File ‹old_recdef.ML›
signature CASE_SPLIT =
sig
  
  val splitto : Proof.context -> thm list -> thm -> thm
end;
signature UTILS =
sig
  exception ERR of {module: string, func: string, mesg: string}
  val end_itlist: ('a -> 'a -> 'a) -> 'a list -> 'a
  val itlist2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
  val pluck: ('a -> bool) -> 'a list -> 'a * 'a list
  val zip3: 'a list -> 'b list -> 'c list -> ('a*'b*'c) list
  val take: ('a -> 'b) -> int * 'a list -> 'b list
end;
signature USYNTAX =
sig
  datatype lambda = VAR   of {Name : string, Ty : typ}
                  | CONST of {Name : string, Ty : typ}
                  | COMB  of {Rator: term, Rand : term}
                  | LAMB  of {Bvar : term, Body : term}
  val alpha : typ
  
  val type_vars  : typ -> typ list
  val type_varsl : typ list -> typ list
  val mk_vartype : string -> typ
  val is_vartype : typ -> bool
  val strip_prod_type : typ -> typ list
  
  val free_vars_lr : term -> term list
  val type_vars_in_term : term -> typ list
  val dest_term  : term -> lambda
  
  val inst      : (typ*typ) list -> term -> term
  
  val mk_abs    :{Bvar  : term, Body : term} -> term
  val mk_imp    :{ant : term, conseq :  term} -> term
  val mk_select :{Bvar : term, Body : term} -> term
  val mk_forall :{Bvar : term, Body : term} -> term
  val mk_exists :{Bvar : term, Body : term} -> term
  val mk_conj   :{conj1 : term, conj2 : term} -> term
  val mk_disj   :{disj1 : term, disj2 : term} -> term
  val mk_pabs   :{varstruct : term, body : term} -> term
  
  val dest_const: term -> {Name : string, Ty : typ}
  val dest_comb : term -> {Rator : term, Rand : term}
  val dest_abs  : string list -> term -> {Bvar : term, Body : term} * string list
  val dest_eq     : term -> {lhs : term, rhs : term}
  val dest_imp    : term -> {ant : term, conseq : term}
  val dest_forall : term -> {Bvar : term, Body : term}
  val dest_exists : term -> {Bvar : term, Body : term}
  val dest_neg    : term -> term
  val dest_conj   : term -> {conj1 : term, conj2 : term}
  val dest_disj   : term -> {disj1 : term, disj2 : term}
  val dest_pair   : term -> {fst : term, snd : term}
  val dest_pabs   : string list -> term -> {varstruct : term, body : term, used : string list}
  val lhs   : term -> term
  val rhs   : term -> term
  val rand  : term -> term
  
  val is_imp    : term -> bool
  val is_forall : term -> bool
  val is_exists : term -> bool
  val is_neg    : term -> bool
  val is_conj   : term -> bool
  val is_disj   : term -> bool
  val is_pair   : term -> bool
  val is_pabs   : term -> bool
  
  val list_mk_abs    : (term list * term) -> term
  val list_mk_imp    : (term list * term) -> term
  val list_mk_forall : (term list * term) -> term
  val list_mk_conj   : term list -> term
  
  val strip_comb     : term -> (term * term list)
  val strip_abs      : term -> (term list * term)
  val strip_imp      : term -> (term list * term)
  val strip_forall   : term -> (term list * term)
  val strip_exists   : term -> (term list * term)
  val strip_disj     : term -> term list
  
  val mk_vstruct : typ -> term list -> term
  val gen_all    : term -> term
  val find_term  : (term -> bool) -> term -> term option
  val dest_relation : term -> term * term * term
  val is_WFR : term -> bool
  val ARB : typ -> term
end;
signature DCTERM =
sig
  val dest_comb: cterm -> cterm * cterm
  val dest_abs: cterm -> cterm * cterm
  val capply: cterm -> cterm -> cterm
  val cabs: cterm -> cterm -> cterm
  val mk_conj: cterm * cterm -> cterm
  val mk_disj: cterm * cterm -> cterm
  val mk_exists: cterm * cterm -> cterm
  val dest_conj: cterm -> cterm * cterm
  val dest_const: cterm -> {Name: string, Ty: typ}
  val dest_disj: cterm -> cterm * cterm
  val dest_eq: cterm -> cterm * cterm
  val dest_exists: cterm -> cterm * cterm
  val dest_forall: cterm -> cterm * cterm
  val dest_imp: cterm -> cterm * cterm
  val dest_neg: cterm -> cterm
  val dest_pair: cterm -> cterm * cterm
  val dest_var: cterm -> {Name:string, Ty:typ}
  val is_conj: cterm -> bool
  val is_disj: cterm -> bool
  val is_eq: cterm -> bool
  val is_exists: cterm -> bool
  val is_forall: cterm -> bool
  val is_imp: cterm -> bool
  val is_neg: cterm -> bool
  val is_pair: cterm -> bool
  val list_mk_disj: cterm list -> cterm
  val strip_abs: cterm -> cterm list * cterm
  val strip_comb: cterm -> cterm * cterm list
  val strip_disj: cterm -> cterm list
  val strip_exists: cterm -> cterm list * cterm
  val strip_forall: cterm -> cterm list * cterm
  val strip_imp: cterm -> cterm list * cterm
  val drop_prop: cterm -> cterm
  val mk_prop: cterm -> cterm
end;
signature RULES =
sig
  val dest_thm: thm -> term list * term
  
  val REFL: cterm -> thm
  val ASSUME: cterm -> thm
  val MP: thm -> thm -> thm
  val MATCH_MP: thm -> thm -> thm
  val CONJUNCT1: thm -> thm
  val CONJUNCT2: thm -> thm
  val CONJUNCTS: thm -> thm list
  val DISCH: cterm -> thm -> thm
  val UNDISCH: thm  -> thm
  val SPEC: cterm -> thm -> thm
  val ISPEC: cterm -> thm -> thm
  val ISPECL: cterm list -> thm -> thm
  val GEN: Proof.context -> cterm -> thm -> thm
  val GENL: Proof.context -> cterm list -> thm -> thm
  val LIST_CONJ: thm list -> thm
  val SYM: thm -> thm
  val DISCH_ALL: thm -> thm
  val FILTER_DISCH_ALL: (term -> bool) -> thm -> thm
  val SPEC_ALL: thm -> thm
  val GEN_ALL: Proof.context -> thm -> thm
  val IMP_TRANS: thm -> thm -> thm
  val PROVE_HYP: thm -> thm -> thm
  val CHOOSE: Proof.context -> cterm * thm -> thm -> thm
  val EXISTS: Proof.context -> cterm * cterm -> thm -> thm
  val IT_EXISTS: Proof.context -> (cterm * cterm) list -> thm -> thm
  val EVEN_ORS: thm list -> thm list
  val DISJ_CASESL: thm -> thm list -> thm
  val list_beta_conv: cterm -> cterm list -> thm
  val SUBS: Proof.context -> thm list -> thm -> thm
  val simpl_conv: Proof.context -> thm list -> cterm -> thm
  val rbeta: thm -> thm
  val tracing: bool Unsynchronized.ref
  val CONTEXT_REWRITE_RULE: Proof.context ->
    term * term list * thm * thm list -> thm -> thm * term list
  val RIGHT_ASSOC: Proof.context -> thm -> thm
  val prove: Proof.context -> bool -> term -> (Proof.context -> tactic) -> thm
end;
signature THRY =
sig
  val match_term: theory -> term -> term -> (term * term) list * (typ * typ) list
  val match_type: theory -> typ -> typ -> (typ * typ) list
  val typecheck: theory -> term -> cterm
  
  val match_info: theory -> string -> {constructors: term list, case_const: term} option
  val induct_info: theory -> string -> {constructors: term list, nchotomy: thm} option
  val extract_info: theory -> {case_congs: thm list, case_rewrites: thm list}
end;
signature PRIM =
sig
  val trace: bool Unsynchronized.ref
  val trace_thms: Proof.context -> string -> thm list -> unit
  val trace_cterm: Proof.context -> string -> cterm -> unit
  type pattern
  val mk_functional: theory -> term list -> {functional: term, pats: pattern list}
  val wfrec_definition0: string -> term -> term -> theory -> thm * theory
  val post_definition: Proof.context -> thm list -> thm * pattern list ->
   {rules: thm,
    rows: int list,
    TCs: term list list,
    full_pats_TCs: (term * term list) list}
  val mk_induction: Proof.context ->
    {fconst: term, R: term, SV: term list, pat_TCs_list: (term * term list) list} -> thm
  val postprocess: Proof.context -> bool ->
    {wf_tac: Proof.context -> tactic,
     terminator: Proof.context -> tactic,
     simplifier: Proof.context -> cterm -> thm} ->
    {rules: thm, induction: thm, TCs: term list list} ->
    {rules: thm, induction: thm, nested_tcs: thm list}
end;
signature TFL =
sig
  val define_i: bool -> thm list -> thm list -> xstring -> term -> term list -> Proof.context ->
    {lhs: term, rules: (thm * int) list, induct: thm, tcs: term list} * Proof.context
  val define: bool -> thm list -> thm list -> xstring -> string -> string list -> Proof.context ->
    {lhs: term, rules: (thm * int) list, induct: thm, tcs: term list} * Proof.context
end;
signature OLD_RECDEF =
sig
  val get_recdef: theory -> string
    -> {lhs: term, simps: thm list, rules: thm list list, induct: thm, tcs: term list} option
  val get_hints: Proof.context -> {simps: thm list, congs: (string * thm) list, wfs: thm list}
  val simp_add: attribute
  val simp_del: attribute
  val cong_add: attribute
  val cong_del: attribute
  val wf_add: attribute
  val wf_del: attribute
  val add_recdef: bool -> xstring -> string -> ((binding * string) * Token.src list) list ->
    Token.src option -> theory -> theory
      * {lhs: term, simps: thm list, rules: thm list list, induct: thm, tcs: term list}
  val add_recdef_i: bool -> xstring -> term -> ((binding * term) * attribute list) list ->
    theory -> theory * {lhs: term, simps: thm list, rules: thm list list, induct: thm, tcs: term list}
end;
structure Old_Recdef: OLD_RECDEF =
struct
structure CaseSplit: CASE_SPLIT =
struct
fun cases_thm_of_induct_thm ctxt =
  Seq.hd o (ALLGOALS (fn i => REPEAT (eresolve_tac ctxt [Drule.thin_rl] i)));
fun case_thm_of_ty ctxt ty  =
    let
      val thy = Proof_Context.theory_of ctxt
      val ty_str = case ty of
                     Type(ty_str, _) => ty_str
                   | TFree(s,_)  => error ("Free type: " ^ s)
                   | TVar((s,_),_) => error ("Free variable: " ^ s)
      val {induct, ...} = BNF_LFP_Compat.the_info thy [BNF_LFP_Compat.Keep_Nesting] ty_str
    in
      cases_thm_of_induct_thm ctxt induct
    end;
fun mk_casesplit_goal_thm ctxt (vstr,ty) gt =
    let
      val thy = Proof_Context.theory_of ctxt;
      val x = Free(vstr,ty);
      val abst = Abs(vstr, ty, Term.abstract_over (x, gt));
      val case_thm = case_thm_of_ty ctxt ty;
      val abs_ct = Thm.cterm_of ctxt abst;
      val free_ct = Thm.cterm_of ctxt x;
      val (Pv, Dv, type_insts) =
          case (Thm.concl_of case_thm) of
            (_ $ (Pv $ (Dv as Var(_, Dty)))) =>
            (Pv, Dv,
             Sign.typ_match thy (Dty, ty) Vartab.empty)
          | _ => error "not a valid case thm";
      val type_cinsts = map (fn (ixn, (S, T)) => ((ixn, S), Thm.ctyp_of ctxt T))
        (Vartab.dest type_insts);
      val Pv = dest_Var (Envir.subst_term_types type_insts Pv);
      val Dv = dest_Var (Envir.subst_term_types type_insts Dv);
    in
      Conv.fconv_rule Drule.beta_eta_conversion
         (case_thm
            |> Thm.instantiate (TVars.make type_cinsts, Vars.empty)
            |> Thm.instantiate (TVars.empty, Vars.make2 (Pv, abs_ct) (Dv, free_ct)))
    end;
exception find_split_exp of string
fun find_term_split (Free v, _ $ _) = SOME v
  | find_term_split (Free v, Const _) = SOME v
  | find_term_split (Free v, Abs _) = SOME v 
  | find_term_split (Free _, Var _) = NONE 
  | find_term_split (a $ b, a2 $ b2) =
    (case find_term_split (a, a2) of
       NONE => find_term_split (b,b2)
     | vopt => vopt)
  | find_term_split (Abs(_,_,t1), Abs(_,_,t2)) =
    find_term_split (t1, t2)
  | find_term_split (Const (x,_), Const(x2,_)) =
    if x = x2 then NONE else 
    raise find_split_exp 
            "Terms are not identical upto a free varaible! (Consts)"
  | find_term_split (Bound i, Bound j) =
    if i = j then NONE else 
    raise find_split_exp 
            "Terms are not identical upto a free varaible! (Bound)"
  | find_term_split _ =
    raise find_split_exp 
            "Terms are not identical upto a free varaible! (Other)";
fun find_thm_split splitth i genth =
    find_term_split (Logic.get_goal (Thm.prop_of genth) i,
                     Thm.concl_of splitth) handle find_split_exp _ => NONE;
fun find_thms_split splitths i genth =
    Library.get_first (fn sth => find_thm_split sth i genth) splitths;
fun splitto ctxt splitths genth =
    let
      val _ = not (null splitths) orelse error "splitto: no given splitths";
      
      fun solve_by_splitth th split =
        Thm.biresolution (SOME ctxt) false [(false,split)] 1 th;
      fun split th =
        (case find_thms_split splitths 1 th of
          NONE =>
           (writeln (cat_lines
            (["th:", Thm.string_of_thm ctxt th, "split ths:"] @
              map (Thm.string_of_thm ctxt) splitths @ ["\n--"]));
            error "splitto: cannot find variable to split on")
        | SOME v =>
            let
              val gt = HOLogic.dest_Trueprop (#1 (Logic.dest_implies (Thm.prop_of th)));
              val split_thm = mk_casesplit_goal_thm ctxt v gt;
              val (subthms, expf) = IsaND.fixed_subgoal_thms ctxt split_thm;
            in
              expf (map recsplitf subthms)
            end)
      and recsplitf th =
        
