--- a/src/HOL/Tools/transfer.ML Mon Mar 08 14:42:40 2010 -0800
+++ b/src/HOL/Tools/transfer.ML Mon Mar 08 15:20:40 2010 -0800
@@ -1,11 +1,16 @@
-(* Author: Amine Chaieb, University of Cambridge, 2009
- Author: Jeremy Avigad, Carnegie Mellon University
+(* Author: Amine Chaieb, University of Cambridge, 2009
+ Jeremy Avigad, Carnegie Mellon University
+ Florian Haftmann, TU Muenchen
+
+Simple transfer principle on theorems.
*)
signature TRANSFER =
sig
+ datatype selection = Direction of term * term | Hints of string list | Prop
+ val transfer: Context.generic -> selection -> string list -> thm -> thm
type entry
- val get: Proof.context -> (thm * entry) list
+ val add: entry * entry -> thm -> Context.generic -> Context.generic
val del: thm -> Context.generic -> Context.generic
val setup: theory -> theory
end;
@@ -15,12 +20,14 @@
(* data administration *)
+val direction_of = Thm.dest_binop o Thm.dest_arg o cprop_of;
+
fun check_morphism_key ctxt key =
let
val _ = (Thm.match o pairself Thm.cprop_of) (@{thm transfer_morphismI}, key)
handle Pattern.MATCH => error
- ("Expected theorem of the form " ^ quote (Display.string_of_thm ctxt @{thm transfer_morphismI}));
- in (Thm.dest_binop o Thm.dest_arg o Thm.cprop_of) key end;
+ ("Transfer: expected theorem of the form " ^ quote (Display.string_of_thm ctxt @{thm transfer_morphismI}));
+ in direction_of key end;
type entry = { inj : thm list, emb : thm list, ret : thm list, cong : thm list,
guess : bool, hints : string list };
@@ -35,23 +42,61 @@
(
type T = (thm * entry) list;
val empty = [];
- val extend = I;
+ val extend = I;
val merge = AList.join Thm.eq_thm (K merge_entry);
);
-val get = Data.get o Context.Proof;
+
+(* data lookup *)
+
+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 a0 aconvc a' andalso D0 aconvc D' end;
+ in case AList.lookup eq_direction (Data.get context) (a, D) of
+ SOME e => ((a0, D0), e)
+ | NONE => error ("Transfer: no such instance: ("
+ ^ Syntax.string_of_term ctxt a ^ ", " ^ Syntax.string_of_term ctxt D ^ ")")
+ end;
-fun del key = Data.map (remove (eq_fst Thm.eq_thm) (key, []));
+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, e) else NONE) (Data.get context);
+ val _ = if null insts then error ("Transfer: no such labels: " ^ commas (map 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;
-val del_attribute = Thm.declaration_attribute del;
+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, ss) =>
+ if Type.could_unify (hd tys, range_type (get_ty k))
+ then SOME (direction_of k, ss)
+ 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 build_simpset inj_only {inj = inj, emb = emb, ret = ret, cong = cg, guess = g, hints = hints} =
- HOL_ss addsimps inj addsimps (if inj_only then [] else emb @ ret) addcongs cg;
-
-fun basic_transfer_rule inj_only a0 D0 e leave ctxt0 th =
+fun transfer_thm inj_only a0 D0 {inj = inj, emb = emb, ret = ret, cong = cg, guess = _, hints = _}
+ leave ctxt0 th =
let
val ([a, D], ctxt) = apfst (map Drule.dest_term o snd)
(Variable.import true (map Drule.mk_term [a0, D0]) ctxt0);
@@ -66,81 +111,32 @@
val certify = Thm.cterm_of (ProofContext.theory_of ctxt'');
val cns = map (certify o Var) ns;
val cfis = map (certify o (fn n => Free (n, bT))) ins;
- val cis = map (Thm.capply a) cfis
+ val cis = map (Thm.capply a) cfis;
val (hs, ctxt''') = Assumption.add_assumes (map (fn ct =>
Thm.capply @{cterm "Trueprop"} (Thm.capply D ct)) cfis) ctxt'';
val th1 = Drule.cterm_instantiate (cns ~~ cis) th;
val th2 = fold Thm.elim_implies hs (fold_rev implies_intr (map cprop_of hs) th1);
