src/HOL/BNF/Tools/bnf_gfp_util.ML

avoid explosion in higher-order unification algorithm

(*  Title:      HOL/BNF/Tools/bnf_gfp_util.ML
    Author:     Dmitriy Traytel, TU Muenchen
    Copyright   2012

Library for the codatatype construction.
*)

signature BNF_GFP_UTIL =
sig
  val mk_rec_simps: int -> thm -> thm list -> thm list list

  val dest_listT: typ -> typ

  val mk_Cons: term -> term -> term
  val mk_Shift: term -> term -> term
  val mk_Succ: term -> term -> term
  val mk_Times: term * term -> term
  val mk_append: term * term -> term
  val mk_congruent: term -> term -> term
  val mk_clists: term -> term
  val mk_diag: term -> term
  val mk_equiv: term -> term -> term
  val mk_fromCard: term -> term -> term
  val mk_list_rec: term -> term -> term
  val mk_nat_rec: term -> term -> term
  val mk_pickWP: term -> term -> term -> term -> term -> term
  val mk_prefCl: term -> term
  val mk_prefixeq: term -> term -> term
  val mk_proj: term -> term
  val mk_quotient: term -> term -> term
  val mk_shift: term -> term -> term
  val mk_size: term -> term
  val mk_thePull: term -> term -> term -> term -> term
  val mk_toCard: term -> term -> term
  val mk_undefined: typ -> term
  val mk_univ: term -> term

  val mk_specN: int -> thm -> thm

  val mk_InN_Field: int -> int -> thm
  val mk_InN_inject: int -> int -> thm
  val mk_InN_not_InM: int -> int -> thm
end;

structure BNF_GFP_Util : BNF_GFP_UTIL =
struct

open BNF_Util

val mk_append = HOLogic.mk_binop @{const_name append};

fun mk_equiv B R =
  Const (@{const_name equiv}, fastype_of B --> fastype_of R --> HOLogic.boolT) $ B $ R;

fun mk_Sigma (A, B) =
  let
    val AT = fastype_of A;
    val BT = fastype_of B;
    val ABT = mk_relT (HOLogic.dest_setT AT, HOLogic.dest_setT (range_type BT));
  in Const (@{const_name Sigma}, AT --> BT --> ABT) $ A $ B end;

fun mk_diag A =
  let
    val AT = fastype_of A;
    val AAT = mk_relT (HOLogic.dest_setT AT, HOLogic.dest_setT AT);
  in Const (@{const_name diag}, AT --> AAT) $ A end;

fun mk_Times (A, B) =
  let val AT = HOLogic.dest_setT (fastype_of A);
  in mk_Sigma (A, Term.absdummy AT B) end;

fun dest_listT (Type (@{type_name list}, [T])) = T
  | dest_listT T = raise TYPE ("dest_setT: set type expected", [T], []);

fun mk_Succ Kl kl =
  let val T = fastype_of kl;
  in
    Const (@{const_name Succ},
      HOLogic.mk_setT T --> T --> HOLogic.mk_setT (dest_listT T)) $ Kl $ kl
  end;

fun mk_Shift Kl k =
  let val T = fastype_of Kl;
  in
    Const (@{const_name Shift}, T --> dest_listT (HOLogic.dest_setT T) --> T) $ Kl $ k
  end;

fun mk_shift lab k =
  let val T = fastype_of lab;
  in
    Const (@{const_name shift}, T --> dest_listT (Term.domain_type T) --> T) $ lab $ k
  end;

fun mk_prefCl A =
  Const (@{const_name prefCl}, fastype_of A --> HOLogic.boolT) $ A;

fun mk_prefixeq xs ys =
  Const (@{const_name prefixeq}, fastype_of xs --> fastype_of ys --> HOLogic.boolT) $ xs $ ys;

fun mk_clists r =
  let val T = fastype_of r;
  in Const (@{const_name clists}, T --> mk_relT (`I (HOLogic.listT (fst (dest_relT T))))) $ r end;

fun mk_toCard A r =
  let
    val AT = fastype_of A;
    val rT = fastype_of r;
  in
    Const (@{const_name toCard},
      AT --> rT --> HOLogic.dest_setT AT --> fst (dest_relT rT)) $ A $ r
  end;