        (case get_first (Seq.pull o solve_by_splitth th) splitths of
          NONE => split th
        | SOME (solved_th, _) => solved_th);
    in
      recsplitf genth
    end;
end;
structure Utils: UTILS =
struct
exception ERR of {module: string, func: string, mesg: string};
fun UTILS_ERR func mesg = ERR {module = "Utils", func = func, mesg = mesg};
fun end_itlist _ [] = raise (UTILS_ERR "end_itlist" "list too short")
  | end_itlist _ [x] = x
  | end_itlist f (x :: xs) = f x (end_itlist f xs);
fun itlist2 f L1 L2 base_value =
 let fun it ([],[]) = base_value
       | it ((a::rst1),(b::rst2)) = f a b (it (rst1,rst2))
       | it _ = raise UTILS_ERR "itlist2" "different length lists"
 in  it (L1,L2)
 end;
fun pluck p  =
  let fun remv ([],_) = raise UTILS_ERR "pluck" "item not found"
        | remv (h::t, A) = if p h then (h, rev A @ t) else remv (t,h::A)
  in fn L => remv(L,[])
  end;
fun take f =
  let fun grab(0, _) = []
        | grab(n, x::rst) = f x::grab(n-1,rst)
  in grab
  end;
fun zip3 [][][] = []
  | zip3 (x::l1) (y::l2) (z::l3) = (x,y,z)::zip3 l1 l2 l3
  | zip3 _ _ _ = raise UTILS_ERR "zip3" "different lengths";
end;
structure USyntax: USYNTAX =
struct
infix 4 ##;
fun USYN_ERR func mesg = Utils.ERR {module = "USyntax", func = func, mesg = mesg};
val mk_prim_vartype = TVar;
fun mk_vartype s = mk_prim_vartype ((s, 0), \<^sort>‹type›);
fun dest_vtype (TVar x) = x
  | dest_vtype _ = raise USYN_ERR "dest_vtype" "not a flexible type variable";
val is_vartype = can dest_vtype;
val type_vars  = map mk_prim_vartype o Misc_Legacy.typ_tvars
fun type_varsl L = distinct (op =) (fold (curry op @ o type_vars) L []);
val alpha  = mk_vartype "'a"
val strip_prod_type = HOLogic.flatten_tupleT;
fun free_vars_lr tm =
  let fun memb x = let fun m[] = false | m(y::rst) = (x=y)orelse m rst in m end
      fun add (t, frees) = case t of
            Free   _ => if (memb t frees) then frees else t::frees
          | Abs (_,_,body) => add(body,frees)
          | f$t =>  add(t, add(f, frees))
          | _ => frees
  in rev(add(tm,[]))
  end;
val type_vars_in_term = map mk_prim_vartype o Misc_Legacy.term_tvars;
fun dest_tybinding (v,ty) = (#1(dest_vtype v),ty)
fun inst theta = subst_vars (map dest_tybinding theta,[])
fun mk_abs{Bvar as Var((s,_),ty),Body}  = Abs(s,ty,abstract_over(Bvar,Body))
  | mk_abs{Bvar as Free(s,ty),Body}  = Abs(s,ty,abstract_over(Bvar,Body))
  | mk_abs _ = raise USYN_ERR "mk_abs" "Bvar is not a variable";
fun mk_imp{ant,conseq} =
   let val c = Const(\<^const_name>‹HOL.implies›,HOLogic.boolT --> HOLogic.boolT --> HOLogic.boolT)
   in list_comb(c,[ant,conseq])
   end;
fun mk_select (r as {Bvar,Body}) =
  let val ty = type_of Bvar
      val c = Const(\<^const_name>‹Eps›,(ty --> HOLogic.boolT) --> ty)
  in list_comb(c,[mk_abs r])
  end;
fun mk_forall (r as {Bvar,Body}) =
  let val ty = type_of Bvar
      val c = Const(\<^const_name>‹All›,(ty --> HOLogic.boolT) --> HOLogic.boolT)
  in list_comb(c,[mk_abs r])
  end;
fun mk_exists (r as {Bvar,Body}) =
  let val ty = type_of Bvar
      val c = Const(\<^const_name>‹Ex›,(ty --> HOLogic.boolT) --> HOLogic.boolT)
  in list_comb(c,[mk_abs r])
  end;
fun mk_conj{conj1,conj2} =
   let val c = Const(\<^const_name>‹HOL.conj›,HOLogic.boolT --> HOLogic.boolT --> HOLogic.boolT)
   in list_comb(c,[conj1,conj2])
   end;
fun mk_disj{disj1,disj2} =
   let val c = Const(\<^const_name>‹HOL.disj›,HOLogic.boolT --> HOLogic.boolT --> HOLogic.boolT)
   in list_comb(c,[disj1,disj2])
   end;
fun prod_ty ty1 ty2 = HOLogic.mk_prodT (ty1,ty2);
local
fun mk_uncurry (xt, yt, zt) =
    Const(\<^const_name>‹case_prod›, (xt --> yt --> zt) --> prod_ty xt yt --> zt)
fun dest_pair(Const(\<^const_name>‹Pair›,_) $ M $ N) = {fst=M, snd=N}
  | dest_pair _ = raise USYN_ERR "dest_pair" "not a pair"
fun is_var (Var _) = true | is_var (Free _) = true | is_var _ = false
in
fun mk_pabs{varstruct,body} =
 let fun mpa (varstruct, body) =
       if is_var varstruct
       then mk_abs {Bvar = varstruct, Body = body}
       else let val {fst, snd} = dest_pair varstruct
            in mk_uncurry (type_of fst, type_of snd, type_of body) $
               mpa (fst, mpa (snd, body))
            end
 in mpa (varstruct, body) end
 handle TYPE _ => raise USYN_ERR "mk_pabs" "";
end;
datatype lambda = VAR   of {Name : string, Ty : typ}
                | CONST of {Name : string, Ty : typ}
                | COMB  of {Rator: term, Rand : term}
                | LAMB  of {Bvar : term, Body : term};
fun dest_term(Var((s,_),ty)) = VAR{Name = s, Ty = ty}
  | dest_term(Free(s,ty))    = VAR{Name = s, Ty = ty}
  | dest_term(Const(s,ty))   = CONST{Name = s, Ty = ty}
  | dest_term(M$N)           = COMB{Rator=M,Rand=N}
  | dest_term(Abs(s,ty,M))   = let  val v = Free(s,ty)
                               in LAMB{Bvar = v, Body = Term.betapply (M,v)}
                               end
  | dest_term(Bound _)       = raise USYN_ERR "dest_term" "Bound";
fun dest_const(Const(s,ty)) = {Name = s, Ty = ty}
  | dest_const _ = raise USYN_ERR "dest_const" "not a constant";
fun dest_comb(t1 $ t2) = {Rator = t1, Rand = t2}
  | dest_comb _ =  raise USYN_ERR "dest_comb" "not a comb";
fun dest_abs used (a as Abs(s, ty, _)) =
     let
       val s' = singleton (Name.variant_list used) s;
       val v = Free(s', ty);
     in ({Bvar = v, Body = Term.betapply (a,v)}, s'::used)
     end
  | dest_abs _ _ =  raise USYN_ERR "dest_abs" "not an abstraction";
fun dest_eq(Const(\<^const_name>‹HOL.eq›,_) $ M $ N) = {lhs=M, rhs=N}
  | dest_eq _ = raise USYN_ERR "dest_eq" "not an equality";
fun dest_imp(Const(\<^const_name>‹HOL.implies›,_) $ M $ N) = {ant=M, conseq=N}
  | dest_imp _ = raise USYN_ERR "dest_imp" "not an implication";
fun dest_forall(Const(\<^const_name>‹All›,_) $ (a as Abs _)) = fst (dest_abs [] a)
  | dest_forall _ = raise USYN_ERR "dest_forall" "not a forall";
fun dest_exists(Const(\<^const_name>‹Ex›,_) $ (a as Abs _)) = fst (dest_abs [] a)
  | dest_exists _ = raise USYN_ERR "dest_exists" "not an existential";
fun dest_neg(Const(\<^const_name>‹Not›,_) $ M) = M
  | dest_neg _ = raise USYN_ERR "dest_neg" "not a negation";
fun dest_conj(Const(\<^const_name>‹HOL.conj›,_) $ M $ N) = {conj1=M, conj2=N}
  | dest_conj _ = raise USYN_ERR "dest_conj" "not a conjunction";
fun dest_disj(Const(\<^const_name>‹HOL.disj›,_) $ M $ N) = {disj1=M, disj2=N}
  | dest_disj _ = raise USYN_ERR "dest_disj" "not a disjunction";
fun mk_pair{fst,snd} =
   let val ty1 = type_of fst
       val ty2 = type_of snd
       val c = Const(\<^const_name>‹Pair›,ty1 --> ty2 --> prod_ty ty1 ty2)
   in list_comb(c,[fst,snd])
   end;
fun dest_pair(Const(\<^const_name>‹Pair›,_) $ M $ N) = {fst=M, snd=N}
  | dest_pair _ = raise USYN_ERR "dest_pair" "not a pair";
local  fun ucheck t = (if #Name (dest_const t) = \<^const_name>‹case_prod› then t
                       else raise Match)
in
fun dest_pabs used tm =
   let val ({Bvar,Body}, used') = dest_abs used tm
   in {varstruct = Bvar, body = Body, used = used'}
   end handle Utils.ERR _ =>
          let val {Rator,Rand} = dest_comb tm
              val _ = ucheck Rator
              val {varstruct = lv, body, used = used'} = dest_pabs used Rand
              val {varstruct = rv, body, used = used''} = dest_pabs used' body
          in {varstruct = mk_pair {fst = lv, snd = rv}, body = body, used = used''}
          end
end;
val lhs   = #lhs o dest_eq
val rhs   = #rhs o dest_eq
val rand  = #Rand o dest_comb
val is_imp    = can dest_imp
val is_forall = can dest_forall
val is_exists = can dest_exists
val is_neg    = can dest_neg
val is_conj   = can dest_conj
val is_disj   = can dest_disj
val is_pair   = can dest_pair
val is_pabs   = can (dest_pabs [])
fun list_mk_abs(L,tm) = fold_rev (fn v => fn M => mk_abs{Bvar=v, Body=M}) L tm;
fun list_mk_imp(A,c) = fold_rev (fn a => fn tm => mk_imp{ant=a,conseq=tm}) A c;
fun list_mk_forall(V,t) = fold_rev (fn v => fn b => mk_forall{Bvar=v, Body=b})V t;
val list_mk_conj = Utils.end_itlist(fn c1 => fn tm => mk_conj{conj1=c1, conj2=tm})
fun gen_all tm = list_mk_forall(Misc_Legacy.term_frees tm, tm);
fun strip_comb tm =
   let fun dest(M$N, A) = dest(M, N::A)
         | dest x = x
   in dest(tm,[])
   end;
fun strip_abs(tm as Abs _) =
       let val ({Bvar,Body}, _) = dest_abs [] tm
           val (bvs, core) = strip_abs Body
       in (Bvar::bvs, core)
       end
  | strip_abs M = ([],M);
fun strip_imp fm =
   if (is_imp fm)
   then let val {ant,conseq} = dest_imp fm
            val (was,wb) = strip_imp conseq
        in ((ant::was), wb)
        end
   else ([],fm);
fun strip_forall fm =
   if (is_forall fm)
   then let val {Bvar,Body} = dest_forall fm
            val (bvs,core) = strip_forall Body
        in ((Bvar::bvs), core)
        end
   else ([],fm);
fun strip_exists fm =
   if (is_exists fm)
   then let val {Bvar, Body} = dest_exists fm
            val (bvs,core) = strip_exists Body
        in (Bvar::bvs, core)
        end
   else ([],fm);
fun strip_disj w =
   if (is_disj w)
   then let val {disj1,disj2} = dest_disj w
        in (strip_disj disj1@strip_disj disj2)
        end
   else [w];
fun mk_vstruct ty V =
  let fun follow_prod_type (Type(\<^type_name>‹Product_Type.prod›,[ty1,ty2])) vs =
              let val (ltm,vs1) = follow_prod_type ty1 vs
                  val (rtm,vs2) = follow_prod_type ty2 vs1
              in (mk_pair{fst=ltm, snd=rtm}, vs2) end
        | follow_prod_type _ (v::vs) = (v,vs)
  in #1 (follow_prod_type ty V)  end;
fun find_term p =
   let fun find tm =
      if (p tm) then SOME tm
      else case tm of
          Abs(_,_,body) => find body
        | (t$u)         => (case find t of NONE => find u | some => some)
        | _             => NONE
   in find
   end;
fun dest_relation tm =
   if (type_of tm = HOLogic.boolT)
   then let val (Const(\<^const_name>‹Set.member›,_) $ (Const(\<^const_name>‹Pair›,_)$y$x) $ R) = tm
        in (R,y,x)
        end handle Bind => raise USYN_ERR "dest_relation" "unexpected term structure"
   else raise USYN_ERR "dest_relation" "not a boolean term";
fun is_WFR \<^Const_>‹Wellfounded.wf_on _ for \<^Const_>‹top_class.top _› _› = true
  | is_WFR _                 = false;
fun ARB ty = mk_select{Bvar=Free("v",ty),
                       Body=Const(\<^const_name>‹True›,HOLogic.boolT)};
end;
structure Dcterm: DCTERM =
struct
fun ERR func mesg = Utils.ERR {module = "Dcterm", func = func, mesg = mesg};
fun dest_comb t = Thm.dest_comb t
  handle CTERM (msg, _) => raise ERR "dest_comb" msg;
fun dest_abs t = Thm.dest_abs_global t
  handle CTERM (msg, _) => raise ERR "dest_abs" msg;
fun capply t u = Thm.apply t u
  handle CTERM (msg, _) => raise ERR "capply" msg;
fun cabs a t = Thm.lambda a t
  handle CTERM (msg, _) => raise ERR "cabs" msg;
val mk_hol_const = Thm.cterm_of \<^theory_context>‹HOL› o Const;
fun mk_exists (r as (Bvar, Body)) =
  let val ty = Thm.typ_of_cterm Bvar
      val c = mk_hol_const(\<^const_name>‹Ex›, (ty --> HOLogic.boolT) --> HOLogic.boolT)
  in capply c (uncurry cabs r) end;
local val c = mk_hol_const(\<^const_name>‹HOL.conj›, HOLogic.boolT --> HOLogic.boolT --> HOLogic.boolT)
in fun mk_conj(conj1,conj2) = capply (capply c conj1) conj2
end;
local val c = mk_hol_const(\<^const_name>‹HOL.disj›, HOLogic.boolT --> HOLogic.boolT --> HOLogic.boolT)
in fun mk_disj(disj1,disj2) = capply (capply c disj1) disj2
end;
fun dest_const ctm =
   (case Thm.term_of ctm
      of Const(s,ty) => {Name = s, Ty = ty}
       | _ => raise ERR "dest_const" "not a constant");
fun dest_var ctm =
   (case Thm.term_of ctm
      of Var((s,_),ty) => {Name=s, Ty=ty}
       | Free(s,ty)    => {Name=s, Ty=ty}
       |             _ => raise ERR "dest_var" "not a variable");
fun dest_monop expected tm =
 let
   fun err () = raise ERR "dest_monop" ("Not a(n) " ^ quote expected);
   val (c, N) = dest_comb tm handle Utils.ERR _ => err ();
   val name = #Name (dest_const c handle Utils.ERR _ => err ());
 in if name = expected then N else err () end;
fun dest_binop expected tm =
 let
   fun err () = raise ERR "dest_binop" ("Not a(n) " ^ quote expected);
   val (M, N) = dest_comb tm handle Utils.ERR _ => err ()
 in (dest_monop expected M, N) handle Utils.ERR _ => err () end;
fun dest_binder expected tm =
  dest_abs (dest_monop expected tm)
  handle Utils.ERR _ => raise ERR "dest_binder" ("Not a(n) " ^ quote expected);
val dest_neg    = dest_monop \<^const_name>‹Not›
val dest_pair   = dest_binop \<^const_name>‹Pair›
val dest_eq     = dest_binop \<^const_name>‹HOL.eq›
val dest_imp    = dest_binop \<^const_name>‹HOL.implies›
val dest_conj   = dest_binop \<^const_name>‹HOL.conj›
val dest_disj   = dest_binop \<^const_name>‹HOL.disj›
val dest_exists = dest_binder \<^const_name>‹Ex›
val dest_forall = dest_binder \<^const_name>‹All›
val is_eq     = can dest_eq
val is_imp    = can dest_imp
val is_forall = can dest_forall
val is_exists = can dest_exists
val is_neg    = can dest_neg
val is_conj   = can dest_conj
val is_disj   = can dest_disj
val is_pair   = can dest_pair
val list_mk_disj = Utils.end_itlist (fn d1 => fn tm => mk_disj (d1, tm));
fun strip break tm =
  let fun dest (p as (ctm,accum)) =
        let val (M,N) = break ctm
        in dest (N, M::accum)
        end handle Utils.ERR _ => p
  in dest (tm,[])
  end;
fun rev2swap (x,l) = (rev l, x);
val strip_comb   = strip (Library.swap o dest_comb)  
val strip_imp    = rev2swap o strip dest_imp
val strip_abs    = rev2swap o strip dest_abs
val strip_forall = rev2swap o strip dest_forall
val strip_exists = rev2swap o strip dest_exists
val strip_disj   = rev o (op::) o strip dest_disj
fun mk_prop ct = if HOLogic.is_judgment ct then ct else HOLogic.mk_judgment ct;
fun drop_prop ct = if HOLogic.is_judgment ct then Thm.dest_arg ct else ct;
end;
structure Rules: RULES =
struct
fun RULES_ERR func mesg = Utils.ERR {module = "Rules", func = func, mesg = mesg};
fun cconcl thm = Dcterm.drop_prop (Thm.cprop_of thm);
fun chyps thm = map Dcterm.drop_prop (Thm.chyps_of thm);
fun dest_thm thm =
  (map HOLogic.dest_Trueprop (Thm.hyps_of thm), HOLogic.dest_Trueprop (Thm.prop_of thm))
    handle TERM _ => raise RULES_ERR "dest_thm" "missing Trueprop";
fun REFL tm = HOLogic.mk_obj_eq (Thm.reflexive tm)
  handle THM (msg, _, _) => raise RULES_ERR "REFL" msg;
fun SYM thm = thm RS sym
  handle THM (msg, _, _) => raise RULES_ERR "SYM" msg;
fun ALPHA thm ctm1 =
  let
    val ctm2 = Thm.cprop_of thm;
    val ctm2_eq = Thm.reflexive ctm2;
    val ctm1_eq = Thm.reflexive ctm1;
  in Thm.equal_elim (Thm.transitive ctm2_eq ctm1_eq) thm end
  handle THM (msg, _, _) => raise RULES_ERR "ALPHA" msg;
fun rbeta th =
  (case Dcterm.strip_comb (cconcl th) of
    (_, [_, r]) => Thm.transitive th (Thm.beta_conversion false r)
  | _ => raise RULES_ERR "rbeta" "");
fun ASSUME ctm = Thm.assume (Dcterm.mk_prop ctm);
fun MP th1 th2 = th2 RS (th1 RS mp)
  handle THM (msg, _, _) => raise RULES_ERR "MP" msg;
fun DISCH tm thm = Thm.implies_intr (Dcterm.mk_prop tm) thm COMP impI
  handle THM (msg, _, _) => raise RULES_ERR "DISCH" msg;
fun DISCH_ALL thm = fold_rev DISCH (Thm.chyps_of thm) thm;
fun FILTER_DISCH_ALL P thm =
 let fun check tm = P (Thm.term_of tm)
 in  fold_rev (fn tm => fn th => if check tm then DISCH tm th else th) (chyps thm) thm
 end;
fun UNDISCH thm =
   let val tm = Dcterm.mk_prop (#1 (Dcterm.dest_imp (cconcl thm)))
   in Thm.implies_elim (thm RS mp) (ASSUME tm) end
   handle Utils.ERR _ => raise RULES_ERR "UNDISCH" ""
     | THM _ => raise RULES_ERR "UNDISCH" "";
fun PROVE_HYP ath bth = MP (DISCH (cconcl ath) bth) ath;
fun IMP_TRANS th1 th2 = th2 RS (th1 RS @{thm tfl_imp_trans})
  handle THM (msg, _, _) => raise RULES_ERR "IMP_TRANS" msg;
fun CONJUNCT1 thm = thm RS conjunct1
  handle THM (msg, _, _) => raise RULES_ERR "CONJUNCT1" msg;
fun CONJUNCT2 thm = thm RS conjunct2
  handle THM (msg, _, _) => raise RULES_ERR "CONJUNCT2" msg;
fun CONJUNCTS th = CONJUNCTS (CONJUNCT1 th) @ CONJUNCTS (CONJUNCT2 th) handle Utils.ERR _ => [th];
fun LIST_CONJ [] = raise RULES_ERR "LIST_CONJ" "empty list"
  | LIST_CONJ [th] = th
  | LIST_CONJ (th :: rst) = MP (MP (conjI COMP (impI RS impI)) th) (LIST_CONJ rst)
      handle THM (msg, _, _) => raise RULES_ERR "LIST_CONJ" msg;
local
  val prop = Thm.prop_of disjI1
  val [_,Q] = Misc_Legacy.term_vars prop
  val disj1 = Thm.forall_intr (Thm.cterm_of \<^context> Q) disjI1
in
fun DISJ1 thm tm = thm RS (Thm.forall_elim (Dcterm.drop_prop tm) disj1)
  handle THM (msg, _, _) => raise RULES_ERR "DISJ1" msg;
end;
local
  val prop = Thm.prop_of disjI2
  val [P,_] = Misc_Legacy.term_vars prop
  val disj2 = Thm.forall_intr (Thm.cterm_of \<^context> P) disjI2
in
fun DISJ2 tm thm = thm RS (Thm.forall_elim (Dcterm.drop_prop tm) disj2)
  handle THM (msg, _, _) => raise RULES_ERR "DISJ2" msg;
end;
fun EVEN_ORS thms =
  let fun blue ldisjs [] _ = []
        | blue ldisjs (th::rst) rdisjs =
            let val tail = tl rdisjs
                val rdisj_tl = Dcterm.list_mk_disj tail
            in fold_rev DISJ2 ldisjs (DISJ1 th rdisj_tl)
               :: blue (ldisjs @ [cconcl th]) rst tail
            end handle Utils.ERR _ => [fold_rev DISJ2 ldisjs th]
   in blue [] thms (map cconcl thms) end;
fun DISJ_CASES th1 th2 th3 =
  let
    val c = Dcterm.drop_prop (cconcl th1);
    val (disj1, disj2) = Dcterm.dest_disj c;
    val th2' = DISCH disj1 th2;
    val th3' = DISCH disj2 th3;
  in
    th3' RS (th2' RS (th1 RS @{thm tfl_disjE}))
      handle THM (msg, _, _) => raise RULES_ERR "DISJ_CASES" msg
  end;
fun organize eq =    
 let fun extract a alist =
     let fun ex (_,[]) = raise RULES_ERR "organize" "not a permutation.1"
           | ex(left,h::t) = if (eq h a) then (h,rev left@t) else ex(h::left,t)
     in ex ([],alist)
     end
     fun place [] [] = []
       | place (a::rst) alist =
           let val (item,next) = extract a alist
           in item::place rst next
           end
       | place _ _ = raise RULES_ERR "organize" "not a permutation.2"
 in place
 end;
fun DISJ_CASESL disjth thl =
   let val c = cconcl disjth
       fun eq th atm =
        exists (fn t => HOLogic.dest_Trueprop t aconv Thm.term_of atm) (Thm.hyps_of th)
       val tml = Dcterm.strip_disj c
       fun DL _ [] = raise RULES_ERR "DISJ_CASESL" "no cases"
         | DL th [th1] = PROVE_HYP th th1
         | DL th [th1,th2] = DISJ_CASES th th1 th2
         | DL th (th1::rst) =
            let val tm = #2 (Dcterm.dest_disj (Dcterm.drop_prop(cconcl th)))
             in DISJ_CASES th th1 (DL (ASSUME tm) rst) end
   in DL disjth (organize eq tml thl)
   end;
local 
  val prop = Thm.prop_of spec
  val x = hd (tl (Misc_Legacy.term_vars prop))
  val TV = dest_TVar (type_of x)
  val gspec = Thm.forall_intr (Thm.cterm_of \<^context> x) spec
in
fun SPEC tm thm =
   let val gspec' =
    Drule.instantiate_normalize (TVars.make1 (TV, Thm.ctyp_of_cterm tm), Vars.empty) gspec
   in thm RS (Thm.forall_elim tm gspec') end
end;
fun SPEC_ALL thm = fold SPEC (#1 (Dcterm.strip_forall(cconcl thm))) thm;
val ISPEC = SPEC
val ISPECL = fold ISPEC;
local
  val prop = Thm.prop_of allI
  val [P] = Misc_Legacy.add_term_vars (prop, [])
  fun cty_theta ctxt = map (fn (i, (S, ty)) => ((i, S), Thm.ctyp_of ctxt ty))
  fun ctm_theta ctxt =
    map (fn (i, (_, tm2)) =>
      let val ctm2 = Thm.cterm_of ctxt tm2
      in ((i, Thm.typ_of_cterm ctm2), ctm2) end)
  fun certify ctxt (ty_theta,tm_theta) =
    (TVars.make (cty_theta ctxt (Vartab.dest ty_theta)),
     Vars.make (ctm_theta ctxt (Vartab.dest tm_theta)))
in
fun GEN ctxt v th =
   let val gth = Thm.forall_intr v th
       val thy = Proof_Context.theory_of ctxt
       val Const(\<^const_name>‹Pure.all›,_)$Abs(x,ty,rst) = Thm.prop_of gth
       val P' = Abs(x,ty, HOLogic.dest_Trueprop rst)  
       val theta = Pattern.match thy (P,P') (Vartab.empty, Vartab.empty);
       val allI2 = Drule.instantiate_normalize (certify ctxt theta) allI
       val thm = Thm.implies_elim allI2 gth
       val tp $ (A $ Abs(_,_,M)) = Thm.prop_of thm
       val prop' = tp $ (A $ Abs(x,ty,M))
   in ALPHA thm (Thm.cterm_of ctxt prop') end
end;
fun GENL ctxt = fold_rev (GEN ctxt);
fun GEN_ALL ctxt thm =
  let
    val prop = Thm.prop_of thm
    val vlist = map (Thm.cterm_of ctxt) (Misc_Legacy.add_term_vars (prop, []))
  in GENL ctxt vlist thm end;
fun MATCH_MP th1 th2 =
   if (Dcterm.is_forall (Dcterm.drop_prop(cconcl th1)))
   then MATCH_MP (th1 RS spec) th2
   else MP th1 th2;
fun CHOOSE ctxt (fvar, exth) fact =
  let
    val lam = #2 (Dcterm.dest_comb (Dcterm.drop_prop (cconcl exth)))
    val redex = Dcterm.capply lam fvar
    val t$u = Thm.term_of redex
    val residue = Thm.cterm_of ctxt (Term.betapply (t, u))
  in
    GEN ctxt fvar (DISCH residue fact) RS (exth RS @{thm tfl_exE})
      handle THM (msg, _, _) => raise RULES_ERR "CHOOSE" msg
  end;
fun EXISTS ctxt (template,witness) thm =
  let val abstr = #2 (Dcterm.dest_comb template) in
    thm RS (infer_instantiate ctxt [(("P", 0), abstr), (("x", 0), witness)] exI)
      handle THM (msg, _, _) => raise RULES_ERR "EXISTS" msg
  end;
fun IT_EXISTS ctxt blist th =
  let
    val blist' = map (apply2 Thm.term_of) blist
    fun ex v M = Thm.cterm_of ctxt (USyntax.mk_exists{Bvar=v,Body = M})
  in
    fold_rev (fn (b as (r1,r2)) => fn thm =>
        EXISTS ctxt (ex r2 (subst_free [b]
                   (HOLogic.dest_Trueprop(Thm.prop_of thm))), Thm.cterm_of ctxt r1)
              thm)
       blist' th
  end;
fun SUBS ctxt thl =
  rewrite_rule ctxt (map (fn th => th RS eq_reflection handle THM _ => th) thl);
fun rew_conv ctxt ctm =
  Raw_Simplifier.rewrite_cterm (true, false, false) (K (K NONE))
    (Variable.declare_term (Thm.term_of ctm) ctxt) ctm;
fun simpl_conv ctxt thl ctm =
  HOLogic.mk_obj_eq (rew_conv (ctxt addsimps thl) ctm);
fun RIGHT_ASSOC ctxt = rewrite_rule ctxt @{thms tfl_disj_assoc};
fun Forall v M = USyntax.mk_forall{Bvar=v, Body=M};
fun is_cong thm =
  case (Thm.prop_of thm) of
    (Const(\<^const_name>‹Pure.imp›,_)$(Const(\<^const_name>‹Trueprop›,_)$ _) $
      (Const(\<^const_name>‹Pure.eq›,_) $ (Const (\<^const_name>‹Wfrec.cut›,_) $ _ $ _ $ _ $ _) $ _)) =>
        false
  | _ => true;
fun dest_equal(Const (\<^const_name>‹Pure.eq›,_) $
               (Const (\<^const_name>‹Trueprop›,_) $ lhs)
               $ (Const (\<^const_name>‹Trueprop›,_) $ rhs)) = {lhs=lhs, rhs=rhs}
  | dest_equal(Const (\<^const_name>‹Pure.eq›,_) $ lhs $ rhs) = {lhs=lhs, rhs=rhs}
  | dest_equal tm = USyntax.dest_eq tm;
fun get_lhs tm = #lhs(dest_equal (HOLogic.dest_Trueprop tm));
fun dest_all used (Const(\<^const_name>‹Pure.all›,_) $ (a as Abs _)) = USyntax.dest_abs used a
  | dest_all _ _ = raise RULES_ERR "dest_all" "not a !!";
val is_all = can (dest_all []);
fun strip_all used fm =
   if (is_all fm)
   then let val ({Bvar, Body}, used') = dest_all used fm
            val (bvs, core, used'') = strip_all used' Body
        in ((Bvar::bvs), core, used'')
        end
   else ([], fm, used);
fun list_break_all(Const(\<^const_name>‹Pure.all›,_) $ Abs (s,ty,body)) =
     let val (L,core) = list_break_all body
     in ((s,ty)::L, core)
     end
  | list_break_all tm = ([],tm);
fun get ([],_,L) = rev L
  | get (ant::rst,n,L) =
      case (list_break_all ant)
        of ([],_) => get (rst, n+1,L)
         | (_,body) =>
            let val eq = Logic.strip_imp_concl body
                val (f,_) = USyntax.strip_comb (get_lhs eq)
                val (vstrl,_) = USyntax.strip_abs f
                val names  =
                  Name.variant_list (Misc_Legacy.add_term_names(body, [])) (map (#1 o dest_Free) vstrl)
            in get (rst, n+1, (names,n)::L) end
            handle TERM _ => get (rst, n+1, L)
              | Utils.ERR _ => get (rst, n+1, L);
fun rename thm =
  let
    val ants = Logic.strip_imp_prems (Thm.prop_of thm)
    val news = get (ants,1,[])
  in fold Thm.rename_params_rule news thm end;
fun list_beta_conv tm =
  let fun rbeta th = Thm.transitive th (Thm.beta_conversion false (#2(Dcterm.dest_eq(cconcl th))))
      fun iter [] = Thm.reflexive tm
        | iter (v::rst) = rbeta (Thm.combination(iter rst) (Thm.reflexive v))
  in iter  end;
val tracing = Unsynchronized.ref false;
fun say s = if !tracing then writeln s else ();
fun print_thms ctxt s L =
  say (cat_lines (s :: map (Thm.string_of_thm ctxt) L));
fun print_term ctxt s t =
  say (cat_lines [s, Syntax.string_of_term ctxt t]);
fun mk_aabs (vstr, body) =
  USyntax.mk_abs {Bvar = vstr, Body = body}
  handle Utils.ERR _ => USyntax.mk_pabs {varstruct = vstr, body = body};
fun list_mk_aabs (vstrl,tm) =
    fold_rev (fn vstr => fn tm => mk_aabs(vstr,tm)) vstrl tm;
fun dest_aabs used tm =
   let val ({Bvar,Body}, used') = USyntax.dest_abs used tm
   in (Bvar, Body, used') end
   handle Utils.ERR _ =>
     let val {varstruct, body, used} = USyntax.dest_pabs used tm
     in (varstruct, body, used) end;
fun strip_aabs used tm =
   let val (vstr, body, used') = dest_aabs used tm
       val (bvs, core, used'') = strip_aabs used' body
   in (vstr::bvs, core, used'') end
   handle Utils.ERR _ => ([], tm, used);
fun dest_combn tm 0 = (tm,[])
  | dest_combn tm n =
     let val {Rator,Rand} = USyntax.dest_comb tm
         val (f,rands) = dest_combn Rator (n-1)
     in (f,Rand::rands)
     end;
local fun dest_pair M = let val {fst,snd} = USyntax.dest_pair M in (fst,snd) end
      fun mk_fst tm =
          let val ty as Type(\<^type_name>‹Product_Type.prod›, [fty,sty]) = type_of tm
          in  Const (\<^const_name>‹Product_Type.fst›, ty --> fty) $ tm  end
      fun mk_snd tm =
          let val ty as Type(\<^type_name>‹Product_Type.prod›, [fty,sty]) = type_of tm
          in  Const (\<^const_name>‹Product_Type.snd›, ty --> sty) $ tm  end
in
fun XFILL tych x vstruct =
  let fun traverse p xocc L =
        if (is_Free p)
        then tych xocc::L
        else let val (p1,p2) = dest_pair p
             in traverse p1 (mk_fst xocc) (traverse p2  (mk_snd xocc) L)
             end
  in
  traverse vstruct x []
end end;
fun VSTRUCT_ELIM ctxt tych a vstr th =
  let val L = USyntax.free_vars_lr vstr
      val bind1 = tych (HOLogic.mk_Trueprop (HOLogic.mk_eq(a,vstr)))
      val thm1 = Thm.implies_intr bind1 (SUBS ctxt [SYM(Thm.assume bind1)] th)
      val thm2 = forall_intr_list (map tych L) thm1
      val thm3 = forall_elim_list (XFILL tych a vstr) thm2
  in refl RS
     rewrite_rule ctxt [Thm.symmetric (@{thm surjective_pairing} RS eq_reflection)] thm3
  end;
fun PGEN ctxt tych a vstr th =
  let val a1 = tych a
  in Thm.forall_intr a1 (VSTRUCT_ELIM ctxt tych a vstr th) end;
fun dest_pbeta_redex used M n =
  let val (f,args) = dest_combn M n
      val _ = dest_aabs used f
  in (strip_aabs used f,args)
  end;
fun pbeta_redex M n = can (fn t => dest_pbeta_redex [] t n) M;
fun dest_impl tm =
  let val ants = Logic.strip_imp_prems tm
      val eq = Logic.strip_imp_concl tm
  in (ants,get_lhs eq)
  end;
fun restricted t = is_some (USyntax.find_term
                            (fn (Const(\<^const_name>‹Wfrec.cut›,_)) =>true | _ => false)
                            t)
fun CONTEXT_REWRITE_RULE main_ctxt (func, G, cut_lemma, congs) th =
 let val globals = func::G
     val ctxt0 = empty_simpset main_ctxt
     val pbeta_reduce = simpl_conv ctxt0 [@{thm split_conv} RS eq_reflection];
     val tc_list = Unsynchronized.ref []: term list Unsynchronized.ref
     val cut_lemma' = cut_lemma RS eq_reflection
     fun prover used ctxt thm =
     let fun cong_prover ctxt thm =
         let val _ = say "cong_prover:"
             val cntxt = Simplifier.prems_of ctxt
             val _ = print_thms ctxt "cntxt:" cntxt
             val _ = say "cong rule:"
             val _ = say (Thm.string_of_thm ctxt thm)
             
