src/HOL/Tools/inductive_package.ML
author wenzelm
Wed Jun 18 18:55:00 2008 +0200 (2008-06-18)
changeset 27252 042aebff17e1
parent 26988 742e26213212
child 27353 71c4dd53d4cb
permissions -rw-r--r--
OldGoals.read_prop;
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(*  Title:      HOL/Tools/inductive_package.ML
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    ID:         $Id$
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    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
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    Author:     Stefan Berghofer and Markus Wenzel, TU Muenchen
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(Co)Inductive Definition module for HOL.
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Features:
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  * least or greatest fixedpoints
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  * mutually recursive definitions
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  * definitions involving arbitrary monotone operators
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  * automatically proves introduction and elimination rules
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  Introduction rules have the form
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  [| M Pj ti, ..., Q x, ... |] ==> Pk t
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  where M is some monotone operator (usually the identity)
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  Q x is any side condition on the free variables
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  ti, t are any terms
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  Pj, Pk are two of the predicates being defined in mutual recursion
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*)
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signature BASIC_INDUCTIVE_PACKAGE =
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sig
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  type inductive_result
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  val morph_result: morphism -> inductive_result -> inductive_result
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  type inductive_info
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  val the_inductive: Proof.context -> string -> inductive_info
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  val print_inductives: Proof.context -> unit
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  val mono_add: attribute
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  val mono_del: attribute
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  val get_monos: Proof.context -> thm list
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  val mk_cases: Proof.context -> term -> thm
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  val inductive_forall_name: string
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  val inductive_forall_def: thm
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  val rulify: thm -> thm
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  val inductive_cases: ((bstring * Attrib.src list) * string list) list ->
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    Proof.context -> thm list list * local_theory
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  val inductive_cases_i: ((bstring * Attrib.src list) * term list) list ->
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    Proof.context -> thm list list * local_theory
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  type inductive_flags
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  val add_inductive_i:
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    inductive_flags -> ((string * typ) * mixfix) list ->
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    (string * typ) list -> ((bstring * Attrib.src list) * term) list -> thm list ->
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      local_theory -> inductive_result * local_theory
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  val add_inductive: bool -> bool -> (string * string option * mixfix) list ->
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    (string * string option * mixfix) list ->
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    ((bstring * Attrib.src list) * string) list -> (Facts.ref * Attrib.src list) list ->
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    local_theory -> inductive_result * local_theory
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  val add_inductive_global: string -> inductive_flags ->
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    ((string * typ) * mixfix) list -> (string * typ) list ->
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    ((bstring * Attrib.src list) * term) list -> thm list -> theory -> inductive_result * theory
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  val arities_of: thm -> (string * int) list
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  val params_of: thm -> term list
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  val partition_rules: thm -> thm list -> (string * thm list) list
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  val partition_rules': thm -> (thm * 'a) list -> (string * (thm * 'a) list) list
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  val unpartition_rules: thm list -> (string * 'a list) list -> 'a list
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  val infer_intro_vars: thm -> int -> thm list -> term list list
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  val setup: theory -> theory
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end;
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signature INDUCTIVE_PACKAGE =
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sig
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  include BASIC_INDUCTIVE_PACKAGE
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  type add_ind_def
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  val declare_rules: string -> bstring -> bool -> bool -> string list ->
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    thm list -> bstring list -> Attrib.src list list -> (thm * string list) list ->
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    thm -> local_theory -> thm list * thm list * thm * local_theory
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  val add_ind_def: add_ind_def
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  val gen_add_inductive_i: add_ind_def ->
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    inductive_flags -> ((string * typ) * mixfix) list ->
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    (string * typ) list -> ((bstring * Attrib.src list) * term) list -> thm list ->
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      local_theory -> inductive_result * local_theory
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  val gen_add_inductive: add_ind_def ->
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    bool -> bool -> (string * string option * mixfix) list ->
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    (string * string option * mixfix) list ->
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    ((bstring * Attrib.src list) * string) list -> (Facts.ref * Attrib.src list) list ->
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    local_theory -> inductive_result * local_theory
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  val gen_ind_decl: add_ind_def -> bool ->
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    OuterParse.token list -> (local_theory -> local_theory) * OuterParse.token list
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end;
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structure InductivePackage: INDUCTIVE_PACKAGE =
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struct
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(** theory context references **)
