src/HOL/Bali/WellType.thy
changeset 12854 00d4a435777f
child 12857 a4386cc9b1c3
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Bali/WellType.thy	Mon Jan 28 17:00:19 2002 +0100
@@ -0,0 +1,598 @@
+(*  Title:      isabelle/Bali/WellType.thy
+    ID:         $Id$
+    Author:     David von Oheimb
+    Copyright   1997 Technische Universitaet Muenchen
+*)
+header {* Well-typedness of Java programs *}
+
+theory WellType = DeclConcepts:
+
+text {*
+improvements over Java Specification 1.0:
+\begin{itemize}
+\item methods of Object can be called upon references of interface or array type
+\end{itemize}
+simplifications:
+\begin{itemize}
+\item the type rules include all static checks on statements and expressions, 
+      e.g. definedness of names (of parameters, locals, fields, methods)
+\end{itemize}
+design issues:
+\begin{itemize}
+\item unified type judgment for statements, variables, expressions, 
+      expression lists
+\item statements are typed like expressions with dummy type Void
+\item the typing rules take an extra argument that is capable of determining 
+  the dynamic type of objects. Therefore, they can be used for both 
+  checking static types and determining runtime types in transition semantics.
+\end{itemize}
+*}
+
+types	lenv
+	= "(lname, ty) table"   (* local variables, including This and Result *)
+
+record env = 
+         prg:: "prog"    (* program *)
+         cls:: "qtname"  (* current package and class name *)
+         lcl:: "lenv"    (* local environment *)     
+  
+translations
+  "lenv" <= (type) "(lname, ty) table"
+  "lenv" <= (type) "lname \<Rightarrow> ty option"
+  "env" <= (type) "\<lparr>prg::prog,cls::qtname,lcl::lenv\<rparr>"
+  "env" <= (type) "\<lparr>prg::prog,cls::qtname,lcl::lenv,\<dots>::'a\<rparr>"
+
+
+
+syntax
+  pkg :: "env \<Rightarrow> pname" (* select the current package from an environment *)
+translations
+  "pkg e" == "pid (cls e)"
+
+section "Static overloading: maximally specific methods "
+
+types
+  emhead = "ref_ty \<times> mhead"
+
+(* Some mnemotic selectors for emhead *)
+constdefs 
+  "declrefT" :: "emhead \<Rightarrow> ref_ty"
+  "declrefT \<equiv> fst"
+
+  "mhd"     :: "emhead \<Rightarrow> mhead"
+  "mhd \<equiv> snd"
+
+lemma declrefT_simp[simp]:"declrefT (r,m) = r"
+by (simp add: declrefT_def)
+
+lemma mhd_simp[simp]:"mhd (r,m) = m"
+by (simp add: mhd_def)
+
+lemma static_mhd_simp[simp]: "static (mhd m) = is_static m"
+by (cases m) (simp add: member_is_static_simp mhd_def)
+
+lemma mhd_resTy_simp [simp]: "resTy (mhd m) = resTy m"
+by (cases m) simp
+
+lemma mhd_is_static_simp [simp]: "is_static (mhd m) = is_static m"
+by (cases m) simp
+
+lemma mhd_accmodi_simp [simp]: "accmodi (mhd m) = accmodi m"
+by (cases m) simp
+
+consts
+  cmheads        :: "prog \<Rightarrow> qtname \<Rightarrow> qtname \<Rightarrow> sig \<Rightarrow> emhead set"
+  Objectmheads   :: "prog \<Rightarrow> qtname           \<Rightarrow> sig \<Rightarrow> emhead set"
+  accObjectmheads:: "prog \<Rightarrow> qtname \<Rightarrow> ref_ty \<Rightarrow> sig \<Rightarrow> emhead set"
+  mheads         :: "prog \<Rightarrow> qtname \<Rightarrow> ref_ty \<Rightarrow> sig \<Rightarrow> emhead set"
+defs
+ cmheads_def:
+"cmheads G S C 
+  \<equiv> \<lambda>sig. (\<lambda>(Cls,mthd). (ClassT Cls,(mhead mthd))) ` o2s (accmethd G S C sig)"
+  Objectmheads_def:
+"Objectmheads G S  
+  \<equiv> \<lambda>sig. (\<lambda>(Cls,mthd). (ClassT Cls,(mhead mthd))) 
+    ` o2s (filter_tab (\<lambda>sig m. accmodi m \<noteq> Private) (accmethd G S Object) sig)"
+  accObjectmheads_def:
+"accObjectmheads G S T
+   \<equiv> if G\<turnstile>RefT T accessible_in (pid S)
+        then Objectmheads G S
+        else \<lambda>sig. {}"
+primrec
+"mheads G S  NullT     = (\<lambda>sig. {})"
+"mheads G S (IfaceT I) = (\<lambda>sig. (\<lambda>(I,h).(IfaceT I,h)) 
+                         ` accimethds G (pid S) I sig \<union> 
+                           accObjectmheads G S (IfaceT I) sig)"
+"mheads G S (ClassT C) = cmheads G S C"
+"mheads G S (ArrayT T) = accObjectmheads G S (ArrayT T)"
+
+
+(* more detailed than necessary for type-safety, see below. *)
+constdefs
+  (* applicable methods, cf. 15.11.2.1 *)
+  appl_methds   :: "prog \<Rightarrow> qtname \<Rightarrow>  ref_ty \<Rightarrow> sig \<Rightarrow> (emhead \<times> ty list)\<spacespace> set"
+ "appl_methds G S rt \<equiv> \<lambda> sig. 