             fun uq_eliminate (thm,imp) =
                 let val tych = Thm.cterm_of ctxt
                     val _ = print_term ctxt "To eliminate:" imp
                     val ants = map tych (Logic.strip_imp_prems imp)
                     val eq = Logic.strip_imp_concl imp
                     val lhs = tych(get_lhs eq)
                     val ctxt' = Simplifier.add_prems (map ASSUME ants) ctxt
                     val lhs_eq_lhs1 = Raw_Simplifier.rewrite_cterm (false,true,false) (prover used) ctxt' lhs
                       handle Utils.ERR _ => Thm.reflexive lhs
                     val _ = print_thms ctxt' "proven:" [lhs_eq_lhs1]
                     val lhs_eq_lhs2 = implies_intr_list ants lhs_eq_lhs1
                     val lhs_eeq_lhs2 = HOLogic.mk_obj_eq lhs_eq_lhs2
                  in
                  lhs_eeq_lhs2 COMP thm
                  end
             fun pq_eliminate (thm, vlist, imp_body, lhs_eq) =
              let val ((vstrl, _, used'), args) = dest_pbeta_redex used lhs_eq (length vlist)
                  val _ = forall (op aconv) (ListPair.zip (vlist, args))
                    orelse error "assertion failed in CONTEXT_REWRITE_RULE"
                  val imp_body1 = subst_free (ListPair.zip (args, vstrl))
                                             imp_body
                  val tych = Thm.cterm_of ctxt
                  val ants1 = map tych (Logic.strip_imp_prems imp_body1)
                  val eq1 = Logic.strip_imp_concl imp_body1
                  val Q = get_lhs eq1
                  val QeqQ1 = pbeta_reduce (tych Q)
                  val Q1 = #2(Dcterm.dest_eq(cconcl QeqQ1))
                  val ctxt' = Simplifier.add_prems (map ASSUME ants1) ctxt
                  val Q1eeqQ2 = Raw_Simplifier.rewrite_cterm (false,true,false) (prover used') ctxt' Q1
                                handle Utils.ERR _ => Thm.reflexive Q1
                  val Q2 = #2 (Logic.dest_equals (Thm.prop_of Q1eeqQ2))
                  val Q3 = tych(list_comb(list_mk_aabs(vstrl,Q2),vstrl))
                  val Q2eeqQ3 = Thm.symmetric(pbeta_reduce Q3 RS eq_reflection)
                  val thA = Thm.transitive(QeqQ1 RS eq_reflection) Q1eeqQ2
                  val QeeqQ3 = Thm.transitive thA Q2eeqQ3 handle THM _ =>
                               (HOLogic.mk_obj_eq Q2eeqQ3
                                RS (HOLogic.mk_obj_eq thA RS trans))
                                RS eq_reflection
                  val impth = implies_intr_list ants1 QeeqQ3
                  val impth1 = HOLogic.mk_obj_eq impth
                  