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val inductive_forall_name = "HOL.induct_forall";
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val inductive_forall_def = thm "induct_forall_def";
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val inductive_conj_name = "HOL.induct_conj";
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val inductive_conj_def = thm "induct_conj_def";
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val inductive_conj = thms "induct_conj";
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val inductive_atomize = thms "induct_atomize";
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val inductive_rulify = thms "induct_rulify";
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val inductive_rulify_fallback = thms "induct_rulify_fallback";
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val notTrueE = TrueI RSN (2, notE);
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val notFalseI = Seq.hd (atac 1 notI);
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val simp_thms' = map (fn s => mk_meta_eq (the (find_first
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  (equal (OldGoals.read_prop HOL.thy s) o prop_of) simp_thms)))
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  ["(~True) = False", "(~False) = True",
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   "(True --> ?P) = ?P", "(False --> ?P) = True",
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   "(?P & True) = ?P", "(True & ?P) = ?P"];
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(** context data **)
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type inductive_result =
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  {preds: term list, elims: thm list, raw_induct: thm,
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   induct: thm, intrs: thm list};
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fun morph_result phi {preds, elims, raw_induct: thm, induct, intrs} =
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  let
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    val term = Morphism.term phi;
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    val thm = Morphism.thm phi;
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    val fact = Morphism.fact phi;
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  in
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   {preds = map term preds, elims = fact elims, raw_induct = thm raw_induct,
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    induct = thm induct, intrs = fact intrs}
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  end;
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type inductive_info =
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  {names: string list, coind: bool} * inductive_result;
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structure InductiveData = GenericDataFun
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(
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  type T = inductive_info Symtab.table * thm list;
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  val empty = (Symtab.empty, []);
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  val extend = I;
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  fun merge _ ((tab1, monos1), (tab2, monos2)) =
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    (Symtab.merge (K true) (tab1, tab2), Thm.merge_thms (monos1, monos2));
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);
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val get_inductives = InductiveData.get o Context.Proof;
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fun print_inductives ctxt =
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  let
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    val (tab, monos) = get_inductives ctxt;
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    val space = Consts.space_of (ProofContext.consts_of ctxt);
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  in
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    [Pretty.strs ("(co)inductives:" :: map #1 (NameSpace.extern_table (space, tab))),
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     Pretty.big_list "monotonicity rules:" (map (ProofContext.pretty_thm ctxt) monos)]
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    |> Pretty.chunks |> Pretty.writeln
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  end;
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(* get and put data *)
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fun the_inductive ctxt name =
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  (case Symtab.lookup (#1 (get_inductives ctxt)) name of
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    NONE => error ("Unknown (co)inductive predicate " ^ quote name)
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  | SOME info => info);
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fun put_inductives names info = InductiveData.map
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  (apfst (fold (fn name => Symtab.update (name, info)) names));
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(** monotonicity rules **)
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val get_monos = #2 o get_inductives;
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val map_monos = InductiveData.map o apsnd;
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fun mk_mono thm =
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  let
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    val concl = concl_of thm;
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    fun eq2mono thm' = [thm' RS (thm' RS eq_to_mono)] @
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      (case concl of
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          (_ $ (_ $ (Const ("Not", _) $ _) $ _)) => []
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        | _ => [thm' RS (thm' RS eq_to_mono2)]);
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    fun dest_less_concl thm = dest_less_concl (thm RS le_funD)
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      handle THM _ => thm RS le_boolD
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  in
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    case concl of
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      Const ("==", _) $ _ $ _ => eq2mono (thm RS meta_eq_to_obj_eq)
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    | _ $ (Const ("op =", _) $ _ $ _) => eq2mono thm
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    | _ $ (Const ("HOL.ord_class.less_eq", _) $ _ $ _) =>
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      [dest_less_concl (Seq.hd (REPEAT (FIRSTGOAL
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         (resolve_tac [le_funI, le_boolI'])) thm))]
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    | _ => [thm]
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  end handle THM _ => error ("Bad monotonicity theorem:\n" ^ Display.string_of_thm thm);
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val mono_add = Thm.declaration_attribute (map_monos o fold Thm.add_thm o mk_mono);
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val mono_del = Thm.declaration_attribute (map_monos o fold Thm.del_thm o mk_mono);
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(** misc utilities **)
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fun message quiet_mode s = if quiet_mode then () else writeln s;
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fun clean_message quiet_mode s = if ! quick_and_dirty then () else message quiet_mode s;
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fun coind_prefix true = "co"
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  | coind_prefix false = "";
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fun log (b:int) m n = if m >= n then 0 else 1 + log b (b * m) n;
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fun make_bool_args f g [] i = []
