val _ = if_debug pth hth2
    	val (info,[th1,th2]) = disamb_thms [hth1,hth2]
    	val (info',v') = disamb_term_from info v
    	fun strip 0 _ th = th
    	  | strip n (p::ps) th =
    	    strip (n-1) ps (implies_elim th (assume p))
    	  | strip _ _ _ = raise ERR "CHOOSE" "strip error"
    	val sg = sign_of thy
    	val cv = cterm_of sg v'
    	val th2 = norm_hyps th2
    	val cvty = ctyp_of_term cv
    	val c = HOLogic.dest_Trueprop (concl_of th2)
    	val cc = cterm_of sg c
    	val a = case concl_of th1 of
    		    _ $ (Const("Ex",_) $ a) => a
    		  | _ => raise ERR "CHOOSE" "Conclusion not existential"
    	val ca = cterm_of (sign_of_thm th1) a
    	val choose_thm' = beta_eta_thm (Drule.instantiate' [SOME cvty] [SOME ca,SOME cc] choose_thm)
    	val th21 = rearrange sg (HOLogic.mk_Trueprop (a $ v')) th2
    	val th22 = strip ((nprems_of th21)-1) (cprems_of th21) th21
    	val th23 = beta_eta_thm (forall_intr cv th22)
    	val th11 = implies_elim_all (beta_eta_thm th1)
    	val th' = th23 COMP (th11 COMP choose_thm')
    	val th = implies_intr_hyps th'
    	val res = HOLThm(rens_of info',th)
    	val _   = message "RESULT:"
    	val _   = if_debug pth res
        in
    	(thy,res)
        end

    fun GEN v hth thy =
        let
          val _ = message "GEN:"
    	val _ = if_debug prin v
    	val _ = if_debug pth hth
    	val (info,th) = disamb_thm hth
    	val (info',v') = disamb_term_from info v
    	val res = HOLThm(rens_of info',mk_GEN v' th (sign_of thy))
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun SPEC tm hth thy =
        let
    	val _ = message "SPEC:"
    	val _ = if_debug prin tm
    	val _ = if_debug pth hth
    	val (info,th) = disamb_thm hth
    	val (info',tm') = disamb_term_from info tm
    	val sg = sign_of thy
    	val ctm = Thm.cterm_of sg tm'
    	val cty = Thm.ctyp_of_term ctm
    	val spec' = Drule.instantiate' [SOME cty] [NONE,SOME ctm] spec_thm
    	val th = th RS spec'
    	val res = HOLThm(rens_of info',th)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun COMB hth1 hth2 thy =
        let
    	val _ = message "COMB:"
    	val _ = if_debug pth hth1
    	val _ = if_debug pth hth2
    	val (info,[th1,th2]) = disamb_thms [hth1,hth2]
    	val sg = sign_of thy
    	val res = HOLThm(rens_of info,mk_COMB th1 th2 sg)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun TRANS hth1 hth2 thy =
        let
    	val _ = message "TRANS:"
    	val _ = if_debug pth hth1
    	val _ = if_debug pth hth2
    	val (info,[th1,th2]) = disamb_thms [hth1,hth2]
    	val th = [th1,th2] MRS trans_thm
    	val res = HOLThm(rens_of info,th)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun CCONTR tm hth thy =
        let
    	val _ = message "SPEC:"
    	val _ = if_debug prin tm
    	val _ = if_debug pth hth
    	val (info,th) = disamb_thm hth
    	val (info',tm') = disamb_term_from info tm
    	val th = norm_hyps th
    	val sg = sign_of thy
    	val ct = cterm_of sg tm'
    	val th1 = rearrange sg (HOLogic.mk_Trueprop (Const("Not",boolT-->boolT) $ tm')) th
    	val ccontr_thm' = Drule.instantiate' [] [SOME ct] ccontr_thm
    	val res1 = uniq_compose ((nprems_of th1) - 1) th1 1 ccontr_thm'
    	val res = HOLThm(rens_of info',res1)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun mk_ABS v th sg =
        let
    	val cv = cterm_of sg v
    	val th1 = implies_elim_all (beta_eta_thm th)
    	val (f,g) = case concl_of th1 of
    			_ $ (Const("op =",_) $ f $ g) => (Term.lambda v f,Term.lambda v g)
    		      | _ => raise ERR "mk_ABS" "Bad conclusion"
    	val (fd,fr) = dom_rng (type_of f)
    	val abs_thm' = Drule.instantiate' [SOME (ctyp_of sg fd), SOME (ctyp_of sg fr)] [SOME (cterm_of sg f), SOME (cterm_of sg g)] abs_thm
    	val th2 = forall_intr cv th1
    	val th3 = th2 COMP abs_thm'
    	val res = implies_intr_hyps th3
        in
    	res
        end

