ProgTutorial/Package/simple_inductive_package.ML
changeset 189 069d525f8f1d
parent 176 3da5f3f07d8b
child 294 ee9d53fbb56b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ProgTutorial/Package/simple_inductive_package.ML	Thu Mar 19 13:28:16 2009 +0100
@@ -0,0 +1,243 @@
+(* @chunk SIMPLE_INDUCTIVE_PACKAGE *)
+signature SIMPLE_INDUCTIVE_PACKAGE =
+sig
+  val add_inductive_i:
+    ((Binding.binding * typ) * mixfix) list ->  (*{predicates}*)
+    (Binding.binding * typ) list ->  (*{parameters}*)
+    (Attrib.binding * term) list ->  (*{rules}*)
+    local_theory -> local_theory
+
+  val add_inductive:
+    (Binding.binding * string option * mixfix) list ->  (*{predicates}*)
+    (Binding.binding * string option * mixfix) list ->  (*{parameters}*)
+    (Attrib.binding * string) list ->  (*{rules}*)
+    local_theory -> local_theory
+end;
+(* @end *)
+
+structure SimpleInductivePackage: SIMPLE_INDUCTIVE_PACKAGE =
+struct
+
+(* @chunk make_definitions *) 
+fun make_defs ((binding, syn), trm) lthy =
+let 
+  val arg = ((binding, syn), (Attrib.empty_binding, trm))
+  val ((_, (_ , thm)), lthy) = LocalTheory.define Thm.internalK arg lthy
+in 
+  (thm, lthy) 
+end
+(* @end *)
+
+(* @chunk definitions_aux *) 
+fun defs_aux lthy orules preds params (pred, arg_types) =
+let 
+  fun mk_all x P = HOLogic.all_const (fastype_of x) $ lambda x P 
+
+  val fresh_args = 
+        arg_types 
+        |> map (pair "z")
+        |> Variable.variant_frees lthy orules 
+        |> map Free
+in
+  list_comb (pred, fresh_args)
+  |> fold_rev (curry HOLogic.mk_imp) orules
+  |> fold_rev mk_all preds
+  |> fold_rev lambda (params @ fresh_args) 
+end
+(* @end *)
+
+(* @chunk definitions *) 
+fun definitions rules params preds prednames syns arg_typess lthy =
+let
+  val thy = ProofContext.theory_of lthy
+  val orules = map (ObjectLogic.atomize_term thy) rules
+  val defs = 
+    map (defs_aux lthy orules preds params) (preds ~~ arg_typess) 
+in
+  fold_map make_defs (prednames ~~ syns ~~ defs) lthy
+end
+(* @end *)
+
+fun inst_spec ct = 
+  Drule.instantiate' [SOME (ctyp_of_term ct)] [NONE, SOME ct] @{thm spec};
+
+(* @chunk induction_tac *)
+fun induction_tac defs prems insts =
+  EVERY1 [ObjectLogic.full_atomize_tac,
+          cut_facts_tac prems,
+          K (rewrite_goals_tac defs),
+          EVERY' (map (dtac o inst_spec) insts),
+          assume_tac]
+(* @end *)
+
+(* @chunk induction_rules *)
+fun inductions rules defs parnames preds Tss lthy1  =
+let
+  val (_, lthy2) = Variable.add_fixes parnames lthy1
+  
+  val Ps = replicate (length preds) "P"
+  val (newprednames, lthy3) = Variable.variant_fixes Ps lthy2
+
+  val thy = ProofContext.theory_of lthy3			      
+
+  val Tss' = map (fn Ts => Ts ---> HOLogic.boolT) Tss
+  val newpreds = map Free (newprednames ~~ Tss')
+  val cnewpreds = map (cterm_of thy) newpreds
+  val rules' = map (subst_free (preds ~~ newpreds)) rules
+
+  fun prove_induction ((pred, newpred), Ts)  =
+  let
+    val (newargnames, lthy4) = 
+          Variable.variant_fixes (replicate (length Ts) "z") lthy3;
+    val newargs = map Free (newargnames ~~ Ts)
+
+    val prem = HOLogic.mk_Trueprop (list_comb (pred, newargs))
+    val goal = Logic.list_implies 
+         (rules', HOLogic.mk_Trueprop (list_comb (newpred, newargs)))
+  in
+    Goal.prove lthy4 [] [prem] goal
+      (fn {prems, ...} => induction_tac defs prems cnewpreds)
+      |> singleton (ProofContext.export lthy4 lthy1)
+  end 
+in
+  map prove_induction (preds ~~ newpreds ~~ Tss)
+end
+(* @end *)
+
+val all_elims = fold (fn ct => fn th => th RS inst_spec ct);
+val imp_elims = fold (fn th => fn th' => [th', th] MRS @{thm mp});
+
+
+(* @chunk subproof1 *) 
+fun subproof2 prem params2 prems2 =  
+ SUBPROOF (fn {prems, ...} =>
+  let
+    val prem' = prems MRS prem;
+    val prem'' = 
+       case prop_of prem' of
+           _ $ (Const (@{const_name All}, _) $ _) =>
+             prem' |> all_elims params2 
+                   |> imp_elims prems2
+         | _ => prem';