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  | make_bool_args f g (x :: xs) i =
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      (if i mod 2 = 0 then f x else g x) :: make_bool_args f g xs (i div 2);
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fun make_bool_args' xs =
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  make_bool_args (K HOLogic.false_const) (K HOLogic.true_const) xs;
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fun find_arg T x [] = sys_error "find_arg"
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  | find_arg T x ((p as (_, (SOME _, _))) :: ps) =
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      apsnd (cons p) (find_arg T x ps)
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  | find_arg T x ((p as (U, (NONE, y))) :: ps) =
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      if (T: typ) = U then (y, (U, (SOME x, y)) :: ps)
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      else apsnd (cons p) (find_arg T x ps);
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fun make_args Ts xs =
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  map (fn (T, (NONE, ())) => Const ("arbitrary", T) | (_, (SOME t, ())) => t)
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    (fold (fn (t, T) => snd o find_arg T t) xs (map (rpair (NONE, ())) Ts));
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fun make_args' Ts xs Us =
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  fst (fold_map (fn T => find_arg T ()) Us (Ts ~~ map (pair NONE) xs));
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fun dest_predicate cs params t =
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  let
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    val k = length params;
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    val (c, ts) = strip_comb t;
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    val (xs, ys) = chop k ts;
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    val i = find_index_eq c cs;
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  in
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    if xs = params andalso i >= 0 then
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      SOME (c, i, ys, chop (length ys)
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        (List.drop (binder_types (fastype_of c), k)))
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    else NONE
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  end;
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fun mk_names a 0 = []
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  | mk_names a 1 = [a]
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  | mk_names a n = map (fn i => a ^ string_of_int i) (1 upto n);
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(** process rules **)
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local
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fun err_in_rule ctxt name t msg =
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  error (cat_lines ["Ill-formed introduction rule " ^ quote name,
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    Syntax.string_of_term ctxt t, msg]);
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fun err_in_prem ctxt name t p msg =
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  error (cat_lines ["Ill-formed premise", Syntax.string_of_term ctxt p,
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    "in introduction rule " ^ quote name, Syntax.string_of_term ctxt t, msg]);
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val bad_concl = "Conclusion of introduction rule must be an inductive predicate";
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val bad_ind_occ = "Inductive predicate occurs in argument of inductive predicate";
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val bad_app = "Inductive predicate must be applied to parameter(s) ";
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fun atomize_term thy = MetaSimplifier.rewrite_term thy inductive_atomize [];
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in
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fun check_rule ctxt cs params ((name, att), rule) =
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  let
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    val params' = Term.variant_frees rule (Logic.strip_params rule);
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    val frees = rev (map Free params');
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    val concl = subst_bounds (frees, Logic.strip_assums_concl rule);
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    val prems = map (curry subst_bounds frees) (Logic.strip_assums_hyp rule);
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    val rule' = Logic.list_implies (prems, concl);
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    val aprems = map (atomize_term (ProofContext.theory_of ctxt)) prems;
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    val arule = list_all_free (params', Logic.list_implies (aprems, concl));
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    fun check_ind err t = case dest_predicate cs params t of
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        NONE => err (bad_app ^
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          commas (map (Syntax.string_of_term ctxt) params))
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      | SOME (_, _, ys, _) =>
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          if exists (fn c => exists (fn t => Logic.occs (c, t)) ys) cs
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          then err bad_ind_occ else ();
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    fun check_prem' prem t =
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      if head_of t mem cs then
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        check_ind (err_in_prem ctxt name rule prem) t
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      else (case t of
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          Abs (_, _, t) => check_prem' prem t
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        | t $ u => (check_prem' prem t; check_prem' prem u)
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        | _ => ());
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    fun check_prem (prem, aprem) =
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      if can HOLogic.dest_Trueprop aprem then check_prem' prem prem
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      else err_in_prem ctxt name rule prem "Non-atomic premise";
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  in
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    (case concl of
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       Const ("Trueprop", _) $ t =>
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         if head_of t mem cs then
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           (check_ind (err_in_rule ctxt name rule') t;
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            List.app check_prem (prems ~~ aprems))
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         else err_in_rule ctxt name rule' bad_concl
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     | _ => err_in_rule ctxt name rule' bad_concl);
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    ((name, att), arule)
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  end;
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val rulify =
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  hol_simplify inductive_conj
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  #> hol_simplify inductive_rulify
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  #> hol_simplify inductive_rulify_fallback
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  #> MetaSimplifier.norm_hhf;