    fun ABS v hth thy =
        let
    	val _ = message "ABS:"
    	val _ = if_debug prin v
    	val _ = if_debug pth hth
    	val (info,th) = disamb_thm hth
    	val (info',v') = disamb_term_from info v
    	val sg = sign_of thy
    	val res = HOLThm(rens_of info',mk_ABS v' th sg)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun GEN_ABS copt vlist hth thy =
        let
    	val _ = message "GEN_ABS:"
    	val _ = case copt of
    		    SOME c => if_debug prin c
    		  | NONE => ()
    	val _ = if_debug (app prin) vlist
    	val _ = if_debug pth hth
    	val (info,th) = disamb_thm hth
    	val (info',vlist') = disamb_terms_from info vlist
    	val sg = sign_of thy
    	val th1 =
    	    case copt of
    		SOME (c as Const(cname,cty)) =>
    		let
    		    fun inst_type ty1 ty2 (TVar _) = raise ERR "GEN_ABS" "Type variable found!"
    		      | inst_type ty1 ty2 (ty as TFree _) = if ty1 = ty
    							    then ty2
    							    else ty
    		      | inst_type ty1 ty2 (ty as Type(name,tys)) =
    			Type(name,map (inst_type ty1 ty2) tys)
    		in
    		    foldr (fn (v,th) =>
    			      let
    				  val cdom = fst (dom_rng (fst (dom_rng cty)))
    				  val vty  = type_of v
    				  val newcty = inst_type cdom vty cty
    				  val cc = cterm_of sg (Const(cname,newcty))
    			      in
    				  mk_COMB (mk_REFL cc) (mk_ABS v th sg) sg
    			      end) th vlist'
    		end
    	      | SOME _ => raise ERR "GEN_ABS" "Bad constant"
    	      | NONE =>
    		foldr (fn (v,th) => mk_ABS v th sg) th vlist'
    	val res = HOLThm(rens_of info',th1)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun NOT_INTRO (hth as HOLThm(rens,th)) thy =
        let
    	val _ = message "NOT_INTRO:"
    	val _ = if_debug pth hth
    	val sg = sign_of thy
    	val th1 = implies_elim_all (beta_eta_thm th)
    	val a = case concl_of th1 of
    		    _ $ (Const("op -->",_) $ a $ Const("False",_)) => a
    		  | _ => raise ERR "NOT_INTRO" "Conclusion of bad form"
    	val ca = cterm_of sg a
    	val th2 = equal_elim (Drule.instantiate' [] [SOME ca] not_intro_thm) th1
    	val res = HOLThm(rens,implies_intr_hyps th2)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun NOT_ELIM (hth as HOLThm(rens,th)) thy =
        let
    	val _ = message "NOT_INTRO:"
    	val _ = if_debug pth hth
    	val sg = sign_of thy
    	val th1 = implies_elim_all (beta_eta_thm th)
    	val a = case concl_of th1 of
    		    _ $ (Const("Not",_) $ a) => a
    		  | _ => raise ERR "NOT_ELIM" "Conclusion of bad form"
    	val ca = cterm_of sg a
    	val th2 = equal_elim (Drule.instantiate' [] [SOME ca] not_elim_thm) th1
    	val res = HOLThm(rens,implies_intr_hyps th2)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    fun DISCH tm hth thy =
        let
    	val _ = message "DISCH:"
    	val _ = if_debug prin tm
    	val _ = if_debug pth hth
    	val (info,th) = disamb_thm hth
    	val (info',tm') = disamb_term_from info tm
    	val prems = prems_of th
    	val sg = sign_of thy
    	val th1 = beta_eta_thm th
    	val th2 = implies_elim_all th1
    	val th3 = implies_intr (cterm_of sg (HOLogic.mk_Trueprop tm')) th2
    	val th4 = th3 COMP disch_thm
    	val res = HOLThm(rens_of info',implies_intr_hyps th4)
    	val _ = message "RESULT:"
    	val _ = if_debug pth res
        in
    	(thy,res)
        end

