src/HOL/Tools/inductive.ML
author wenzelm
Fri Jul 24 22:59:08 2009 +0200 (2009-07-24)
changeset 32181 7e460c2d4223
parent 32172 c4e55f30d527
child 32602 f2b741473860
permissions -rw-r--r--
more antiquotations instead of adhoc ML stuff;
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(*  Title:      HOL/Tools/inductive.ML
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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 =
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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: (Attrib.binding * string list) list -> local_theory ->
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    thm list list * local_theory
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  val inductive_cases_i: (Attrib.binding * term list) list -> local_theory ->
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    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 -> ((binding * typ) * mixfix) list ->
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    (string * typ) list -> (Attrib.binding * term) list -> thm list -> local_theory ->
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    inductive_result * local_theory
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  val add_inductive: bool -> bool ->
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    (binding * string option * mixfix) list ->
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    (binding * string option * mixfix) list ->
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    (Attrib.binding * string) list ->
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    (Facts.ref * Attrib.src list) list ->
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    bool -> local_theory -> inductive_result * local_theory
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  val add_inductive_global: string -> inductive_flags ->
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    ((binding * typ) * mixfix) list -> (string * typ) list -> (Attrib.binding * term) list ->
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    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 =
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sig
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  include BASIC_INDUCTIVE
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  type add_ind_def
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  val declare_rules: string -> binding -> bool -> bool -> string list ->
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    thm list -> binding 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 -> inductive_flags ->
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    ((binding * typ) * mixfix) list -> (string * typ) list -> (Attrib.binding * term) list ->
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    thm list -> local_theory -> inductive_result * local_theory
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  val gen_add_inductive: add_ind_def -> bool -> bool ->
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    (binding * string option * mixfix) list ->
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    (binding * string option * mixfix) list ->
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    (Attrib.binding * string) list -> (Facts.ref * Attrib.src list) list ->
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    bool -> 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 -> (bool -> local_theory -> local_theory) * OuterParse.token list
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end;
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structure Inductive: INDUCTIVE =
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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 mk_meta_eq
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  @{lemma "(~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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    by (fact simp_thms)+};
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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 (Display.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 _ =>
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    error ("Bad monotonicity theorem:\n" ^ Display.string_of_thm_without_context 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 (@{const_name undefined}, 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 (fn c' => c' = 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 ((binding, att), rule) =
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  let
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    val err_name = Binding.str_of binding;
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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 err_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 err_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 err_name rule') t;
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            List.app check_prem (prems ~~ aprems))
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         else err_in_rule ctxt err_name rule' bad_concl
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     | _ => err_in_rule ctxt err_name rule' bad_concl);
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    ((binding, 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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  #> Simplifier.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 fork_mono predT fp_fun monos ctxt =
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 (message (quiet_mode orelse skip_mono andalso !quick_and_dirty orelse fork_mono)