+      {(mh,pTs') |mh pTs'. mh \<in> mheads G S rt \<lparr>name=name sig,parTs=pTs'\<rparr> \<and> 
+                           G\<turnstile>(parTs sig)[\<preceq>]pTs'}"
+
+  (* more specific methods, cf. 15.11.2.2 *)
+  more_spec     :: "prog \<Rightarrow> emhead \<times> ty list \<Rightarrow> emhead \<times> ty list \<Rightarrow> bool"
+ "more_spec G \<equiv> \<lambda>(mh,pTs). \<lambda>(mh',pTs'). G\<turnstile>pTs[\<preceq>]pTs'"
+(*more_spec G \<equiv>\<lambda>((d,h),pTs). \<lambda>((d',h'),pTs'). G\<turnstile>RefT d\<preceq>RefT d'\<and>G\<turnstile>pTs[\<preceq>]pTs'*)
+
+  (* maximally specific methods, cf. 15.11.2.2 *)
+   max_spec     :: "prog \<Rightarrow> qtname \<Rightarrow> ref_ty \<Rightarrow> sig \<Rightarrow> (emhead \<times> ty list)\<spacespace> set"
+
+ "max_spec G S rt sig \<equiv>{m. m \<in>appl_methds G S rt sig \<and>
+		      (\<forall>m'\<in>appl_methds G S rt sig. more_spec G m' m \<longrightarrow> m'=m)}"
+(*
+rules (* all properties of more_spec, appl_methods and max_spec we actually need
+         these can easily be proven from the above definitions *)
+
+max_spec2mheads "max_spec G S rt (mn, pTs) = insert (mh, pTs') A \<Longrightarrow>
+      mh\<in>mheads G S rt (mn, pTs') \<and> G\<turnstile>pTs[\<preceq>]pTs'"
+*)
+
+lemma max_spec2appl_meths: 
+  "x \<in> max_spec G S T sig \<Longrightarrow> x \<in> appl_methds G S T sig" 
+by (auto simp: max_spec_def)
+
+lemma appl_methsD: "(mh,pTs')\<in>appl_methds G S T \<lparr>name=mn,parTs=pTs\<rparr> \<Longrightarrow>  
+   mh \<in> mheads G S T \<lparr>name=mn,parTs=pTs'\<rparr> \<and> G\<turnstile>pTs[\<preceq>]pTs'"
+by (auto simp: appl_methds_def)
+
+lemma max_spec2mheads: 
+"max_spec G S rt \<lparr>name=mn,parTs=pTs\<rparr> = insert (mh, pTs') A 
+ \<Longrightarrow> mh \<in> mheads G S rt \<lparr>name=mn,parTs=pTs'\<rparr> \<and> G\<turnstile>pTs[\<preceq>]pTs'"
+apply (auto dest: equalityD2 subsetD max_spec2appl_meths appl_methsD)
+done
+
+
+constdefs
+  empty_dt :: "dyn_ty"
+ "empty_dt \<equiv> \<lambda>a. None"
+
+  invmode :: "('a::type)member_scheme \<Rightarrow> expr \<Rightarrow> inv_mode"
+"invmode m e \<equiv> if static m then Static else if e=Super then SuperM else IntVir"
+
+lemma invmode_nonstatic [simp]: 
+  "invmode \<lparr>access=a,static=False,\<dots>=x\<rparr> (Acc (LVar e)) = IntVir"
+apply (unfold invmode_def)
+apply (simp (no_asm))
+done
+
+
+lemma invmode_Static_eq [simp]: "(invmode m e = Static) = static m"
+apply (unfold invmode_def)
+apply (simp (no_asm))
+done
+
+
+lemma invmode_IntVir_eq: "(invmode m e = IntVir) = (\<not>(static m) \<and> e\<noteq>Super)"
+apply (unfold invmode_def)
+apply (simp (no_asm))
+done
+
+lemma Null_staticD: 
+  "a'=Null \<longrightarrow> (static m) \<Longrightarrow> invmode m e = IntVir \<longrightarrow> a' \<noteq> Null"
+apply (clarsimp simp add: invmode_IntVir_eq)
+done
+
+