    val spaces = String.concat o separate " "

    fun new_definition thyname constname rhs thy =
        let
    	val constname = rename_const thyname thy constname
            val sg = sign_of thy
            val redeclared = isSome (Sign.const_type sg (Sign.intern_const sg constname));
    	val _ = warning ("Introducing constant " ^ constname)
    	val (thmname,thy) = get_defname thyname constname thy
    	val (info,rhs') = disamb_term rhs
    	val ctype = type_of rhs'
    	val csyn = mk_syn thy constname
    	val thy1 = case HOL4DefThy.get thy of
    		       Replaying _ => thy
    		     | _ => Theory.add_consts_i [(constname,ctype,csyn)] thy
    	val eq = mk_defeq constname rhs' thy1
    	val (thy2,thms) = PureThy.add_defs_i false [((thmname,eq),[])] thy1
    	val def_thm = hd thms
    	val thm' = def_thm RS meta_eq_to_obj_eq_thm
    	val (thy',th) = (thy2, thm')
    	val fullcname = Sign.intern_const (sign_of thy') constname
    	val thy'' = add_hol4_const_mapping thyname constname true fullcname thy'
    	val (linfo,tm24) = disamb_term (mk_teq constname rhs' thy'')
    	val sg = sign_of thy''
    	val rew = rewrite_hol4_term eq thy''
    	val crhs = cterm_of sg (#2 (Logic.dest_equals (prop_of rew)))
    	val thy22 = if (def_name constname) = thmname andalso not redeclared andalso csyn = NoSyn
    		    then
    			add_dump ("constdefs\n  " ^ (quotename constname) ^ " :: \"" ^ string_of_ctyp (ctyp_of sg ctype) ^ "\" " ^ (Syntax.string_of_mixfix csyn) ^ "\n  " ^ (smart_string_of_cterm crhs)) thy''
    		    else
    			add_dump ("consts\n  " ^ (quotename constname) ^ " :: \"" ^ string_of_ctyp (ctyp_of sg ctype) ^
    				  "\" " ^ (Syntax.string_of_mixfix csyn) ^ "\n\ndefs\n  " ^ (quotename thmname) ^ ": " ^ (smart_string_of_cterm crhs))
    				 thy''

    	val hth = case Shuffler.set_prop thy22 (HOLogic.mk_Trueprop tm24) [("",th)] of
    		     SOME (_,res) => HOLThm(rens_of linfo,res)
    		   | NONE => raise ERR "new_definition" "Bad conclusion"
    	val fullname = Sign.full_name sg thmname
    	val thy22' = case opt_get_output_thy thy22 of
    			 "" => add_hol4_mapping thyname thmname fullname thy22
    		       | output_thy =>
    			 let
    			     val moved_thmname = output_thy ^ "." ^ thyname ^ "." ^ thmname
    			 in
    			     thy22 |> add_hol4_move fullname moved_thmname
    				   |> add_hol4_mapping thyname thmname moved_thmname
    			 end
    	val _ = message "new_definition:"
    	val _ = if_debug pth hth
        in
    	(thy22',hth)
        end
        handle e => (message "exception in new_definition"; print_exn e)

    val commafy = String.concat o separate ", "

    local
        val helper = thm "termspec_help"
    in
    fun new_specification thyname thmname names hth thy =
        case HOL4DefThy.get thy of
    	Replaying _ => (thy,hth)
          | _ =>
    	let
    	    val _ = message "NEW_SPEC:"
    	    val _ = if_debug pth hth
    	    val names = map (rename_const thyname thy) names
    	    val _ = warning ("Introducing constants " ^ (commafy names))
    	    val (HOLThm(rens,th)) = norm_hthm (sign_of thy) hth
    	    val thy1 = case HOL4DefThy.get thy of
    			   Replaying _ => thy
    			 | _ =>
    			   let
    			       fun dest_eta_abs (Abs(x,xT,body)) = (x,xT,body)
    				 | dest_eta_abs body =
    				   let
    				       val (dT,rT) = dom_rng (type_of body)
    				   in
    				       ("x",dT,body $ Bound 0)
    				   end
    				   handle TYPE _ => raise ERR "new_specification" "not an abstraction type"
    			       fun dest_exists (Const("Ex",_) $ abody) =
    				   dest_eta_abs abody
    				 | dest_exists tm =
    				   raise ERR "new_specification" "Bad existential formula"