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    "  Proving monotonicity ...";
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  (if skip_mono then SkipProof.prove else if fork_mono then Goal.prove_future else Goal.prove) ctxt
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    [] []
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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,
berghofe@21024
   325
      REPEAT (resolve_tac [le_funI, le_boolI'] 1),
berghofe@21024
   326
      REPEAT (FIRST
berghofe@21024
   327
        [atac 1,
wenzelm@21367
   328
         resolve_tac (List.concat (map mk_mono monos) @ get_monos ctxt) 1,
berghofe@21024
   329
         etac le_funE 1, dtac le_boolD 1])]));
berghofe@5094
   330
wenzelm@6424
   331
wenzelm@10735
   332
(* prove introduction rules *)
berghofe@5094
   333
wenzelm@26477
   334
fun prove_intrs quiet_mode coind mono fp_def k params intr_ts rec_preds_defs ctxt =
berghofe@5094
   335
  let
wenzelm@26477
   336
    val _ = clean_message quiet_mode "  Proving the introduction rules ...";
berghofe@5094
   337
berghofe@21024
   338
    val unfold = funpow k (fn th => th RS fun_cong)
berghofe@21024
   339
      (mono RS (fp_def RS
berghofe@21024
   340
        (if coind then def_gfp_unfold else def_lfp_unfold)));
berghofe@5094
   341
berghofe@5094
   342
    fun select_disj 1 1 = []
berghofe@5094
   343
      | select_disj _ 1 = [rtac disjI1]
berghofe@5094
   344
      | select_disj n i = (rtac disjI2)::(select_disj (n - 1) (i - 1));
berghofe@5094
   345
berghofe@21024
   346
    val rules = [refl, TrueI, notFalseI, exI, conjI];
berghofe@21024
   347
berghofe@22605
   348
    val intrs = map_index (fn (i, intr) => rulify
berghofe@22605
   349
      (SkipProof.prove ctxt (map (fst o dest_Free) params) [] intr (fn _ => EVERY
berghofe@21024
   350
       [rewrite_goals_tac rec_preds_defs,
berghofe@21024
   351
        rtac (unfold RS iffD2) 1,
berghofe@21024
   352
        EVERY1 (select_disj (length intr_ts) (i + 1)),
wenzelm@17985
   353
        (*Not ares_tac, since refl must be tried before any equality assumptions;
wenzelm@17985
   354
          backtracking may occur if the premises have extra variables!*)
berghofe@21024
   355
        DEPTH_SOLVE_1 (resolve_tac rules 1 APPEND assume_tac 1)]))) intr_ts
berghofe@5094
   356
berghofe@5094
   357
  in (intrs, unfold) end;
berghofe@5094
   358
wenzelm@6424
   359
wenzelm@10735
   360
(* prove elimination rules *)
berghofe@5094
   361
wenzelm@26477
   362
fun prove_elims quiet_mode cs params intr_ts intr_names unfold rec_preds_defs ctxt =
berghofe@5094
   363
  let
wenzelm@26477
   364
    val _ = clean_message quiet_mode "  Proving the elimination rules ...";
berghofe@5094
   365
berghofe@22605
   366
    val ([pname], ctxt') = ctxt |>
berghofe@22605
   367
      Variable.add_fixes (map (fst o dest_Free) params) |> snd |>
berghofe@22605
   368
      Variable.variant_fixes ["P"];
berghofe@21024
   369
    val P = HOLogic.mk_Trueprop (Free (pname, HOLogic.boolT));
berghofe@21024
   370
berghofe@21024
   371
    fun dest_intr r =
berghofe@21024
   372
      (the (dest_predicate cs params (HOLogic.dest_Trueprop (Logic.strip_assums_concl r))),
berghofe@21024
   373
       Logic.strip_assums_hyp r, Logic.strip_params r);
berghofe@21024
   374
berghofe@21024
   375
    val intrs = map dest_intr intr_ts ~~ intr_names;
berghofe@21024
   376
berghofe@21024
   377
    val rules1 = [disjE, exE, FalseE];
berghofe@21024
   378
    val rules2 = [conjE, FalseE, notTrueE];
berghofe@21024
   379
berghofe@21024
   380
    fun prove_elim c =
berghofe@21024
   381
      let
berghofe@21024
   382
        val Ts = List.drop (binder_types (fastype_of c), length params);
berghofe@21024
   383
        val (anames, ctxt'') = Variable.variant_fixes (mk_names "a" (length Ts)) ctxt';
berghofe@21024
   384
        val frees = map Free (anames ~~ Ts);
berghofe@21024
   385
berghofe@21024
   386
        fun mk_elim_prem ((_, _, us, _), ts, params') =
berghofe@21024
   387
          list_all (params',
berghofe@21024
   388
            Logic.list_implies (map (HOLogic.mk_Trueprop o HOLogic.mk_eq)
berghofe@21024
   389
              (frees ~~ us) @ ts, P));
berghofe@21024
   390
        val c_intrs = (List.filter (equal c o #1 o #1 o #1) intrs);
berghofe@21024
   391
        val prems = HOLogic.mk_Trueprop (list_comb (c, params @ frees)) ::
berghofe@21024
   392
           map mk_elim_prem (map #1 c_intrs)
berghofe@21024
   393
      in
berghofe@21048
   394
        (SkipProof.prove ctxt'' [] prems P
berghofe@21024
   395
          (fn {prems, ...} => EVERY
berghofe@21024
   396
            [cut_facts_tac [hd prems] 1,
berghofe@21024
   397
             rewrite_goals_tac rec_preds_defs,
berghofe@21024
   398
             dtac (unfold RS iffD1) 1,
berghofe@21024
   399
             REPEAT (FIRSTGOAL (eresolve_tac rules1)),
berghofe@21024
   400
             REPEAT (FIRSTGOAL (eresolve_tac rules2)),
berghofe@21024
   401
             EVERY (map (fn prem =>
berghofe@21024
   402
               DEPTH_SOLVE_1 (ares_tac [rewrite_rule rec_preds_defs prem, conjI] 1)) (tl prems))])
berghofe@21024
   403
          |> rulify
berghofe@21048
   404
          |> singleton (ProofContext.export ctxt'' ctxt),
berghofe@21048
   405
         map #2 c_intrs)
berghofe@21024
   406
      end
berghofe@21024
   407
berghofe@21024
   408
   in map prove_elim cs end;
berghofe@5094
   409
wenzelm@6424
   410
wenzelm@10735
   411
(* derivation of simplified elimination rules *)
berghofe@5094
   412
wenzelm@11682
   413
local
wenzelm@11682
   414
wenzelm@11682
   415
(*delete needless equality assumptions*)
wenzelm@29064
   416