- val th3 = Simplifier.asm_full_simplify (Simplifier.context ctxt'''
- (build_simpset inj_only e)) (fold_rev implies_intr (map cprop_of hs) th2);
+ val simpset = (Simplifier.context ctxt''' HOL_ss)
+ addsimps inj addsimps (if inj_only then [] else emb @ ret) addcongs cg;
+ val th3 = Simplifier.asm_full_simplify simpset
+ (fold_rev implies_intr (map cprop_of hs) th2);
in hd (Variable.export ctxt''' ctxt0 [th3]) end;
-fun transfer_rule (a, D) leave (gctxt, th) =
- let
- fun transfer_ruleh a D leave ctxt th =
- let
- val al = get ctxt;
- val certify = Thm.cterm_of (ProofContext.theory_of ctxt);
- val a0 = certify a;
- val D0 = certify D;
- fun h (th', e) =
- let
- val (a',D') = (Thm.dest_binop o Thm.dest_arg o cprop_of) th'
- in if a0 aconvc a' andalso D0 aconvc D' then SOME e else NONE end;
- in case get_first h al of
- SOME e => basic_transfer_rule false a0 D0 e leave ctxt th
- | NONE => error "Transfer: corresponding instance not found in context data"
- end;
- in
- (gctxt, transfer_ruleh a D leave (Context.proof_of gctxt) th)
- end;
+fun transfer_thm_multiple inj_only insts leave ctxt thm =
+ Conjunction.intr_balanced (map
+ (fn ((a, D), e) => transfer_thm false a D e leave ctxt thm) insts);
-fun splits P [] = []
- | splits P (xxs as (x :: xs)) =
- let
- val pss = filter (P x) xxs;
- val qss = filter_out (P x) xxs;
- in if null pss then [qss] else if null qss then [pss] else pss:: splits P qss end;
+datatype selection = Direction of term * term | Hints of string list | Prop;
-fun all_transfers leave (gctxt, th) =
- let
- val ctxt = Context.proof_of gctxt;
- val tys = map snd (Term.add_vars (prop_of th) []);
- 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 Thm.dest_binop o Thm.dest_arg o cprop_of;
- val get_aD = Thm.dest_binop o Thm.dest_arg o cprop_of;
- val insts =
- map_filter (fn tys =>
- get_first (fn (k,ss) =>
- if Type.could_unify (hd tys, range_type (get_ty k))
- then SOME (get_aD k, ss)
- else NONE) (get ctxt)) tyss;
- val _ =
- if null insts then
- error "Transfer guesser: there were no possible instances, use direction: in order to provide a direction"
- else ();
- val ths = map (fn ((a, D), e) => basic_transfer_rule false a D e leave ctxt th) insts;
- val cth = Conjunction.intr_balanced ths;
- in (gctxt, cth) end;
+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_rule_by_hint ls leave (gctxt, th) =
- let
- val ctxt = Context.proof_of gctxt;
- val get_aD = Thm.dest_binop o Thm.dest_arg o cprop_of;
- val insts = map_filter (fn (k,e) => if exists (member (op =) (#hints e)) ls
- then SOME (get_aD k, e) else NONE) (get ctxt);
- val _ = if null insts then error "Transfer: No labels provided are stored in the context" else ();
- val ths = map (fn ((a,D),e) => basic_transfer_rule false a D e leave ctxt th) insts;
- val cth = Conjunction.intr_balanced ths;
- in (gctxt, cth) end;
-
-fun transferred_attribute ls NONE leave =
- if null ls then all_transfers leave else transfer_rule_by_hint ls leave
- | transferred_attribute _ (SOME (a, D)) leave = transfer_rule (a, D) leave;
+fun transfer context selection leave thm =
+ transfer_thm_multiple false (insts_for context thm selection) leave (Context.proof_of context) thm;
-(* adding transfer data *)
+(* maintaining transfer data *)
fun merge_update eq m (k, v) [] = [(k, v)]
| merge_update eq m (k, v) ((k', v') :: al) =
@@ -159,13 +155,13 @@
hints = subtract (op =) hints0 (union (op =) hints1 hints2) }
end;
-fun add ((inja, injd), (emba, embd), (reta, retd), (cga, cgd), g, (hintsa, hintsd)) key =