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end;
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(** proofs for (co)inductive predicates **)
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(* prove monotonicity *)
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fun prove_mono quiet_mode skip_mono predT fp_fun monos ctxt =
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 (message (quiet_mode orelse skip_mono andalso !quick_and_dirty)
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    "  Proving monotonicity ...";
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  (if skip_mono then SkipProof.prove else Goal.prove) ctxt [] []
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    (HOLogic.mk_Trueprop
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      (Const (@{const_name Orderings.mono}, (predT --> predT) --> HOLogic.boolT) $ fp_fun))
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    (fn _ => EVERY [rtac @{thm monoI} 1,
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      REPEAT (resolve_tac [le_funI, le_boolI'] 1),
berghofe@21024
   322
      REPEAT (FIRST
berghofe@21024
   323
        [atac 1,
wenzelm@21367
   324
         resolve_tac (List.concat (map mk_mono monos) @ get_monos ctxt) 1,
berghofe@21024
   325
         etac le_funE 1, dtac le_boolD 1])]));
berghofe@5094
   326
wenzelm@6424
   327
wenzelm@10735
   328
(* prove introduction rules *)
berghofe@5094
   329
wenzelm@26477
   330
fun prove_intrs quiet_mode coind mono fp_def k params intr_ts rec_preds_defs ctxt =
berghofe@5094
   331
  let
wenzelm@26477
   332
    val _ = clean_message quiet_mode "  Proving the introduction rules ...";
berghofe@5094
   333
berghofe@21024
   334
    val unfold = funpow k (fn th => th RS fun_cong)
berghofe@21024
   335
      (mono RS (fp_def RS
berghofe@21024
   336
        (if coind then def_gfp_unfold else def_lfp_unfold)));
berghofe@5094
   337
berghofe@5094
   338
    fun select_disj 1 1 = []
berghofe@5094
   339
      | select_disj _ 1 = [rtac disjI1]
berghofe@5094
   340
      | select_disj n i = (rtac disjI2)::(select_disj (n - 1) (i - 1));
berghofe@5094
   341
berghofe@21024
   342
    val rules = [refl, TrueI, notFalseI, exI, conjI];
berghofe@21024
   343
berghofe@22605
   344
    val intrs = map_index (fn (i, intr) => rulify
berghofe@22605
   345
      (SkipProof.prove ctxt (map (fst o dest_Free) params) [] intr (fn _ => EVERY
berghofe@21024
   346
       [rewrite_goals_tac rec_preds_defs,
berghofe@21024
   347
        rtac (unfold RS iffD2) 1,
berghofe@21024
   348
        EVERY1 (select_disj (length intr_ts) (i + 1)),
wenzelm@17985
   349
        (*Not ares_tac, since refl must be tried before any equality assumptions;
wenzelm@17985
   350
          backtracking may occur if the premises have extra variables!*)
berghofe@21024
   351
        DEPTH_SOLVE_1 (resolve_tac rules 1 APPEND assume_tac 1)]))) intr_ts
berghofe@5094
   352
berghofe@5094
   353
  in (intrs, unfold) end;
berghofe@5094
   354
wenzelm@6424
   355
wenzelm@10735
   356
(* prove elimination rules *)
berghofe@5094
   357
wenzelm@26477
   358
fun prove_elims quiet_mode cs params intr_ts intr_names unfold rec_preds_defs ctxt =
berghofe@5094
   359
  let
wenzelm@26477
   360
    val _ = clean_message quiet_mode "  Proving the elimination rules ...";
berghofe@5094
   361
berghofe@22605
   362
    val ([pname], ctxt') = ctxt |>
berghofe@22605
   363
      Variable.add_fixes (map (fst o dest_Free) params) |> snd |>
berghofe@22605
   364
      Variable.variant_fixes ["P"];
berghofe@21024
   365
    val P = HOLogic.mk_Trueprop (Free (pname, HOLogic.boolT));
berghofe@21024
   366
berghofe@21024
   367
    fun dest_intr r =
berghofe@21024
   368
      (the (dest_predicate cs params (HOLogic.dest_Trueprop (Logic.strip_assums_concl r))),
berghofe@21024
   369
       Logic.strip_assums_hyp r, Logic.strip_params r);
berghofe@21024
   370
berghofe@21024
   371
    val intrs = map dest_intr intr_ts ~~ intr_names;
berghofe@21024
   372
berghofe@21024
   373
    val rules1 = [disjE, exE, FalseE];
berghofe@21024
   374
    val rules2 = [conjE, FalseE, notTrueE];
berghofe@21024
   375
berghofe@21024
   376
    fun prove_elim c =
berghofe@21024
   377
      let
berghofe@21024
   378
        val Ts = List.drop (binder_types (fastype_of c), length params);
berghofe@21024
   379
        val (anames, ctxt'') = Variable.variant_fixes (mk_names "a" (length Ts)) ctxt';
berghofe@21024
   380
        val frees = map Free (anames ~~ Ts);
berghofe@21024
   381
berghofe@21024
   382
        fun mk_elim_prem ((_, _, us, _), ts, params') =
berghofe@21024
   383
          list_all (params',
berghofe@21024
   384
            Logic.list_implies (map (HOLogic.mk_Trueprop o HOLogic.mk_eq)
berghofe@21024
   385
              (frees ~~ us) @ ts, P));
berghofe@21024
   386
        val c_intrs = (List.filter (equal c o #1 o #1 o #1) intrs);
berghofe@21024
   387
        val prems = HOLogic.mk_Trueprop (list_comb (c, params @ frees)) ::
berghofe@21024
   388
           map mk_elim_prem (map #1 c_intrs)
berghofe@21024
   389
      in
berghofe@21048
   390
        (SkipProof.prove ctxt'' [] prems P
berghofe@21024
   391
          (fn {prems, ...} => EVERY
berghofe@21024
   392
            [cut_facts_tac [hd prems] 1,
berghofe@21024
   393
             rewrite_goals_tac rec_preds_defs,
berghofe@21024
   394
             dtac (unfold RS iffD1) 1,
berghofe@21024
   395
             REPEAT (FIRSTGOAL (eresolve_tac rules1)),
berghofe@21024
   396
             REPEAT (FIRSTGOAL (eresolve_tac rules2)),
berghofe@21024
   397
             EVERY (map (fn prem =>
berghofe@21024
   398
               DEPTH_SOLVE_1 (ares_tac [rewrite_rule rec_preds_defs prem, conjI] 1)) (tl prems))])
berghofe@21024
   399
          |> rulify
berghofe@21048
   400
          |> singleton (ProofContext.export ctxt'' ctxt),
berghofe@21048
   401
         map #2 c_intrs)
berghofe@21024
   402
      end
berghofe@21024
   403
berghofe@21024
   404
   in map prove_elim cs end;
berghofe@5094
   405
wenzelm@6424
   406
wenzelm@10735
   407
(* derivation of simplified elimination rules *)
berghofe@5094
   408
wenzelm@11682
   409
local
wenzelm@11682
   410
wenzelm@11682
   411
(*delete needless equality assumptions*)
wenzelm@25365
   412
val refl_thin = Goal.prove_global HOL.thy [] [] @{prop "!!P. a = a ==> P ==> P"}
haftmann@22838
   413
  (fn _ => assume_tac 1);
berghofe@21024
   414
val elim_rls = [asm_rl, FalseE, refl_thin, conjE, exE];
wenzelm@11682
   415
val elim_tac = REPEAT o Tactic.eresolve_tac elim_rls;
wenzelm@11682
   416
berghofe@23762
   417
fun simp_case_tac ss i =
berghofe@23762
   418
  EVERY' [elim_tac, asm_full_simp_tac ss, elim_tac, REPEAT o bound_hyp_subst_tac] i;
wenzelm@21367
   419
wenzelm@11682
   420
in
wenzelm@9598
   421
wenzelm@21367
   422
fun mk_cases ctxt prop =
wenzelm@7107
   423
  let
wenzelm@21367
   424
    val thy = ProofContext.theory_of ctxt;
wenzelm@21367
   425
    val ss = Simplifier.local_simpset_of ctxt;
wenzelm@21367
   426
wenzelm@21526
   427
    fun err msg =
wenzelm@21526
   428
      error (Pretty.string_of (Pretty.block
wenzelm@24920
   429
        [Pretty.str msg, Pretty.fbrk, Syntax.pretty_term ctxt prop]));
wenzelm@21526
   430
wenzelm@24861
   431
    val elims = Induct.find_casesP ctxt prop;
wenzelm@21367
   432
wenzelm@21367
   433
    val cprop = Thm.cterm_of thy prop;
berghofe@23762
   434
    val tac = ALLGOALS (simp_case_tac ss) THEN prune_params_tac;
wenzelm@21367
   435
    fun mk_elim rl =
wenzelm@21367
   436
      Thm.implies_intr cprop (Tactic.rule_by_tactic tac (Thm.assume cprop RS rl))
wenzelm@21367
   437
      |> singleton (Variable.export (Variable.auto_fixes prop ctxt) ctxt);
wenzelm@7107
   438
  in
wenzelm@7107
   439
    (case get_first (try mk_elim) elims of
skalberg@15531
   440
      SOME r => r
wenzelm@21526
   441
    | NONE => err "Proposition not an inductive predicate:")
wenzelm@7107
   442
  end;
wenzelm@7107
   443
wenzelm@11682
   444
end;
wenzelm@11682
   445
wenzelm@7107
   446