val refl_thin = Goal.prove_global @{theory HOL} [] [] @{prop "!!P. a = a ==> P ==> P"}
haftmann@22838
   417
  (fn _ => assume_tac 1);
berghofe@21024
   418
val elim_rls = [asm_rl, FalseE, refl_thin, conjE, exE];
wenzelm@11682
   419
val elim_tac = REPEAT o Tactic.eresolve_tac elim_rls;
wenzelm@11682
   420
berghofe@23762
   421
fun simp_case_tac ss i =
berghofe@23762
   422
  EVERY' [elim_tac, asm_full_simp_tac ss, elim_tac, REPEAT o bound_hyp_subst_tac] i;
wenzelm@21367
   423
wenzelm@11682
   424
in
wenzelm@9598
   425
wenzelm@21367
   426
fun mk_cases ctxt prop =
wenzelm@7107
   427
  let
wenzelm@21367
   428
    val thy = ProofContext.theory_of ctxt;
wenzelm@32149
   429
    val ss = simpset_of ctxt;
wenzelm@21367
   430
wenzelm@21526
   431
    fun err msg =
wenzelm@21526
   432
      error (Pretty.string_of (Pretty.block
wenzelm@24920
   433
        [Pretty.str msg, Pretty.fbrk, Syntax.pretty_term ctxt prop]));
wenzelm@21526
   434
wenzelm@24861
   435
    val elims = Induct.find_casesP ctxt prop;
wenzelm@21367
   436
wenzelm@21367
   437
    val cprop = Thm.cterm_of thy prop;
berghofe@23762
   438
    val tac = ALLGOALS (simp_case_tac ss) THEN prune_params_tac;
wenzelm@21367
   439
    fun mk_elim rl =
wenzelm@21367
   440
      Thm.implies_intr cprop (Tactic.rule_by_tactic tac (Thm.assume cprop RS rl))
wenzelm@21367
   441
      |> singleton (Variable.export (Variable.auto_fixes prop ctxt) ctxt);
wenzelm@7107
   442
  in
wenzelm@7107
   443
    (case get_first (try mk_elim) elims of
skalberg@15531
   444
      SOME r => r
wenzelm@21526
   445
    | NONE => err "Proposition not an inductive predicate:")
wenzelm@7107
   446
  end;
wenzelm@7107
   447
wenzelm@11682
   448
end;
wenzelm@11682
   449
wenzelm@7107
   450
wenzelm@21367
   451
(* inductive_cases *)
wenzelm@7107
   452
wenzelm@21367
   453
fun gen_inductive_cases prep_att prep_prop args lthy =
wenzelm@9598
   454
  let
wenzelm@21367
   455
    val thy = ProofContext.theory_of lthy;
wenzelm@12876
   456
    val facts = args |> map (fn ((a, atts), props) =>
wenzelm@21367
   457
      ((a, map (prep_att thy) atts),
wenzelm@21367
   458
        map (Thm.no_attributes o single o mk_cases lthy o prep_prop lthy) props));
haftmann@31177
   459
  in lthy |> LocalTheory.notes Thm.generatedK facts |>> map snd end;
berghofe@5094
   460
wenzelm@24509
   461
val inductive_cases = gen_inductive_cases Attrib.intern_src Syntax.read_prop;
wenzelm@24509
   462
val inductive_cases_i = gen_inductive_cases (K I) Syntax.check_prop;
wenzelm@7107
   463
wenzelm@6424
   464
wenzelm@30722
   465
val ind_cases_setup =
wenzelm@30722
   466
  Method.setup @{binding ind_cases}
wenzelm@30722
   467
    (Scan.lift (Scan.repeat1 Args.name_source --
wenzelm@30722
   468
      Scan.optional (Args.$$$ "for" |-- Scan.repeat1 Args.name) []) >>
wenzelm@30722
   469
      (fn (raw_props, fixes) => fn ctxt =>
wenzelm@30722
   470
        let
wenzelm@30722
   471
          val (_, ctxt') = Variable.add_fixes fixes ctxt;
wenzelm@30722
   472
          val props = Syntax.read_props ctxt' raw_props;
wenzelm@30722
   473
          val ctxt'' = fold Variable.declare_term props ctxt';
wenzelm@30722
   474
          val rules = ProofContext.export ctxt'' ctxt (map (mk_cases ctxt'') props)
wenzelm@30722
   475
        in Method.erule 0 rules end))
wenzelm@30722
   476
    "dynamic case analysis on predicates";
wenzelm@9598
   477
wenzelm@9598
   478
wenzelm@10735
   479
(* prove induction rule *)
berghofe@5094
   480
wenzelm@26477
   481
fun prove_indrule quiet_mode cs argTs bs xs rec_const params intr_ts mono
berghofe@21024
   482
    fp_def rec_preds_defs ctxt =
berghofe@5094
   483
  let
wenzelm@26477
   484
    val _ = clean_message quiet_mode "  Proving the induction rule ...";
wenzelm@20047
   485
    val thy = ProofContext.theory_of ctxt;
berghofe@5094
   486
berghofe@21024
   487
    (* predicates for induction rule *)
berghofe@21024
   488
berghofe@22605
   489
    val (pnames, ctxt') = ctxt |>
berghofe@22605
   490
      Variable.add_fixes (map (fst o dest_Free) params) |> snd |>
berghofe@22605
   491
      Variable.variant_fixes (mk_names "P" (length cs));
berghofe@21024
   492
    val preds = map Free (pnames ~~
berghofe@21024
   493
      map (fn c => List.drop (binder_types (fastype_of c), length params) --->
berghofe@21024
   494
        HOLogic.boolT) cs);
berghofe@21024
   495
berghofe@21024
   496
    (* transform an introduction rule into a premise for induction rule *)
berghofe@21024
   497
berghofe@21024
   498
    fun mk_ind_prem r =
berghofe@21024
   499
      let
berghofe@21024
   500
        fun subst s = (case dest_predicate cs params s of
berghofe@21024
   501
            SOME (_, i, ys, (_, Ts)) =>
berghofe@21024
   502
              let
berghofe@21024
   503
                val k = length Ts;
berghofe@21024
   504
                val bs = map Bound (k - 1 downto 0);
berghofe@23762
   505
                val P = list_comb (List.nth (preds, i),
berghofe@23762
   506
                  map (incr_boundvars k) ys @ bs);
berghofe@21024
   507
                val Q = list_abs (mk_names "x" k ~~ Ts,
berghofe@23762
   508
                  HOLogic.mk_binop inductive_conj_name
berghofe@23762
   509
                    (list_comb (incr_boundvars k s, bs), P))
berghofe@21024
   510
              in (Q, case Ts of [] => SOME (s, P) | _ => NONE) end
berghofe@21024
   511
          | NONE => (case s of
berghofe@21024
   512
              (t $ u) => (fst (subst t) $ fst (subst u), NONE)
berghofe@21024
   513
            | (Abs (a, T, t)) => (Abs (a, T, fst (subst t)), NONE)
berghofe@21024
   514
            | _ => (s, NONE)));
berghofe@7293
