Theory AxSem

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theory AxSem = Evaln + TypeSafe
files [AxSem.ML]:
(*  Title:      isabelle/Bali/AxSem.thy
    ID:         $Id: AxSem.thy,v 1.109 2000/11/25 23:58:27 oheimb Exp $
    Author:     David von Oheimb
    Copyright   1998 Technische Universitaet Muenchen

Axiomatic semantics of Java expressions and statements (see also Eval.thy)

design issues:
* a strong version of validity for triples with premises, namely one that takes
  the recursive depth needed to complete execution, enables correctness proof
* auxiliary variables are handled first-class (-> Thomas Kleymann)
* expressions not flattened to elementary assignments (as usual for axiomatic
  semantics) but treated first-class => explicit result value handling
* intermediate values not on triple, but on assertion level (with result entry)
* multiple results with semantical substitution mechnism not requiring a stack 
* because of dynamic method binding, terms need to be dependent on state.
  this is also useful for conditional expressions and statements
* result values in triples exactly as in eval relation (also for xcpt states)
* validity: additional assumption of state conformance and well-typedness,
  which is required for soundness and thus rule hazard required of completeness

restrictions:
* all triples in a derivation are of the same type (due to weak polymorphism)
*)

AxSem = Evaln + TypeSafe +

types  res = vals (* result entry *)
syntax
  Val  :: "val      \<Rightarrow> res"
  Var  :: "var      \<Rightarrow> res"
  Vals :: "val list \<Rightarrow> res"
translations
  "Val  x"     => "(In1 x)"
  "Var  x"     => "(In2 x)"
  "Vals x"     => "(In3 x)"

syntax
  "Val_"    :: [pttrn] => pttrn     ("Val:_"  [951] 950)
  "Var_"    :: [pttrn] => pttrn     ("Var:_"  [951] 950)
  "Vals_"   :: [pttrn] => pttrn     ("Vals:_" [951] 950)
translations
  "\<lambda>Val:v . b"  == "(\<lambda>v. b) \<circ> the_In1"
  "\<lambda>Var:v . b"  == "(\<lambda>v. b) \<circ> the_In2"
  "\<lambda>Vals:v. b"  == "(\<lambda>v. b) \<circ> the_In3"

  (* relation on result values, state and auxiliary variables *)
types 'a assn   =        "res \<Rightarrow> state \<Rightarrow> 'a \<Rightarrow> bool"
translations
      "res"    <= (type) "AxSem.res"
      "a assn" <= (type) "vals \<Rightarrow> state \<Rightarrow> a \<Rightarrow> bool"

constdefs
  assn_imp   :: "'a assn \<Rightarrow> 'a assn \<Rightarrow> bool"             (infixr "\<Rightarrow>" 25)
 "P \<Rightarrow> Q \<equiv> \<forall>Y s Z. P Y s Z \<longrightarrow> Q Y s Z"
  
  peek_and   :: "'a assn \<Rightarrow> (state \<Rightarrow>  bool) \<Rightarrow> 'a assn" (infixl "\<and>." 13)
 "P \<and>. p \<equiv> \<lambda>Y s Z. P Y s Z \<and> p s"

  assn_supd  :: "'a assn \<Rightarrow> (state \<Rightarrow> state) \<Rightarrow> 'a assn" (infixl ";." 13)
 "P ;. f \<equiv> \<lambda>Y s' Z. \<exists>s. P Y s Z \<and> s' = f s"

  supd_assn  :: "(state \<Rightarrow> state) \<Rightarrow> 'a assn \<Rightarrow> 'a assn" (infixr ".;" 13)
 "f .; P \<equiv> \<lambda>Y s. P Y (f s)"

  subst_res   :: "'a assn \<Rightarrow> res \<Rightarrow> 'a assn"              ("_\<leftarrow>_"  [60,61] 60)
 "P\<leftarrow>w \<equiv> \<lambda>Y. P w"

  subst_Bool  :: "'a assn \<Rightarrow> bool \<Rightarrow> 'a assn"             ("_\<leftarrow>=_" [60,61] 60)
 "P\<leftarrow>=b \<equiv> \<lambda>Y s Z. \<exists>v. P (Val v) s Z \<and> (normal s \<longrightarrow> the_Bool v=b)"

  peek_res    :: "(res \<Rightarrow> 'a assn) \<Rightarrow> 'a assn"
 "peek_res Pf \<equiv> \<lambda>Y. Pf Y Y"

  peek_st    :: "(st \<Rightarrow> 'a assn) \<Rightarrow> 'a assn"
 "peek_st P \<equiv> \<lambda>Y s. P (snd s) Y s"

  ign_res    ::  "        'a assn \<Rightarrow> 'a assn"            ("_\<down>" [1000] 1000)
  "P\<down>        \<equiv> \<lambda>Y s Z. \<exists>Y. P Y s Z"

syntax
  Normal     ::          "'a assn \<Rightarrow> 'a assn"
"@peek_res"  :: "pttrn \<Rightarrow> 'a assn \<Rightarrow> 'a assn"            ("\<lambda>_:. _" [0,3] 3)
"@peek_st"   :: "pttrn \<Rightarrow> 'a assn \<Rightarrow> 'a assn"            ("\<lambda>_.. _" [0,3] 3)

translations
  "Normal P" == "P \<and>. normal"
  "\<lambda>w:. P"   == "peek_res (\<lambda>w. P)"
  "\<lambda>s.. P"   == "peek_st (\<lambda>s. P)"

constdefs
  ign_res_eq :: "'a assn \<Rightarrow> res \<Rightarrow> 'a assn"               ("_\<down>=_"  [60,61] 60)
 "P\<down>=w       \<equiv> \<lambda>Y:. P\<down> \<and>. (\<lambda>s. Y=w)"

