--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Tools/legacy_transfer.ML Tue Apr 03 22:04:50 2012 +0200
@@ -0,0 +1,270 @@
+(* Title: HOL/Tools/transfer.ML
+ Author: Amine Chaieb, University of Cambridge, 2009
+ Jeremy Avigad, Carnegie Mellon University
+ Florian Haftmann, TU Muenchen
+
+Simple transfer principle on theorems.
+*)
+
+signature LEGACY_TRANSFER =
+sig
+ datatype selection = Direction of term * term | Hints of string list | Prop
+ val transfer: Context.generic -> selection -> string list -> thm -> thm list
+ type entry
+ val add: thm -> bool -> entry -> Context.generic -> Context.generic
+ val del: thm -> entry -> Context.generic -> Context.generic
+ val drop: thm -> Context.generic -> Context.generic
+ val setup: theory -> theory
+end;
+
+structure Legacy_Transfer : LEGACY_TRANSFER =
+struct
+
+(* data administration *)
+
+val direction_of = Thm.dest_binop o Thm.dest_arg o cprop_of;
+
+val transfer_morphism_key = Drule.strip_imp_concl (Thm.cprop_of @{thm transfer_morphismI});
+
+fun check_morphism_key ctxt key =
+ let
+ val _ = Thm.match (transfer_morphism_key, Thm.cprop_of key)
+ handle Pattern.MATCH => error ("Transfer: expected theorem of the form "
+ ^ quote (Syntax.string_of_term ctxt (Thm.term_of transfer_morphism_key)));
+ in direction_of key end;
+
+type entry = { inj : thm list, embed : thm list, return : thm list, cong : thm list,
+ hints : string list };
+
+val empty_entry = { inj = [], embed = [], return = [], cong = [], hints = [] };
+fun merge_entry ({ inj = inj1, embed = embed1, return = return1, cong = cong1, hints = hints1 } : entry,
+ { inj = inj2, embed = embed2, return = return2, cong = cong2, hints = hints2 } : entry) =
+ { inj = merge Thm.eq_thm (inj1, inj2), embed = merge Thm.eq_thm (embed1, embed2),
+ return = merge Thm.eq_thm (return1, return2), cong = merge Thm.eq_thm (cong1, cong2),
+ hints = merge (op =) (hints1, hints2) };
+
+structure Data = Generic_Data
+(
+ type T = (thm * entry) list;
+ val empty = [];
+ val extend = I;
+ val merge = AList.join Thm.eq_thm (K merge_entry);
+);
+
+
+(* data lookup *)
+
+fun transfer_rules_of ({ inj, embed, return, cong, ... } : entry) =
+ (inj, embed, return, cong);
+
+fun get_by_direction context (a, D) =
+ let
+ val ctxt = Context.proof_of context;
+ val certify = Thm.cterm_of (Context.theory_of context);
+ val a0 = certify a;
+ val D0 = certify D;
+ fun eq_direction ((a, D), thm') =
+ let
+ val (a', D') = direction_of thm';
+ in a aconvc a' andalso D aconvc D' end;
+ in case AList.lookup eq_direction (Data.get context) (a0, D0) of
+ SOME e => ((a0, D0), transfer_rules_of e)
+ | NONE => error ("Transfer: no such instance: ("
+ ^ Syntax.string_of_term ctxt a ^ ", " ^ Syntax.string_of_term ctxt D ^ ")")
+ end;
+
+fun get_by_hints context hints =
+ let
+ val insts = map_filter (fn (k, e) => if exists (member (op =) (#hints e)) hints
+ then SOME (direction_of k, transfer_rules_of e) else NONE) (Data.get context);
+ val _ = if null insts then error ("Transfer: no such labels: " ^ commas_quote hints) else ();
+ in insts end;
+
+fun splits P [] = []
+ | splits P (xs as (x :: _)) =
+ let
+ val (pss, qss) = List.partition (P x) xs;
+ in if null pss then [qss] else if null qss then [pss] else pss :: splits P qss end;
+
+fun get_by_prop context t =
+ let
+ val tys = map snd (Term.add_vars t []);
+ val _ = if null tys then error "Transfer: unable to guess instance" else ();
+ val tyss = splits (curry Type.could_unify) tys;
