src/HOL/NSA/transfer.ML
author wenzelm
Sun Mar 07 12:19:47 2010 +0100 (2010-03-07)
changeset 35625 9c818cab0dd0
parent 35624 c4e29a0bb8c1
child 37744 3daaf23b9ab4
permissions -rw-r--r--
modernized structure Object_Logic;
     1 (*  Title       : HOL/Hyperreal/transfer.ML
     2     ID          : $Id$
     3     Author      : Brian Huffman
     4 
     5 Transfer principle tactic for nonstandard analysis.
     6 *)
     7 
     8 signature TRANSFER =
     9 sig
    10   val transfer_tac: Proof.context -> thm list -> int -> tactic
    11   val add_const: string -> theory -> theory
    12   val setup: theory -> theory
    13 end;
    14 
    15 structure Transfer: TRANSFER =
    16 struct
    17 
    18 structure TransferData = Generic_Data
    19 (
    20   type T = {
    21     intros: thm list,
    22     unfolds: thm list,
    23     refolds: thm list,
    24     consts: string list
    25   };
    26   val empty = {intros = [], unfolds = [], refolds = [], consts = []};
    27   val extend = I;
    28   fun merge
    29     ({intros = intros1, unfolds = unfolds1,
    30       refolds = refolds1, consts = consts1},
    31      {intros = intros2, unfolds = unfolds2,
    32       refolds = refolds2, consts = consts2}) : T =
    33    {intros = Thm.merge_thms (intros1, intros2),
    34     unfolds = Thm.merge_thms (unfolds1, unfolds2),
    35     refolds = Thm.merge_thms (refolds1, refolds2),
    36     consts = Library.merge (op =) (consts1, consts2)};
    37 );
    38 
    39 fun unstar_typ (Type ("StarDef.star",[t])) = unstar_typ t
    40   | unstar_typ (Type (a, Ts)) = Type (a, map unstar_typ Ts)
    41   | unstar_typ T = T
    42 
    43 fun unstar_term consts term =
    44   let
    45     fun unstar (Const(a,T) $ t) = if member (op =) consts a then (unstar t)
    46           else (Const(a,unstar_typ T) $ unstar t)
    47       | unstar (f $ t) = unstar f $ unstar t
    48       | unstar (Const(a,T)) = Const(a,unstar_typ T)
    49       | unstar (Abs(a,T,t)) = Abs(a,unstar_typ T,unstar t)
    50       | unstar t = t
    51   in
    52     unstar term
    53   end
    54 
    55 fun transfer_thm_of ctxt ths t =
    56   let
    57     val thy = ProofContext.theory_of ctxt;
    58     val {intros,unfolds,refolds,consts} = TransferData.get (Context.Proof ctxt);
    59     val meta = Local_Defs.meta_rewrite_rule ctxt;
    60     val ths' = map meta ths;
    61     val unfolds' = map meta unfolds and refolds' = map meta refolds;
    62     val (_$_$t') = concl_of (MetaSimplifier.rewrite true unfolds' (cterm_of thy t))
    63     val u = unstar_term consts t'
    64     val tac =
    65       rewrite_goals_tac (ths' @ refolds' @ unfolds') THEN
    66       ALLGOALS Object_Logic.full_atomize_tac THEN
    67       match_tac [transitive_thm] 1 THEN
    68       resolve_tac [@{thm transfer_start}] 1 THEN
    69       REPEAT_ALL_NEW (resolve_tac intros) 1 THEN
    70       match_tac [reflexive_thm] 1
    71   in Goal.prove ctxt [] [] (Logic.mk_equals (t,u)) (K tac) end
    72 
    73 fun transfer_tac ctxt ths =
    74     SUBGOAL (fn (t,i) =>
    75         (fn th =>
    76             let
    77               val tr = transfer_thm_of ctxt ths t
    78               val (_$l$r) = concl_of tr;
    79               val trs = if l aconv r then [] else [tr];
    80             in rewrite_goals_tac trs th end))
    81 
    82 local
    83 
    84 fun map_intros f = TransferData.map
    85   (fn {intros,unfolds,refolds,consts} =>
    86     {intros=f intros, unfolds=unfolds, refolds=refolds, consts=consts})
    87 
    88 fun map_unfolds f = TransferData.map
    89   (fn {intros,unfolds,refolds,consts} =>
    90     {intros=intros, unfolds=f unfolds, refolds=refolds, consts=consts})
    91 
    92 fun map_refolds f = TransferData.map
    93   (fn {intros,unfolds,refolds,consts} =>
    94     {intros=intros, unfolds=unfolds, refolds=f refolds, consts=consts})
    95 in
    96 val intro_add = Thm.declaration_attribute (map_intros o Thm.add_thm);
    97 val intro_del = Thm.declaration_attribute (map_intros o Thm.del_thm);
    98 
    99 val unfold_add = Thm.declaration_attribute (map_unfolds o Thm.add_thm);
   100 val unfold_del = Thm.declaration_attribute (map_unfolds o Thm.del_thm);
   101 
   102 val refold_add = Thm.declaration_attribute (map_refolds o Thm.add_thm);
   103 val refold_del = Thm.declaration_attribute (map_refolds o Thm.del_thm);
   104 end
   105 
   106 fun add_const c = Context.theory_map (TransferData.map
   107   (fn {intros,unfolds,refolds,consts} =>
   108     {intros=intros, unfolds=unfolds, refolds=refolds, consts=c::consts}))
   109 
   110 val setup =
   111   Attrib.setup @{binding transfer_intro} (Attrib.add_del intro_add intro_del)
   112     "declaration of transfer introduction rule" #>
   113   Attrib.setup @{binding transfer_unfold} (Attrib.add_del unfold_add unfold_del)
   114     "declaration of transfer unfolding rule" #>
   115   Attrib.setup @{binding transfer_refold} (Attrib.add_del refold_add refold_del)
   116     "declaration of transfer refolding rule" #>
   117   Method.setup @{binding transfer} (Attrib.thms >> (fn ths => fn ctxt =>
   118     SIMPLE_METHOD' (transfer_tac ctxt ths))) "transfer principle";
   119 
   120 end;