wenzelm@21367
   447
(* inductive_cases *)
wenzelm@7107
   448
wenzelm@21367
   449
fun gen_inductive_cases prep_att prep_prop args lthy =
wenzelm@9598
   450
  let
wenzelm@21367
   451
    val thy = ProofContext.theory_of lthy;
wenzelm@12876
   452
    val facts = args |> map (fn ((a, atts), props) =>
wenzelm@21367
   453
      ((a, map (prep_att thy) atts),
wenzelm@21367
   454
        map (Thm.no_attributes o single o mk_cases lthy o prep_prop lthy) props));
wenzelm@24815
   455
  in lthy |> LocalTheory.notes Thm.theoremK facts |>> map snd end;
berghofe@5094
   456
wenzelm@24509
   457
val inductive_cases = gen_inductive_cases Attrib.intern_src Syntax.read_prop;
wenzelm@24509
   458
val inductive_cases_i = gen_inductive_cases (K I) Syntax.check_prop;
wenzelm@7107
   459
wenzelm@6424
   460
berghofe@22275
   461
fun ind_cases src = Method.syntax (Scan.lift (Scan.repeat1 Args.name --
berghofe@22275
   462
    Scan.optional (Args.$$$ "for" |-- Scan.repeat1 Args.name) [])) src
berghofe@22275
   463
  #> (fn ((raw_props, fixes), ctxt) =>
berghofe@22275
   464
    let
berghofe@22275
   465
      val (_, ctxt') = Variable.add_fixes fixes ctxt;
wenzelm@24509
   466
      val props = Syntax.read_props ctxt' raw_props;
berghofe@22275
   467
      val ctxt'' = fold Variable.declare_term props ctxt';
berghofe@22275
   468
      val rules = ProofContext.export ctxt'' ctxt (map (mk_cases ctxt'') props)
berghofe@22275
   469
    in Method.erule 0 rules end);
wenzelm@9598
   470
wenzelm@9598
   471
wenzelm@9598
   472
wenzelm@10735
   473
(* prove induction rule *)
berghofe@5094
   474
wenzelm@26477
   475
fun prove_indrule quiet_mode cs argTs bs xs rec_const params intr_ts mono
berghofe@21024
   476
    fp_def rec_preds_defs ctxt =
berghofe@5094
   477
  let
wenzelm@26477
   478
    val _ = clean_message quiet_mode "  Proving the induction rule ...";
wenzelm@20047
   479
    val thy = ProofContext.theory_of ctxt;
berghofe@5094
   480
berghofe@21024
   481
    (* predicates for induction rule *)
berghofe@21024
   482
berghofe@22605
   483
    val (pnames, ctxt') = ctxt |>
berghofe@22605
   484
      Variable.add_fixes (map (fst o dest_Free) params) |> snd |>
berghofe@22605
   485
      Variable.variant_fixes (mk_names "P" (length cs));
berghofe@21024
   486
    val preds = map Free (pnames ~~
berghofe@21024
   487
      map (fn c => List.drop (binder_types (fastype_of c), length params) --->
berghofe@21024
   488
        HOLogic.boolT) cs);
berghofe@21024
   489
berghofe@21024
   490
    (* transform an introduction rule into a premise for induction rule *)
berghofe@21024
   491
berghofe@21024
   492
    fun mk_ind_prem r =
berghofe@21024
   493
      let
berghofe@21024
   494
        fun subst s = (case dest_predicate cs params s of
berghofe@21024
   495
            SOME (_, i, ys, (_, Ts)) =>
berghofe@21024
   496
              let
berghofe@21024
   497
                val k = length Ts;
berghofe@21024
   498
                val bs = map Bound (k - 1 downto 0);
berghofe@23762
   499
                val P = list_comb (List.nth (preds, i),
berghofe@23762
   500
                  map (incr_boundvars k) ys @ bs);
berghofe@21024
   501
                val Q = list_abs (mk_names "x" k ~~ Ts,
berghofe@23762
   502
                  HOLogic.mk_binop inductive_conj_name
berghofe@23762
   503
                    (list_comb (incr_boundvars k s, bs), P))
berghofe@21024
   504
              in (Q, case Ts of [] => SOME (s, P) | _ => NONE) end
berghofe@21024
   505
          | NONE => (case s of
berghofe@21024
   506
              (t $ u) => (fst (subst t) $ fst (subst u), NONE)
berghofe@21024
   507
            | (Abs (a, T, t)) => (Abs (a, T, fst (subst t)), NONE)
berghofe@21024
   508
            | _ => (s, NONE)));
berghofe@7293
   509
berghofe@21024
   510
        fun mk_prem (s, prems) = (case subst s of
berghofe@21024
   511
              (_, SOME (t, u)) => t :: u :: prems
berghofe@21024
   512
            | (t, _) => t :: prems);
berghofe@21024
   513
berghofe@21024
   514
        val SOME (_, i, ys, _) = dest_predicate cs params
berghofe@21024
   515
          (HOLogic.dest_Trueprop (Logic.strip_assums_concl r))
berghofe@21024
   516
berghofe@21024
   517
      in list_all_free (Logic.strip_params r,
berghofe@21024
   518
        Logic.list_implies (map HOLogic.mk_Trueprop (foldr mk_prem
berghofe@21024
   519
          [] (map HOLogic.dest_Trueprop (Logic.strip_assums_hyp r))),
berghofe@21024
   520
            HOLogic.mk_Trueprop (list_comb (List.nth (preds, i), ys))))
berghofe@21024
   521
      end;
berghofe@21024
   522
berghofe@21024
   523
    val ind_prems = map mk_ind_prem intr_ts;
berghofe@21024
   524
wenzelm@21526
   525
berghofe@21024
   526
    (* make conclusions for induction rules *)
berghofe@21024
   527
berghofe@21024
   528
    val Tss = map (binder_types o fastype_of) preds;
berghofe@21024
   529
    val (xnames, ctxt'') =
berghofe@21024
   530
      Variable.variant_fixes (mk_names "x" (length (flat Tss))) ctxt';
berghofe@21024
   531
    val mutual_ind_concl = HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj
berghofe@21024
   532
        (map (fn (((xnames, Ts), c), P) =>
berghofe@21024
   533
           let val frees = map Free (xnames ~~ Ts)
berghofe@21024
   534
           in HOLogic.mk_imp
berghofe@21024
   535
             (list_comb (c, params @ frees), list_comb (P, frees))
berghofe@21024
   536
           end) (unflat Tss xnames ~~ Tss ~~ cs ~~ preds)));
berghofe@5094
   537
paulson@13626
   538
berghofe@5094
   539
    (* make predicate for instantiation of abstract induction rule *)
berghofe@5094
   540
berghofe@21024
   541
    val ind_pred = fold_rev lambda (bs @ xs) (foldr1 HOLogic.mk_conj
berghofe@21024
   542
      (map_index (fn (i, P) => foldr HOLogic.mk_imp
berghofe@21024
   543
         (list_comb (P, make_args' argTs xs (binder_types (fastype_of P))))
berghofe@21024
   544
         (make_bool_args HOLogic.mk_not I bs i)) preds));
berghofe@5094
   545
berghofe@5094
   546
    val ind_concl = HOLogic.mk_Trueprop
haftmann@23881
   547
      (HOLogic.mk_binrel "HOL.ord_class.less_eq" (rec_const, ind_pred));
berghofe@5094
   548
paulson@13626
   549
    val raw_fp_induct = (mono RS (fp_def RS def_lfp_induct));
paulson@13626
   550
berghofe@21024
   551
    val induct = SkipProof.prove ctxt'' [] ind_prems ind_concl
wenzelm@20248
   552
      (fn {prems, ...} => EVERY
wenzelm@17985
   553
        [rewrite_goals_tac [inductive_conj_def],
berghofe@21024
   554
         DETERM (rtac raw_fp_induct 1),
berghofe@21024
   555
         REPEAT (resolve_tac [le_funI, le_boolI] 1),
haftmann@22460
   556
         rewrite_goals_tac (inf_fun_eq :: inf_bool_eq :: simp_thms'),
berghofe@21024
   557
         (*This disjE separates out the introduction rules*)
berghofe@21024
   558
         REPEAT (FIRSTGOAL (eresolve_tac [disjE, exE, FalseE])),
berghofe@5094
   559
         (*Now break down the individual cases.  No disjE here in case
berghofe@5094
   560
           some premise involves disjunction.*)
paulson@13747
   561
         REPEAT (FIRSTGOAL (etac conjE ORELSE' bound_hyp_subst_tac)),
berghofe@21024
   562
         REPEAT (FIRSTGOAL
berghofe@21024
   563
           (resolve_tac [conjI, impI] ORELSE' (etac notE THEN' atac))),
berghofe@21024
   564
         EVERY (map (fn prem => DEPTH_SOLVE_1 (ares_tac [rewrite_rule
berghofe@22980
   565
             (inductive_conj_def :: rec_preds_defs @ simp_thms') prem,
berghofe@22980
   566
           conjI, refl] 1)) prems)]);
berghofe@5094
   567
berghofe@21024
   568
    val lemma = SkipProof.prove ctxt'' [] []
wenzelm@17985
   569
      (Logic.mk_implies (ind_concl, mutual_ind_concl)) (fn _ => EVERY
berghofe@21024
   570
        [rewrite_goals_tac rec_preds_defs,
berghofe@5094
   571
         REPEAT (EVERY
berghofe@5094
   572
           [REPEAT (resolve_tac [conjI, impI] 1),
berghofe@21024
   573
            REPEAT (eresolve_tac [le_funE, le_boolE] 1),
berghofe@21024
   574
            atac 1,
berghofe@21024
   575