+ val get_ty = typ_of o ctyp_of_term o fst o direction_of;
+ val insts = map_filter (fn tys => get_first (fn (k, e) =>
+ if Type.could_unify (hd tys, range_type (get_ty k))
+ then SOME (direction_of k, transfer_rules_of e)
+ else NONE) (Data.get context)) tyss;
+ val _ = if null insts then
+ error "Transfer: no instances, provide direction or hints explicitly" else ();
+ in insts end;
+
+
+(* applying transfer data *)
+
+fun transfer_thm ((raw_a, raw_D), (inj, embed, return, cong)) leave ctxt1 thm =
+ let
+ (* identify morphism function *)
+ val ([a, D], ctxt2) = ctxt1
+ |> Variable.import true (map Drule.mk_term [raw_a, raw_D])
+ |>> map Drule.dest_term o snd;
+ val transform = Thm.apply @{cterm "Trueprop"} o Thm.apply D;
+ val T = Thm.typ_of (Thm.ctyp_of_term a);
+ val (aT, bT) = (Term.range_type T, Term.domain_type T);
+
+ (* determine variables to transfer *)
+ val ctxt3 = ctxt2
+ |> Variable.declare_thm thm
+ |> Variable.declare_term (term_of a)
+ |> Variable.declare_term (term_of D);
+ val certify = Thm.cterm_of (Proof_Context.theory_of ctxt3);
+ val vars = filter (fn ((v, _), T) => Type.could_unify (T, aT) andalso
+ not (member (op =) leave v)) (Term.add_vars (Thm.prop_of thm) []);
+ val c_vars = map (certify o Var) vars;
+ val (vs', ctxt4) = Variable.variant_fixes (map (fst o fst) vars) ctxt3;
+ val c_vars' = map (certify o (fn v => Free (v, bT))) vs';
+ val c_exprs' = map (Thm.apply a) c_vars';
+
+ (* transfer *)
+ val (hyps, ctxt5) = ctxt4
+ |> Assumption.add_assumes (map transform c_vars');
+ val simpset =
+ Simplifier.context ctxt5 HOL_ss addsimps (inj @ embed @ return)
+ |> fold Simplifier.add_cong cong;
+ val thm' = thm
+ |> Drule.cterm_instantiate (c_vars ~~ c_exprs')
+ |> fold_rev Thm.implies_intr (map cprop_of hyps)
+ |> Simplifier.asm_full_simplify simpset
+ in singleton (Variable.export ctxt5 ctxt1) thm' end;
+
+fun transfer_thm_multiple insts leave ctxt thm =
+ map (fn inst => transfer_thm inst leave ctxt thm) insts;
+
+datatype selection = Direction of term * term | Hints of string list | Prop;
+
+fun insts_for context thm (Direction direction) = [get_by_direction context direction]
+ | insts_for context thm (Hints hints) = get_by_hints context hints
+ | insts_for context thm Prop = get_by_prop context (Thm.prop_of thm);
+
+fun transfer context selection leave thm =
+ transfer_thm_multiple (insts_for context thm selection) leave (Context.proof_of context) thm;
+
+
+(* maintaining transfer data *)
+
+fun extend_entry ctxt (a, D) guess
+ { inj = inj1, embed = embed1, return = return1, cong = cong1, hints = hints1 }
+ { inj = inj2, embed = embed2, return = return2, cong = cong2, hints = hints2 } =
+ let
+ fun add_del eq del add = union eq add #> subtract eq del;
+ val guessed = if guess
+ then map (fn thm => transfer_thm
+ ((a, D), (if null inj1 then inj2 else inj1, [], [], cong1)) [] ctxt thm RS sym) embed1
+ else [];
+ in
+ { inj = union Thm.eq_thm inj1 inj2, embed = union Thm.eq_thm embed1 embed2,
+ return = union Thm.eq_thm guessed (union Thm.eq_thm return1 return2),
+ cong = union Thm.eq_thm cong1 cong2, hints = union (op =) hints1 hints2 }
+ end;
+
+fun diminish_entry
+ { inj = inj0, embed = embed0, return = return0, cong = cong0, hints = hints0 }
+ { inj = inj2, embed = embed2, return = return2, cong = cong2, hints = hints2 } =
+ { inj = subtract Thm.eq_thm inj0 inj2, embed = subtract Thm.eq_thm embed0 embed2,
+ return = subtract Thm.eq_thm return0 return2, cong = subtract Thm.eq_thm cong0 cong2,