                  val ant_th = Utils.itlist2 (PGEN ctxt' tych) args vstrl impth1
              in ant_th COMP thm
              end
             fun q_eliminate (thm, imp) =
              let val (vlist, imp_body, used') = strip_all used imp
                  val (ants,Q) = dest_impl imp_body
              in if (pbeta_redex Q) (length vlist)
                 then pq_eliminate (thm, vlist, imp_body, Q)
                 else
                 let val tych = Thm.cterm_of ctxt
                     val ants1 = map tych ants
                     val ctxt' = Simplifier.add_prems (map ASSUME ants1) ctxt
                     val Q_eeq_Q1 = Raw_Simplifier.rewrite_cterm
                        (false,true,false) (prover used') ctxt' (tych Q)
                      handle Utils.ERR _ => Thm.reflexive (tych Q)
                     val lhs_eeq_lhs2 = implies_intr_list ants1 Q_eeq_Q1
                     val lhs_eq_lhs2 = HOLogic.mk_obj_eq lhs_eeq_lhs2
                     val ant_th = forall_intr_list(map tych vlist)lhs_eq_lhs2
                 in
                 ant_th COMP thm
              end end
             fun eliminate thm =
               case Thm.prop_of thm of
                 Const(\<^const_name>‹Pure.imp›,_) $ imp $ _ =>
                   eliminate
                    (if not(is_all imp)
                     then uq_eliminate (thm, imp)
                     else q_eliminate (thm, imp))
                            