            rewrite_goals_tac simp_thms',
berghofe@21024
   576
            atac 1])])
berghofe@5094
   577
berghofe@21024
   578
  in singleton (ProofContext.export ctxt'' ctxt) (induct RS lemma) end;
berghofe@5094
   579
wenzelm@6424
   580
wenzelm@6424
   581
berghofe@21024
   582
(** specification of (co)inductive predicates **)
wenzelm@10729
   583
berghofe@26534
   584
fun mk_ind_def quiet_mode skip_mono alt_name coind cs intr_ts monos params cnames_syn ctxt =
berghofe@5094
   585
  let
haftmann@24915
   586
    val fp_name = if coind then @{const_name Inductive.gfp} else @{const_name Inductive.lfp};
berghofe@5094
   587
berghofe@21024
   588
    val argTs = fold (fn c => fn Ts => Ts @
berghofe@21024
   589
      (List.drop (binder_types (fastype_of c), length params) \\ Ts)) cs [];
berghofe@21024
   590
    val k = log 2 1 (length cs);
berghofe@21024
   591
    val predT = replicate k HOLogic.boolT ---> argTs ---> HOLogic.boolT;
berghofe@21024
   592
    val p :: xs = map Free (Variable.variant_frees ctxt intr_ts
berghofe@21024
   593
      (("p", predT) :: (mk_names "x" (length argTs) ~~ argTs)));
berghofe@21024
   594
    val bs = map Free (Variable.variant_frees ctxt (p :: xs @ intr_ts)
berghofe@21024
   595
      (map (rpair HOLogic.boolT) (mk_names "b" k)));
berghofe@21024
   596
berghofe@21024
   597
    fun subst t = (case dest_predicate cs params t of
berghofe@21024
   598
        SOME (_, i, ts, (Ts, Us)) =>
berghofe@23762
   599
          let
berghofe@23762
   600
            val l = length Us;
berghofe@23762
   601
            val zs = map Bound (l - 1 downto 0)
berghofe@21024
   602
          in
berghofe@21024
   603
            list_abs (map (pair "z") Us, list_comb (p,
berghofe@23762
   604
              make_bool_args' bs i @ make_args argTs
berghofe@23762
   605
                ((map (incr_boundvars l) ts ~~ Ts) @ (zs ~~ Us))))
berghofe@21024
   606
          end
berghofe@21024
   607
      | NONE => (case t of
berghofe@21024
   608
          t1 $ t2 => subst t1 $ subst t2
berghofe@21024
   609
        | Abs (x, T, u) => Abs (x, T, subst u)
berghofe@21024
   610
        | _ => t));
berghofe@5149
   611
berghofe@5094
   612
    (* transform an introduction rule into a conjunction  *)
berghofe@21024
   613
    (*   [| p_i t; ... |] ==> p_j u                       *)
berghofe@5094
   614
    (* is transformed into                                *)
berghofe@21024
   615
    (*   b_j & x_j = u & p b_j t & ...                    *)
berghofe@5094
   616
berghofe@5094
   617
    fun transform_rule r =
berghofe@5094
   618
      let
berghofe@21024
   619
        val SOME (_, i, ts, (Ts, _)) = dest_predicate cs params
berghofe@21048
   620
          (HOLogic.dest_Trueprop (Logic.strip_assums_concl r));
berghofe@21048
   621
        val ps = make_bool_args HOLogic.mk_not I bs i @
berghofe@21048
   622
          map HOLogic.mk_eq (make_args' argTs xs Ts ~~ ts) @
berghofe@21048
   623
          map (subst o HOLogic.dest_Trueprop)
berghofe@21048
   624
            (Logic.strip_assums_hyp r)
berghofe@21024
   625
      in foldr (fn ((x, T), P) => HOLogic.exists_const T $ (Abs (x, T, P)))
berghofe@21048
   626
        (if null ps then HOLogic.true_const else foldr1 HOLogic.mk_conj ps)
berghofe@21048
   627
        (Logic.strip_params r)
berghofe@5094
   628
      end
berghofe@5094
   629
berghofe@5094
   630
    (* make a disjunction of all introduction rules *)
berghofe@5094
   631
berghofe@21024
   632
    val fp_fun = fold_rev lambda (p :: bs @ xs)
berghofe@21024
   633
      (if null intr_ts then HOLogic.false_const
berghofe@21024
   634
       else foldr1 HOLogic.mk_disj (map transform_rule intr_ts));
berghofe@5094
   635
berghofe@21024
   636
    (* add definiton of recursive predicates to theory *)
berghofe@5094
   637
berghofe@14235
   638
    val rec_name = if alt_name = "" then
berghofe@21024
   639
      space_implode "_" (map fst cnames_syn) else alt_name;
berghofe@5094
   640
berghofe@21024
   641
    val ((rec_const, (_, fp_def)), ctxt') = ctxt |>
wenzelm@26128
   642
      LocalTheory.define Thm.internalK
berghofe@21024
   643
        ((rec_name, case cnames_syn of [(_, syn)] => syn | _ => NoSyn),
berghofe@21024
   644
         (("", []), fold_rev lambda params
berghofe@21024
   645
           (Const (fp_name, (predT --> predT) --> predT) $ fp_fun)));
berghofe@21024
   646
    val fp_def' = Simplifier.rewrite (HOL_basic_ss addsimps [fp_def])
berghofe@21024
   647
      (cterm_of (ProofContext.theory_of ctxt') (list_comb (rec_const, params)));
berghofe@21024
   648
    val specs = if length cs < 2 then [] else
berghofe@21024
   649
      map_index (fn (i, (name_mx, c)) =>
berghofe@21024
   650
        let
berghofe@21024
   651
          val Ts = List.drop (binder_types (fastype_of c), length params);
berghofe@21024
   652
          val xs = map Free (Variable.variant_frees ctxt intr_ts
berghofe@21024
   653
            (mk_names "x" (length Ts) ~~ Ts))
berghofe@21024
   654
        in
berghofe@21024
   655
          (name_mx, (("", []), fold_rev lambda (params @ xs)
berghofe@21024
   656
            (list_comb (rec_const, params @ make_bool_args' bs i @
berghofe@21024
   657
              make_args argTs (xs ~~ Ts)))))
berghofe@21024
   658
        end) (cnames_syn ~~ cs);
wenzelm@26128
   659
    val (consts_defs, ctxt'') = fold_map (LocalTheory.define Thm.internalK) specs ctxt';
berghofe@21024
   660
    val preds = (case cs of [_] => [rec_const] | _ => map #1 consts_defs);
berghofe@5094
   661
berghofe@26534
   662
    val mono = prove_mono quiet_mode skip_mono predT fp_fun monos ctxt''
berghofe@5094
   663
berghofe@21024
   664
  in (ctxt'', rec_name, mono, fp_def', map (#2 o #2) consts_defs,
berghofe@21024
   665
    list_comb (rec_const, params), preds, argTs, bs, xs)
berghofe@21024
   666
  end;
berghofe@5094
   667
wenzelm@26128
   668
fun declare_rules kind rec_name coind no_ind cnames intrs intr_names intr_atts
berghofe@23762
   669
      elims raw_induct ctxt =
berghofe@23762
   670
  let
berghofe@23762
   671
    val ind_case_names = RuleCases.case_names intr_names;
berghofe@23762
   672
    val induct =
berghofe@23762
   673
      if coind then
berghofe@23762
   674
        (raw_induct, [RuleCases.case_names [rec_name],
berghofe@23762
   675
          RuleCases.case_conclusion (rec_name, intr_names),
wenzelm@24861
   676
          RuleCases.consumes 1, Induct.coinduct_pred (hd cnames)])
berghofe@23762
   677
      else if no_ind orelse length cnames > 1 then
berghofe@23762
   678
        (raw_induct, [ind_case_names, RuleCases.consumes 0])
berghofe@23762
   679
      else (raw_induct RSN (2, rev_mp), [ind_case_names, RuleCases.consumes 1]);
berghofe@23762
   680
berghofe@23762
   681
    val (intrs', ctxt1) =
berghofe@23762
   682
      ctxt |>
wenzelm@26128
   683
      LocalTheory.notes kind
berghofe@23762
   684
        (map (NameSpace.qualified rec_name) intr_names ~~
berghofe@23762
   685
         intr_atts ~~ map (fn th => [([th],
berghofe@23762
   686
           [Attrib.internal (K (ContextRules.intro_query NONE))])]) intrs) |>>
berghofe@24744
   687
      map (hd o snd);
berghofe@23762
   688
    val (((_, elims'), (_, [induct'])), ctxt2) =
berghofe@23762
   689
      ctxt1 |>
wenzelm@26128
   690
      LocalTheory.note kind ((NameSpace.qualified rec_name "intros", []), intrs') ||>>
berghofe@23762
   691
      fold_map (fn (name, (elim, cases)) =>
wenzelm@26128
   692
        LocalTheory.note kind ((NameSpace.qualified (Sign.base_name name) "cases",
berghofe@23762
   693
          [Attrib.internal (K (RuleCases.case_names cases)),
berghofe@23762
   694
           Attrib.internal (K (RuleCases.consumes 1)),
wenzelm@24861
   695
           Attrib.internal (K (Induct.cases_pred name)),
berghofe@23762
   696
           Attrib.internal (K (ContextRules.elim_query NONE))]), [elim]) #>
berghofe@23762
   697
        apfst (hd o snd)) (if null elims then [] else cnames ~~ elims) ||>>
wenzelm@26128
   698
      LocalTheory.note kind ((NameSpace.qualified rec_name (coind_prefix coind ^ "induct"),