+ hints = subtract (op =) hints0 hints2 };
+
+fun add key guess entry context =
+ let
+ val ctxt = Context.proof_of context;
+ val a_D = check_morphism_key ctxt key;
+ in
+ context
+ |> Data.map (AList.map_default Thm.eq_thm
+ (key, empty_entry) (extend_entry ctxt a_D guess entry))
+ end;
+
+fun del key entry = Data.map (AList.map_entry Thm.eq_thm key (diminish_entry entry));
+
+fun drop key = Data.map (AList.delete Thm.eq_thm key);
+
+
+(* syntax *)
+
+local
+
+fun these scan = Scan.optional scan [];
+fun these_pair scan = Scan.optional scan ([], []);
+
+fun keyword k = Scan.lift (Args.$$$ k) >> K ();
+fun keyword_colon k = Scan.lift (Args.$$$ k -- Args.colon) >> K ();
+
+val addN = "add";
+val delN = "del";
+val keyN = "key";
+val modeN = "mode";
+val automaticN = "automatic";
+val manualN = "manual";
+val injN = "inj";
+val embedN = "embed";
+val returnN = "return";
+val congN = "cong";
+val labelsN = "labels";
+
+val leavingN = "leaving";
+val directionN = "direction";
+
+val any_keyword = keyword_colon addN || keyword_colon delN || keyword_colon keyN
+ || keyword_colon modeN || keyword_colon injN || keyword_colon embedN || keyword_colon returnN
+ || keyword_colon congN || keyword_colon labelsN
+ || keyword_colon leavingN || keyword_colon directionN;
+
+val thms = Scan.repeat (Scan.unless any_keyword Attrib.multi_thm) >> flat;
+val names = Scan.repeat (Scan.unless any_keyword (Scan.lift Args.name))
+
+val mode = keyword_colon modeN |-- ((Scan.lift (Args.$$$ manualN) >> K false)
+ || (Scan.lift (Args.$$$ automaticN) >> K true));
+val inj = (keyword_colon injN |-- thms) -- these (keyword_colon delN |-- thms);
+val embed = (keyword_colon embedN |-- thms) -- these (keyword_colon delN |-- thms);
+val return = (keyword_colon returnN |-- thms) -- these (keyword_colon delN |-- thms);
+val cong = (keyword_colon congN |-- thms) -- these (keyword_colon delN |-- thms);
+val labels = (keyword_colon labelsN |-- names) -- these (keyword_colon delN |-- names);
+
+val entry_pair = these_pair inj -- these_pair embed
+ -- these_pair return -- these_pair cong -- these_pair labels
+ >> (fn (((((inja, injd), (embeda, embedd)), (returna, returnd)), (conga, congd)),
+ (hintsa, hintsd)) =>
+ ({ inj = inja, embed = embeda, return = returna, cong = conga, hints = hintsa },
+ { inj = injd, embed = embedd, return = returnd, cong = congd, hints = hintsd }));
+
+val selection = (keyword_colon directionN |-- (Args.term -- Args.term) >> Direction)
+ || these names >> (fn hints => if null hints then Prop else Hints hints);
+
+in
+
+val transfer_attribute = keyword delN >> K (Thm.declaration_attribute drop)
+ || keyword addN |-- Scan.optional mode true -- entry_pair
+ >> (fn (guess, (entry_add, entry_del)) => Thm.declaration_attribute
+ (fn thm => add thm guess entry_add #> del thm entry_del))
+ || keyword_colon keyN |-- Attrib.thm
+ >> (fn key => Thm.declaration_attribute
+ (fn thm => add key false
+ { inj = [], embed = [], return = [thm], cong = [], hints = [] }));
+
+val transferred_attribute = selection -- these (keyword_colon leavingN |-- names)
+ >> (fn (selection, leave) => Thm.rule_attribute (fn context =>
+ Conjunction.intr_balanced o transfer context selection leave));
+
+end;
+
+
+(* theory setup *)
+
+val setup =
+ Attrib.setup @{binding transfer} transfer_attribute
+ "Installs transfer data" #>
+ Attrib.setup @{binding transferred} transferred_attribute
+ "Transfers theorems";
+
+end;