+types tys  =        "ty + ty list"
+translations
+  "tys"   <= (type) "ty + ty list"
+
+consts
+  wt    :: "(env\<spacespace> \<times> dyn_ty\<spacespace> \<times>  term \<times> tys) set"
+(*wt    :: " env \<Rightarrow> dyn_ty \<Rightarrow> (term \<times> tys) set" not feasible because of 
+					      \<spacespace>  changing env in Try stmt *)
+
+syntax
+wt      :: "env \<Rightarrow> dyn_ty \<Rightarrow> [term,tys]  \<Rightarrow> bool" ("_,_|=_::_" [51,51,51,51] 50)
+wt_stmt :: "env \<Rightarrow> dyn_ty \<Rightarrow>  stmt       \<Rightarrow> bool" ("_,_|=_:<>" [51,51,51   ] 50)
+ty_expr :: "env \<Rightarrow> dyn_ty \<Rightarrow> [expr ,ty ] \<Rightarrow> bool" ("_,_|=_:-_" [51,51,51,51] 50)
+ty_var  :: "env \<Rightarrow> dyn_ty \<Rightarrow> [var  ,ty ] \<Rightarrow> bool" ("_,_|=_:=_" [51,51,51,51] 50)
+ty_exprs:: "env \<Rightarrow> dyn_ty \<Rightarrow> [expr list,
+	         \<spacespace>        \<spacespace>  ty   list] \<Rightarrow> bool" ("_,_|=_:#_" [51,51,51,51] 50)
+
+syntax (xsymbols)
+wt      :: "env \<Rightarrow> dyn_ty \<Rightarrow> [term,tys] \<Rightarrow> bool" ("_,_\<Turnstile>_\<Colon>_"  [51,51,51,51] 50)
+wt_stmt :: "env \<Rightarrow> dyn_ty \<Rightarrow>  stmt       \<Rightarrow> bool" ("_,_\<Turnstile>_\<Colon>\<surd>"  [51,51,51   ] 50)
+ty_expr :: "env \<Rightarrow> dyn_ty \<Rightarrow> [expr ,ty ] \<Rightarrow> bool" ("_,_\<Turnstile>_\<Colon>-_" [51,51,51,51] 50)
+ty_var  :: "env \<Rightarrow> dyn_ty \<Rightarrow> [var  ,ty ] \<Rightarrow> bool" ("_,_\<Turnstile>_\<Colon>=_" [51,51,51,51] 50)
+ty_exprs:: "env \<Rightarrow> dyn_ty \<Rightarrow> [expr list,
+		  \<spacespace>        \<spacespace>  ty   list] \<Rightarrow> bool"("_,_\<Turnstile>_\<Colon>\<doteq>_" [51,51,51,51] 50)
+
+translations
+	"E,dt\<Turnstile>t\<Colon>T" == "(E,dt,t,T) \<in> wt"
+	"E,dt\<Turnstile>s\<Colon>\<surd>"  == "E,dt\<Turnstile>In1r s\<Colon>Inl (PrimT Void)"
+	"E,dt\<Turnstile>e\<Colon>-T" == "E,dt\<Turnstile>In1l e\<Colon>Inl T"
+	"E,dt\<Turnstile>e\<Colon>=T" == "E,dt\<Turnstile>In2  e\<Colon>Inl T"
+	"E,dt\<Turnstile>e\<Colon>\<doteq>T" == "E,dt\<Turnstile>In3  e\<Colon>Inr T"
+
+syntax (* for purely static typing *)
+  wt_      :: "env \<Rightarrow> [term,tys] \<Rightarrow> bool" ("_|-_::_" [51,51,51] 50)
+  wt_stmt_ :: "env \<Rightarrow>  stmt       \<Rightarrow> bool" ("_|-_:<>" [51,51   ] 50)
+  ty_expr_ :: "env \<Rightarrow> [expr ,ty ] \<Rightarrow> bool" ("_|-_:-_" [51,51,51] 50)
+  ty_var_  :: "env \<Rightarrow> [var  ,ty ] \<Rightarrow> bool" ("_|-_:=_" [51,51,51] 50)
+  ty_exprs_:: "env \<Rightarrow> [expr list,
+		     \<spacespace> ty   list] \<Rightarrow> bool" ("_|-_:#_" [51,51,51] 50)
+
+syntax (xsymbols)
+  wt_      :: "env \<Rightarrow> [term,tys] \<Rightarrow> bool" ("_\<turnstile>_\<Colon>_"  [51,51,51] 50)
+  wt_stmt_ ::  "env \<Rightarrow>  stmt       \<Rightarrow> bool" ("_\<turnstile>_\<Colon>\<surd>"  [51,51   ] 50)