    			       val (consts,_) = Library.foldl (fn ((cs,ex),cname) =>
    							  let
    							      val (_,cT,p) = dest_exists ex
    							  in
    							      ((cname,cT,mk_syn thy cname)::cs,p)
    							  end) (([],HOLogic.dest_Trueprop (concl_of th)),names)
    			       val sg = sign_of thy
    			       val str = Library.foldl (fn (acc,(c,T,csyn)) =>
    						   acc ^ "\n  " ^ (quotename c) ^ " :: \"" ^ string_of_ctyp (ctyp_of sg T) ^ "\" " ^ (Syntax.string_of_mixfix csyn)) ("consts",consts)
    			       val thy' = add_dump str thy
    			   in
    			       Theory.add_consts_i consts thy'
    			   end

    	    val thy1 = foldr (fn(name,thy)=>
    				snd (get_defname thyname name thy)) thy1 names
    	    fun new_name name = fst (get_defname thyname name thy1)
    	    val (thy',res) = SpecificationPackage.add_specification_i NONE
    				 (map (fn name => (new_name name,name,false)) names)
    				 (thy1,th)
    	    val res' = Drule.freeze_all res
    	    val hth = HOLThm(rens,res')
    	    val rew = rewrite_hol4_term (concl_of res') thy'
    	    val th  = equal_elim rew res'
    	    fun handle_const (name,thy) =
    		let
    		    val defname = def_name name
    		    val (newname,thy') = get_defname thyname name thy
    		in
    		    (if defname = newname
    		     then quotename name
    		     else (quotename newname) ^ ": " ^ (quotename name),thy')
    		end
    	    val (new_names,thy') = foldr (fn(name,(names,thy)) =>
    					    let
    						val (name',thy') = handle_const (name,thy)
    					    in
    						(name'::names,thy')
    					    end) ([],thy') names
    	    val thy'' = add_dump ("specification (" ^ (spaces new_names) ^ ") " ^ thmname ^ ": " ^ (smart_string_of_thm th) ^
    				  "\n  by (import " ^ thyname ^ " " ^ thmname ^ ")")
    				 thy'
    	    val _ = message "RESULT:"
    	    val _ = if_debug pth hth
    	in
    	    intern_store_thm false thyname thmname hth thy''
    	end
    	handle e => (message "exception in new_specification"; print_exn e)

    end

    fun new_axiom name tm thy = raise ERR "new_axiom" ("Oh, no you don't! (" ^ name ^ ")")

    fun to_isa_thm (hth as HOLThm(_,th)) =
        let
    	val (HOLThm args) = norm_hthm (sign_of_thm th) hth
        in
    	apsnd strip_shyps args
        end

    fun to_isa_term tm = tm

    local
        val light_nonempty = thm "light_ex_imp_nonempty"
        val ex_imp_nonempty = thm "ex_imp_nonempty"
        val typedef_hol2hol4 = thm "typedef_hol2hol4"
        val typedef_hol2hollight = thm "typedef_hol2hollight"
    in
    fun new_type_definition thyname thmname tycname hth thy =
        case HOL4DefThy.get thy of
    	Replaying _ => (thy,hth)
          | _ =>
    	let
    	    val _ = message "TYPE_DEF:"
    	    val _ = if_debug pth hth
    	    val _ = warning ("Introducing type " ^ tycname)
    	    val (HOLThm(rens,td_th)) = norm_hthm (sign_of thy) hth
    	    val th2 = beta_eta_thm (td_th RS ex_imp_nonempty)
    	    val c = case concl_of th2 of
    			_ $ (Const("Ex",_) $ Abs(_,_,Const("op :",_) $ _ $ c)) => c
    		      | _ => raise ERR "new_type_definition" "Bad type definition theorem"
    	    val tfrees = term_tfrees c
    	    val tnames = map fst tfrees
    	    val tsyn = mk_syn thy tycname
    	    val typ = (tycname,tnames,tsyn)
    	    val (thy',typedef_info) = TypedefPackage.add_typedef_i false (SOME thmname) typ c NONE (rtac th2 1) thy

