(* Title : HOL/Hyperreal/transfer.ML ID : $Id: transfer.ML,v 1.5 2005/09/15 23:42:57 huffman Exp $ Author : Brian Huffman Transfer principle tactic for nonstandard analysis *) signature TRANSFER_TAC = sig val transfer_tac: thm list -> int -> tactic val add_const: string -> theory -> theory val setup: (theory -> theory) list end; structure Transfer: TRANSFER_TAC = struct structure TransferData = TheoryDataFun (struct val name = "HOL/transfer"; type T = { intros: thm list, unfolds: thm list, refolds: thm list, consts: string list }; val empty = {intros = [], unfolds = [], refolds = [], consts = []}; val copy = I; val extend = I; fun merge _ ({intros = intros1, unfolds = unfolds1, refolds = refolds1, consts = consts1}, {intros = intros2, unfolds = unfolds2, refolds = refolds2, consts = consts2}) = {intros = Drule.merge_rules (intros1, intros2), unfolds = Drule.merge_rules (unfolds1, unfolds2), refolds = Drule.merge_rules (refolds1, refolds2), consts = merge_lists consts1 consts2}; fun print _ _ = (); end); val transfer_start = thm "transfer_start" fun unstar_typ (Type ("StarDef.star",[t])) = unstar_typ t | unstar_typ (Type (a, Ts)) = Type (a, map unstar_typ Ts) | unstar_typ T = T fun unstar_term consts term = let fun unstar (Const(a,T) $ t) = if (a mem consts) then (unstar t) else (Const(a,unstar_typ T) $ unstar t) | unstar (f $ t) = unstar f $ unstar t | unstar (Const(a,T)) = Const(a,unstar_typ T) | unstar (Abs(a,T,t)) = Abs(a,unstar_typ T,unstar t) | unstar t = t in unstar term end val atomizers = map thm ["atomize_all", "atomize_imp", "atomize_eq"] fun transfer_thm_of thy ths t = let val {intros,unfolds,refolds,consts} = TransferData.get thy val (_$_$t') = concl_of (Tactic.rewrite true unfolds (cterm_of thy t)) val u = unstar_term consts t' val ct = cterm_of thy (Logic.mk_equals (t,u)) val tacs = [ rewrite_goals_tac atomizers , match_tac [transitive_thm] 1 , resolve_tac [transfer_start] 1 , REPEAT_ALL_NEW (resolve_tac intros) 1 , match_tac [reflexive_thm] 1 ] in prove_goalw_cterm (ths @ refolds @ unfolds) ct (fn _ => tacs) end fun transfer_tac ths = SUBGOAL (fn (t,i) => (fn th => let val thy = theory_of_thm th val tr = transfer_thm_of thy ths t in rewrite_goals_tac [tr] th end ) ) local fun map_intros f = TransferData.map (fn {intros,unfolds,refolds,consts} => {intros=f intros, unfolds=unfolds, refolds=refolds, consts=consts}) fun map_unfolds f = TransferData.map (fn {intros,unfolds,refolds,consts} => {intros=intros, unfolds=f unfolds, refolds=refolds, consts=consts}) fun map_refolds f = TransferData.map (fn {intros,unfolds,refolds,consts} => {intros=intros, unfolds=unfolds, refolds=f refolds, consts=consts}) in fun intro_add_global (thy, thm) = (map_intros (Drule.add_rule thm) thy, thm); fun intro_del_global (thy, thm) = (map_intros (Drule.del_rule thm) thy, thm); fun unfold_add_global (thy, thm) = (map_unfolds (Drule.add_rule thm) thy, thm); fun unfold_del_global (thy, thm) = (map_unfolds (Drule.del_rule thm) thy, thm); fun refold_add_global (thy, thm) = (map_refolds (Drule.add_rule thm) thy, thm); fun refold_del_global (thy, thm) = (map_refolds (Drule.del_rule thm) thy, thm); end fun add_const c = TransferData.map (fn {intros,unfolds,refolds,consts} => {intros=intros, unfolds=unfolds, refolds=refolds, consts=c::consts}) local val undef_local = Attrib.add_del_args Attrib.undef_local_attribute Attrib.undef_local_attribute; in val intro_attr = (Attrib.add_del_args intro_add_global intro_del_global, undef_local); val unfold_attr = (Attrib.add_del_args unfold_add_global unfold_del_global, undef_local); val refold_attr = (Attrib.add_del_args refold_add_global refold_del_global, undef_local); end val transfer_method = Method.SIMPLE_METHOD' HEADGOAL o transfer_tac; val setup = [ TransferData.init, Attrib.add_attributes [ ("transfer_intro", intro_attr, "declaration of transfer introduction rule"), ("transfer_unfold", unfold_attr, "declaration of transfer unfolding rule"), ("transfer_refold", refold_attr, "declaration of transfer refolding rule") ], Method.add_method ("transfer", Method.thms_args transfer_method, "transfer principle") ]; end;