+  ty_expr_ :: "env \<Rightarrow> [expr ,ty ] \<Rightarrow> bool" ("_\<turnstile>_\<Colon>-_" [51,51,51] 50)
+  ty_var_  :: "env \<Rightarrow> [var  ,ty ] \<Rightarrow> bool" ("_\<turnstile>_\<Colon>=_" [51,51,51] 50)
+  ty_exprs_ :: "env \<Rightarrow> [expr list,
+		    \<spacespace>  ty   list] \<Rightarrow> bool" ("_\<turnstile>_\<Colon>\<doteq>_" [51,51,51] 50)
+
+translations
+	"E\<turnstile>t\<Colon> T" == "E,empty_dt\<Turnstile>t\<Colon> T"
+	"E\<turnstile>s\<Colon>\<surd>" == "E,empty_dt\<Turnstile>s\<Colon>\<surd>"
+	"E\<turnstile>e\<Colon>-T" == "E,empty_dt\<Turnstile>e\<Colon>-T"
+	"E\<turnstile>e\<Colon>=T" == "E,empty_dt\<Turnstile>e\<Colon>=T"
+	"E\<turnstile>e\<Colon>\<doteq>T" == "E,empty_dt\<Turnstile>e\<Colon>\<doteq>T"
+
+
+inductive wt intros 
+
+
+(* well-typed statements *)
+
+  Skip:					"E,dt\<Turnstile>Skip\<Colon>\<surd>"
+
+  Expr:	"\<lbrakk>E,dt\<Turnstile>e\<Colon>-T\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>Expr e\<Colon>\<surd>"
+  (* cf. 14.6 *)
+  Lab:  "E,dt\<Turnstile>c\<Colon>\<surd> \<Longrightarrow>                   
+                                         E,dt\<Turnstile>l\<bullet> c\<Colon>\<surd>" 
+
+  Comp:	"\<lbrakk>E,dt\<Turnstile>c1\<Colon>\<surd>; 
+	  E,dt\<Turnstile>c2\<Colon>\<surd>\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>c1;; c2\<Colon>\<surd>"
+
+  (* cf. 14.8 *)
+  If:	"\<lbrakk>E,dt\<Turnstile>e\<Colon>-PrimT Boolean;
+	  E,dt\<Turnstile>c1\<Colon>\<surd>;
+	  E,dt\<Turnstile>c2\<Colon>\<surd>\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>If(e) c1 Else c2\<Colon>\<surd>"
+
+  (* cf. 14.10 *)
+  Loop:	"\<lbrakk>E,dt\<Turnstile>e\<Colon>-PrimT Boolean;
+	  E,dt\<Turnstile>c\<Colon>\<surd>\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>l\<bullet> While(e) c\<Colon>\<surd>"
+  (* cf. 14.13, 14.15, 14.16 *)
+  Do:                                   "E,dt\<Turnstile>Do jump\<Colon>\<surd>"
+
+  (* cf. 14.16 *)
+  Throw: "\<lbrakk>E,dt\<Turnstile>e\<Colon>-Class tn;
+	  prg E\<turnstile>tn\<preceq>\<^sub>C SXcpt Throwable\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>Throw e\<Colon>\<surd>"
+  (* cf. 14.18 *)
+  Try:	"\<lbrakk>E,dt\<Turnstile>c1\<Colon>\<surd>; prg E\<turnstile>tn\<preceq>\<^sub>C SXcpt Throwable;
+	  lcl E (VName vn)=None; E \<lparr>lcl := lcl E(VName vn\<mapsto>Class tn)\<rparr>,dt\<Turnstile>c2\<Colon>\<surd>\<rbrakk>
+          \<Longrightarrow>
+					 E,dt\<Turnstile>Try c1 Catch(tn vn) c2\<Colon>\<surd>"
+
+  (* cf. 14.18 *)
+  Fin:	"\<lbrakk>E,dt\<Turnstile>c1\<Colon>\<surd>; E,dt\<Turnstile>c2\<Colon>\<surd>\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>c1 Finally c2\<Colon>\<surd>"
+
+  Init:	"\<lbrakk>is_class (prg E) C\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>Init C\<Colon>\<surd>"
+  (* Init is created on the fly during evaluation (see Eval.thy). The class