fun mk_fromCard A r =
  let
    val AT = fastype_of A;
    val rT = fastype_of r;
  in
    Const (@{const_name fromCard},
      AT --> rT --> fst (dest_relT rT) --> HOLogic.dest_setT AT) $ A $ r
  end;

fun mk_Cons x xs =
  let val T = fastype_of xs;
  in Const (@{const_name Cons}, dest_listT T --> T --> T) $ x $ xs end;

fun mk_size t = HOLogic.size_const (fastype_of t) $ t;

fun mk_quotient A R =
  let val T = fastype_of A;
  in Const (@{const_name quotient}, T --> fastype_of R --> HOLogic.mk_setT T) $ A $ R end;

fun mk_proj R =
  let val ((AT, BT), T) = `dest_relT (fastype_of R);
  in Const (@{const_name proj}, T --> AT --> HOLogic.mk_setT BT) $ R end;

fun mk_univ f =
  let val ((AT, BT), T) = `dest_funT (fastype_of f);
  in Const (@{const_name univ}, T --> HOLogic.mk_setT AT --> BT) $ f end;

fun mk_congruent R f =
  Const (@{const_name congruent}, fastype_of R --> fastype_of f --> HOLogic.boolT) $ R $ f;

fun mk_undefined T = Const (@{const_name undefined}, T);

fun mk_nat_rec Zero Suc =
  let val T = fastype_of Zero;
  in Const (@{const_name nat_rec}, T --> fastype_of Suc --> HOLogic.natT --> T) $ Zero $ Suc end;

fun mk_list_rec Nil Cons =
  let
    val T = fastype_of Nil;
    val (U, consT) = `(Term.domain_type) (fastype_of Cons);
  in
    Const (@{const_name list_rec}, T --> consT --> HOLogic.listT U --> T) $ Nil $ Cons
  end;

fun mk_thePull B1 B2 f1 f2 =
  let
    val fT1 = fastype_of f1;
    val fT2 = fastype_of f2;
    val BT1 = domain_type fT1;
    val BT2 = domain_type fT2;
  in
    Const (@{const_name thePull}, HOLogic.mk_setT BT1 --> HOLogic.mk_setT BT2 --> fT1 --> fT2 -->
      mk_relT (BT1, BT2)) $ B1 $ B2 $ f1 $ f2
  end;

fun mk_pickWP A f1 f2 b1 b2 =
  let
    val fT1 = fastype_of f1;
    val fT2 = fastype_of f2;
    val AT = domain_type fT1;
    val BT1 = range_type fT1;
    val BT2 = range_type fT2;
  in
    Const (@{const_name pickWP}, HOLogic.mk_setT AT --> fT1 --> fT2 --> BT1 --> BT2 --> AT) $
      A $ f1 $ f2 $ b1 $ b2
  end;

fun mk_InN_not_InM 1 _ = @{thm Inl_not_Inr}
  | mk_InN_not_InM n m =
    if n > m then mk_InN_not_InM m n RS @{thm not_sym}
    else mk_InN_not_InM (n - 1) (m - 1) RS @{thm not_arg_cong_Inr};

fun mk_InN_Field 1 1 = @{thm TrueE[OF TrueI]}
  | mk_InN_Field _ 1 = @{thm Inl_Field_csum}
  | mk_InN_Field 2 2 = @{thm Inr_Field_csum}
  | mk_InN_Field n m = mk_InN_Field (n - 1) (m - 1) RS @{thm Inr_Field_csum};

fun mk_InN_inject 1 _ = @{thm TrueE[OF TrueI]}
  | mk_InN_inject _ 1 = @{thm Inl_inject}
  | mk_InN_inject 2 2 = @{thm Inr_inject}
  | mk_InN_inject n m = @{thm Inr_inject} RS mk_InN_inject (n - 1) (m - 1);

fun mk_specN 0 thm = thm
  | mk_specN n thm = mk_specN (n - 1) (thm RS spec);

fun mk_rec_simps n rec_thm defs = map (fn i =>
  map (fn def => def RS rec_thm RS mk_nthI n i RS fun_cong) defs) (1 upto n);

end;