berghofe@23762
   699
        map (Attrib.internal o K) (#2 induct)), [rulify (#1 induct)]);
berghofe@23762
   700
berghofe@23762
   701
    val ctxt3 = if no_ind orelse coind then ctxt2 else
berghofe@23762
   702
      let val inducts = cnames ~~ ProjectRule.projects ctxt2 (1 upto length cnames) induct'
berghofe@23762
   703
      in
berghofe@23762
   704
        ctxt2 |>
wenzelm@26128
   705
        LocalTheory.notes kind [((NameSpace.qualified rec_name "inducts", []),
berghofe@23762
   706
          inducts |> map (fn (name, th) => ([th],
berghofe@23762
   707
            [Attrib.internal (K ind_case_names),
berghofe@23762
   708
             Attrib.internal (K (RuleCases.consumes 1)),
wenzelm@24861
   709
             Attrib.internal (K (Induct.induct_pred name))])))] |> snd
berghofe@23762
   710
      end
berghofe@23762
   711
  in (intrs', elims', induct', ctxt3) end;
berghofe@23762
   712
berghofe@26534
   713
type inductive_flags =
wenzelm@26477
   714
  {quiet_mode: bool, verbose: bool, kind: string, alt_name: bstring,
berghofe@26534
   715
   coind: bool, no_elim: bool, no_ind: bool, skip_mono: bool}
berghofe@26534
   716
berghofe@26534
   717
type add_ind_def =
berghofe@26534
   718
  inductive_flags ->
berghofe@23762
   719
  term list -> ((string * Attrib.src list) * term) list -> thm list ->
berghofe@23762
   720
  term list -> (string * mixfix) list ->
berghofe@23762
   721
  local_theory -> inductive_result * local_theory
berghofe@23762
   722
berghofe@26534
   723
fun add_ind_def {quiet_mode, verbose, kind, alt_name, coind, no_elim, no_ind, skip_mono}
wenzelm@24815
   724
    cs intros monos params cnames_syn ctxt =
berghofe@9072
   725
  let
wenzelm@25288
   726
    val _ = null cnames_syn andalso error "No inductive predicates given";
wenzelm@26477
   727
    val _ = message (quiet_mode andalso not verbose)
wenzelm@26477
   728
      ("Proofs for " ^ coind_prefix coind ^ "inductive predicate(s) " ^
wenzelm@26477
   729
        commas_quote (map fst cnames_syn));
berghofe@9072
   730
wenzelm@21526
   731
    val cnames = map (Sign.full_name (ProofContext.theory_of ctxt) o #1) cnames_syn;  (* FIXME *)
berghofe@23762
   732
    val ((intr_names, intr_atts), intr_ts) =
berghofe@23762
   733
      apfst split_list (split_list (map (check_rule ctxt cs params) intros));
berghofe@21024
   734
berghofe@21024
   735
    val (ctxt1, rec_name, mono, fp_def, rec_preds_defs, rec_const, preds,
berghofe@26534
   736
      argTs, bs, xs) = mk_ind_def quiet_mode skip_mono alt_name coind cs intr_ts
berghofe@26534
   737
        monos params cnames_syn ctxt;
berghofe@9072
   738
wenzelm@26477
   739
    val (intrs, unfold) = prove_intrs quiet_mode coind mono fp_def (length bs + length xs)
berghofe@22605
   740
      params intr_ts rec_preds_defs ctxt1;
berghofe@21048
   741
    val elims = if no_elim then [] else
wenzelm@26477
   742
      prove_elims quiet_mode cs params intr_ts intr_names unfold rec_preds_defs ctxt1;
berghofe@22605
   743
    val raw_induct = zero_var_indexes
berghofe@21024
   744
      (if no_ind then Drule.asm_rl else
berghofe@23762
   745
       if coind then
berghofe@23762
   746
         singleton (ProofContext.export
berghofe@23762
   747
           (snd (Variable.add_fixes (map (fst o dest_Free) params) ctxt1)) ctxt1)
berghofe@23762
   748
           (rotate_prems ~1 (ObjectLogic.rulify (rule_by_tactic
haftmann@25510
   749
             (rewrite_tac [le_fun_def, le_bool_def, sup_fun_eq, sup_bool_eq] THEN
berghofe@23762
   750
               fold_tac rec_preds_defs) (mono RS (fp_def RS def_coinduct)))))
berghofe@21024
   751
       else
wenzelm@26477
   752
         prove_indrule quiet_mode cs argTs bs xs rec_const params intr_ts mono fp_def
berghofe@22605
   753
           rec_preds_defs ctxt1);
berghofe@5094
   754
wenzelm@26128
   755
    val (intrs', elims', induct, ctxt2) = declare_rules kind rec_name coind no_ind
berghofe@23762
   756
      cnames intrs intr_names intr_atts elims raw_induct ctxt1;
berghofe@21048
   757
wenzelm@21526
   758
    val names = map #1 cnames_syn;
berghofe@21048
   759
    val result =
berghofe@21048
   760
      {preds = preds,
berghofe@21048
   761
       intrs = intrs',
berghofe@21048
   762
       elims = elims',
berghofe@21048
   763
       raw_induct = rulify raw_induct,
berghofe@23762
   764
       induct = induct};
wenzelm@21367
   765
berghofe@23762
   766
    val ctxt3 = ctxt2
wenzelm@21526
   767
      |> LocalTheory.declaration (fn phi =>
wenzelm@25380
   768
        let val result' = morph_result phi result;
wenzelm@25380
   769
        in put_inductives cnames (*global names!?*) ({names = cnames, coind = coind}, result') end);
berghofe@23762
   770
  in (result, ctxt3) end;
berghofe@5094
   771
wenzelm@6424
   772
wenzelm@10735
   773
(* external interfaces *)
berghofe@5094
   774
wenzelm@26477
   775
fun gen_add_inductive_i mk_def
berghofe@26534
   776
    (flags as {quiet_mode, verbose, kind, alt_name, coind, no_elim, no_ind, skip_mono})
wenzelm@25029
   777
    cnames_syn pnames spec monos lthy =
berghofe@5094
   778
  let
wenzelm@25029
   779
    val thy = ProofContext.theory_of lthy;
wenzelm@6424
   780
    val _ = Theory.requires thy "Inductive" (coind_prefix coind ^ "inductive definitions");
berghofe@5094
   781
berghofe@21766
   782
wenzelm@25029
   783
    (* abbrevs *)
wenzelm@25029
   784
wenzelm@25029
   785
    val (_, ctxt1) = Variable.add_fixes (map (fst o fst) cnames_syn) lthy;
berghofe@21766
   786
wenzelm@25029
   787
    fun get_abbrev ((name, atts), t) =
wenzelm@25029
   788
      if can (Logic.strip_assums_concl #> Logic.dest_equals) t then
wenzelm@25029
   789
        let
wenzelm@25029
   790
          val _ = name = "" andalso null atts orelse
wenzelm@25029
   791
            error "Abbreviations may not have names or attributes";
wenzelm@25029
   792
          val ((x, T), rhs) = LocalDefs.abs_def (snd (LocalDefs.cert_def ctxt1 t));
wenzelm@25029
   793
          val mx =
wenzelm@25029
   794
            (case find_first (fn ((c, _), _) => c = x) cnames_syn of
wenzelm@25029
   795
              NONE => error ("Undeclared head of abbreviation " ^ quote x)
wenzelm@25029
   796
            | SOME ((_, T'), mx) =>
wenzelm@25029
   797
                if T <> T' then error ("Bad type specification for abbreviation " ^ quote x)
wenzelm@25029
   798
                else mx);
wenzelm@25029
   799
        in SOME ((x, mx), rhs) end
wenzelm@25029
   800
      else NONE;
berghofe@21766
   801
wenzelm@25029
   802
    val abbrevs = map_filter get_abbrev spec;
wenzelm@25029
   803
    val bs = map (fst o fst) abbrevs;
wenzelm@25029
   804
berghofe@21766
   805
wenzelm@25029
   806
    (* predicates *)
berghofe@21766
   807
wenzelm@25029
   808
    val pre_intros = filter_out (is_some o get_abbrev) spec;
wenzelm@25029
   809
    val cnames_syn' = filter_out (member (op =) bs o fst o fst) cnames_syn;
berghofe@24744
   810
    val cs = map (Free o fst) cnames_syn';
wenzelm@25029
   811
    val ps = map Free pnames;
berghofe@5094
   812
wenzelm@25143
   813
    val (_, ctxt2) = lthy |> Variable.add_fixes (map (fst o fst) cnames_syn');
wenzelm@25143
   814
    val _ = map (fn abbr => LocalDefs.fixed_abbrev abbr ctxt2) abbrevs;
wenzelm@25143
   815
    val ctxt3 = ctxt2 |> fold (snd oo LocalDefs.fixed_abbrev) abbrevs;
wenzelm@25143
   816
    val expand = Assumption.export_term ctxt3 lthy #> ProofContext.cert_term lthy;
wenzelm@25029
   817
wenzelm@25029
   818
    fun close_rule r = list_all_free (rev (fold_aterms
berghofe@21024
   819
      (fn t as Free (v as (s, _)) =>
wenzelm@25029
   820
          if Variable.is_fixed ctxt1 s orelse
wenzelm@25029
   821
            member (op =) ps t then I else insert (op =) v
wenzelm@25029
   822
        | _ => I) r []), r);
berghofe@5094
   823
haftmann@26736
   824
    val intros = map (apsnd (Syntax.check_term lthy #> close_rule #> expand)) pre_intros;
wenzelm@25029
   825
    val preds = map (fn ((c, _), mx) => (c, mx)) cnames_syn';
berghofe@21048