+   * isn't necessarily accessible from the points Init is called. Therefor
+   * we only demand is_class and not is_acc_class here 
+   *)
+
+(* well-typed expressions *)
+
+  (* cf. 15.8 *)
+  NewC:	"\<lbrakk>is_acc_class (prg E) (pkg E) C\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>NewC C\<Colon>-Class C"
+  (* cf. 15.9 *)
+  NewA:	"\<lbrakk>is_acc_type (prg E) (pkg E) T;
+	  E,dt\<Turnstile>i\<Colon>-PrimT Integer\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>New T[i]\<Colon>-T.[]"
+
+  (* cf. 15.15 *)
+  Cast:	"\<lbrakk>E,dt\<Turnstile>e\<Colon>-T; is_acc_type (prg E) (pkg E) T';
+	  prg E\<turnstile>T\<preceq>? T'\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>Cast T' e\<Colon>-T'"
+
+  (* cf. 15.19.2 *)
+  Inst:	"\<lbrakk>E,dt\<Turnstile>e\<Colon>-RefT T; is_acc_type (prg E) (pkg E) (RefT T');
+	  prg E\<turnstile>RefT T\<preceq>? RefT T'\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>e InstOf T'\<Colon>-PrimT Boolean"
+
+  (* cf. 15.7.1 *)
+  Lit:	"\<lbrakk>typeof dt x = Some T\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>Lit x\<Colon>-T"
+
+  (* cf. 15.10.2, 15.11.1 *)
+  Super: "\<lbrakk>lcl E This = Some (Class C); C \<noteq> Object;
+	  class (prg E) C = Some c\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>Super\<Colon>-Class (super c)"
+
+  (* cf. 15.13.1, 15.10.1, 15.12 *)
+  Acc:	"\<lbrakk>E,dt\<Turnstile>va\<Colon>=T\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>Acc va\<Colon>-T"
+
+  (* cf. 15.25, 15.25.1 *)
+  Ass:	"\<lbrakk>E,dt\<Turnstile>va\<Colon>=T; va \<noteq> LVar This;
+	  E,dt\<Turnstile>v \<Colon>-T';
+	  prg E\<turnstile>T'\<preceq>T\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>va:=v\<Colon>-T'"
+
+  (* cf. 15.24 *)
+  Cond:	"\<lbrakk>E,dt\<Turnstile>e0\<Colon>-PrimT Boolean;
+	  E,dt\<Turnstile>e1\<Colon>-T1; E,dt\<Turnstile>e2\<Colon>-T2;
+	  prg E\<turnstile>T1\<preceq>T2 \<and> T = T2  \<or>  prg E\<turnstile>T2\<preceq>T1 \<and> T = T1\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>e0 ? e1 : e2\<Colon>-T"
+
+  (* cf. 15.11.1, 15.11.2, 15.11.3 *)
+  Call:	"\<lbrakk>E,dt\<Turnstile>e\<Colon>-RefT statT;
+	  E,dt\<Turnstile>ps\<Colon>\<doteq>pTs;
+	  max_spec (prg E) (cls E) statT \<lparr>name=mn,parTs=pTs\<rparr> 
+            = {((statDeclT,m),pTs')}
+         \<rbrakk> \<Longrightarrow>
+		   E,dt\<Turnstile>{statT,invmode m e}e\<cdot>mn({pTs'}ps)\<Colon>-(resTy m)"
+
+  Methd: "\<lbrakk>is_class (prg E) C;
+	  methd (prg E) C sig = Some m;
+	  E,dt\<Turnstile>Body (declclass m) (stmt (mbody (mthd m)))\<Colon>-T\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>Methd C sig\<Colon>-T"
+ (* The class C is the dynamic class of the method call (cf. Eval.thy). 
+  * It hasn't got to be directly accessible from the current package (pkg E). 
+  * Only the static class must be accessible (enshured indirectly by Call). 
