src/HOL/Hyperreal/transfer.ML
author huffman
Mon Sep 12 23:14:41 2005 +0200 (2005-09-12 ago)
changeset 17332 4910cf8c0cd2
parent 17329 72637e062a0d
child 17333 605c97701833
permissions -rw-r--r--
added theorem attributes transfer_intro, transfer_unfold, transfer_refold; simplified some proofs; some rearranging
     1 signature TRANSFER_TAC =
     2 sig
     3   val transfer_tac: thm list -> int -> tactic
     4   val setup: (theory -> theory) list
     5 end;
     6 
     7 structure Transfer: TRANSFER_TAC =
     8 struct
     9 
    10 (* TODO: make this list extensible *)
    11 val star_consts =
    12   [ "StarType.star_of", "StarType.Ifun"
    13   , "StarType.unstar", "StarType.Iset" ]
    14 
    15 structure TransferData = TheoryDataFun
    16 (struct
    17   val name = "HOL/transfer";
    18   type T = {
    19     intros: thm list,
    20     unfolds: thm list,
    21     refolds: thm list,
    22     consts: string list
    23   };
    24   val empty = {intros = [], unfolds = [], refolds = [], consts = star_consts};
    25   val copy = I;
    26   val extend = I;
    27   fun merge _
    28     ({intros = intros1, unfolds = unfolds1,
    29       refolds = refolds1, consts = consts1},
    30      {intros = intros2, unfolds = unfolds2,
    31       refolds = refolds2, consts = consts2}) =
    32    {intros = Drule.merge_rules (intros1, intros2),
    33     unfolds = Drule.merge_rules (unfolds1, unfolds2),
    34     refolds = Drule.merge_rules (refolds1, refolds2),
    35     consts = merge_lists consts1 consts2};
    36   fun print _ _ = ();
    37 end);
    38 
    39 val transfer_start = thm "transfer_start"
    40 
    41 fun unstar_typ (Type ("StarType.star",[t])) = unstar_typ t
    42   | unstar_typ (Type (a, Ts)) = Type (a, map unstar_typ Ts)
    43   | unstar_typ T = T
    44 
    45 fun unstar_term consts term =
    46   let
    47     fun delete a = exists (fn x => x = a) consts
    48     fun unstar (Const(a,T) $ t) = if (delete a) then (unstar t)
    49           else (Const(a,unstar_typ T) $ unstar t)
    50       | unstar (f $ t) = unstar f $ unstar t
    51       | unstar (Const(a,T)) = Const(a,unstar_typ T)
    52       | unstar (Abs(a,T,t)) = Abs(a,unstar_typ T,unstar t) 
    53       | unstar t = t
    54   in
    55     unstar term
    56   end
    57 
    58 val atomizers = map thm ["atomize_all", "atomize_imp", "atomize_eq"]
    59 
    60 fun transfer_thm_of thy ths t =
    61   let
    62     val {intros,unfolds,refolds,consts} = TransferData.get thy
    63     val (_$_$t') = concl_of (Tactic.rewrite true unfolds (cterm_of thy t))
    64     val u = unstar_term consts t'
    65     val ct = cterm_of thy (Logic.mk_equals (t,u))
    66     val tacs =
    67       [ rewrite_goals_tac atomizers
    68       , match_tac [transitive_thm] 1
    69       , resolve_tac [transfer_start] 1
    70       , REPEAT_ALL_NEW (resolve_tac intros) 1
    71       , match_tac [reflexive_thm] 1 ]
    72   in
    73     prove_goalw_cterm (ths @ refolds @ unfolds) ct (fn _ => tacs)
    74   end
    75 
    76 fun transfer_tac ths =
    77     SUBGOAL (fn (t,i) =>
    78         (fn th =>
    79             let val thy = theory_of_thm th
    80                 val tr = transfer_thm_of thy ths t
    81             in rewrite_goals_tac [tr] th
    82             end
    83         )
    84     )
    85 
    86 local
    87 fun map_intros f = TransferData.map
    88   (fn {intros,unfolds,refolds,consts} =>
    89     {intros=f intros, unfolds=unfolds, refolds=refolds, consts=consts})
    90 
    91 fun map_unfolds f = TransferData.map
    92   (fn {intros,unfolds,refolds,consts} =>
    93     {intros=intros, unfolds=f unfolds, refolds=refolds, consts=consts})
    94 
    95 fun map_refolds f = TransferData.map
    96   (fn {intros,unfolds,refolds,consts} =>
    97     {intros=intros, unfolds=unfolds, refolds=f refolds, consts=consts})
    98 
    99 fun map_consts f = TransferData.map
   100   (fn {intros,unfolds,refolds,consts} =>
   101     {intros=intros, unfolds=unfolds, refolds=refolds, consts=f consts})
   102 in
   103 fun intro_add_global (thy, thm) = (map_intros (Drule.add_rule thm) thy, thm);
   104 fun intro_del_global (thy, thm) = (map_intros (Drule.del_rule thm) thy, thm);
   105 
   106 fun unfold_add_global (thy, thm) = (map_unfolds (Drule.add_rule thm) thy, thm);
   107 fun unfold_del_global (thy, thm) = (map_unfolds (Drule.del_rule thm) thy, thm);
   108 
   109 fun refold_add_global (thy, thm) = (map_refolds (Drule.add_rule thm) thy, thm);
   110 fun refold_del_global (thy, thm) = (map_refolds (Drule.del_rule thm) thy, thm);
   111 end
   112 
   113 local
   114   val undef_local =
   115     Attrib.add_del_args
   116       Attrib.undef_local_attribute
   117       Attrib.undef_local_attribute;
   118 in
   119   val intro_attr =
   120    (Attrib.add_del_args intro_add_global intro_del_global, undef_local);
   121   val unfold_attr =
   122    (Attrib.add_del_args unfold_add_global unfold_del_global, undef_local);
   123   val refold_attr =
   124    (Attrib.add_del_args refold_add_global refold_del_global, undef_local);
   125 end
   126 
   127 val transfer_method = Method.SIMPLE_METHOD' HEADGOAL o transfer_tac;
   128 
   129 val setup =
   130   [ TransferData.init,
   131     Attrib.add_attributes
   132     [ ("transfer_intro", intro_attr,
   133        "declaration of transfer introduction rule"),
   134       ("transfer_unfold", unfold_attr,
   135        "declaration of transfer unfolding rule"),
   136       ("transfer_refold", refold_attr,
   137        "declaration of transfer refolding rule")
   138     ],
   139     Method.add_method
   140     ("transfer", Method.thms_args transfer_method, "transfer principle")
   141   ];
   142 
   143 end;