   515
berghofe@21024
   516
        fun mk_prem (s, prems) = (case subst s of
berghofe@21024
   517
              (_, SOME (t, u)) => t :: u :: prems
berghofe@21024
   518
            | (t, _) => t :: prems);
berghofe@21024
   519
berghofe@21024
   520
        val SOME (_, i, ys, _) = dest_predicate cs params
berghofe@21024
   521
          (HOLogic.dest_Trueprop (Logic.strip_assums_concl r))
berghofe@21024
   522
berghofe@21024
   523
      in list_all_free (Logic.strip_params r,
wenzelm@30190
   524
        Logic.list_implies (map HOLogic.mk_Trueprop (List.foldr mk_prem
berghofe@21024
   525
          [] (map HOLogic.dest_Trueprop (Logic.strip_assums_hyp r))),
berghofe@21024
   526
            HOLogic.mk_Trueprop (list_comb (List.nth (preds, i), ys))))
berghofe@21024
   527
      end;
berghofe@21024
   528
berghofe@21024
   529
    val ind_prems = map mk_ind_prem intr_ts;
berghofe@21024
   530
wenzelm@21526
   531
berghofe@21024
   532
    (* make conclusions for induction rules *)
berghofe@21024
   533
berghofe@21024
   534
    val Tss = map (binder_types o fastype_of) preds;
berghofe@21024
   535
    val (xnames, ctxt'') =
berghofe@21024
   536
      Variable.variant_fixes (mk_names "x" (length (flat Tss))) ctxt';
berghofe@21024
   537
    val mutual_ind_concl = HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj
berghofe@21024
   538
        (map (fn (((xnames, Ts), c), P) =>
berghofe@21024
   539
           let val frees = map Free (xnames ~~ Ts)
berghofe@21024
   540
           in HOLogic.mk_imp
berghofe@21024
   541
             (list_comb (c, params @ frees), list_comb (P, frees))
berghofe@21024
   542
           end) (unflat Tss xnames ~~ Tss ~~ cs ~~ preds)));
berghofe@5094
   543
paulson@13626
   544
berghofe@5094
   545
    (* make predicate for instantiation of abstract induction rule *)
berghofe@5094
   546
berghofe@21024
   547
    val ind_pred = fold_rev lambda (bs @ xs) (foldr1 HOLogic.mk_conj
wenzelm@30190
   548
      (map_index (fn (i, P) => List.foldr HOLogic.mk_imp
berghofe@21024
   549
         (list_comb (P, make_args' argTs xs (binder_types (fastype_of P))))
berghofe@21024
   550
         (make_bool_args HOLogic.mk_not I bs i)) preds));
berghofe@5094
   551
berghofe@5094
   552
    val ind_concl = HOLogic.mk_Trueprop
haftmann@23881
   553
      (HOLogic.mk_binrel "HOL.ord_class.less_eq" (rec_const, ind_pred));
berghofe@5094
   554
paulson@13626
   555
    val raw_fp_induct = (mono RS (fp_def RS def_lfp_induct));
paulson@13626
   556
berghofe@21024
   557
    val induct = SkipProof.prove ctxt'' [] ind_prems ind_concl
wenzelm@20248
   558
      (fn {prems, ...} => EVERY
wenzelm@17985
   559
        [rewrite_goals_tac [inductive_conj_def],
berghofe@21024
   560
         DETERM (rtac raw_fp_induct 1),
berghofe@21024
   561
         REPEAT (resolve_tac [le_funI, le_boolI] 1),
haftmann@22460
   562
         rewrite_goals_tac (inf_fun_eq :: inf_bool_eq :: simp_thms'),
berghofe@21024
   563
         (*This disjE separates out the introduction rules*)
berghofe@21024
   564
         REPEAT (FIRSTGOAL (eresolve_tac [disjE, exE, FalseE])),
berghofe@5094
   565
         (*Now break down the individual cases.  No disjE here in case
berghofe@5094
   566
           some premise involves disjunction.*)
paulson@13747
   567
         REPEAT (FIRSTGOAL (etac conjE ORELSE' bound_hyp_subst_tac)),
berghofe@21024
   568
         REPEAT (FIRSTGOAL
berghofe@21024
   569
           (resolve_tac [conjI, impI] ORELSE' (etac notE THEN' atac))),
berghofe@21024
   570
         EVERY (map (fn prem => DEPTH_SOLVE_1 (ares_tac [rewrite_rule
berghofe@22980
   571
             (inductive_conj_def :: rec_preds_defs @ simp_thms') prem,
berghofe@22980
   572
           conjI, refl] 1)) prems)]);
berghofe@5094
   573
berghofe@21024
   574
    val lemma = SkipProof.prove ctxt'' [] []
wenzelm@17985
   575
      (Logic.mk_implies (ind_concl, mutual_ind_concl)) (fn _ => EVERY
berghofe@21024
   576
        [rewrite_goals_tac rec_preds_defs,
berghofe@5094
   577
         REPEAT (EVERY
berghofe@5094
   578
           [REPEAT (resolve_tac [conjI, impI] 1),
berghofe@21024
   579
            REPEAT (eresolve_tac [le_funE, le_boolE] 1),
berghofe@21024
   580
            atac 1,
berghofe@21024
   581
            rewrite_goals_tac simp_thms',
berghofe@21024
   582
            atac 1])])
berghofe@5094
   583
berghofe@21024
   584
  in singleton (ProofContext.export ctxt'' ctxt) (induct RS lemma) end;
berghofe@5094
   585
wenzelm@6424
   586
wenzelm@6424
   587
berghofe@21024
   588
(** specification of (co)inductive predicates **)
wenzelm@10729
   589
wenzelm@29388
   590
fun mk_ind_def quiet_mode skip_mono fork_mono alt_name coind cs intr_ts monos params cnames_syn ctxt =
berghofe@5094
   591
  let
haftmann@24915
   592
    val fp_name = if coind then @{const_name Inductive.gfp} else @{const_name Inductive.lfp};
berghofe@5094
   593
berghofe@21024
   594
    val argTs = fold (fn c => fn Ts => Ts @
berghofe@21024
   595
      (List.drop (binder_types (fastype_of c), length params) \\ Ts)) cs [];
berghofe@21024
   596
    val k = log 2 1 (length cs);
berghofe@21024
   597
    val predT = replicate k HOLogic.boolT ---> argTs ---> HOLogic.boolT;
berghofe@21024
   598
    val p :: xs = map Free (Variable.variant_frees ctxt intr_ts
berghofe@21024
   599
      (("p", predT) :: (mk_names "x" (length argTs) ~~ argTs)));
berghofe@21024
   600
    val bs = map Free (Variable.variant_frees ctxt (p :: xs @ intr_ts)
berghofe@21024
   601
      (map (rpair HOLogic.boolT) (mk_names "b" k)));
berghofe@21024
   602
berghofe@21024
   603
    fun subst t = (case dest_predicate cs params t of
berghofe@21024