+  *)
+
+  Body:	"\<lbrakk>is_class (prg E) D;
+	  E,dt\<Turnstile>blk\<Colon>\<surd>;
+	  (lcl E) Result = Some T;
+          is_type (prg E) T\<rbrakk> \<Longrightarrow>
+   					 E,dt\<Turnstile>Body D blk\<Colon>-T"
+  (* the class D implementing the method must not directly be accessible 
+   * from the current package (pkg E), but can also be indirectly accessible 
+   * due to inheritance (enshured in Call)
+   * The result type hasn't got to be accessible in Java! (If it is not 
+   * accessible you can only assign it to Object) 
+   *)
+
+(* well-typed variables *)
+
+  (* cf. 15.13.1 *)
+  LVar:	"\<lbrakk>lcl E vn = Some T; is_acc_type (prg E) (pkg E) T\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>LVar vn\<Colon>=T"
+  (* cf. 15.10.1 *)
+  FVar:	"\<lbrakk>E,dt\<Turnstile>e\<Colon>-Class C; 
+	  accfield (prg E) (cls E) C fn = Some (fd,f)\<rbrakk> \<Longrightarrow>
+			                 E,dt\<Turnstile>{fd,static f}e..fn\<Colon>=(type f)"
+  (* cf. 15.12 *)
+  AVar:	"\<lbrakk>E,dt\<Turnstile>e\<Colon>-T.[]; 
+	  E,dt\<Turnstile>i\<Colon>-PrimT Integer\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>e.[i]\<Colon>=T"
+
+
+(* well-typed expression lists *)
+
+  (* cf. 15.11.??? *)
+  Nil:					"E,dt\<Turnstile>[]\<Colon>\<doteq>[]"
+
+  (* cf. 15.11.??? *)
+  Cons:	"\<lbrakk>E,dt\<Turnstile>e \<Colon>-T;
+	  E,dt\<Turnstile>es\<Colon>\<doteq>Ts\<rbrakk> \<Longrightarrow>
+					 E,dt\<Turnstile>e#es\<Colon>\<doteq>T#Ts"
+
+
+declare not_None_eq [simp del] 
+declare split_if [split del] split_if_asm [split del]
+declare split_paired_All [simp del] split_paired_Ex [simp del]
+ML_setup {*
+simpset_ref() := simpset() delloop "split_all_tac"
+*}
+inductive_cases wt_stmt_cases: "E,dt\<Turnstile>c\<Colon>\<surd>"
+inductive_cases wt_elim_cases:
+	"E,dt\<Turnstile>In2  (LVar vn)               \<Colon>T"
+	"E,dt\<Turnstile>In2  ({fd,s}e..fn)           \<Colon>T"
+	"E,dt\<Turnstile>In2  (e.[i])                 \<Colon>T"
+	"E,dt\<Turnstile>In1l (NewC C)                \<Colon>T"
+	"E,dt\<Turnstile>In1l (New T'[i])             \<Colon>T"
+	"E,dt\<Turnstile>In1l (Cast T' e)             \<Colon>T"
+	"E,dt\<Turnstile>In1l (e InstOf T')           \<Colon>T"
+	"E,dt\<Turnstile>In1l (Lit x)                 \<Colon>T"
+	"E,dt\<Turnstile>In1l (Super)                 \<Colon>T"
+	"E,dt\<Turnstile>In1l (Acc va)                \<Colon>T"
+	"E,dt\<Turnstile>In1l (Ass va v)              \<Colon>T"
+	"E,dt\<Turnstile>In1l (e0 ? e1 : e2)          \<Colon>T"
+	"E,dt\<Turnstile>In1l ({statT,mode}e\<cdot>mn({pT'}p))\<Colon>T"
+	"E,dt\<Turnstile>In1l (Methd C sig)           \<Colon>T"
+	"E,dt\<Turnstile>In1l (Body D blk)            \<Colon>T"
+	"E,dt\<Turnstile>In3  ([])                    \<Colon>Ts"
+	"E,dt\<Turnstile>In3  (e#es)                  \<Colon>Ts"
+	"E,dt\<Turnstile>In1r  Skip                   \<Colon>x"
+	"E,dt\<Turnstile>In1r (Expr e)                \<Colon>x"
+	"E,dt\<Turnstile>In1r (c1;; c2)               \<Colon>x"
+        "E,dt\<Turnstile>In1r (l\<bullet> c)                  \<Colon>x" 
+	"E,dt\<Turnstile>In1r (If(e) c1 Else c2)      \<Colon>x"
+	"E,dt\<Turnstile>In1r (l\<bullet> While(e) c)         \<Colon>x"
+        "E,dt\<Turnstile>In1r (Do jump)               \<Colon>x"
+	"E,dt\<Turnstile>In1r (Throw e)               \<Colon>x"
+	"E,dt\<Turnstile>In1r (Try c1 Catch(tn vn) c2)\<Colon>x"