  RefVar     :: "(state \<Rightarrow> vvar × state) \<Rightarrow> 'a assn \<Rightarrow> 'a assn"(infixr "..;" 13)
 "vf ..; P \<equiv> \<lambda>Y s. let (v,s') = vf s in P (Var v) s'"
 
  Alloc      :: "prog \<Rightarrow> obj_tag \<Rightarrow> 'a assn \<Rightarrow> 'a assn"
 "Alloc G otag P \<equiv> \<lambda>Y s Z.
                   \<forall>s' a. G\<turnstile>s \<midarrow>halloc otag\<succ>a\<rightarrow> s'\<longrightarrow> P (Val (Addr a)) s' Z"

  SXAlloc     :: "prog \<Rightarrow> 'a assn \<Rightarrow> 'a assn"
 "SXAlloc G P \<equiv> \<lambda>Y s Z. \<forall>s'. G\<turnstile>s \<midarrow>sxalloc\<rightarrow> s' \<longrightarrow> P Y s' Z"

  type_ok  :: "prog \<Rightarrow> term \<Rightarrow> state \<Rightarrow> bool"
 "type_ok G t s \<equiv> \<exists>L T. (normal s \<longrightarrow> (G,L)\<turnstile>t\<Colon>T) \<and> s\<Colon>\<preceq>(G,L)"

datatype    'a triple =      triple ('a assn) term ('a assn) (** should be
something like triple = \<forall>'a. triple ('a assn) term ('a assn)  **)
     
                                        ("{(1_)}/ _>/ {(1_)}"      [3,65,3]75)
types    'a triples = 'a triple set

syntax

  var_triple   :: "['a assn, var         ,'a assn] \<Rightarrow> 'a triple"
                                         ("{(1_)}/ _=>/ {(1_)}"    [3,80,3] 75)
  expr_triple  :: "['a assn, expr        ,'a assn] \<Rightarrow> 'a triple"
                                         ("{(1_)}/ _->/ {(1_)}"    [3,80,3] 75)
  exprs_triple :: "['a assn, expr list   ,'a assn] \<Rightarrow> 'a triple"
                                         ("{(1_)}/ _#>/ {(1_)}"    [3,65,3] 75)
  stmt_triple  :: "['a assn, stmt,        'a assn] \<Rightarrow> 'a triple"
                                         ("{(1_)}/ ._./ {(1_)}"     [3,65,3] 75)

syntax (xsymbols)

  triple       :: "['a assn, term        ,'a assn] \<Rightarrow> 'a triple"
                                         ("{(1_)}/ _\<succ>/ {(1_)}"     [3,65,3] 75)
  var_triple   :: "['a assn, var         ,'a assn] \<Rightarrow> 'a triple"
                                         ("{(1_)}/ _=\<succ>/ {(1_)}"    [3,80,3] 75)
  expr_triple  :: "['a assn, expr        ,'a assn] \<Rightarrow> 'a triple"
                                         ("{(1_)}/ _-\<succ>/ {(1_)}"    [3,80,3] 75)
  exprs_triple :: "['a assn, expr list   ,'a assn] \<Rightarrow> 'a triple"
                                         ("{(1_)}/ _\<doteq>\<succ>/ {(1_)}"    [3,65,3] 75)

translations
  "{P} e-\<succ> {Q}" == "{P} In1l e\<succ> {Q}"
  "{P} e=\<succ> {Q}" == "{P} In2  e\<succ> {Q}"
  "{P} e\<doteq>\<succ> {Q}" == "{P} In3  e\<succ> {Q}"
  "{P} .c. {Q}" == "{P} In1r c\<succ> {Q}"

constdefs
  mtriples  :: "('c \<Rightarrow> 'sig \<Rightarrow> 'a assn) \<Rightarrow> ('c \<Rightarrow> 'sig \<Rightarrow> expr) \<Rightarrow> 
                ('c \<Rightarrow> 'sig \<Rightarrow> 'a assn) \<Rightarrow> ('c ×  'sig) set \<Rightarrow> 'a triples"
                                     ("{{(1_)}/ _-\<succ>/ {(1_)} | _}"[3,65,3,65]75)
 "{{P} tf-\<succ> {Q} | ms} \<equiv> (\<lambda>(C,sig). {Normal(P C sig)} tf C sig-\<succ> {Q C sig})``ms"
  
consts

 triple_valid :: "prog \<Rightarrow> nat \<Rightarrow>        'a triple  \<Rightarrow> bool"
                                                (   "_\<Turnstile>_:_" [61,0, 58] 57)
    ax_valids :: "prog \<Rightarrow> 'b triples \<Rightarrow> 'a triples \<Rightarrow> bool"
                                                ("_,_|\<Turnstile>_"   [61,58,58] 57)
    ax_derivs :: "prog \<Rightarrow> ('b triples × 'a triples) set"