   604
        SOME (_, i, ts, (Ts, Us)) =>
berghofe@23762
   605
          let
berghofe@23762
   606
            val l = length Us;
berghofe@23762
   607
            val zs = map Bound (l - 1 downto 0)
berghofe@21024
   608
          in
berghofe@21024
   609
            list_abs (map (pair "z") Us, list_comb (p,
berghofe@23762
   610
              make_bool_args' bs i @ make_args argTs
berghofe@23762
   611
                ((map (incr_boundvars l) ts ~~ Ts) @ (zs ~~ Us))))
berghofe@21024
   612
          end
berghofe@21024
   613
      | NONE => (case t of
berghofe@21024
   614
          t1 $ t2 => subst t1 $ subst t2
berghofe@21024
   615
        | Abs (x, T, u) => Abs (x, T, subst u)
berghofe@21024
   616
        | _ => t));
berghofe@5149
   617
berghofe@5094
   618
    (* transform an introduction rule into a conjunction  *)
berghofe@21024
   619
    (*   [| p_i t; ... |] ==> p_j u                       *)
berghofe@5094
   620
    (* is transformed into                                *)
berghofe@21024
   621
    (*   b_j & x_j = u & p b_j t & ...                    *)
berghofe@5094
   622
berghofe@5094
   623
    fun transform_rule r =
berghofe@5094
   624
      let
berghofe@21024
   625
        val SOME (_, i, ts, (Ts, _)) = dest_predicate cs params
berghofe@21048
   626
          (HOLogic.dest_Trueprop (Logic.strip_assums_concl r));
berghofe@21048
   627
        val ps = make_bool_args HOLogic.mk_not I bs i @
berghofe@21048
   628
          map HOLogic.mk_eq (make_args' argTs xs Ts ~~ ts) @
berghofe@21048
   629
          map (subst o HOLogic.dest_Trueprop)
berghofe@21048
   630
            (Logic.strip_assums_hyp r)
wenzelm@30190
   631
      in List.foldr (fn ((x, T), P) => HOLogic.exists_const T $ (Abs (x, T, P)))
berghofe@21048
   632
        (if null ps then HOLogic.true_const else foldr1 HOLogic.mk_conj ps)
berghofe@21048
   633
        (Logic.strip_params r)
berghofe@5094
   634
      end
berghofe@5094
   635
berghofe@5094
   636
    (* make a disjunction of all introduction rules *)
berghofe@5094
   637
berghofe@21024
   638
    val fp_fun = fold_rev lambda (p :: bs @ xs)
berghofe@21024
   639
      (if null intr_ts then HOLogic.false_const
berghofe@21024
   640
       else foldr1 HOLogic.mk_disj (map transform_rule intr_ts));
berghofe@5094
   641
berghofe@21024
   642
    (* add definiton of recursive predicates to theory *)
berghofe@5094
   643
wenzelm@28083
   644
    val rec_name =
haftmann@28965
   645
      if Binding.is_empty alt_name then
wenzelm@30223
   646
        Binding.name (space_implode "_" (map (Binding.name_of o fst) cnames_syn))
wenzelm@28083
   647
      else alt_name;
berghofe@5094
   648
berghofe@21024
   649
    val ((rec_const, (_, fp_def)), ctxt') = ctxt |>
wenzelm@26128
   650
      LocalTheory.define Thm.internalK
berghofe@21024
   651
        ((rec_name, case cnames_syn of [(_, syn)] => syn | _ => NoSyn),
haftmann@28965
   652
         (Attrib.empty_binding, fold_rev lambda params
berghofe@21024
   653
           (Const (fp_name, (predT --> predT) --> predT) $ fp_fun)));
berghofe@21024
   654
    val fp_def' = Simplifier.rewrite (HOL_basic_ss addsimps [fp_def])
berghofe@21024
   655
      (cterm_of (ProofContext.theory_of ctxt') (list_comb (rec_const, params)));
berghofe@21024
   656
    val specs = if length cs < 2 then [] else
berghofe@21024
   657
      map_index (fn (i, (name_mx, c)) =>
berghofe@21024
   658
        let
berghofe@21024
   659
          val Ts = List.drop (binder_types (fastype_of c), length params);
berghofe@21024
   660
          val xs = map Free (Variable.variant_frees ctxt intr_ts
berghofe@21024
   661
            (mk_names "x" (length Ts) ~~ Ts))
berghofe@21024
   662
        in
haftmann@28965
   663
          (name_mx, (Attrib.empty_binding, fold_rev lambda (params @ xs)
berghofe@21024
   664
            (list_comb (rec_const, params @ make_bool_args' bs i @
berghofe@21024
   665
              make_args argTs (xs ~~ Ts)))))
berghofe@21024
   666
        end) (cnames_syn ~~ cs);
wenzelm@26128
   667
    val (consts_defs, ctxt'') = fold_map (LocalTheory.define Thm.internalK) specs ctxt';
berghofe@21024
   668
    val preds = (case cs of [_] => [rec_const] | _ => map #1 consts_defs);
berghofe@5094
   669
wenzelm@29388
   670
    val mono = prove_mono quiet_mode skip_mono fork_mono predT fp_fun monos ctxt'';
wenzelm@29388
   671
    val ((_, [mono']), ctxt''') =
wenzelm@29388
   672
      LocalTheory.note Thm.internalK (Attrib.empty_binding, [mono]) ctxt'';
berghofe@5094
   673
wenzelm@29388
   674
  in (ctxt''', rec_name, mono', fp_def', map (#2 o #2) consts_defs,
berghofe@21024
   675
    list_comb (rec_const, params), preds, argTs, bs, xs)
berghofe@21024
   676
  end;
berghofe@5094
   677
wenzelm@28083
   678
fun declare_rules kind rec_binding coind no_ind cnames intrs intr_bindings intr_atts
berghofe@23762
   679
      elims raw_induct ctxt =
berghofe@23762
   680
  let
wenzelm@30223
   681
    val rec_name = Binding.name_of rec_binding;
wenzelm@30223
   682
    val rec_qualified = Binding.qualify false rec_name;
wenzelm@30223
   683
    val intr_names = map Binding.name_of intr_bindings;
berghofe@23762
   684
    val ind_case_names = RuleCases.case_names intr_names;
berghofe@23762
   685
    val induct =
berghofe@23762
   686
      if coind then
berghofe@23762
   687
        (raw_induct, [RuleCases.case_names [rec_name],
berghofe@23762
   688
          RuleCases.case_conclusion (rec_name, intr_names),
wenzelm@24861
   689
          RuleCases.consumes 1, Induct.coinduct_pred (hd cnames)])
berghofe@23762
   690
      else if no_ind orelse length cnames > 1 then
berghofe@23762
   691