                | _ => thm  
         in SOME(eliminate (rename thm)) end
         handle Utils.ERR _ => NONE    
        fun restrict_prover ctxt thm =
          let val _ = say "restrict_prover:"
              val cntxt = rev (Simplifier.prems_of ctxt)
              val _ = print_thms ctxt "cntxt:" cntxt
              val Const(\<^const_name>‹Pure.imp›,_) $ (Const(\<^const_name>‹Trueprop›,_) $ A) $ _ =
                Thm.prop_of thm
              fun genl tm = let val vlist = subtract (op aconv) globals
                                           (Misc_Legacy.add_term_frees(tm,[]))
                            in fold_rev Forall vlist tm
                            end
              
              val func_name = dest_Const_name func
              fun is_func (Const (name,_)) = (name = func_name)
                | is_func _                = false
              val rcontext = rev cntxt
              val cncl = HOLogic.dest_Trueprop o Thm.prop_of
              val antl = case rcontext of [] => []
                         | _   => [USyntax.list_mk_conj(map cncl rcontext)]
              val TC = genl(USyntax.list_mk_imp(antl, A))
              val _ = print_term ctxt "func:" func
              val _ = print_term ctxt "TC:" (HOLogic.mk_Trueprop TC)
              val _ = tc_list := (TC :: !tc_list)
              val nestedp = is_some (USyntax.find_term is_func TC)
              val _ = if nestedp then say "nested" else say "not_nested"
              val th' = if nestedp then raise RULES_ERR "solver" "nested function"
                        else let val cTC = Thm.cterm_of ctxt (HOLogic.mk_Trueprop TC)
                             in case rcontext of
                                [] => SPEC_ALL(ASSUME cTC)
                               | _ => MP (SPEC_ALL (ASSUME cTC))
                                         (LIST_CONJ rcontext)
                             end
              val th'' = th' RS thm
          in SOME (th'')
          end handle Utils.ERR _ => NONE    
    in
    (if (is_cong thm) then cong_prover else restrict_prover) ctxt thm
    end
    val ctm = Thm.cprop_of th
    val names = Misc_Legacy.add_term_names (Thm.term_of ctm, [])
    val th1 =
      Raw_Simplifier.rewrite_cterm (false, true, false)
        (prover names) (ctxt0 addsimps [cut_lemma'] |> fold Simplifier.add_eqcong congs) ctm
    val th2 = Thm.equal_elim th1 th
 in
 (th2, filter_out restricted (!tc_list))
 end;
fun prove ctxt strict t tac =
  let
    val ctxt' = Proof_Context.augment t ctxt;
  in
    if strict
    then Goal.prove ctxt' [] [] t (tac o #context)
    else Goal.prove ctxt' [] [] t (tac o #context)
      handle ERROR msg => (warning msg; raise RULES_ERR "prove" msg)
  end;
end;
structure Thry: THRY =
struct
fun THRY_ERR func mesg = Utils.ERR {module = "Thry", func = func, mesg = mesg};
local
fun tybind (ixn, (S, T)) = (TVar (ixn, S), T);
in
fun match_term thry pat ob =
  let
    val (ty_theta, tm_theta) = Pattern.match thry (pat,ob) (Vartab.empty, Vartab.empty);
    fun tmbind (ixn, (T, t)) = (Var (ixn, Envir.subst_type ty_theta T), t)
  in (map tmbind (Vartab.dest tm_theta), map tybind (Vartab.dest ty_theta))
  end;
fun match_type thry pat ob =
  map tybind (Vartab.dest (Sign.typ_match thry (pat, ob) Vartab.empty));
end;
fun typecheck thy t =
  Thm.global_cterm_of thy t
    handle TYPE (msg, _, _) => raise THRY_ERR "typecheck" msg
      | TERM (msg, _) => raise THRY_ERR "typecheck" msg;
fun match_info thy dtco =
  case (BNF_LFP_Compat.get_info thy [BNF_LFP_Compat.Keep_Nesting] dtco,
         BNF_LFP_Compat.get_constrs thy dtco) of
      (SOME {case_name, ... }, SOME constructors) =>
        SOME {case_const = Const (case_name, Sign.the_const_type thy case_name), constructors = map Const constructors}
    | _ => NONE;
fun induct_info thy dtco = case BNF_LFP_Compat.get_info thy [BNF_LFP_Compat.Keep_Nesting] dtco of
        NONE => NONE
      | SOME {nchotomy, ...} =>
          SOME {nchotomy = nchotomy,
                constructors = (map Const o the o BNF_LFP_Compat.get_constrs thy) dtco};
fun extract_info thy =
 let val infos = map snd (Symtab.dest (BNF_LFP_Compat.get_all thy [BNF_LFP_Compat.Keep_Nesting]))
 in {case_congs = map (mk_meta_eq o #case_cong) infos,
     case_rewrites = maps (map mk_meta_eq o #case_rewrites) infos}
 end;
end;
structure Prim: PRIM =
struct
val trace = Unsynchronized.ref false;
fun TFL_ERR func mesg = Utils.ERR {module = "Tfl", func = func, mesg = mesg};
val concl = #2 o Rules.dest_thm;
val list_mk_type = Utils.end_itlist (curry (op -->));
fun gvvariant names =
  let val slist = Unsynchronized.ref names
      val vname = Unsynchronized.ref "u"
      fun new() =
         if member (op =) (!slist) (!vname)
         then (vname := Symbol.bump_string (!vname);  new())
         else (slist := !vname :: !slist;  !vname)
  in
  fn ty => Free(new(), ty)
  end;
fun ipartition gv (constructors,rows) =
  let fun pfail s = raise TFL_ERR "partition.part" s
      fun part {constrs = [],   rows = [],   A} = rev A
        | part {constrs = [],   rows = _::_, A} = pfail"extra cases in defn"
        | part {constrs = _::_, rows = [],   A} = pfail"cases missing in defn"
        | part {constrs = c::crst, rows,     A} =
          let val (c, T) = dest_Const c
              val L = binder_types T
              val (in_group, not_in_group) =
               fold_rev (fn (row as (p::rst, rhs)) =>
                         fn (in_group,not_in_group) =>
                  let val (pc,args) = USyntax.strip_comb p
                  in if (dest_Const_name pc = c)
                     then ((args@rst, rhs)::in_group, not_in_group)
                     else (in_group, row::not_in_group)
                  end)      rows ([],[])
              val col_types = Utils.take type_of (length L, #1(hd in_group))
          in
          part{constrs = crst, rows = not_in_group,
               A = {constructor = c,
                    new_formals = map gv col_types,
                    group = in_group}::A}
          end
  in part{constrs = constructors, rows = rows, A = []}
  end;
type pattern = term * (int * bool)
fun pattern_map f (tm,x) = (f tm, x);
fun pattern_subst theta = pattern_map (subst_free theta);
val pat_of = fst;
fun row_of_pat x = fst (snd x);
fun given x = snd (snd x);
fun fresh_constr ty_match colty gv c =
  let val Ty = dest_Const_type c
      val L = binder_types Ty
      and ty = body_type Ty
      val ty_theta = ty_match ty colty
      val c' = USyntax.inst ty_theta c
      val gvars = map (USyntax.inst ty_theta o gv) L
  in (c', gvars)
  end;
fun mk_group name rows =
  fold_rev (fn (row as ((prfx, p::rst), rhs)) =>
            fn (in_group,not_in_group) =>
               let val (pc,args) = USyntax.strip_comb p
               in if ((dest_Const_name pc = name) handle TERM _ => false)
                  then (((prfx,args@rst), rhs)::in_group, not_in_group)
                  else (in_group, row::not_in_group) end)
      rows ([],[]);
fun partition _ _ (_,_,_,[]) = raise TFL_ERR "partition" "no rows"
  | partition gv ty_match
              (constructors, colty, res_ty, rows as (((prfx,_),_)::_)) =
let val fresh = fresh_constr ty_match colty gv
     fun part {constrs = [],      rows, A} = rev A
       | part {constrs = c::crst, rows, A} =
         let val (c',gvars) = fresh c
             val (in_group, not_in_group) = mk_group (dest_Const_name c') rows
             val in_group' =
                 if (null in_group)  
                 then [((prfx, #2(fresh c)), (USyntax.ARB res_ty, (~1,false)))]
                 else in_group
         in
         part{constrs = crst,
              rows = not_in_group,
              A = {constructor = c',
                   new_formals = gvars,
                   group = in_group'}::A}
         end
in part{constrs=constructors, rows=rows, A=[]}
end;
fun mk_pat (c,l) =
  let val L = length (binder_types (type_of c))
      fun build (prfx,tag,plist) =
          let val (args, plist') = chop L plist
          in (prfx,tag,list_comb(c,args)::plist') end
  in map build l end;
fun v_to_prfx (prfx, v::pats) = (v::prfx,pats)
  | v_to_prfx _ = raise TFL_ERR "mk_case" "v_to_prfx";
fun v_to_pats (v::prfx,tag, pats) = (prfx, tag, v::pats)
  | v_to_pats _ = raise TFL_ERR "mk_case" "v_to_pats";
fun mk_case ty_info ty_match usednames range_ty =
 let
 fun mk_case_fail s = raise TFL_ERR "mk_case" s
 val fresh_var = gvvariant usednames
 val divide = partition fresh_var ty_match
 fun expand _ ty ((_,[]), _) = mk_case_fail"expand_var_row"
   | expand constructors ty (row as ((prfx, p::rst), rhs)) =
       if (is_Free p)
       then let val fresh = fresh_constr ty_match ty fresh_var
                fun expnd (c,gvs) =
                  let val capp = list_comb(c,gvs)
                  in ((prfx, capp::rst), pattern_subst[(p,capp)] rhs)
                  end
            in map expnd (map fresh constructors)  end
       else [row]
 fun mk{rows=[],...} = mk_case_fail"no rows"
   | mk{path=[], rows = ((prfx, []), (tm,tag))::_} =  
        ([(prfx,tag,[])], tm)
   | mk{path=[], rows = _::_} = mk_case_fail"blunder"
   | mk{path as u::rstp, rows as ((prfx, []), rhs)::rst} =
        mk{path = path,
           rows = ((prfx, [fresh_var(type_of u)]), rhs)::rst}
   | mk{path = u::rstp, rows as ((_, p::_), _)::_} =
     let val (pat_rectangle,rights) = ListPair.unzip rows
         val col0 = map(hd o #2) pat_rectangle
     in
     if (forall is_Free col0)
     then let val rights' = map (fn(v,e) => pattern_subst[(v,u)] e)
                                (ListPair.zip (col0, rights))
              val pat_rectangle' = map v_to_prfx pat_rectangle
              val (pref_patl,tm) = mk{path = rstp,
                                      rows = ListPair.zip (pat_rectangle',
                                                           rights')}
          in (map v_to_pats pref_patl, tm)
          end
     else
     let val pty as Type (ty_name,_) = type_of p
     in
     case (ty_info ty_name)
     of NONE => mk_case_fail("Not a known datatype: "^ty_name)
      | SOME{case_const,constructors} =>
        let
            val case_const_name = dest_Const_name case_const
            val nrows = maps (expand constructors pty) rows
            val subproblems = divide(constructors, pty, range_ty, nrows)
            val groups      = map #group subproblems
            and new_formals = map #new_formals subproblems
            and constructors' = map #constructor subproblems
            val news = map (fn (nf,rows) => {path = nf@rstp, rows=rows})
                           (ListPair.zip (new_formals, groups))
            val rec_calls = map mk news
            val (pat_rect,dtrees) = ListPair.unzip rec_calls
            val case_functions = map USyntax.list_mk_abs
                                  (ListPair.zip (new_formals, dtrees))
            val types = map type_of (case_functions@[u]) @ [range_ty]
            val case_const' = Const(case_const_name, list_mk_type types)
            val tree = list_comb(case_const', case_functions@[u])
            val pat_rect1 = flat (ListPair.map mk_pat (constructors', pat_rect))
        in (pat_rect1,tree)
        end
     end end
 in mk
 end;
fun FV_multiset tm =
   case (USyntax.dest_term tm)
     of USyntax.VAR{Name = c, Ty = T} => [Free(c, T)]
      | USyntax.CONST _ => []
      | USyntax.COMB{Rator, Rand} => FV_multiset Rator @ FV_multiset Rand
      | USyntax.LAMB _ => raise TFL_ERR "FV_multiset" "lambda";
fun no_repeat_vars thy pat =
 let fun check [] = true
       | check (v::rst) =
         if member (op aconv) rst v then
            raise TFL_ERR "no_repeat_vars"
                          (quote (#1 (dest_Free v)) ^
                          " occurs repeatedly in the pattern " ^
                          quote (Syntax.string_of_term_global thy pat))
         else check rst
 in check (FV_multiset pat)
 end;
fun dest_atom (Free p) = p
  | dest_atom (Const p) = p
  | dest_atom  _ = raise TFL_ERR "dest_atom" "function name not an identifier";
fun same_name (p,q) = #1(dest_atom p) = #1(dest_atom q);
local fun mk_functional_err s = raise TFL_ERR "mk_functional" s
      fun single [_$_] =
              mk_functional_err "recdef does not allow currying"
        | single [f] = f
        | single fs  =
              