+	"E,dt\<Turnstile>In1r (c1 Finally c2)         \<Colon>x"
+	"E,dt\<Turnstile>In1r (Init C)                \<Colon>x"
+declare not_None_eq [simp] 
+declare split_if [split] split_if_asm [split]
+declare split_paired_All [simp] split_paired_Ex [simp]
+ML_setup {*
+simpset_ref() := simpset() addloop ("split_all_tac", split_all_tac)
+*}
+
+lemma is_acc_class_is_accessible: 
+  "is_acc_class G P C \<Longrightarrow> G\<turnstile>(Class C) accessible_in P"
+by (auto simp add: is_acc_class_def)
+
+lemma is_acc_iface_is_iface: "is_acc_iface G P I \<Longrightarrow> is_iface G I"
+by (auto simp add: is_acc_iface_def)
+
+lemma is_acc_iface_is_accessible: 
+  "is_acc_iface G P I \<Longrightarrow> G\<turnstile>(Iface I) accessible_in P"
+by (auto simp add: is_acc_iface_def)
+
+lemma is_acc_type_is_type: "is_acc_type G P T \<Longrightarrow> is_type G T"
+by (auto simp add: is_acc_type_def)
+
+lemma is_acc_iface_is_accessible: "is_acc_type G P T \<Longrightarrow> G\<turnstile>T accessible_in P"
+by (auto simp add: is_acc_type_def)
+
+lemma wt_Methd_is_methd: 
+  "E\<turnstile>In1l (Methd C sig)\<Colon>T \<Longrightarrow> is_methd (prg E) C sig"
+apply (erule_tac wt_elim_cases)
+apply clarsimp
+apply (erule is_methdI, assumption)
+done
+
+(* Special versions of some typing rules, better suited to pattern match the
+ * conclusion (no selectors in the conclusion\<dots>)
+ *)
+
+lemma wt_Super:
+"\<lbrakk>lcl E This = Some (Class C); C \<noteq> Object;
+  class (prg E) C = Some c;D=super c\<rbrakk> 
+ \<Longrightarrow> E,dt\<Turnstile>Super\<Colon>-Class D"
+by (auto elim: wt.Super)
+ 
+lemma wt_Call: 
+"\<lbrakk>E,dt\<Turnstile>e\<Colon>-RefT statT; E,dt\<Turnstile>ps\<Colon>\<doteq>pTs;  
+  max_spec (prg E) (cls E) statT \<lparr>name=mn,parTs=pTs\<rparr> 
+    = {((statDeclC,m),pTs')};rT=(resTy m);   
+ mode = invmode m e\<rbrakk> \<Longrightarrow> E,dt\<Turnstile>{statT,mode}e\<cdot>mn({pTs'}ps)\<Colon>-rT"
+by (auto elim: wt.Call)
+
+
+
+lemma invocationTypeExpr_noClassD: 
+"\<lbrakk> E\<turnstile>e\<Colon>-RefT statT\<rbrakk>
+ \<Longrightarrow> (\<forall> statC. statT \<noteq> ClassT statC) \<longrightarrow> invmode m e \<noteq> SuperM"
+proof -
+  assume wt: "E\<turnstile>e\<Colon>-RefT statT"
+  show ?thesis
+  proof (cases "e=Super")
+    case True
+    with wt obtain "C" where "statT = ClassT C" by (blast elim: wt_elim_cases)
+    then show ?thesis by blast
+  next 
+    case False then show ?thesis 
+      by (auto simp add: invmode_def split: split_if_asm)
+  qed
+qed
+
+lemma wt_Super: 
+"\<lbrakk>lcl E This = Some (Class C); C \<noteq> Object; class (prg E) C = Some c; D=super c\<rbrakk> 
+\<Longrightarrow> E,dt\<Turnstile>Super\<Colon>-Class D"
+by (auto elim: wt.Super)
+
+
+lemma wt_FVar:	
+"\<lbrakk>E,dt\<Turnstile>e\<Colon>-Class C; accfield (prg E) (cls E) C fn = Some (fd,f);
+  sf=static f; fT=(type f)\<rbrakk> \<Longrightarrow> E,dt\<Turnstile>{fd,sf}e..fn\<Colon>=fT"
+by (auto elim: wt.FVar)
+
+lemma wt_init [iff]: "E,dt\<Turnstile>Init C\<Colon>\<surd> = is_class (prg E) C"
+by (auto elim: wt_elim_cases intro: "wt.Init")
+
+declare wt.Skip [iff]
+
+lemma wt_StatRef: 
+  "is_acc_type (prg E) (pkg E) (RefT rt) \<Longrightarrow> E\<turnstile>StatRef rt\<Colon>-RefT rt"
+apply (rule wt.Cast)
+apply  (rule wt.Lit)
+apply   (simp (no_asm))
+apply  (simp (no_asm_simp))
+apply (rule cast.widen)
+apply (simp (no_asm))
+done
+
+lemma wt_Inj_elim: 