        (raw_induct, [ind_case_names, RuleCases.consumes 0])
berghofe@23762
   692
      else (raw_induct RSN (2, rev_mp), [ind_case_names, RuleCases.consumes 1]);
berghofe@23762
   693
berghofe@23762
   694
    val (intrs', ctxt1) =
berghofe@23762
   695
      ctxt |>
wenzelm@26128
   696
      LocalTheory.notes kind
wenzelm@28107
   697
        (map rec_qualified intr_bindings ~~ intr_atts ~~ map (fn th => [([th],
blanchet@29868
   698
           [Attrib.internal (K (ContextRules.intro_query NONE)),
wenzelm@31902
   699
            Attrib.internal (K Nitpick_Ind_Intros.add)])]) intrs) |>>
berghofe@24744
   700
      map (hd o snd);
berghofe@23762
   701
    val (((_, elims'), (_, [induct'])), ctxt2) =
berghofe@23762
   702
      ctxt1 |>
haftmann@28965
   703
      LocalTheory.note kind ((rec_qualified (Binding.name "intros"), []), intrs') ||>>
berghofe@23762
   704
      fold_map (fn (name, (elim, cases)) =>
wenzelm@30435
   705
        LocalTheory.note kind ((Binding.qualified_name (Long_Name.qualify (Long_Name.base_name name) "cases"),
berghofe@23762
   706
          [Attrib.internal (K (RuleCases.case_names cases)),
berghofe@23762
   707
           Attrib.internal (K (RuleCases.consumes 1)),
wenzelm@24861
   708
           Attrib.internal (K (Induct.cases_pred name)),
berghofe@23762
   709
           Attrib.internal (K (ContextRules.elim_query NONE))]), [elim]) #>
berghofe@23762
   710
        apfst (hd o snd)) (if null elims then [] else cnames ~~ elims) ||>>
wenzelm@28107
   711
      LocalTheory.note kind
haftmann@28965
   712
        ((rec_qualified (Binding.name (coind_prefix coind ^ "induct")),
wenzelm@28107
   713
          map (Attrib.internal o K) (#2 induct)), [rulify (#1 induct)]);
berghofe@23762
   714
berghofe@23762
   715
    val ctxt3 = if no_ind orelse coind then ctxt2 else
wenzelm@32172
   716
      let val inducts = cnames ~~ Project_Rule.projects ctxt2 (1 upto length cnames) induct'
berghofe@23762
   717
      in
berghofe@23762
   718
        ctxt2 |>
haftmann@28965
   719
        LocalTheory.notes kind [((rec_qualified (Binding.name "inducts"), []),
berghofe@23762
   720
          inducts |> map (fn (name, th) => ([th],
berghofe@23762
   721
            [Attrib.internal (K ind_case_names),
berghofe@23762
   722
             Attrib.internal (K (RuleCases.consumes 1)),
wenzelm@24861
   723
             Attrib.internal (K (Induct.induct_pred name))])))] |> snd
berghofe@23762
   724
      end
berghofe@23762
   725
  in (intrs', elims', induct', ctxt3) end;
berghofe@23762
   726
berghofe@26534
   727
type inductive_flags =
haftmann@29581
   728
  {quiet_mode: bool, verbose: bool, kind: string, alt_name: binding,
wenzelm@29388
   729
   coind: bool, no_elim: bool, no_ind: bool, skip_mono: bool, fork_mono: bool}
berghofe@26534
   730
berghofe@26534
   731
type add_ind_def =
berghofe@26534
   732
  inductive_flags ->
wenzelm@28084
   733
  term list -> (Attrib.binding * term) list -> thm list ->
haftmann@29581
   734
  term list -> (binding * mixfix) list ->
berghofe@23762
   735
  local_theory -> inductive_result * local_theory
berghofe@23762
   736
wenzelm@29388
   737
fun add_ind_def {quiet_mode, verbose, kind, alt_name, coind, no_elim, no_ind, skip_mono, fork_mono}
wenzelm@24815
   738
    cs intros monos params cnames_syn ctxt =
berghofe@9072
   739
  let
wenzelm@25288
   740
    val _ = null cnames_syn andalso error "No inductive predicates given";
wenzelm@30223
   741
    val names = map (Binding.name_of o fst) cnames_syn;
wenzelm@26477
   742
    val _ = message (quiet_mode andalso not verbose)
wenzelm@28083
   743
      ("Proofs for " ^ coind_prefix coind ^ "inductive predicate(s) " ^ commas_quote names);
berghofe@9072
   744
berghofe@30089
   745
    val cnames = map (LocalTheory.full_name ctxt o #1) cnames_syn;  (* FIXME *)
berghofe@23762
   746
    val ((intr_names, intr_atts), intr_ts) =
berghofe@23762
   747
      apfst split_list (split_list (map (check_rule ctxt cs params) intros));
berghofe@21024
   748
berghofe@21024
   749
    val (ctxt1, rec_name, mono, fp_def, rec_preds_defs, rec_const, preds,
wenzelm@29388
   750
      argTs, bs, xs) = mk_ind_def quiet_mode skip_mono fork_mono alt_name coind cs intr_ts
berghofe@26534
   751
        monos params cnames_syn ctxt;
berghofe@9072
   752
wenzelm@26477
   753
    val (intrs, unfold) = prove_intrs quiet_mode coind mono fp_def (length bs + length xs)
berghofe@22605
   754
      params intr_ts rec_preds_defs ctxt1;
berghofe@21048
   755
    val elims = if no_elim then [] else
wenzelm@30223
   756
      prove_elims quiet_mode cs params intr_ts (map Binding.name_of intr_names)
wenzelm@28083
   757
        unfold rec_preds_defs ctxt1;
berghofe@22605
   758
    val raw_induct = zero_var_indexes
berghofe@21024
   759
      (if no_ind then Drule.asm_rl else
berghofe@23762
   760
       if coind then
berghofe@23762
   761
         singleton (ProofContext.export
berghofe@23762
   762
           (snd (Variable.add_fixes (map (fst o dest_Free) params) ctxt1)) ctxt1)
wenzelm@28839
   763
           (rotate_prems ~1 (ObjectLogic.rulify
wenzelm@28839
   764
             (fold_rule rec_preds_defs
wenzelm@28839
   765
               (rewrite_rule [le_fun_def, le_bool_def, sup_fun_eq, sup_bool_eq]
wenzelm@28839
   766
                (mono RS (fp_def RS def_coinduct))))))
berghofe@21024
   767
       else
wenzelm@26477
   768
         prove_indrule quiet_mode cs argTs bs xs rec_const params intr_ts mono fp_def
berghofe@22605
   769
           rec_preds_defs ctxt1);
berghofe@5094
   770
wenzelm@26128
   771
    val (intrs', elims', induct, ctxt2) = declare_rules kind rec_name coind no_ind
berghofe@23762
   772