              if length (distinct same_name fs) < length fs
              then mk_functional_err
                   "The function being declared appears with multiple types"
              else mk_functional_err
                   (string_of_int (length fs) ^
                    " distinct function names being declared")
in
fun mk_functional thy clauses =
 let val (L,R) = ListPair.unzip (map HOLogic.dest_eq clauses
                   handle TERM _ => raise TFL_ERR "mk_functional"
                        "recursion equations must use the = relation")
     val (funcs,pats) = ListPair.unzip (map (fn (t$u) =>(t,u)) L)
     val atom = single (distinct (op aconv) funcs)
     val (fname,ftype) = dest_atom atom
     val _ = map (no_repeat_vars thy) pats
     val rows = ListPair.zip (map (fn x => ([]:term list,[x])) pats,
                              map_index (fn (i, t) => (t,(i,true))) R)
     val names = List.foldr Misc_Legacy.add_term_names [] R
     val atype = type_of(hd pats)
     and aname = singleton (Name.variant_list names) "a"
     val a = Free(aname,atype)
     val ty_info = Thry.match_info thy
     val ty_match = Thry.match_type thy
     val range_ty = type_of (hd R)
     val (patts, case_tm) = mk_case ty_info ty_match (aname::names) range_ty
                                    {path=[a], rows=rows}
     val patts1 = map (fn (_,tag,[pat]) => (pat,tag)) patts
          handle Match => mk_functional_err "error in pattern-match translation"
     val patts2 = Library.sort (Library.int_ord o apply2 row_of_pat) patts1
     val finals = map row_of_pat patts2
     val originals = map (row_of_pat o #2) rows
     val _ = case (subtract (op =) finals originals)
             of [] => ()
          | L => mk_functional_err
 ("The following clauses are redundant (covered by preceding clauses): " ^
                   commas (map (fn i => string_of_int (i + 1)) L))
 in {functional = Abs(Long_Name.base_name fname, ftype,
                      abstract_over (atom, absfree (aname,atype) case_tm)),
     pats = patts2}
end end;
fun const_def sign (c, Ty, rhs) =
  singleton (Syntax.check_terms (Proof_Context.init_global sign))
    (Const(\<^const_name>‹Pure.eq›,dummyT) $ Const(c,Ty) $ rhs);
fun poly_tvars (Type(a,Ts)) = Type(a, map (poly_tvars) Ts)
  | poly_tvars (TFree (a,sort)) = TVar (("?" ^ a, 0), sort)
  | poly_tvars (TVar ((a,i),sort)) = TVar (("?" ^ a, i+1), sort);
local
  val f_eq_wfrec_R_M =
    #ant(USyntax.dest_imp(#2(USyntax.strip_forall (concl @{thm tfl_wfrec}))))
  val {lhs=f, rhs} = USyntax.dest_eq f_eq_wfrec_R_M
  val _ = dest_Free f
  val (wfrec,_) = USyntax.strip_comb rhs
in
fun wfrec_definition0 fid R (functional as Abs(x, Ty, _)) thy =
  let
    val def_name = Thm.def_name (Long_Name.base_name fid)
    val wfrec_R_M = map_types poly_tvars (wfrec $ map_types poly_tvars R) $ functional
    val def_term = const_def thy (fid, Ty, wfrec_R_M)
    val (def, thy') = Global_Theory.add_def (Binding.name def_name, def_term) thy
  in (def, thy') end;
end;
fun extraction_thms thy =
 let val {case_rewrites,case_congs} = Thry.extract_info thy
 in (case_rewrites, case_congs)
 end;
fun merge full_pats TCs =
let fun insert (p,TCs) =
      let fun insrt ((x as (h,[]))::rst) =
                 if (p aconv h) then (p,TCs)::rst else x::insrt rst
            | insrt (x::rst) = x::insrt rst
            | insrt[] = raise TFL_ERR "merge.insert" "pattern not found"
      in insrt end
    fun pass ([],ptcl_final) = ptcl_final
      | pass (ptcs::tcl, ptcl) = pass(tcl, insert ptcs ptcl)
in
  pass (TCs, map (fn p => (p,[])) full_pats)
end;
fun post_definition ctxt meta_tflCongs (def, pats) =
 let val thy = Proof_Context.theory_of ctxt
     val tych = Thry.typecheck thy
     val f = #lhs(USyntax.dest_eq(concl def))
     val corollary = Rules.MATCH_MP @{thm tfl_wfrec} def
     val pats' = filter given pats
     val given_pats = map pat_of pats'
     val rows = map row_of_pat pats'
     val WFR = #ant(USyntax.dest_imp(concl corollary))
     val R = #Rand(USyntax.dest_comb WFR)
     val corollary' = Rules.UNDISCH corollary  
     val corollaries = map (fn pat => Rules.SPEC (tych pat) corollary') given_pats
     val (case_rewrites,context_congs) = extraction_thms thy
     