syntax

 triples_valid:: "prog \<Rightarrow> nat \<Rightarrow>         'a triples \<Rightarrow> bool"
                                                (  "_||=_:_" [61,0, 58] 57)
     ax_valid :: "prog \<Rightarrow>  'b triples \<Rightarrow> 'a triple  \<Rightarrow> bool"
                                                ( "_,_|=_"   [61,58,58] 57)
     ax_Derivs:: "prog \<Rightarrow>  'b triples \<Rightarrow> 'a triples \<Rightarrow> bool"
                                                ("_,_||-_"   [61,58,58] 57)
     ax_Deriv :: "prog \<Rightarrow>  'b triples \<Rightarrow> 'a triple  \<Rightarrow> bool"
                                                ( "_,_|-_"   [61,58,58] 57)

syntax (xsymbols)

 triples_valid:: "prog \<Rightarrow> nat \<Rightarrow>         'a triples \<Rightarrow> bool"
                                                (  "_|\<Turnstile>_:_" [61,0, 58] 57)
     ax_valid :: "prog \<Rightarrow>  'b triples \<Rightarrow> 'a triple  \<Rightarrow> bool"
                                                ( "_,_\<Turnstile>_"   [61,58,58] 57)
     ax_Derivs:: "prog \<Rightarrow>  'b triples \<Rightarrow> 'a triples \<Rightarrow> bool"
                                                ("_,_|\<turnstile>_"   [61,58,58] 57)
     ax_Deriv :: "prog \<Rightarrow>  'b triples \<Rightarrow> 'a triple  \<Rightarrow> bool"
                                                ( "_,_\<turnstile>_"   [61,58,58] 57)

defs  triple_valid_def   "G\<Turnstile>n:t  \<equiv> case t of {P} t\<succ> {Q} \<Rightarrow>
                          \<forall>Y s Z. P Y s Z \<longrightarrow> type_ok G t s \<longrightarrow>
                          (\<forall>Y' s'. G\<turnstile>s \<midarrow>t\<succ>\<midarrow>n\<rightarrow> (Y',s') \<longrightarrow> Q Y' s' Z)"
translations         "G|\<Turnstile>n:ts" == "Ball ts (triple_valid G n)"
defs   ax_valids_def "G,A|\<Turnstile>ts  \<equiv>  \<forall>n. G|\<Turnstile>n:A \<longrightarrow> G|\<Turnstile>n:ts"
translations         "G,A \<Turnstile>t"  == "G,A|\<Turnstile>{t}"
                     "G,A|\<turnstile>ts" == "(A,ts) \<in> ax_derivs G"
                     "G,A \<turnstile>t"  == "G,A|\<turnstile>{t}"

inductive "ax_derivs G" intrs

  empty " G,A|\<turnstile>{}"
  insert"\<lbrakk>G,A\<turnstile>t; G,A|\<turnstile>ts\<rbrakk> \<Longrightarrow>
          G,A|\<turnstile>insert t ts"

  asm    "ts\<subseteq>A \<Longrightarrow> G,A|\<turnstile>ts"

(* could be added for convenience and efficiency, but is not necessary
  cut    "\<lbrakk>G,A'|\<turnstile>ts; G,A|\<turnstile>A'\<rbrakk> \<Longrightarrow>
           G,A |\<turnstile>ts"
*)
  weaken"\<lbrakk>G,A|\<turnstile>ts'; ts \<subseteq> ts'\<rbrakk> \<Longrightarrow> G,A|\<turnstile>ts"

  conseq"\<forall>Y s Z . P  Y s Z  \<longrightarrow> (\<exists>P' Q'. G,A\<turnstile>{P'} t\<succ> {Q'} \<and> (\<forall>Y' s'. 
        (\<forall>Y   Z'. P' Y s Z' \<longrightarrow> Q' Y' s' Z') \<longrightarrow>
                                Q  Y' s' Z ))
                                         \<Longrightarrow> G,A\<turnstile>{P } t\<succ> {Q }"

  hazard"G,A\<turnstile>{P \<and>. Not \<circ> type_ok G t} t\<succ> {Q}"

  Xcpt  "G,A\<turnstile>{P\<leftarrow>(arbitrary3 t) \<and>. Not \<circ> normal} t\<succ> {P}"

  (* variables *)
  LVar  " G,A\<turnstile>{Normal (\<lambda>s.. P\<leftarrow>Var (lvar vn s))} LVar vn=\<succ> {P}"

  FVar  "\<lbrakk>G,A\<turnstile>{Normal P} .init C. {Q};
          G,A\<turnstile>{Q} e-\<succ> {\<lambda>Val:a:. fvar C stat fn a ..; R}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} {C,stat}e..fn=\<succ> {R}"

  AVar  "\<lbrakk>G,A\<turnstile>{Normal P} e1-\<succ> {Q};
          \<forall>a. G,A\<turnstile>{Q\<leftarrow>Val a} e2-\<succ> {\<lambda>Val:i:. avar G i a ..; R}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} e1.[e2]=\<succ> {R}"
  (* expressions *)