      cnames intrs intr_names intr_atts elims raw_induct ctxt1;
berghofe@21048
   773
berghofe@21048
   774
    val result =
berghofe@21048
   775
      {preds = preds,
berghofe@21048
   776
       intrs = intrs',
berghofe@21048
   777
       elims = elims',
berghofe@21048
   778
       raw_induct = rulify raw_induct,
berghofe@23762
   779
       induct = induct};
wenzelm@21367
   780
berghofe@23762
   781
    val ctxt3 = ctxt2
wenzelm@21526
   782
      |> LocalTheory.declaration (fn phi =>
wenzelm@25380
   783
        let val result' = morph_result phi result;
wenzelm@25380
   784
        in put_inductives cnames (*global names!?*) ({names = cnames, coind = coind}, result') end);
berghofe@23762
   785
  in (result, ctxt3) end;
berghofe@5094
   786
wenzelm@6424
   787
wenzelm@10735
   788
(* external interfaces *)
berghofe@5094
   789
wenzelm@26477
   790
fun gen_add_inductive_i mk_def
wenzelm@29388
   791
    (flags as {quiet_mode, verbose, kind, alt_name, coind, no_elim, no_ind, skip_mono, fork_mono})
wenzelm@25029
   792
    cnames_syn pnames spec monos lthy =
berghofe@5094
   793
  let
wenzelm@25029
   794
    val thy = ProofContext.theory_of lthy;
wenzelm@6424
   795
    val _ = Theory.requires thy "Inductive" (coind_prefix coind ^ "inductive definitions");
berghofe@5094
   796
berghofe@21766
   797
wenzelm@25029
   798
    (* abbrevs *)
wenzelm@25029
   799
wenzelm@30223
   800
    val (_, ctxt1) = Variable.add_fixes (map (Binding.name_of o fst o fst) cnames_syn) lthy;
berghofe@21766
   801
wenzelm@25029
   802
    fun get_abbrev ((name, atts), t) =
wenzelm@25029
   803
      if can (Logic.strip_assums_concl #> Logic.dest_equals) t then
wenzelm@25029
   804
        let
haftmann@29006
   805
          val _ = Binding.is_empty name andalso null atts orelse
wenzelm@25029
   806
            error "Abbreviations may not have names or attributes";
wenzelm@25029
   807
          val ((x, T), rhs) = LocalDefs.abs_def (snd (LocalDefs.cert_def ctxt1 t));
wenzelm@28083
   808
          val var =
wenzelm@30223
   809
            (case find_first (fn ((c, _), _) => Binding.name_of c = x) cnames_syn of
wenzelm@25029
   810
              NONE => error ("Undeclared head of abbreviation " ^ quote x)
wenzelm@28083
   811
            | SOME ((b, T'), mx) =>
wenzelm@25029
   812
                if T <> T' then error ("Bad type specification for abbreviation " ^ quote x)
wenzelm@28083
   813
                else (b, mx));
wenzelm@28083
   814
        in SOME (var, rhs) end
wenzelm@25029
   815
      else NONE;
berghofe@21766
   816
wenzelm@25029
   817
    val abbrevs = map_filter get_abbrev spec;
wenzelm@30223
   818
    val bs = map (Binding.name_of o fst o fst) abbrevs;
wenzelm@25029
   819
berghofe@21766
   820
wenzelm@25029
   821
    (* predicates *)
berghofe@21766
   822
wenzelm@25029
   823
    val pre_intros = filter_out (is_some o get_abbrev) spec;
wenzelm@30223
   824
    val cnames_syn' = filter_out (member (op =) bs o Binding.name_of o fst o fst) cnames_syn;
wenzelm@30223
   825
    val cs = map (Free o apfst Binding.name_of o fst) cnames_syn';
wenzelm@25029
   826
    val ps = map Free pnames;
berghofe@5094
   827
wenzelm@30223
   828
    val (_, ctxt2) = lthy |> Variable.add_fixes (map (Binding.name_of o fst o fst) cnames_syn');
wenzelm@25143
   829
    val _ = map (fn abbr => LocalDefs.fixed_abbrev abbr ctxt2) abbrevs;
wenzelm@25143
   830
    val ctxt3 = ctxt2 |> fold (snd oo LocalDefs.fixed_abbrev) abbrevs;
wenzelm@25143
   831
    val expand = Assumption.export_term ctxt3 lthy #> ProofContext.cert_term lthy;
wenzelm@25029
   832
wenzelm@25029
   833
    fun close_rule r = list_all_free (rev (fold_aterms
berghofe@21024
   834
      (fn t as Free (v as (s, _)) =>
wenzelm@25029
   835
          if Variable.is_fixed ctxt1 s orelse
wenzelm@25029
   836
            member (op =) ps t then I else insert (op =) v
wenzelm@25029
   837
        | _ => I) r []), r);
berghofe@5094
   838
haftmann@26736
   839
    val intros = map (apsnd (Syntax.check_term lthy #> close_rule #> expand)) pre_intros;
wenzelm@25029
   840
    val preds = map (fn ((c, _), mx) => (c, mx)) cnames_syn';
berghofe@21048
   841
  in
wenzelm@25029
   842
    lthy
wenzelm@25029
   843
    |> mk_def flags cs intros monos ps preds
wenzelm@25029
   844
    ||> fold (snd oo LocalTheory.abbrev Syntax.mode_default) abbrevs
berghofe@21048
   845
  end;
berghofe@5094
   846
wenzelm@29388
   847
fun gen_add_inductive mk_def verbose coind cnames_syn pnames_syn intro_srcs raw_monos int lthy =
berghofe@5094
   848
  let
wenzelm@30486
   849
    val ((vars, intrs), _) = lthy
wenzelm@30486
   850
      |> ProofContext.set_mode ProofContext.mode_abbrev
wenzelm@30486
   851
      |> Specification.read_spec (cnames_syn @ pnames_syn) intro_srcs;
wenzelm@24721
   852
    val (cs, ps) = chop (length cnames_syn) vars;
wenzelm@24721
   853
    val monos = Attrib.eval_thms lthy raw_monos;
haftmann@31177
   854
    val flags = {quiet_mode = false, verbose = verbose, kind = Thm.generatedK,
wenzelm@29388
   855
      alt_name = Binding.empty, coind = coind, no_elim = false, no_ind = false,
wenzelm@29388
   856
      skip_mono = false, fork_mono = not int};
wenzelm@26128
   857
  in
wenzelm@26128
   858
    lthy
wenzelm@26128
   859
    |> LocalTheory.set_group (serial_string ())
wenzelm@30223
   860
    |> gen_add_inductive_i mk_def flags cs (map (apfst Binding.name_of o fst) ps) intrs monos
wenzelm@26128
   861
  end;
berghofe@5094
   862
berghofe@23762
   863
val add_inductive_i = gen_add_inductive_i add_ind_def;
berghofe@23762
   864
val add_inductive = gen_add_inductive add_ind_def;
berghofe@23762
   865
wenzelm@26128
   866