     val case_simpset =
       put_simpset HOL_basic_ss ctxt
          addsimps case_rewrites
          |> fold (Simplifier.add_cong o #case_cong_weak o snd)
              (Symtab.dest (BNF_LFP_Compat.get_all thy [BNF_LFP_Compat.Keep_Nesting]))
     val corollaries' = map (Simplifier.simplify case_simpset) corollaries
     val extract =
      Rules.CONTEXT_REWRITE_RULE ctxt (f, [R], @{thm cut_apply}, meta_tflCongs @ context_congs)
     val (rules, TCs) = ListPair.unzip (map extract corollaries')
     val rules0 = map (rewrite_rule ctxt @{thms tfl_cut_def}) rules
     val mk_cond_rule = Rules.FILTER_DISCH_ALL(not o curry (op aconv) WFR)
     val rules1 = Rules.LIST_CONJ(map mk_cond_rule rules0)
 in
 {rules = rules1,
  rows = rows,
  full_pats_TCs = merge (map pat_of pats) (ListPair.zip (given_pats, TCs)),
  TCs = TCs}
 end;
fun alpha_ex_unroll (xlist, tm) =
  let val (qvars,body) = USyntax.strip_exists tm
      val vlist = #2 (USyntax.strip_comb (USyntax.rhs body))
      val plist = ListPair.zip (vlist, xlist)
      val args = map (the o AList.lookup (op aconv) plist) qvars
                   handle Option.Option => raise Fail "TFL.alpha_ex_unroll: no correspondence"
      fun build ex      []   = []
        | build (_$rex) (v::rst) =
           let val ex1 = Term.betapply(rex, v)
           in  ex1 :: build ex1 rst
           end
     val (nex::exl) = rev (tm::build tm args)
  in
  (nex, ListPair.zip (args, rev exl))
  end;
fun mk_case ctxt ty_info usednames =
 let
 val thy = Proof_Context.theory_of ctxt
 val divide = ipartition (gvvariant usednames)
 val tych = Thry.typecheck thy
 fun tych_binding(x,y) = (tych x, tych y)
 fun fail s = raise TFL_ERR "mk_case" s
 fun mk{rows=[],...} = fail"no rows"
   | mk{path=[], rows = [([], (thm, bindings))]} =
                         Rules.IT_EXISTS ctxt (map tych_binding bindings) thm
   | mk{path = u::rstp, rows as (p::_, _)::_} =
     let val (pat_rectangle,rights) = ListPair.unzip rows
         val col0 = map hd pat_rectangle
         val pat_rectangle' = map tl pat_rectangle
     in
     if (forall is_Free col0) 
     then let val rights' = map (fn ((thm,theta),v) => (thm,theta@[(u,v)]))
                                (ListPair.zip (rights, col0))
          in mk{path = rstp, rows = ListPair.zip (pat_rectangle', rights')}
          end
     else                     
     let val Type (ty_name,_) = type_of p
     in
     case (ty_info ty_name)
     of NONE => fail("Not a known datatype: "^ty_name)
      | SOME{constructors,nchotomy} =>
        let val thm' = Rules.ISPEC (tych u) nchotomy
            val disjuncts = USyntax.strip_disj (concl thm')
            val subproblems = divide(constructors, rows)
            val groups      = map #group subproblems
            and new_formals = map #new_formals subproblems
            val existentials = ListPair.map alpha_ex_unroll
                                   (new_formals, disjuncts)
            val constraints = map #1 existentials
            val vexl = map #2 existentials
            fun expnd tm (pats,(th,b)) = (pats, (Rules.SUBS ctxt [Rules.ASSUME (tych tm)] th, b))
            val news = map (fn (nf,rows,c) => {path = nf@rstp,
                                               rows = map (expnd c) rows})
                           (Utils.zip3 new_formals groups constraints)
            val recursive_thms = map mk news
            val build_exists = Library.foldr
                                (fn((x,t), th) =>
                                 Rules.CHOOSE ctxt (tych x, Rules.ASSUME (tych t)) th)
            val thms' = ListPair.map build_exists (vexl, recursive_thms)
            val same_concls = Rules.EVEN_ORS thms'
        in Rules.DISJ_CASESL thm' same_concls
        end
     end end
 in mk
 end;
fun complete_cases ctxt =
 let val thy = Proof_Context.theory_of ctxt
     val tych = Thry.typecheck thy
     val ty_info = Thry.induct_info thy
 in fn pats =>
 let val names = List.foldr Misc_Legacy.add_term_names [] pats
     val T = type_of (hd pats)
     val aname = singleton (Name.variant_list names) "a"
     val vname = singleton (Name.variant_list (aname::names)) "v"
     val a = Free (aname, T)
     val v = Free (vname, T)
     val a_eq_v = HOLogic.mk_eq(a,v)
     val ex_th0 = Rules.EXISTS ctxt (tych (USyntax.mk_exists{Bvar=v,Body=a_eq_v}), tych a)
                           (Rules.REFL (tych a))
     val th0 = Rules.ASSUME (tych a_eq_v)
     val rows = map (fn x => ([x], (th0,[]))) pats
 in
 Rules.GEN ctxt (tych a)
       (Rules.RIGHT_ASSOC ctxt
          (Rules.CHOOSE ctxt (tych v, ex_th0)
                (mk_case ctxt ty_info (vname::aname::names)
                 {path=[v], rows=rows})))
 end end;
local infix 5 ==>
      fun (tm1 ==> tm2) = USyntax.mk_imp{ant = tm1, conseq = tm2}
in
fun build_ih f (P,SV) (pat,TCs) =
 let val pat_vars = USyntax.free_vars_lr pat
     val globals = pat_vars@SV
     fun nested tm = is_some (USyntax.find_term (curry (op aconv) f) tm)
     fun dest_TC tm =
         let val (cntxt,R_y_pat) = USyntax.strip_imp(#2(USyntax.strip_forall tm))
             val (R,y,_) = USyntax.dest_relation R_y_pat
             val P_y = if (nested tm) then R_y_pat ==> P$y else P$y
         in case cntxt
              of [] => (P_y, (tm,[]))
               | _  => let
                    val imp = USyntax.list_mk_conj cntxt ==> P_y
                    val lvs = subtract (op aconv) globals (USyntax.free_vars_lr imp)
                    val locals = #2(Utils.pluck (curry (op aconv) P) lvs) handle Utils.ERR _ => lvs
                    in (USyntax.list_mk_forall(locals,imp), (tm,locals)) end
         end
 in case TCs
    of [] => (USyntax.list_mk_forall(pat_vars, P$pat), [])
     |  _ => let val (ihs, TCs_locals) = ListPair.unzip(map dest_TC TCs)
                 val ind_clause = USyntax.list_mk_conj ihs ==> P$pat
             in (USyntax.list_mk_forall(pat_vars,ind_clause), TCs_locals)
             end
 end
end;
fun prove_case ctxt f (tm,TCs_locals,thm) =
 let val tych = Thry.typecheck (Proof_Context.theory_of ctxt)
     val antc = tych(#ant(USyntax.dest_imp tm))
     val thm' = Rules.SPEC_ALL thm
     fun nested tm = is_some (USyntax.find_term (curry (op aconv) f) tm)
     fun get_cntxt TC = tych(#ant(USyntax.dest_imp(#2(USyntax.strip_forall(concl TC)))))
     fun mk_ih ((TC,locals),th2,nested) =
         Rules.GENL ctxt (map tych locals)
            (if nested then Rules.DISCH (get_cntxt TC) th2 handle Utils.ERR _ => th2
             else if USyntax.is_imp (concl TC) then Rules.IMP_TRANS TC th2
             else Rules.MP th2 TC)
 in
 Rules.DISCH antc
 (if USyntax.is_imp(concl thm') 
  then let val th1 = Rules.ASSUME antc
           val TCs = map #1 TCs_locals
           val ylist = map (#2 o USyntax.dest_relation o #2 o USyntax.strip_imp o
                            #2 o USyntax.strip_forall) TCs
           val TClist = map (fn(TC,lvs) => (Rules.SPEC_ALL(Rules.ASSUME(tych TC)),lvs))
                            TCs_locals
           val th2list = map (fn t => Rules.SPEC (tych t) th1) ylist
           val nlist = map nested TCs
           val triples = Utils.zip3 TClist th2list nlist
           val Pylist = map mk_ih triples
       in Rules.MP thm' (Rules.LIST_CONJ Pylist) end
  else thm')
 end;
fun LEFT_ABS_VSTRUCT ctxt tych thm =
  let fun CHOOSER v (tm,thm) =
        let val ex_tm = USyntax.mk_exists{Bvar=v,Body=tm}
        in (ex_tm, Rules.CHOOSE ctxt (tych v, Rules.ASSUME (tych ex_tm)) thm)
        end
      val [veq] = filter (can USyntax.dest_eq) (#1 (Rules.dest_thm thm))
      val {lhs,rhs} = USyntax.dest_eq veq
      val L = USyntax.free_vars_lr rhs
  in  #2 (fold_rev CHOOSER L (veq,thm))  end;
fun mk_induction ctxt {fconst, R, SV, pat_TCs_list} =
let
    val thy = Proof_Context.theory_of ctxt
    val tych = Thry.typecheck thy
    val Sinduction = Rules.UNDISCH (Rules.ISPEC (tych R) @{thm tfl_wf_induct})
    val (pats,TCsl) = ListPair.unzip pat_TCs_list
    val case_thm = complete_cases ctxt pats
    val domain = (type_of o hd) pats
    val Pname = singleton (Name.variant_list (List.foldr (Library.foldr Misc_Legacy.add_term_names)
                              [] (pats::TCsl))) "P"
    val P = Free(Pname, domain --> HOLogic.boolT)
    val Sinduct = Rules.SPEC (tych P) Sinduction
    val Sinduct_assumf = USyntax.rand ((#ant o USyntax.dest_imp o concl) Sinduct)
    val Rassums_TCl' = map (build_ih fconst (P,SV)) pat_TCs_list
    val (Rassums,TCl') = ListPair.unzip Rassums_TCl'
    val Rinduct_assum = Rules.ASSUME (tych (USyntax.list_mk_conj Rassums))
    val cases = map (fn pat => Term.betapply (Sinduct_assumf, pat)) pats
    val tasks = Utils.zip3 cases TCl' (Rules.CONJUNCTS Rinduct_assum)
    val proved_cases = map (prove_case ctxt fconst) tasks
    val v =
      Free (singleton
        (Name.variant_list (List.foldr Misc_Legacy.add_term_names [] (map concl proved_cases))) "v",
          domain)
    val vtyped = tych v
    val substs = map (Rules.SYM o Rules.ASSUME o tych o (curry HOLogic.mk_eq v)) pats
    val proved_cases1 = ListPair.map (fn (th,th') => Rules.SUBS ctxt [th]th')
                          (substs, proved_cases)
    val abs_cases = map (LEFT_ABS_VSTRUCT ctxt tych) proved_cases1
    val dant = Rules.GEN ctxt vtyped (Rules.DISJ_CASESL (Rules.ISPEC vtyped case_thm) abs_cases)
    val dc = Rules.MP Sinduct dant
    val Parg_ty = type_of(#Bvar(USyntax.dest_forall(concl dc)))
    val vars = map (gvvariant[Pname]) (USyntax.strip_prod_type Parg_ty)
    val dc' = fold_rev (Rules.GEN ctxt o tych) vars
                       (Rules.SPEC (tych(USyntax.mk_vstruct Parg_ty vars)) dc)
in
   Rules.GEN ctxt (tych P) (Rules.DISCH (tych(concl Rinduct_assum)) dc')
end
handle Utils.ERR _ => raise TFL_ERR "mk_induction" "failed derivation";
fun simplify_induction thy hth ind =
  let val tych = Thry.typecheck thy
      val (asl,_) = Rules.dest_thm ind
      val (_,tc_eq_tc') = Rules.dest_thm hth
      val tc = USyntax.lhs tc_eq_tc'
      fun loop [] = ind
        | loop (asm::rst) =
          if (can (Thry.match_term thy asm) tc)
          then Rules.UNDISCH
                 (Rules.MATCH_MP
                     (Rules.MATCH_MP @{thm tfl_simp_thm} (Rules.DISCH (tych asm) ind))
                     hth)
         else loop rst
  in loop asl
end;
fun elim_tc tcthm (rule,induction) =
   (Rules.MP rule tcthm, Rules.PROVE_HYP tcthm induction)
fun trace_thms ctxt s L =
  if !trace then writeln (cat_lines (s :: map (Thm.string_of_thm ctxt) L))
  else ();
fun trace_cterm ctxt s ct =
  if !trace then
    writeln (cat_lines [s, Syntax.string_of_term ctxt (Thm.term_of ct)])
  else ();
fun postprocess ctxt strict {wf_tac, terminator, simplifier} {rules,induction,TCs} =
  let
    val thy = Proof_Context.theory_of ctxt;
    val tych = Thry.typecheck thy;
   
    val ((rules1, induction1), ctxt') =
      let
        val thm =
          Rules.prove ctxt strict (HOLogic.mk_Trueprop (hd(#1(Rules.dest_thm rules)))) wf_tac
        val ctxt' = Variable.declare_thm thm ctxt
      in ((Rules.PROVE_HYP thm rules, Rules.PROVE_HYP thm induction), ctxt')
      end handle Utils.ERR _ => ((rules, induction), ctxt);
   
   fun simplify_tc tc (r,ind) =
       let val tc1 = tych tc
           val _ = trace_cterm ctxt' "TC before simplification: " tc1
           val tc_eq = simplifier ctxt' tc1
           val _ = trace_thms ctxt' "result: " [tc_eq]
       in
       elim_tc (Rules.MATCH_MP @{thm tfl_eq_True} tc_eq) (r,ind)
       handle Utils.ERR _ =>
        (elim_tc (Rules.MATCH_MP(Rules.MATCH_MP @{thm tfl_rev_eq_mp} tc_eq)
                  (Rules.prove ctxt' strict (HOLogic.mk_Trueprop(USyntax.rhs(concl tc_eq)))
                           terminator))
                 (r,ind)
         handle Utils.ERR _ =>
          (Rules.UNDISCH(Rules.MATCH_MP (Rules.MATCH_MP @{thm tfl_simp_thm} r) tc_eq),
           simplify_induction thy tc_eq ind))
       end
   
   fun simplify_nested_tc tc =
      let val tc_eq = simplifier ctxt' (tych (#2 (USyntax.strip_forall tc)))
      in
      Rules.GEN_ALL ctxt'
       (Rules.MATCH_MP @{thm tfl_eq_True} tc_eq
        handle Utils.ERR _ =>
          (Rules.MATCH_MP(Rules.MATCH_MP @{thm tfl_rev_eq_mp} tc_eq)
                      (Rules.prove ctxt' strict (HOLogic.mk_Trueprop (USyntax.rhs(concl tc_eq)))
                               terminator)
            handle Utils.ERR _ => tc_eq))
      end
   
   fun strip_imp tm = if USyntax.is_neg tm then ([],tm) else USyntax.strip_imp tm
   fun loop ([],extras,R,ind) = (rev R, ind, extras)
     | loop ((r,ftcs)::rst, nthms, R, ind) =
        let val tcs = #1(strip_imp (concl r))
            val extra_tcs = subtract (op aconv) tcs ftcs
            val extra_tc_thms = map simplify_nested_tc extra_tcs
            val (r1,ind1) = fold simplify_tc tcs (r,ind)
            val r2 = Rules.FILTER_DISCH_ALL(not o USyntax.is_WFR) r1
        in loop(rst, nthms@extra_tc_thms, r2::R, ind1)
        end
   val rules_tcs = ListPair.zip (Rules.CONJUNCTS rules1, TCs)
   val (rules2,ind2,extras) = loop(rules_tcs,[],[],induction1)
in
  {induction = ind2, rules = Rules.LIST_CONJ rules2, nested_tcs = extras}
end;
end;
structure Tfl: TFL =
struct
fun termination_goals rules =
    map (Type.legacy_freeze o HOLogic.dest_Trueprop)
      (fold_rev (union (op aconv) o Thm.prems_of) rules []);
fun std_postprocessor ctxt strict wfs =
  Prim.postprocess ctxt strict
   {wf_tac = fn ctxt' => REPEAT (ares_tac ctxt' wfs 1),
    terminator = fn ctxt' =>
      asm_simp_tac ctxt' 1
      THEN TRY (Arith_Data.arith_tac ctxt' 1 ORELSE
        fast_force_tac (ctxt' addSDs @{thms not0_implies_Suc}) 1),
    simplifier = fn ctxt' => Rules.simpl_conv ctxt' []};
val concl = #2 o Rules.dest_thm;
local
val solved = not o can USyntax.dest_eq o #2 o USyntax.strip_forall o concl
fun id_thm th =
   let val {lhs,rhs} = USyntax.dest_eq (#2 (USyntax.strip_forall (#2 (Rules.dest_thm th))));
   in lhs aconv rhs end
   handle Utils.ERR _ => false;
val P_imp_P_eq_True = @{thm eqTrueI} RS eq_reflection;
fun mk_meta_eq r =
  (case Thm.concl_of r of
     Const(\<^const_name>‹Pure.eq›,_)$_$_ => r
  |   _ $(Const(\<^const_name>‹HOL.eq›,_)$_$_) => r RS eq_reflection
  |   _ => r RS P_imp_P_eq_True)
fun rewrite ctxt L = rewrite_rule ctxt (map mk_meta_eq (filter_out id_thm L))
fun join_assums ctxt th =
  let val tych = Thm.cterm_of ctxt
      val {lhs,rhs} = USyntax.dest_eq(#2 (USyntax.strip_forall (concl th)))
      val cntxtl = (#1 o USyntax.strip_imp) lhs  
      val cntxtr = (#1 o USyntax.strip_imp) rhs  
      val cntxt = union (op aconv) cntxtl cntxtr
  in
    Rules.GEN_ALL ctxt
      (Rules.DISCH_ALL
         (rewrite ctxt (map (Rules.ASSUME o tych) cntxt) (Rules.SPEC_ALL th)))
  end
  val gen_all = USyntax.gen_all
in
fun proof_stage ctxt strict wfs {f, R, rules, full_pats_TCs, TCs} =
  let
    val _ = writeln "Proving induction theorem ..."
    val ind =
      Prim.mk_induction ctxt
        {fconst=f, R=R, SV=[], pat_TCs_list=full_pats_TCs}
    val _ = writeln "Postprocessing ...";
    val {rules, induction, nested_tcs} =
      std_postprocessor ctxt strict wfs {rules=rules, induction=ind, TCs=TCs}
  in
  case nested_tcs
  of [] => {induction=induction, rules=rules,tcs=[]}
  | L  => let val _ = writeln "Simplifying nested TCs ..."
              val (solved,simplified,stubborn) =
               fold_rev (fn th => fn (So,Si,St) =>
                     if (id_thm th) then (So, Si, th::St) else
                     if (solved th) then (th::So, Si, St)
                     else (So, th::Si, St)) nested_tcs ([],[],[])
              val simplified' = map (join_assums ctxt) simplified
              val dummy = (Prim.trace_thms ctxt "solved =" solved;
                           Prim.trace_thms ctxt "simplified' =" simplified')
              fun rewr th =
                full_simplify (Variable.declare_thm th ctxt addsimps (solved @ simplified')) th;
              val dummy = Prim.trace_thms ctxt "Simplifying the induction rule..." [induction]
              val induction' = rewr induction
              val dummy = Prim.trace_thms ctxt "Simplifying the recursion rules..." [rules]
              val rules'     = rewr rules
              val _ = writeln "... Postprocessing finished";
          in
          {induction = induction',
               rules = rules',
                 tcs = map (gen_all o USyntax.rhs o #2 o USyntax.strip_forall o concl)
                           (simplified@stubborn)}
          end
  end;
fun curry_rule ctxt rl =
  Split_Rule.split_rule_var ctxt (Term.head_of (HOLogic.dest_Trueprop (Thm.concl_of rl))) rl;
fun meta_outer ctxt =
  curry_rule ctxt o Drule.export_without_context o
  rule_by_tactic ctxt
    (REPEAT (FIRSTGOAL (resolve_tac ctxt [allI, impI, conjI] ORELSE' eresolve_tac ctxt [conjE])));
val spec'=
  Rule_Insts.read_instantiate \<^context> [((("x", 0), Position.none), "P::'b=>bool")] [] spec;
fun rulify_no_asm ctxt th =
  Object_Logic.rulify_no_asm (Variable.declare_thm th ctxt) th;
fun simplify_defn ctxt strict congs wfs pats def0 =
  let
    val thy = Proof_Context.theory_of ctxt;
    val def = HOLogic.mk_obj_eq (Thm.unvarify_global thy def0)
    val {rules, rows, TCs, full_pats_TCs} = Prim.post_definition ctxt congs (def, pats)
    val {lhs=f,rhs} = USyntax.dest_eq (concl def)
    val (_,[R,_]) = USyntax.strip_comb rhs
    val _ = Prim.trace_thms ctxt "congs =" congs
    