- Data.map (fn al =>
+fun add (e0 as {inj = inja, emb = emba, ret = reta, cong = cga, guess = g, hints = hintsa},
+ ed as {inj = injd, emb = embd, ret = retd, cong = cgd, guess = _, hints = hintsd}) key context =
+ context
+ |> Data.map (fn al =>
let
- val ctxt0 = ProofContext.init (Thm.theory_of_thm key); (*FIXME*)
- val (a0, D0) = check_morphism_key ctxt0 key;
- val e0 = {inj = inja, emb = emba, ret = reta, cong = cga, guess = g, hints = hintsa};
- val ed = {inj = injd, emb = embd, ret = retd, cong = cgd, guess = g, hints = hintsd};
+ val ctxt = Context.proof_of context;
+ val (a0, D0) = check_morphism_key ctxt key;
val entry = if g then
let
val inj' = if null inja then #inj
@@ -173,13 +169,13 @@
| NONE => error "Transfer: cannot generate return rules on the fly, either add injectivity axiom or force manual mode with mode: manual")
else inja
val ret' = merge Thm.eq_thm (reta, map
- (fn th => basic_transfer_rule true a0 D0 {inj = inj', emb = [], ret = [], cong = cga, guess = g,
- hints = hintsa} [] ctxt0 th RS sym) emba);
+ (fn th => transfer_thm true a0 D0 {inj = inj', emb = [], ret = [], cong = cga, guess = g,
+ hints = hintsa} [] ctxt th RS sym) emba);
in {inj = inja, emb = emba, ret = ret', cong = cga, guess = g, hints = hintsa} end
else e0;
in merge_update Thm.eq_thm (merge_entries ed) (key, entry) al end);
-fun add_attribute args = Thm.declaration_attribute (add args);
+fun del key = Data.map (remove (eq_fst Thm.eq_thm) (key, []));
(* syntax *)
@@ -220,20 +216,23 @@
val cong = (keyword_colon congN |-- thms) -- these (keyword_colon delN |-- thms);
val labels = (keyword_colon labelsN |-- names) -- these (keyword_colon delN |-- names);
-val entry = Scan.optional mode true -- these_pair inj -- these_pair embed
- -- these_pair return -- these_pair cong -- these_pair labels;
+val entry_pair = Scan.optional mode true -- these_pair inj -- these_pair embed
+ -- these_pair return -- these_pair cong -- these_pair labels
+ >> (fn (((((g, (inja, injd)), (emba, embd)), (reta, retd)), (cga, cgd)), (hintsa, hintsd)) =>
+ ({inj = inja, emb = emba, ret = reta, cong = cga, guess = g, hints = hintsa},
+ {inj = injd, emb = embd, ret = retd, cong = cgd, guess = g, hints = hintsd}));
-val transfer_directive = these names -- Scan.option (keyword_colon directionN
- |-- (Args.term -- Args.term)) -- these (keyword_colon leavingN |-- names);
+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_syntax = (Scan.lift (Args.$$$ delN >> K del_attribute)
- || Scan.unless any_keyword (keyword addN) |-- entry
- >> (fn (((((g, inj), embed), ret), cg), hints) => add_attribute (inj, embed, ret, cg, g, hints)))
+val transfer_attribute = Scan.lift (Args.$$$ delN >> K (Thm.declaration_attribute del))
+ || Scan.unless any_keyword (keyword addN) |-- entry_pair
+ >> (fn entry_pair => Thm.declaration_attribute (add entry_pair))
-val transferred_syntax = transfer_directive
- >> (fn ((hints, aD), leave) => transferred_attribute hints aD leave);
+val transferred_attribute = selection -- these (keyword_colon leavingN |-- names)
+ >> (fn (selection, leave) => Thm.rule_attribute (fn context => transfer context selection leave));
end;
@@ -241,9 +240,9 @@
(* theory setup *)
val setup =
- Attrib.setup @{binding transfer} transfer_syntax
+ Attrib.setup @{binding transfer} transfer_attribute
"Installs transfer data" #>
- Attrib.setup @{binding transferred} transferred_syntax
+ Attrib.setup @{binding transferred} transferred_attribute
"Transfers theorems";
end;