fun add_inductive_global group flags cnames_syn pnames pre_intros monos thy =
wenzelm@25380
   867
  let
haftmann@29006
   868
    val name = Sign.full_name thy (fst (fst (hd cnames_syn)));
wenzelm@25380
   869
    val ctxt' = thy
wenzelm@25380
   870
      |> TheoryTarget.init NONE
wenzelm@26128
   871
      |> LocalTheory.set_group group
wenzelm@25380
   872
      |> add_inductive_i flags cnames_syn pnames pre_intros monos |> snd
wenzelm@25380
   873
      |> LocalTheory.exit;
wenzelm@25380
   874
    val info = #2 (the_inductive ctxt' name);
wenzelm@25380
   875
  in (info, ProofContext.theory_of ctxt') end;
wenzelm@6424
   876
wenzelm@6424
   877
berghofe@22789
   878
(* read off arities of inductive predicates from raw induction rule *)
berghofe@22789
   879
fun arities_of induct =
berghofe@22789
   880
  map (fn (_ $ t $ u) =>
berghofe@22789
   881
      (fst (dest_Const (head_of t)), length (snd (strip_comb u))))
berghofe@22789
   882
    (HOLogic.dest_conj (HOLogic.dest_Trueprop (concl_of induct)));
berghofe@22789
   883
berghofe@22789
   884
(* read off parameters of inductive predicate from raw induction rule *)
berghofe@22789
   885
fun params_of induct =
berghofe@22789
   886
  let
berghofe@22789
   887
    val (_ $ t $ u :: _) =
berghofe@22789
   888
      HOLogic.dest_conj (HOLogic.dest_Trueprop (concl_of induct));
berghofe@22789
   889
    val (_, ts) = strip_comb t;
berghofe@22789
   890
    val (_, us) = strip_comb u
berghofe@22789
   891
  in
berghofe@22789
   892
    List.take (ts, length ts - length us)
berghofe@22789
   893
  end;
berghofe@22789
   894
berghofe@22789
   895
val pname_of_intr =
berghofe@22789
   896
  concl_of #> HOLogic.dest_Trueprop #> head_of #> dest_Const #> fst;
berghofe@22789
   897
berghofe@22789
   898
(* partition introduction rules according to predicate name *)
berghofe@25822
   899
fun gen_partition_rules f induct intros =
berghofe@25822
   900
  fold_rev (fn r => AList.map_entry op = (pname_of_intr (f r)) (cons r)) intros
berghofe@22789
   901
    (map (rpair [] o fst) (arities_of induct));
berghofe@22789
   902
berghofe@25822
   903
val partition_rules = gen_partition_rules I;
berghofe@25822
   904
fun partition_rules' induct = gen_partition_rules fst induct;
berghofe@25822
   905
berghofe@22789
   906
fun unpartition_rules intros xs =
berghofe@22789
   907
  fold_map (fn r => AList.map_entry_yield op = (pname_of_intr r)
berghofe@22789
   908
    (fn x :: xs => (x, xs)) #>> the) intros xs |> fst;
berghofe@22789
   909
berghofe@22789
   910
(* infer order of variables in intro rules from order of quantifiers in elim rule *)
berghofe@22789
   911
fun infer_intro_vars elim arity intros =
berghofe@22789
   912
  let
berghofe@22789
   913
    val thy = theory_of_thm elim;
berghofe@22789
   914
    val _ :: cases = prems_of elim;
berghofe@22789
   915
    val used = map (fst o fst) (Term.add_vars (prop_of elim) []);
berghofe@22789
   916
    fun mtch (t, u) =
berghofe@22789
   917
      let
berghofe@22789
   918
        val params = Logic.strip_params t;
berghofe@22789
   919
        val vars = map (Var o apfst (rpair 0))
berghofe@22789
   920
          (Name.variant_list used (map fst params) ~~ map snd params);
berghofe@22789
   921
        val ts = map (curry subst_bounds (rev vars))
berghofe@22789
   922
          (List.drop (Logic.strip_assums_hyp t, arity));
berghofe@22789
   923
        val us = Logic.strip_imp_prems u;
berghofe@22789
   924
        val tab = fold (Pattern.first_order_match thy) (ts ~~ us)
berghofe@22789
   925
          (Vartab.empty, Vartab.empty);
berghofe@22789
   926
      in
wenzelm@32035
   927
        map (Envir.subst_term tab) vars
berghofe@22789
   928
      end
berghofe@22789
   929
  in
berghofe@22789
   930
    map (mtch o apsnd prop_of) (cases ~~ intros)
berghofe@22789
   931
  end;
berghofe@22789
   932
berghofe@22789
   933
wenzelm@25978
   934
wenzelm@6437
   935
(** package setup **)
wenzelm@6437
   936
wenzelm@6437
   937
(* setup theory *)
wenzelm@6437
   938
wenzelm@8634
   939
val setup =
wenzelm@30722
   940
  ind_cases_setup #>
wenzelm@30528
   941
  Attrib.setup @{binding mono} (Attrib.add_del mono_add mono_del)
wenzelm@30528
   942
    "declaration of monotonicity rule";
wenzelm@6437
   943
wenzelm@6437
   944
wenzelm@6437
   945
(* outer syntax *)
wenzelm@6424
   946
wenzelm@17057
   947
local structure P = OuterParse and K = OuterKeyword in
wenzelm@6424
   948
wenzelm@27353
   949
val _ = OuterKeyword.keyword "monos";
wenzelm@24867
   950
berghofe@23762
   951
fun gen_ind_decl mk_def coind =
wenzelm@21367
   952
  P.fixes -- P.for_fixes --
wenzelm@30486
   953
  Scan.optional SpecParse.where_alt_specs [] --
wenzelm@22102
   954
  Scan.optional (P.$$$ "monos" |-- P.!!! SpecParse.xthms1) []
wenzelm@26988
   955
  >> (fn (((preds, params), specs), monos) =>
wenzelm@30486
   956
      (snd oo gen_add_inductive mk_def true coind preds params specs monos));
berghofe@23762
   957
berghofe@23762
   958
val ind_decl = gen_ind_decl add_ind_def;
wenzelm@6424
   959
wenzelm@29388
   960
val _ = OuterSyntax.local_theory' "inductive" "define inductive predicates" K.thy_decl (ind_decl false);
wenzelm@29388
   961
val _ = OuterSyntax.local_theory' "coinductive" "define coinductive predicates" K.thy_decl (ind_decl true);
wenzelm@6723
   962
wenzelm@24867
   963
val _ =
wenzelm@26988
   964
  OuterSyntax.local_theory "inductive_cases"
wenzelm@21367
   965
    "create simplified instances of elimination rules (improper)" K.thy_script
wenzelm@30486
   966
    (P.and_list1 SpecParse.specs >> (snd oo inductive_cases));
wenzelm@7107
   967
berghofe@5094
   968
end;
wenzelm@6424
   969
wenzelm@6424
   970
end;