    	    val th3 = (#type_definition typedef_info) RS typedef_hol2hol4

    	    val fulltyname = Sign.intern_type (sign_of thy') tycname
    	    val thy'' = add_hol4_type_mapping thyname tycname true fulltyname thy'

    	    val sg = sign_of thy''
    	    val (hth' as HOLThm args) = norm_hthm sg (HOLThm(rens,th3))
    	    val _ = if has_ren hth' then warning ("Theorem " ^ thmname ^ " needs variable-disambiguating")
    		    else ()
    	    val thy4 = add_hol4_pending thyname thmname args thy''

    	    val sg = sign_of thy4
    	    val rew = rewrite_hol4_term (concl_of td_th) thy4
    	    val th  = equal_elim rew (Thm.transfer sg td_th)
    	    val c   = case HOLogic.dest_Trueprop (prop_of th) of
    			  Const("Ex",exT) $ P =>
    			  let
    			      val PT = domain_type exT
    			  in
    			      Const("Collect",PT-->HOLogic.mk_setT (domain_type PT)) $ P
    			  end
    			| _ => error "Internal error in ProofKernel.new_typedefinition"
    	    val tnames_string = if null tnames
    				then ""
    				else "(" ^ (commafy tnames) ^ ") "
    	    val proc_prop = if null tnames
    			    then smart_string_of_cterm
    			    else Library.setmp show_all_types true smart_string_of_cterm
    	    val thy5 = add_dump ("typedef (open) " ^ tnames_string ^ (quotename tycname) ^ " = " ^ (proc_prop (cterm_of sg c)) ^ " "
    				 ^ (Syntax.string_of_mixfix tsyn) ^ "\n  by (rule typedef_helper,import " ^ thyname ^ " " ^ thmname ^ ")") thy4

    	    val thy6 = add_dump ("lemmas " ^ thmname ^ " = typedef_hol2hol4 [OF type_definition_" ^ tycname ^ "]") thy5

    	    val _ = message "RESULT:"
    	    val _ = if_debug pth hth'
    	in
    	    (thy6,hth')
    	end
    	handle e => (message "exception in new_type_definition"; print_exn e)

    fun add_dump_constdefs thy defname constname rhs ty =
        let
    	val n = quotename constname
    	val t = string_of_ctyp (ctyp_of thy ty)
    	val syn = Syntax.string_of_mixfix (mk_syn thy constname)
    	(*val eq = smart_string_of_cterm (cterm_of thy (Const(rhs, ty)))*)
            val eq = quote (constname ^ " == "^rhs)
    	val d = case defname of NONE => "" | SOME defname => (quotename defname)^" : "
        in
    	add_dump ("constdefs\n  " ^ n ^ " :: \"" ^ t ^ "\" " ^ syn ^ "\n  " ^ d ^ eq) thy
        end

    fun add_dump_syntax thy name =
        let
          val n = quotename name
          val syn = Syntax.string_of_mixfix (mk_syn thy name)
        in
          add_dump ("syntax\n  "^n^" :: _ "^syn) thy
        end

    (*val type_intro_replay_history = ref (Symtab.empty:unit Symtab.table)
    fun choose_upon_replay_history thy s dth =
        case Symtab.lookup (!type_intro_replay_history) s of
    	NONE => (type_intro_replay_history := Symtab.update (s, ()) (!type_intro_replay_history); dth)
          | SOME _ => HOLThm([], PureThy.get_thm thy (PureThy.Name s))
    *)