  NewC  "\<lbrakk>G,A\<turnstile>{Normal P} .init C. {Alloc G (CInst C) Q}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} NewC C-\<succ> {Q}"

  NewA  "\<lbrakk>G,A\<turnstile>{Normal P} .init_comp_ty T. {Q};  G,A\<turnstile>{Q} e-\<succ>
          {\<lambda>Val:i:. xupd (check_neg i) .; Alloc G (Arr T (the_Intg i)) R}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} New T[e]-\<succ> {R}"

  Cast  "\<lbrakk>G,A\<turnstile>{Normal P} e-\<succ> {\<lambda>Val:v:. \<lambda>s..
          xupd (raise_if (¬G,s\<turnstile>v fits T) ClassCast) .; Q\<leftarrow>Val v}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} Cast T e-\<succ> {Q}"

  Inst  "\<lbrakk>G,A\<turnstile>{Normal P} e-\<succ> {\<lambda>Val:v:. \<lambda>s..
                  Q\<leftarrow>Val (Bool (v\<noteq>Null \<and> G,s\<turnstile>v fits RefT T))}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} e InstOf T-\<succ> {Q}"

  Lit                           "G,A\<turnstile>{Normal (P\<leftarrow>Val v)} Lit v-\<succ> {P}"

  Super " G,A\<turnstile>{Normal (\<lambda>s.. P\<leftarrow>Val (val_this s))} Super-\<succ> {P}"

  Acc   "\<lbrakk>G,A\<turnstile>{Normal P} va=\<succ> {\<lambda>Var:(v,f):. Q\<leftarrow>Val v}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} Acc va-\<succ> {Q}"

  Ass   "\<lbrakk>G,A\<turnstile>{Normal P} va=\<succ> {Q};
     \<forall>vf. G,A\<turnstile>{Q\<leftarrow>Var vf} e-\<succ> {\<lambda>Val:v:. assign (snd vf) v .; R}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} va:=e-\<succ> {R}"

  Cond  "\<lbrakk>G,A \<turnstile>{Normal P} e0-\<succ> {P'};
          \<forall>b. G,A\<turnstile>{P'\<leftarrow>=b} (if b then e1 else e2)-\<succ> {Q}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} e0 ? e1 : e2-\<succ> {Q}"

  Call  "\<lbrakk>G,A\<turnstile>{Normal P} e-\<succ> {Q}; \<forall>a. G,A\<turnstile>{Q\<leftarrow>Val a} args\<doteq>\<succ> {R a};
          \<forall>a vs D l. G,A\<turnstile>{(R a\<leftarrow>Vals vs \<and>.
               (\<lambda>s. D = target mode (snd s) a cT \<and> l = locals (snd s)) ;.
               init_lvars G D (mn,pTs) mode a vs) \<and>.
               (\<lambda>s. normal s \<longrightarrow> G\<turnstile>mode\<rightarrow>D\<preceq>t)}
              Methd D (mn,pTs)-\<succ> {set_lvars l .; S}\<rbrakk> \<Longrightarrow>
         G,A\<turnstile>{Normal P} {t,cT,mode}e..mn({pTs}args)-\<succ> {S}"

  Methd "\<lbrakk>G,A\<union> {{P} Methd-\<succ> {Q} | ms} |\<turnstile> {{P} body G-\<succ> {Q} | ms}\<rbrakk> \<Longrightarrow>
                                 G,A|\<turnstile>{{P} Methd-\<succ>  {Q} | ms}"

  Body  "\<lbrakk>G,A\<turnstile>{Normal P} .init D. {Q}; G,A\<turnstile>{Q} .c. {R}; G,A\<turnstile>{R} e-\<succ> {S}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} Body D c e-\<succ> {S}"
  
  (* expression lists *)

  Nil                           "G,A\<turnstile>{Normal (P\<leftarrow>Vals [])} []\<doteq>\<succ> {P}"

  Cons  "\<lbrakk>G,A\<turnstile>{Normal P} e-\<succ> {Q};
          \<forall>v. G,A\<turnstile>{Q\<leftarrow>Val v} es\<doteq>\<succ> {\<lambda>Vals:vs:. R\<leftarrow>Vals (v#vs)}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} e#es\<doteq>\<succ> {R}"

  (* statements *)

  Skip                          "G,A\<turnstile>{Normal (P\<leftarrow>\<bullet>)} .Skip. {P}"

  Expr  "\<lbrakk>G,A\<turnstile>{Normal P} e-\<succ> {Q\<leftarrow>\<bullet>}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} .Expr e. {Q}"

  Comp  "\<lbrakk>G,A\<turnstile>{Normal P} .c1. {Q};
          G,A\<turnstile>{Q} .c2. {R}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} .c1;;c2. {R}"

  If    "\<lbrakk>G,A \<turnstile>{Normal P} e-\<succ> {P'};
          \<forall>b. G,A\<turnstile>{P'\<leftarrow>=b} .(if b then c1 else c2). {Q}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} .If(e) c1 Else c2. {Q}"
(* unfolding variant of Loop, not needed here
  LoopU "\<lbrakk>G,A \<turnstile>{Normal P} e-\<succ> {P'};
          \<forall>b. G,A\<turnstile>{P'\<leftarrow>=b} .(if b then c;;While(e) c else Skip).{Q}\<rbrakk>
         \<Longrightarrow>              G,A\<turnstile>{Normal P} .While(e) c. {Q}"
*)
  Loop  "\<lbrakk>G,A\<turnstile>{P} e-\<succ> {P'}; G,A\<turnstile>{Normal (P'\<leftarrow>=True)} .c. {P}\<rbrakk> \<Longrightarrow>
                            G,A\<turnstile>{P} .While(e) c. {(P'\<leftarrow>=False)\<down>=\<bullet>}"