    val {induction, rules, tcs} =
      proof_stage ctxt strict wfs
       {f = f, R = R, rules = rules,
        full_pats_TCs = full_pats_TCs,
        TCs = TCs}
    val rules' = map (Drule.export_without_context o rulify_no_asm ctxt) (Rules.CONJUNCTS rules)
  in
    {induct = meta_outer ctxt (rulify_no_asm ctxt (induction RS spec')),
     rules = ListPair.zip(rules', rows),
     tcs = (termination_goals rules') @ tcs}
  end
  handle Utils.ERR {mesg,func,module} =>
    error (mesg ^ "\n    (In TFL function " ^ module ^ "." ^ func ^ ")");
local
  fun get_related_thms i =
      map_filter ((fn (r,x) => if x = i then SOME r else NONE));
  fun solve_eq _ (_, [], _) =  error "derive_init_eqs: missing rules"
    | solve_eq _ (_, [a], i) = [(a, i)]
    | solve_eq ctxt (th, splitths, i) =
      (writeln "Proving unsplit equation...";
      [((Drule.export_without_context o rulify_no_asm ctxt)
          (CaseSplit.splitto ctxt splitths th), i)])
      handle ERROR s =>
             (warning ("recdef (solve_eq): " ^ s); map (fn x => (x,i)) splitths);
in
fun derive_init_eqs ctxt rules eqs =
  map (Thm.trivial o Thm.cterm_of ctxt o HOLogic.mk_Trueprop) eqs
  |> map_index (fn (i, e) => solve_eq ctxt (e, (get_related_thms i rules), i))
  |> flat;
end;
fun define_i strict congs wfs fid R eqs ctxt =
  let
    val thy = Proof_Context.theory_of ctxt
    val {functional, pats} = Prim.mk_functional thy eqs
    val (def, thy') = Prim.wfrec_definition0 fid R functional thy
    val ctxt' = Proof_Context.transfer thy' ctxt
    val (lhs, _) = Logic.dest_equals (Thm.prop_of def)
    val {induct, rules, tcs} = simplify_defn ctxt' strict congs wfs pats def
    val rules' = if strict then derive_init_eqs ctxt' rules eqs else rules
  in ({lhs = lhs, rules = rules', induct = induct, tcs = tcs}, ctxt') end;
fun define strict congs wfs fid R seqs ctxt =
  define_i strict congs wfs fid
    (Syntax.read_term ctxt R) (map (Syntax.read_term ctxt) seqs) ctxt
      handle Utils.ERR {mesg,...} => error mesg;
end;
end;
type hints = {simps: thm list, congs: (string * thm) list, wfs: thm list};
fun mk_hints (simps, congs, wfs) = {simps = simps, congs = congs, wfs = wfs}: hints;
fun map_hints f ({simps, congs, wfs}: hints) = mk_hints (f (simps, congs, wfs));
fun map_simps f = map_hints (fn (simps, congs, wfs) => (f simps, congs, wfs));
fun map_congs f = map_hints (fn (simps, congs, wfs) => (simps, f congs, wfs));
fun map_wfs f = map_hints (fn (simps, congs, wfs) => (simps, congs, f wfs));
local
val cong_head =
  dest_Const_name o Term.head_of o fst o Logic.dest_equals o Thm.concl_of;
fun prep_cong raw_thm =
  let val thm = safe_mk_meta_eq raw_thm in (cong_head thm, thm) end;
in
fun add_cong raw_thm congs =
  let
    val (c, thm) = prep_cong raw_thm;
    val _ = if AList.defined (op =) congs c
      then warning ("Overwriting recdef congruence rule for " ^ quote c)
      else ();
  in AList.update (op =) (c, thm) congs end;
fun del_cong raw_thm congs =
  let
    val (c, _) = prep_cong raw_thm;
    val _ = if AList.defined (op =) congs c
      then ()
      else warning ("No recdef congruence rule for " ^ quote c);
  in AList.delete (op =) c congs end;
end;
type recdef_info = {lhs: term, simps: thm list, rules: thm list list, induct: thm, tcs: term list};
structure Data = Generic_Data
(
  type T = recdef_info Symtab.table * hints;
  val empty = (Symtab.empty, mk_hints ([], [], [])): T;
  fun merge
   ((tab1, {simps = simps1, congs = congs1, wfs = wfs1}),
    (tab2, {simps = simps2, congs = congs2, wfs = wfs2})) : T =
      (Symtab.merge (K true) (tab1, tab2),
        mk_hints (Thm.merge_thms (simps1, simps2),
          AList.merge (op =) (K true) (congs1, congs2),
          Thm.merge_thms (wfs1, wfs2)));
);
val get_recdef = Symtab.lookup o #1 o Data.get o Context.Theory;
fun put_recdef name info =
  (Context.theory_map o Data.map o apfst) (fn tab =>
    Symtab.update_new (name, info) tab
      handle Symtab.DUP _ => error ("Duplicate recursive function definition " ^ quote name));
val get_hints = #2 o Data.get o Context.Proof;
val map_hints = Data.map o apsnd;
fun attrib f = Thm.declaration_attribute (map_hints o f);
val simp_add = attrib (map_simps o Thm.add_thm);
val simp_del = attrib (map_simps o Thm.del_thm);
val cong_add = attrib (map_congs o add_cong);
val cong_del = attrib (map_congs o del_cong);
val wf_add = attrib (map_wfs o Thm.add_thm);
val wf_del = attrib (map_wfs o Thm.del_thm);
val recdef_simpN = "recdef_simp";
val recdef_congN = "recdef_cong";
val recdef_wfN = "recdef_wf";
val recdef_modifiers =
 [Args.$$$ recdef_simpN -- Args.colon >> K (Method.modifier simp_add ⌂),
  Args.$$$ recdef_simpN -- Args.add -- Args.colon >> K (Method.modifier simp_add ⌂),
  Args.$$$ recdef_simpN -- Args.del -- Args.colon >> K (Method.modifier simp_del ⌂),
  Args.$$$ recdef_congN -- Args.colon >> K (Method.modifier cong_add ⌂),
  Args.$$$ recdef_congN -- Args.add -- Args.colon >> K (Method.modifier cong_add ⌂),
  Args.$$$ recdef_congN -- Args.del -- Args.colon >> K (Method.modifier cong_del ⌂),
  Args.$$$ recdef_wfN -- Args.colon >> K (Method.modifier wf_add ⌂),
  Args.$$$ recdef_wfN -- Args.add -- Args.colon >> K (Method.modifier wf_add ⌂),
  Args.$$$ recdef_wfN -- Args.del -- Args.colon >> K (Method.modifier wf_del ⌂)] @
  Clasimp.clasimp_modifiers;
fun prepare_hints opt_src ctxt =
  let
    val ctxt' =
      (case opt_src of
        NONE => ctxt
      | SOME src => #2 (Token.syntax (Method.sections recdef_modifiers) src ctxt));
    val {simps, congs, wfs} = get_hints ctxt';
    val ctxt'' = ctxt' addsimps simps |> Simplifier.del_cong @{thm imp_cong};
  in ((rev (map snd congs), wfs), ctxt'') end;
fun prepare_hints_i () ctxt =
  let
    val {simps, congs, wfs} = get_hints ctxt;
    val ctxt' = ctxt addsimps simps |> Simplifier.del_cong @{thm imp_cong};
  in ((rev (map snd congs), wfs), ctxt') end;
fun gen_add_recdef tfl_fn prep_att prep_hints not_permissive raw_name R eq_srcs hints thy =
  let
    val _ = legacy_feature "Old 'recdef' command -- use 'fun' or 'function' instead";
    val name = Sign.intern_const thy raw_name;
    val bname = Long_Name.base_name name;
    val _ = writeln ("Defining recursive function " ^ quote name ^ " ...");
    val ((eq_names, eqs), raw_eq_atts) = apfst split_list (split_list eq_srcs);
    val eq_atts = map (map (prep_att thy)) raw_eq_atts;
    val ((congs, wfs), ctxt) = prep_hints hints (Proof_Context.init_global thy);
    
    val ({lhs, rules = rules_idx, induct, tcs}, ctxt1) =
      tfl_fn not_permissive congs wfs name R eqs ctxt;
    val rules = (map o map) fst (partition_eq (eq_snd (op = : int * int -> bool)) rules_idx);
    val simp_att =
      if null tcs then [Simplifier.simp_add,
        Named_Theorems.add \<^named_theorems>‹nitpick_simp›]
      else [];
    val ((simps' :: rules', [induct']), thy2) =
      Proof_Context.theory_of ctxt1
      |> Sign.add_path bname
      |> Global_Theory.add_thmss
        (((Binding.name "simps", flat rules), simp_att) :: ((eq_names ~~ rules) ~~ eq_atts))
      ||>> Global_Theory.add_thms [((Binding.name "induct", induct), [])]
      ||> Spec_Rules.add_global (Binding.name bname) Spec_Rules.equational_recdef [lhs] (flat rules)
      ||> null tcs ? Code.declare_default_eqns_global (map (rpair true) (flat rules));
    val result = {lhs = lhs, simps = simps', rules = rules', induct = induct', tcs = tcs};
    val thy3 =
      thy2
      |> put_recdef name result
      |> Sign.parent_path;
  in (thy3, result) end;
val add_recdef = gen_add_recdef Tfl.define Attrib.attribute_cmd_global prepare_hints;
fun add_recdef_i x y z w = gen_add_recdef Tfl.define_i (K I) prepare_hints_i x y z w ();
val _ =
  Theory.setup
   (Attrib.setup \<^binding>‹recdef_simp› (Attrib.add_del simp_add simp_del)
      "declaration of recdef simp rule" #>
    Attrib.setup \<^binding>‹recdef_cong› (Attrib.add_del cong_add cong_del)
      "declaration of recdef cong rule" #>
    Attrib.setup \<^binding>‹recdef_wf› (Attrib.add_del wf_add wf_del)
      "declaration of recdef wf rule");
val hints =
  \<^keyword>‹(› |--
    Parse.!!! ((Parse.token \<^keyword>‹hints› ::: Parse.args) --| \<^keyword>‹)›);
val recdef_decl =
  Scan.optional
    (\<^keyword>‹(› -- Parse.!!! (\<^keyword>‹permissive› -- \<^keyword>‹)›) >> K false) true --
  Parse.name -- Parse.term -- Scan.repeat1 (Parse_Spec.opt_thm_name ":" -- Parse.prop)
    -- Scan.option hints
  >> (fn ((((p, f), R), eqs), src) =>
      #1 o add_recdef p f R (map (fn ((x, y), z) => ((x, z), y)) eqs) src);
val _ =
  Outer_Syntax.command \<^command_keyword>‹recdef› "define general recursive functions (obsolete TFL)"
    (recdef_decl >> Toplevel.theory);
end;