    fun type_introduction thyname thmname tycname abs_name rep_name (P,t) hth thy =
        case HOL4DefThy.get thy of
    	Replaying _ => (thy, handle_error (fn () => HOLThm([], PureThy.get_thm thy (PureThy.Name (thmname^"_@intern")))) hth)
          | _ =>
    	let
                val _ = message "TYPE_INTRO:"
    	    val _ = if_debug pth hth
    	    val _ = warning ("Introducing type " ^ tycname ^ " (with morphisms " ^ abs_name ^ " and " ^ rep_name ^ ")")
    	    val (HOLThm(rens,td_th)) = norm_hthm (sign_of thy) hth
    	    val sg = sign_of thy
    	    val tT = type_of t
    	    val light_nonempty' =
    		Drule.instantiate' [SOME (ctyp_of sg tT)]
    				   [SOME (cterm_of sg P),
    				    SOME (cterm_of sg t)] light_nonempty
    	    val th2 = beta_eta_thm (td_th RS (beta_eta_thm light_nonempty'))
    	    val c = case concl_of th2 of
    			_ $ (Const("Ex",_) $ Abs(_,_,Const("op :",_) $ _ $ c)) => c
    		      | _ => raise ERR "type_introduction" "Bad type definition theorem"
    	    val tfrees = term_tfrees c
    	    val tnames = sort string_ord (map fst tfrees)
    	    val tsyn = mk_syn thy tycname
    	    val typ = (tycname,tnames,tsyn)
    	    val (thy',typedef_info) = TypedefPackage.add_typedef_i false NONE typ c (SOME(rep_name,abs_name)) (rtac th2 1) thy
    	    val fulltyname = Sign.intern_type (sign_of thy') tycname
    	    val aty = Type (fulltyname, map mk_vartype tnames)
    	    val abs_ty = tT --> aty
    	    val rep_ty = aty --> tT
                val typedef_hol2hollight' =
    		Drule.instantiate'
    		    [SOME (ctyp_of thy' aty), SOME (ctyp_of thy' tT)]
    		    [NONE, NONE, NONE, SOME (cterm_of thy' (Free ("a", aty))), SOME (cterm_of thy' (Free ("r", tT)))]
                        typedef_hol2hollight
    	    val th4 = (#type_definition typedef_info) RS typedef_hol2hollight'
                val _ = if Drule.tvars_of th4 = [] then () else raise ERR "type_introduction" "no type variables expected any more"
                val _ = if Drule.vars_of th4 = [] then () else raise ERR "type_introduction" "no term variables expected any more"
    	    val _ = message ("step 3: thyname="^thyname^", tycname="^tycname^", fulltyname="^fulltyname)
                val thy'' = add_hol4_type_mapping thyname tycname true fulltyname thy'
                val _ = message "step 4"
    	    val sg = sign_of thy''
    	    val (hth' as HOLThm args) = norm_hthm sg (HOLThm(rens,th4))
    	    val thy4 = add_hol4_pending thyname thmname args thy''

    	    val sg = sign_of thy4
    	    val P' = P (* why !? #2 (Logic.dest_equals (concl_of (rewrite_hol4_term P thy4))) *)
    	    val c   =
    		let
    		    val PT = type_of P'
    		in
    		    Const("Collect",PT-->HOLogic.mk_setT (domain_type PT)) $ P'
    		end

    	    val tnames_string = if null tnames
    				then ""
    				else "(" ^ (commafy tnames) ^ ") "
    	    val proc_prop = if null tnames
    			    then smart_string_of_cterm
    			    else Library.setmp show_all_types true smart_string_of_cterm
    	    val thy = add_dump ("typedef (open) " ^ tnames_string ^ (quotename tycname) ^
                  " = " ^ (proc_prop (cterm_of sg c)) ^ " " ^
    	      (Syntax.string_of_mixfix tsyn) ^ " morphisms "^
                  (quote rep_name)^" "^(quote abs_name)^"\n"^
    	      ("  apply (rule light_ex_imp_nonempty[where t="^
                  (proc_prop (cterm_of sg t))^"])\n"^
    	      ("  by (import " ^ thyname ^ " " ^ (quotename thmname) ^ ")"))) thy4
    	    val str_aty = string_of_ctyp (ctyp_of thy aty)
                val thy = add_dump_syntax thy rep_name
                val thy = add_dump_syntax thy abs_name
    	    val thy = add_dump ("lemmas " ^ (quote (thmname^"_@intern")) ^
                  " = typedef_hol2hollight \n"^
                  "  [where a=\"a :: "^str_aty^"\" and r=r" ^
    	      " ,\n   OF "^(quotename ("type_definition_" ^ tycname)) ^ "]") thy
    	    val _ = message "RESULT:"
    	    val _ = if_debug pth hth'
    	in
    	    (thy,hth')
    	end
    	handle e => (message "exception in type_introduction"; print_exn e)
    end

    val prin = prin

    end