   826
  in
wenzelm@25029
   827
    lthy
wenzelm@25029
   828
    |> mk_def flags cs intros monos ps preds
wenzelm@25029
   829
    ||> fold (snd oo LocalTheory.abbrev Syntax.mode_default) abbrevs
berghofe@21048
   830
  end;
berghofe@5094
   831
wenzelm@24721
   832
fun gen_add_inductive mk_def verbose coind cnames_syn pnames_syn intro_srcs raw_monos lthy =
berghofe@5094
   833
  let
wenzelm@25114
   834
    val ((vars, specs), _) = lthy |> ProofContext.set_mode ProofContext.mode_abbrev
wenzelm@25114
   835
      |> Specification.read_specification
wenzelm@25114
   836
          (cnames_syn @ pnames_syn) (map (fn (a, s) => [(a, [s])]) intro_srcs);
wenzelm@24721
   837
    val (cs, ps) = chop (length cnames_syn) vars;
wenzelm@24721
   838
    val intrs = map (apsnd the_single) specs;
wenzelm@24721
   839
    val monos = Attrib.eval_thms lthy raw_monos;
wenzelm@26477
   840
    val flags = {quiet_mode = false, verbose = verbose, kind = Thm.theoremK, alt_name = "",
berghofe@26534
   841
      coind = coind, no_elim = false, no_ind = false, skip_mono = false};
wenzelm@26128
   842
  in
wenzelm@26128
   843
    lthy
wenzelm@26128
   844
    |> LocalTheory.set_group (serial_string ())
wenzelm@26128
   845
    |> gen_add_inductive_i mk_def flags cs (map fst ps) intrs monos
wenzelm@26128
   846
  end;
berghofe@5094
   847
berghofe@23762
   848
val add_inductive_i = gen_add_inductive_i add_ind_def;
berghofe@23762
   849
val add_inductive = gen_add_inductive add_ind_def;
berghofe@23762
   850
wenzelm@26128
   851
fun add_inductive_global group flags cnames_syn pnames pre_intros monos thy =
wenzelm@25380
   852
  let
wenzelm@25380
   853
    val name = Sign.full_name thy (fst (fst (hd cnames_syn)));
wenzelm@25380
   854
    val ctxt' = thy
wenzelm@25380
   855
      |> TheoryTarget.init NONE
wenzelm@26128
   856
      |> LocalTheory.set_group group
wenzelm@25380
   857
      |> add_inductive_i flags cnames_syn pnames pre_intros monos |> snd
wenzelm@25380
   858
      |> LocalTheory.exit;
wenzelm@25380
   859
    val info = #2 (the_inductive ctxt' name);
wenzelm@25380
   860
  in (info, ProofContext.theory_of ctxt') end;
wenzelm@6424
   861
wenzelm@6424
   862
berghofe@22789
   863
(* read off arities of inductive predicates from raw induction rule *)
berghofe@22789
   864
fun arities_of induct =
berghofe@22789
   865
  map (fn (_ $ t $ u) =>
berghofe@22789
   866
      (fst (dest_Const (head_of t)), length (snd (strip_comb u))))
berghofe@22789
   867
    (HOLogic.dest_conj (HOLogic.dest_Trueprop (concl_of induct)));
berghofe@22789
   868
berghofe@22789
   869
(* read off parameters of inductive predicate from raw induction rule *)
berghofe@22789
   870
fun params_of induct =
berghofe@22789
   871
  let
berghofe@22789
   872
    val (_ $ t $ u :: _) =
berghofe@22789
   873
      HOLogic.dest_conj (HOLogic.dest_Trueprop (concl_of induct));
berghofe@22789
   874
    val (_, ts) = strip_comb t;
berghofe@22789
   875
    val (_, us) = strip_comb u
berghofe@22789
   876
  in
berghofe@22789
   877
    List.take (ts, length ts - length us)
berghofe@22789
   878
  end;
berghofe@22789
   879
berghofe@22789
   880
val pname_of_intr =
berghofe@22789
   881
  concl_of #> HOLogic.dest_Trueprop #> head_of #> dest_Const #> fst;
berghofe@22789
   882
berghofe@22789
   883
(* partition introduction rules according to predicate name *)
berghofe@25822
   884
fun gen_partition_rules f induct intros =
berghofe@25822
   885
  fold_rev (fn r => AList.map_entry op = (pname_of_intr (f r)) (cons r)) intros
berghofe@22789
   886
    (map (rpair [] o fst) (arities_of induct));
berghofe@22789
   887
berghofe@25822
   888
val partition_rules = gen_partition_rules I;
berghofe@25822
   889
fun partition_rules' induct = gen_partition_rules fst induct;
berghofe@25822
   890
berghofe@22789
   891
fun unpartition_rules intros xs =
berghofe@22789
   892
  fold_map (fn r => AList.map_entry_yield op = (pname_of_intr r)
berghofe@22789
   893
    (fn x :: xs => (x, xs)) #>> the) intros xs |> fst;
berghofe@22789
   894
berghofe@22789
   895
(* infer order of variables in intro rules from order of quantifiers in elim rule *)
berghofe@22789
   896
fun infer_intro_vars elim arity intros =
berghofe@22789
   897
  let
berghofe@22789
   898
    val thy = theory_of_thm elim;
berghofe@22789
   899
    val _ :: cases = prems_of elim;
berghofe@22789
   900
    val used = map (fst o fst) (Term.add_vars (prop_of elim) []);
berghofe@22789
   901
    fun mtch (t, u) =
berghofe@22789
   902
      let
berghofe@22789
   903
        val params = Logic.strip_params t;
berghofe@22789
   904
        val vars = map (Var o apfst (rpair 0))
berghofe@22789
   905
          (Name.variant_list used (map fst params) ~~ map snd params);
berghofe@22789
   906
        val ts = map (curry subst_bounds (rev vars))
berghofe@22789
   907
          (List.drop (Logic.strip_assums_hyp t, arity));
berghofe@22789
   908
        val us = Logic.strip_imp_prems u;
berghofe@22789
   909
        val tab = fold (Pattern.first_order_match thy) (ts ~~ us)
berghofe@22789
   910
          (Vartab.empty, Vartab.empty);
berghofe@22789
   911
      in
berghofe@22789
   912
        map (Envir.subst_vars tab) vars
berghofe@22789
   913
      end
berghofe@22789
   914
  in
berghofe@22789
   915
    map (mtch o apsnd prop_of) (cases ~~ intros)
berghofe@22789
   916
  end;
berghofe@22789
   917
berghofe@22789
   918
wenzelm@25978
   919
wenzelm@6437
   920
(** package setup **)
wenzelm@6437
   921
wenzelm@6437
   922
(* setup theory *)
wenzelm@6437
   923
wenzelm@8634
   924
val setup =
berghofe@23762
   925
  Method.add_methods [("ind_cases", ind_cases,
berghofe@21024
   926
    "dynamic case analysis on predicates")] #>
berghofe@23762
   927
  Attrib.add_attributes [("mono", Attrib.add_del_args mono_add mono_del,
wenzelm@18728
   928
    "declaration of monotonicity rule")];
wenzelm@6437
   929
wenzelm@6437
   930
wenzelm@6437
   931
(* outer syntax *)
wenzelm@6424
   932
wenzelm@17057
   933
local structure P = OuterParse and K = OuterKeyword in
wenzelm@6424
   934
wenzelm@24867
   935
val _ = OuterSyntax.keywords ["monos"];
wenzelm@24867
   936
wenzelm@21367
   937
fun flatten_specification specs = specs |> maps
wenzelm@21367
   938
  (fn (a, (concl, [])) => concl |> map
wenzelm@21367
   939
        (fn ((b, atts), [B]) =>
wenzelm@21367
   940
              if a = "" then ((b, atts), B)
wenzelm@21367
   941
              else if b = "" then ((a, atts), B)
wenzelm@21367
   942
              else error ("Illegal nested case names " ^ quote (NameSpace.append a b))
wenzelm@21367
   943
          | ((b, _), _) => error ("Illegal simultaneous specification " ^ quote b))
wenzelm@21367
   944
    | (a, _) => error ("Illegal local specification parameters for " ^ quote a));
wenzelm@6424
   945
berghofe@23762
   946
fun gen_ind_decl mk_def coind =
wenzelm@21367
   947
  P.fixes -- P.for_fixes --
wenzelm@22102
   948
  Scan.optional (P.$$$ "where" |-- P.!!! SpecParse.specification) [] --
wenzelm@22102
   949
  Scan.optional (P.$$$ "monos" |-- P.!!! SpecParse.xthms1) []
wenzelm@26988
   950
  >> (fn (((preds, params), specs), monos) =>
wenzelm@26988
   951
      (snd o gen_add_inductive mk_def true coind preds params (flatten_specification specs) monos));
berghofe@23762
   952
berghofe@23762
   953
val ind_decl = gen_ind_decl add_ind_def;
wenzelm@6424
   954
wenzelm@26988
   955
val _ = OuterSyntax.local_theory "inductive" "define inductive predicates" K.thy_decl (ind_decl false);
wenzelm@26988
   956
val _ = OuterSyntax.local_theory "coinductive" "define coinductive predicates" K.thy_decl (ind_decl true);
wenzelm@6723
   957
wenzelm@24867
   958
val _ =
wenzelm@26988
   959
  OuterSyntax.local_theory "inductive_cases"
wenzelm@21367
   960
    "create simplified instances of elimination rules (improper)" K.thy_script
wenzelm@26988
   961
    (P.and_list1 SpecParse.spec >> (fn specs => snd o inductive_cases specs));
wenzelm@7107
   962
berghofe@5094
   963
end;
wenzelm@6424
   964
wenzelm@6424
   965
end;