+  "\<And>E. E,dt\<Turnstile>t\<Colon>U \<Longrightarrow> case t of 
+                       In1 ec \<Rightarrow> (case ec of 
+                                    Inl e \<Rightarrow> \<exists>T. U=Inl T  
+                                  | Inr s \<Rightarrow> U=Inl (PrimT Void))  
+                     | In2 e \<Rightarrow> (\<exists>T. U=Inl T) 
+                     | In3 e \<Rightarrow> (\<exists>T. U=Inr T)"
+apply (erule wt.induct)
+apply auto
+done
+
+ML {*
+fun wt_fun name inj rhs =
+let
+  val lhs = "E,dt\<Turnstile>" ^ inj ^ " t\<Colon>U"
+  val () = qed_goal name (the_context()) (lhs ^ " = (" ^ rhs ^ ")") 
+	(K [Auto_tac, ALLGOALS (ftac (thm "wt_Inj_elim")) THEN Auto_tac])
+  fun is_Inj (Const (inj,_) $ _) = true
+    | is_Inj _                   = false
+  fun pred (t as (_ $ (Const ("Pair",_) $
+     _ $ (Const ("Pair", _) $ _ $ (Const ("Pair", _) $ _ $
+       x))) $ _ )) = is_Inj x
+in
+  make_simproc name lhs pred (thm name)
+end
+
+val wt_expr_proc  = wt_fun "wt_expr_eq"  "In1l" "\<exists>T.  U=Inl T  \<and> E,dt\<Turnstile>t\<Colon>-T"
+val wt_var_proc   = wt_fun "wt_var_eq"   "In2"  "\<exists>T.  U=Inl T  \<and> E,dt\<Turnstile>t\<Colon>=T"
+val wt_exprs_proc = wt_fun "wt_exprs_eq" "In3"  "\<exists>Ts. U=Inr Ts \<and> E,dt\<Turnstile>t\<Colon>\<doteq>Ts"
+val wt_stmt_proc  = wt_fun "wt_stmt_eq"  "In1r" "U=Inl(PrimT Void)\<and>E,dt\<Turnstile>t\<Colon>\<surd>"
+*}
+
+ML {*
+Addsimprocs [wt_expr_proc,wt_var_proc,wt_exprs_proc,wt_stmt_proc]
+*}
+
+lemma Inj_eq_lemma [simp]: 
+  "(\<forall>T. (\<exists>T'. T = Inj T' \<and> P T') \<longrightarrow> Q T) = (\<forall>T'. P T' \<longrightarrow> Q (Inj T'))"
+by auto
+
+(* unused *)
+lemma single_valued_tys_lemma [rule_format (no_asm)]: 
+  "\<forall>S T. G\<turnstile>S\<preceq>T \<longrightarrow> G\<turnstile>T\<preceq>S \<longrightarrow> S = T \<Longrightarrow> E,dt\<Turnstile>t\<Colon>T \<Longrightarrow>  
+     G = prg E \<longrightarrow> (\<forall>T'. E,dt\<Turnstile>t\<Colon>T' \<longrightarrow> T  = T')"
+apply (cases "E", erule wt.induct)
+apply (safe del: disjE)
+apply (simp_all (no_asm_use) split del: split_if_asm)
+apply (safe del: disjE)
+(* 17 subgoals *)
+apply (tactic {* ALLGOALS (fn i => if i = 9 then EVERY'[thin_tac "?E,dt\<Turnstile>e0\<Colon>-PrimT Boolean", thin_tac "?E,dt\<Turnstile>e1\<Colon>-?T1", thin_tac "?E,dt\<Turnstile>e2\<Colon>-?T2"] i else thin_tac "All ?P" i) *})
+(*apply (safe del: disjE elim!: wt_elim_cases)*)
+apply (tactic {*ALLGOALS (eresolve_tac (thms "wt_elim_cases"))*})
+apply (simp_all (no_asm_use) split del: split_if_asm)
+apply (erule_tac [10] V = "All ?P" in thin_rl) (* Call *)
+apply ((blast del: equalityCE dest: sym [THEN trans])+)
+done
+
+(* unused *)
+lemma single_valued_tys: 
+"ws_prog (prg E) \<Longrightarrow> single_valued {(t,T). E,dt\<Turnstile>t\<Colon>T}"
+apply (unfold single_valued_def)
+apply clarsimp
+apply (rule single_valued_tys_lemma)
+apply (auto intro!: widen_antisym)
+done
+
+lemma typeof_empty_is_type [rule_format (no_asm)]: 
+  "typeof (\<lambda>a. None) v = Some T \<longrightarrow> is_type G T"
+apply (rule val.induct)
+apply    	auto
+done
+
+(* unused *)
+lemma typeof_is_type [rule_format (no_asm)]: 
+ "(\<forall>a. v \<noteq> Addr a) \<longrightarrow> (\<exists>T. typeof dt v = Some T \<and> is_type G T)"
+apply (rule val.induct)
+prefer 5 
+apply     fast
+apply  (simp_all (no_asm))
+done
+
+end