+  in 
+    rtac prem'' 1 
+  end)
+(* @end *)
+
+(* @chunk subproof2 *) 
+fun subproof1 rules preds i = 
+ SUBPROOF (fn {params, prems, context = ctxt', ...} =>
+  let
+    val (prems1, prems2) = chop (length prems - length rules) prems;
+    val (params1, params2) = chop (length params - length preds) params;
+  in
+    rtac (ObjectLogic.rulify (all_elims params1 (nth prems2 i))) 1 
+    THEN
+    EVERY1 (map (fn prem => subproof2 prem params2 prems2 ctxt') prems1)
+  end)
+(* @end *)
+
+fun introductions_tac defs rules preds i ctxt =
+  EVERY1 [ObjectLogic.rulify_tac,
+          K (rewrite_goals_tac defs),
+          REPEAT o (resolve_tac [@{thm allI},@{thm impI}]),
+          subproof1 rules preds i ctxt]
+
+
+(* @chunk intro_rules *) 
+fun introductions rules parnames preds defs lthy1 = 
+let
+  val (_, lthy2) = Variable.add_fixes parnames lthy1
+
+  fun prove_intro (i, goal) =
+    Goal.prove lthy2 [] [] goal
+       (fn {context, ...} => introductions_tac defs rules preds i context)
+       |> singleton (ProofContext.export lthy2 lthy1)
+in
+  map_index prove_intro rules
+end
+(* @end *)
+
+(* @chunk add_inductive_i *)
+fun add_inductive_i preds params specs lthy =
+let
+  val params' = map (fn (p, T) => Free (Binding.name_of p, T)) params;
+  val preds' = map (fn ((R, T), _) => list_comb (Free (Binding.name_of R, T), params')) preds;
+  val Tss = map (binder_types o fastype_of) preds';   
+  val (ass, rules) = split_list specs;  (* FIXME: ass not used? *)  
+
+  val prednames = map (fst o fst) preds
+  val syns = map snd preds
+  val parnames = map (Binding.name_of o fst) params
+
+  val (defs, lthy1) = definitions rules params' preds' prednames syns Tss lthy;
+      
+  val inducts = inductions rules defs parnames preds' Tss lthy1 	
+  
+  val intros = introductions rules parnames preds' defs lthy1
+
+  val mut_name = space_implode "_" (map (Binding.name_of o fst o fst) preds);
+  val case_names = map (Binding.name_of o fst o fst) specs
+in
+    lthy1 
+    |> LocalTheory.notes Thm.theoremK (map (fn (((a, atts), _), th) =>
+        ((Binding.qualify false mut_name a, atts), [([th], [])])) (specs ~~ intros)) 
+    |-> (fn intross => LocalTheory.note Thm.theoremK
+         ((Binding.qualify false mut_name (Binding.name "intros"), []), maps snd intross)) 
+    |>> snd 
+    ||>> (LocalTheory.notes Thm.theoremK (map (fn (((R, _), _), th) =>
+         ((Binding.qualify false (Binding.name_of R) (Binding.name "induct"),
+          [Attrib.internal (K (RuleCases.case_names case_names)),
+           Attrib.internal (K (RuleCases.consumes 1)),
+           Attrib.internal (K (Induct.induct_pred ""))]), [([th], [])]))
+          (preds ~~ inducts)) #>> maps snd) 
+    |> snd
+end
+(* @end *)
+
+(* @chunk read_specification *)
+fun read_specification' vars specs lthy =
+let 
+  val specs' = map (fn (a, s) => (a, [s])) specs
+  val ((varst, specst), _) = 
+                   Specification.read_specification vars specs' lthy
+  val specst' = map (apsnd the_single) specst
+in   
+  (varst, specst')
+end 
+(* @end *)
+
+(* @chunk add_inductive *)
+fun add_inductive preds params specs lthy =
+let
+  val (vars, specs') = read_specification' (preds @ params) specs lthy;
+  val (preds', params') = chop (length preds) vars;
+  val params'' = map fst params'
+in
+  add_inductive_i preds' params'' specs' lthy
+end;
+(* @end *)
+
+(* @chunk parser *)
+val spec_parser = 
+   OuterParse.opt_target --
+   OuterParse.fixes -- 
+   OuterParse.for_fixes --
+   Scan.optional 
+     (OuterParse.$$$ "where" |--
+        OuterParse.!!! 
+          (OuterParse.enum1 "|" 
+             (SpecParse.opt_thm_name ":" -- OuterParse.prop))) []
+(* @end *)
+
+(* @chunk syntax *)
+val specification =
+  spec_parser >>
+    (fn (((loc, preds), params), specs) =>
+      Toplevel.local_theory loc (add_inductive preds params specs))
+
+val _ = OuterSyntax.command "simple_inductive" "define inductive predicates"
+          OuterKeyword.thy_decl specification
+(* @end *)
+
+end;