  Throw "\<lbrakk>G,A\<turnstile>{Normal P} e-\<succ> {\<lambda>Val:a:. xupd (throw a) .; Q\<leftarrow>\<bullet>}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} .Throw e. {Q}"

  Try   "\<lbrakk>G,A\<turnstile>{Normal P} .c1. {SXAlloc G Q};
          G,A\<turnstile>{Q \<and>. (\<lambda>s.  G,s\<turnstile>catch C) ;. new_xcpt_var vn} .c2. {R};
              (Q \<and>. (\<lambda>s. ¬G,s\<turnstile>catch C)) \<Rightarrow> R\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} .Try c1 Catch(C vn) c2. {R}"

  Fin   "\<lbrakk>G,A\<turnstile>{Normal P} .c1. {Q};
      \<forall>x. G,A\<turnstile>{Q \<and>. (\<lambda>s. x = fst s) ;. xupd (\<lambda>x. None)}
              .c2. {xupd (xcpt_if (x\<noteq>None) x) .; R}\<rbrakk> \<Longrightarrow>
                                 G,A\<turnstile>{Normal P} .c1 Finally c2. {R}"

  Done                        "G,A\<turnstile>{Normal (P\<leftarrow>\<bullet> \<and>. initd C)} .init C. {P}"

  Init  "\<lbrakk>the (class G C) = (sc,si,fs,ms,ini);
          G,A\<turnstile>{Normal ((P \<and>. Not \<circ> initd C) ;. supd (init_class_obj G C))}
              .(if C = Object then Skip else init sc). {Q};
      \<forall>l. G,A\<turnstile>{Q \<and>. (\<lambda>s. l = locals (snd s)) ;. set_lvars empty}
              .ini. {set_lvars l .; R}\<rbrakk> \<Longrightarrow>
                               G,A\<turnstile>{Normal (P \<and>. Not \<circ> initd C)} .init C. {R}"

rules (** these terms are the same as above, but with generalized typing **)
  polymorphic_conseq
        "\<forall>Y s Z . P  Y s Z  \<longrightarrow> (\<exists>P' Q'. G,A\<turnstile>{P'} t\<succ> {Q'} \<and> (\<forall>Y' s'. 
        (\<forall>Y   Z'. P' Y s Z' \<longrightarrow> Q' Y' s' Z') \<longrightarrow>
                                Q  Y' s' Z ))
                                         \<Longrightarrow> G,A\<turnstile>{P } t\<succ> {Q }"

  polymorphic_Loop
        "\<lbrakk>G,A\<turnstile>{P} e-\<succ> {P'}; G,A\<turnstile>{Normal (P'\<leftarrow>=True)} .c. {P}\<rbrakk> \<Longrightarrow>
                            G,A\<turnstile>{P} .While(e) c. {(P'\<leftarrow>=False)\<down>=\<bullet>}"
end

theorem assn_imp_def2:

  (P \<Rightarrow> Q) = (ALL Y s Z. P Y s Z --> Q Y s Z)

theorem inj_triple:

  inj (split (%P. split (triple P)))

theorem triple_inj_eq:

  ({P} t> {Q} = {P'} t'> {Q'}) = (P = P' & t = t' & Q = Q')

assertion transformers

theorem assn_supd_def2:

  (P ;. f) Y s' Z = (EX s. P Y s Z & s' = f s)

theorem supd_assn_def2:

  (f .; P) Y s = P Y (f s)

theorem supd_assn_supdD:

  (f .; Q ;. f) Y s Z ==> Q Y s Z

theorem supd_assn_supdI:

  Q Y s Z ==> (f .; Q ;. f) Y s Z

peek_and

theorem peek_and_def2:

  (P \<and>. p) Y s = (%Z. P Y s Z & p s)

theorem peek_and_Not:

  (P \<and>. (%s. ¬ f s)) = (P \<and>. Not o f)

theorem peek_and_and:

  (P \<and>. p \<and>. p) = (P \<and>. p)

theorem peek_and_commut:

  (P \<and>. p \<and>. q) = (P \<and>. q \<and>. p)

theorem peek_and_Normal:

  (Normal P \<and>. p) = Normal (P \<and>. p)

subst_res

theorem subst_res_def2:

  (P\<leftarrow>w) Y = P w

theorem subst_subst_res:

  P\<leftarrow>w\<leftarrow>v = P\<leftarrow>w

theorem peek_and_subst_res:

  (P \<and>. p)\<leftarrow>w = (P\<leftarrow>w \<and>. p)

subst_Bool

theorem subst_Bool_def2:

  (P\<leftarrow>=b) Y s Z = (EX v. P (In1 v) s Z & (normal s --> the_Bool v = b))

theorem subst_Bool_the_BoolI:

  P (In1 b) s Z ==> (P\<leftarrow>=the_Bool b) Y s Z

peek_res

theorem peek_res_def2:

  peek_res P Y = P Y Y

theorem peek_res_subst_res:

  peek_res P\<leftarrow>w = P w\<leftarrow>w

theorem peek_subst_res_allI:

  (!!a. T a (P (f a)\<leftarrow>f a)) ==> ALL a. T a (peek_res P\<leftarrow>f a)

peek_st

theorem peek_st_def2:

  peek_st Pf Y s = Pf (snd s) Y s

theorem peek_st_triv:

  (\<lambda>s.. P) = P

theorem peek_st_st:

  (\<lambda>s.. peek_st (P s)) = (\<lambda>s.. P s s)

theorem peek_st_split:

  peek_st P = (%Y s. P (snd s) Y s)

theorem peek_st_subst_res:

  peek_st P\<leftarrow>w = (\<lambda>s.. P s\<leftarrow>w)

theorem peek_st_Normal:

  (\<lambda>s.. Normal (P s)) = Normal (peek_st P)

ign_res

theorem ign_res_def2:

  P\<down> Y s Z = (EX Y. P Y s Z)

theorem ign_ign_res:

  P\<down>\<down> = P\<down>

theorem ign_subst_res:

  P\<down>\<leftarrow>w = P\<down>

theorem peek_and_ign_res:

  (P \<and>. p)\<down> = (P\<down> \<and>. p)

ign_res_eq

theorem ign_res_eq_def2:

  (P\<down>=w) Y s Z = ((EX Y. P Y s Z) & Y = w)

theorem ign_ign_res_eq:

  (P\<down>=w)\<down> = P\<down>

theorem ign_res_eq_subst_res:

  P\<down>=w\<leftarrow>w = P\<down>

theorem subst_Bool_ign_res_eq:

  (P\<leftarrow>=b\<down>=x) Y s Z = ((P\<leftarrow>=b) Y s Z & Y = x)

RefVar

theorem RefVar_def2:

  (vf ..; P) Y s = P (In2 (fst (vf s))) (snd (vf s))

allocation

theorem Alloc_def2:

  Alloc G otag P Y s Z =
  (ALL s' a. G|-s -halloc otag>a-> s' --> P (In1 (Addr a)) s' Z)

theorem SXAlloc_def2:

  SXAlloc G P Y s Z = (ALL s'. G|-s -sxalloc-> s' --> P Y s' Z)

validity

theorem triple_valid_def2:

  G\<Turnstile>n:{P} t> {Q} =
  (ALL Y s Z.
      P Y s Z -->
      (EX L. (normal s --> (EX T. (G, L)|-t::T)) & s\<Colon>\<preceq>(G, L)) -->
      (ALL Y' s'. G|-s -t>-n-> (Y', s') --> Q Y' s' Z))

rules derived by induction

theorem cut_valid:

  [| G,A'|\<Turnstile>ts; G,A|\<Turnstile>A' |] ==> G,A|\<Turnstile>ts

theorem ax_thin:

  [| G,A'||-ts; A' <= A |] ==> G,A||-ts

theorem ax_thin_insert:

  G,A|-t ==> G,insert x A|-t

theorem subset_mtriples_iff:

  (ts <= {{P} mb-\<succ> {Q} | ms}) =
  (EX ms'. ms' <= ms & ts = {{P} mb-\<succ> {Q} | ms'})

rules derived from conseq

theorem conseq12:

  [| G,A|-{P'} t> {Q'};
     ALL Y s Z.
        P Y s Z -->
        (ALL Y' s'. (ALL Y Z'. P' Y s Z' --> Q' Y' s' Z') --> Q Y' s' Z) |]
  ==> G,A|-{P} t> {Q}

theorem conseq12':

  [| G,A|-{P'} t> {Q'};
     ALL s Y' s'.
        (ALL Y Z. P' Y s Z --> Q' Y' s' Z) --> (ALL Y Z. P Y s Z --> Q Y' s' Z) |]
  ==> G,A|-{P} t> {Q}

theorem conseq12_from_conseq12':

  [| G,A|-{P'} t> {Q'};
     ALL Y s Z.
        P Y s Z -->
        (ALL Y' s'. (ALL Y Z'. P' Y s Z' --> Q' Y' s' Z') --> Q Y' s' Z) |]
  ==> G,A|-{P} t> {Q}

theorem conseq1:

  [| G,A|-{P'} t> {Q}; P \<Rightarrow> P' |] ==> G,A|-{P} t> {Q}

theorem conseq2:

  [| G,A|-{P} t> {Q'}; Q' \<Rightarrow> Q |] ==> G,A|-{P} t> {Q}

theorem ax_escape:

  ALL Y s Z. P Y s Z --> G,A|-{%Y' s' Z'. (Y', s') = (Y, s)} t> {%Y s Z'. Q Y s Z}
  ==> G,A|-{P} t> {Q}

theorem ax_constant:

  (C ==> G,A|-{P} t> {Q}) ==> G,A|-{%Y s Z. C & P Y s Z} t> {Q}

theorem ax_impossible:

  G,A|-{%Y s Z. False} t> {Q}

theorem ax_nochange_lemma:

  [| P Y s; All (op = w) |] ==> P w s

theorem ax_nochange:

  G,A|-{%Y s. op = (Y, s)} t> {%Y s. op = (Y, s)} ==> G,A|-{P} t> {P}

theorem ax_trivial:

  G,A|-{P} t> {%Y s Z. True}

theorem ax_disj:

  [| G,A|-{P1} t> {Q1}; G,A|-{P2} t> {Q2} |]
  ==> G,A|-{%Y s Z. P1 Y s Z | P2 Y s Z} t> {%Y s Z. Q1 Y s Z | Q2 Y s Z}

theorem ax_supd_shuffle:

  (EX Q. G,A|-{P} .c1. {Q} & G,A|-{Q ;. f} .c2. {R}) =
  (EX Q'. G,A|-{P} .c1. {f .; Q'} & G,A|-{Q'} .c2. {R})

theorem ax_cases:

  [| G,A|-{P \<and>. C} t> {Q}; G,A|-{P \<and>. Not o C} t> {Q} |]
  ==> G,A|-{P} t> {Q}

theorem peek_and_forget1_Normal:

  G,A|-{Normal P} t> {Q} ==> G,A|-{Normal (P \<and>. p)} t> {Q}

theorem peek_and_forget1:

  G,A|-{P} t> {Q} ==> G,A|-{P \<and>. p} t> {Q}

theorem ax_NormalD:

  G,A|-{P} t> {Q} ==> G,A|-{Normal P} t> {Q}

theorem peek_and_forget2:

  G,A|-{P} t> {Q \<and>. p} ==> G,A|-{P} t> {Q}

theorem ax_subst_Val_allI:

  ALL v. G,A|-{P' v\<leftarrow>In1 v} t> {Q v}
  ==> ALL v. G,A|-{(\<lambda>w:. P' (the_In1 w))\<leftarrow>In1 v} t> {Q v}

theorem ax_subst_Var_allI:

  ALL v. G,A|-{P' v\<leftarrow>In2 v} t> {Q v}
  ==> ALL v. G,A|-{(\<lambda>w:. P' (the_In2 w))\<leftarrow>In2 v} t> {Q v}

theorem ax_subst_Vals_allI:

  ALL v. G,A|-{P' v\<leftarrow>In3 v} t> {Q v}
  ==> ALL v. G,A|-{(\<lambda>w:. P' (the_In3 w))\<leftarrow>In3 v} t> {Q v}

alternative axioms

theorem ax_Lit2:

  G,A|-{Normal P} Lit v-> {Normal (P\<down>=In1 v)}

theorem ax_Lit2_test_complete:

  G,A|-{Normal (P\<leftarrow>In1 v)} Lit v-> {P}

theorem ax_LVar2:

  G,A|-{Normal P} LVar vn=> {Normal (\<lambda>s.. P\<down>=In2 (lvar vn s))}

theorem ax_Super2:

  G,A|-{Normal P} Super->
  {Normal (\<lambda>s.. P\<down>=In1 (the (locals s (Inr ()))))}

theorem ax_Nil2:

  G,A|-{Normal P} []#> {Normal (P\<down>=In3 [])}

misc derived structural rules

theorem ax_finite_mtriples:

  [| finite F; ALL (C, sig):F. G,A|-{Normal (P C sig)} mb C sig-> {Q C sig} |]
  ==> G,A||-{{P} mb-\<succ> {Q} | F}

theorem ax_derivs_insertD:

  G,A||-insert t ts ==> G,A|-t & G,A||-ts

theorem ax_methods_spec:

  [| G,A||-split f `` ms; (C, sig) : ms |] ==> G,A|-f C sig

theorem ax_finite_pointwise:

  [| finite F; (ALL (C, sig):F. G,A|-f C sig) --> (ALL (C, sig):F. G,A|-g C sig);
     G,A||-split f `` F |]
  ==> G,A||-split g `` F

theorem ax_no_hazard:

  G,A|-{P \<and>. type_ok G t} t> {Q} ==> G,A|-{P} t> {Q}

theorem ax_free_wt:

  (EX T L. (G, L)|-t::T) --> G,A|-{Normal P} t> {Q} ==> G,A|-{Normal P} t> {Q}

theorems ax_Xcpts:

  G,A|-{P\<leftarrow>In1 arbitrary \<and>. Not o normal} x-> {P}
  G,A|-{P\<leftarrow>In2 arbitrary \<and>. Not o normal} x=> {P}
  G,A|-{P\<leftarrow>In3 arbitrary \<and>. Not o normal} x#> {P}
  G,A|-{P\<leftarrow>dummy_res \<and>. Not o normal} .x. {P}

theorem ax_Skip:

  G,A|-{P\<leftarrow>dummy_res} .Skip. {P}

theorem ax_SkipI:

  P \<Rightarrow> Q\<leftarrow>dummy_res ==> G,A|-{P} .Skip. {Q}

derived rules for methd call

theorem ax_Call_Static:

  [| the (cmethd G C (mn, pTs)) = (md, (m, pns, rT), lvars, bdy);
     ALL vs l.
        G,A|-{R\<leftarrow>In3 vs \<and>. (%s. l = locals (snd s)) ;.
              init_lvars G C (mn, pTs) Static any_Addr vs}
        Methd C (mn, pTs)-> {set_lvars l .; S};
     G,A|-{Normal P} e-> {Q}; G,A|-{Q\<down>} args#> {R} |]
  ==> G,A|-{Normal P} {t,ClassT C,Static}e..mn( {pTs}args)-> {S}

theorem ax_Call_known_DynT:

  [| the (cmethd G C (mn, pTs)) = (md, (m, pns, rT), lvars, bdy);
     G\<turnstile>IntVir\<rightarrow>C\<preceq>t;
     ALL a vs l.
        G,A|-{R a\<leftarrow>In3 vs \<and>. (%s. l = locals (snd s)) ;.
              init_lvars G C (mn, pTs) IntVir a vs}
        Methd C (mn, pTs)-> {set_lvars l .; S};
     ALL a. G,A|-{Q\<leftarrow>In1 a} args#>
        {R a \<and>. (%s. C = obj_class (lookup_obj (snd s) a))};
     G,A|-{Normal P} e-> {Q} |]
  ==> G,A|-{Normal P} {t,cT,IntVir}e..mn( {pTs}args)-> {S}

theorem ax_Methd1:

  [| G,A Un {{P} Methd-\<succ> {Q} | ms}||-{{P} body G-\<succ> {Q} | ms};
     (C, sig) : ms |]
  ==> G,A|-{Normal (P C sig)} Methd C sig-> {Q C sig}

theorem ax_MethdN:

  G,insert ({Normal P} Methd C sig-> {Q}) A|-{Normal P} body G C sig-> {Q}
  ==> G,A|-{Normal P} Methd C sig-> {Q}

theorem ax_StatRef:

  G,A|-{Normal (P\<leftarrow>In1 Null)} StatRef rt-> {P}

rules derived from Init and Done

theorem ax_InitS:

  [| the (class G C) = (sc, si, fs, ms, ini); C ~= Object;
     ALL l. G,A|-{Q \<and>. (%s. l = locals (snd s)) ;. set_lvars empty} .ini.
        {set_lvars l .; R};
     G,A|-{Normal (P \<and>. Not o initd C ;. supd (init_class_obj G C))}
     .init sc. {Q} |]
  ==> G,A|-{Normal (P \<and>. Not o initd C)} .init C. {R}

theorem ax_Init_Skip_lemma:

  ALL l. G,A|-{P\<leftarrow>dummy_res \<and>. (%s. l = locals (snd s)) ;.
               set_lvars l'}
     .Skip. {set_lvars l .; P}

theorem ax_triv_InitS:

  [| the (class G C) = (sc, si, fs, ms, Skip); C ~= Object;
     P\<leftarrow>dummy_res \<Rightarrow> (supd (init_class_obj G C) .; P);
     G,A|-{Normal (P \<and>. initd C)} .init sc.
     {(P \<and>. initd C)\<leftarrow>dummy_res} |]
  ==> G,A|-{Normal P\<leftarrow>dummy_res} .init C. {P \<and>. initd C}

theorem ax_Init_Object:

  wf_prog G
  ==> G,A|-{Normal
             (supd (init_class_obj G Object) .; P\<leftarrow>dummy_res \<and>.
              Not o initd Object)}
      .init Object. {P \<and>. initd Object}

theorem ax_triv_Init_Object:

  [| wf_prog G; P \<Rightarrow> (supd (init_class_obj G Object) .; P) |]
  ==> G,A|-{Normal P\<leftarrow>dummy_res} .init Object. {P \<and>. initd Object}

introduction rules for Alloc and SXAlloc

theorem ax_SXAlloc_Normal:

  G,A|-{P} .c. {Normal Q} ==> G,A|-{P} .c. {SXAlloc G Q}

theorem ax_Alloc:

  G,A|-{P} t>
  {Normal
    (%Y (x, s) Z.
        ALL a. new_Addr (heap s) = Some a -->
               Q (In1 (Addr a)) (Norm (init_obj G (CInst C) (Inl a) s)) Z) \<and>.
   heap_free 2}
  ==> G,A|-{P} t> {Alloc G (CInst C) Q}

theorem ax_Alloc_Arr:

  G,A|-{P} t>
  {\<lambda>Val:i:. Normal
                     (%Y (x, s) Z.
                         ¬ the_Intg i < #0 &
                         (ALL a. new_Addr (heap s) = Some a -->
                                 Q (In1 (Addr a))
                                  (Norm (init_obj G (Arr T (the_Intg i)) (Inl a)
  s))
                                  Z)) \<and>.
                    heap_free 2}
  ==> G,A|-{P} t>
      {\<lambda>Val:i:. xupd (check_neg i) .; Alloc G (Arr T (the_Intg i)) Q}

theorem ax_SXAlloc_catch_SXcpt:

  G,A|-{P} t>
  {(%Y (x, s) Z.
       x = Some (StdXcpt xn) &
       (ALL a. new_Addr (heap s) = Some a -->
               Q Y (Some (XcptLoc a), init_obj G (CInst (SXcpt xn)) (Inl a) s)
                Z)) \<and>.
   heap_free 2}
  ==> G,A|-{P} t> {SXAlloc G (%Y s Z. Q Y s Z & G,s\<turnstile>catch SXcpt xn)}