CpsG.thy~
changeset 97 c7ba70dc49bd
parent 96 4805c6333fef
parent 93 524bd3caa6b6
child 98 382293d415f3
--- a/CpsG.thy~	Thu Jan 28 14:57:36 2016 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,3980 +0,0 @@
-theory CpsG
-imports PIPDefs 
-begin
-
-(* I am going to use this file as a start point to retrofiting 
-   PIPBasics.thy, which is originally called CpsG.ghy *)
-
-locale valid_trace = 
-  fixes s
-  assumes vt : "vt s"
-
-locale valid_trace_e = valid_trace +
-  fixes e
-  assumes vt_e: "vt (e#s)"
-begin
-
-lemma pip_e: "PIP s e"
-  using vt_e by (cases, simp)  
-
-end
-
-lemma runing_ready: 
-  shows "runing s \<subseteq> readys s"
-  unfolding runing_def readys_def
-  by auto 
-
-lemma readys_threads:
-  shows "readys s \<subseteq> threads s"
-  unfolding readys_def
-  by auto
-
-lemma wq_v_neq [simp]:
-   "cs \<noteq> cs' \<Longrightarrow> wq (V thread cs#s) cs' = wq s cs'"
-  by (auto simp:wq_def Let_def cp_def split:list.splits)
-
-lemma runing_head:
-  assumes "th \<in> runing s"
-  and "th \<in> set (wq_fun (schs s) cs)"
-  shows "th = hd (wq_fun (schs s) cs)"
-  using assms
-  by (simp add:runing_def readys_def s_waiting_def wq_def)
-
-context valid_trace
-begin
-
-lemma actor_inv: 
-  assumes "PIP s e"
-  and "\<not> isCreate e"
-  shows "actor e \<in> runing s"
-  using assms
-  by (induct, auto)
-
-
-lemma isP_E:
-  assumes "isP e"
-  obtains cs where "e = P (actor e) cs"
-  using assms by (cases e, auto)
-
-lemma isV_E:
-  assumes "isV e"
-  obtains cs where "e = V (actor e) cs"
-  using assms by (cases e, auto) 
-
-
-lemma ind [consumes 0, case_names Nil Cons, induct type]:
-  assumes "PP []"
-     and "(\<And>s e. valid_trace s \<Longrightarrow> valid_trace (e#s) \<Longrightarrow>
-                   PP s \<Longrightarrow> PIP s e \<Longrightarrow> PP (e # s))"
-     shows "PP s"
-proof(rule vt.induct[OF vt])
-  from assms(1) show "PP []" .
-next
-  fix s e
-  assume h: "vt s" "PP s" "PIP s e"
-  show "PP (e # s)"
-  proof(cases rule:assms(2))
-    from h(1) show v1: "valid_trace s" by (unfold_locales, simp)
-  next
-    from h(1,3) have "vt (e#s)" by auto
-    thus "valid_trace (e # s)" by (unfold_locales, simp)
-  qed (insert h, auto)
-qed
-
-lemma wq_distinct: "distinct (wq s cs)"
-proof(induct rule:ind)
-  case (Cons s e)
-  from Cons(4,3)
-  show ?case 
-  proof(induct)
-    case (thread_P th s cs1)
-    show ?case 
-    proof(cases "cs = cs1")
-      case True
-      thus ?thesis (is "distinct ?L")
-      proof - 
-        have "?L = wq_fun (schs s) cs1 @ [th]" using True
-          by (simp add:wq_def wf_def Let_def split:list.splits)
-        moreover have "distinct ..."
-        proof -
-          have "th \<notin> set (wq_fun (schs s) cs1)"
-          proof
-            assume otherwise: "th \<in> set (wq_fun (schs s) cs1)"
-            from runing_head[OF thread_P(1) this]
-            have "th = hd (wq_fun (schs s) cs1)" .
-            hence "(Cs cs1, Th th) \<in> (RAG s)" using otherwise
-              by (simp add:s_RAG_def s_holding_def wq_def cs_holding_def)
-            with thread_P(2) show False by auto
-          qed
-          moreover have "distinct (wq_fun (schs s) cs1)"
-              using True thread_P wq_def by auto 
-          ultimately show ?thesis by auto
-        qed
-        ultimately show ?thesis by simp
-      qed
-    next
-      case False
-      with thread_P(3)
-      show ?thesis
-        by (auto simp:wq_def wf_def Let_def split:list.splits)
-    qed
-  next
-    case (thread_V th s cs1)
-    thus ?case
-    proof(cases "cs = cs1")
-      case True
-      show ?thesis (is "distinct ?L")
-      proof(cases "(wq s cs)")
-        case Nil
-        thus ?thesis
-          by (auto simp:wq_def wf_def Let_def split:list.splits)
-      next
-        case (Cons w_hd w_tl)
-        moreover have "distinct (SOME q. distinct q \<and> set q = set w_tl)"
-        proof(rule someI2)
-          from thread_V(3)[unfolded Cons]
-          show  "distinct w_tl \<and> set w_tl = set w_tl" by auto
-        qed auto
-        ultimately show ?thesis
-          by (auto simp:wq_def wf_def Let_def True split:list.splits)
-      qed 
-    next
-      case False
-      with thread_V(3)
-      show ?thesis
-        by (auto simp:wq_def wf_def Let_def split:list.splits)
-    qed
-  qed (insert Cons, auto simp: wq_def Let_def split:list.splits)
-qed (unfold wq_def Let_def, simp)
-
-end
-
-context valid_trace_e
-begin
-
-text {*
-  The following lemma shows that only the @{text "P"}
-  operation can add new thread into waiting queues. 
-  Such kind of lemmas are very obvious, but need to be checked formally.
-  This is a kind of confirmation that our modelling is correct.
-*}
-
-lemma wq_in_inv: 
-  assumes s_ni: "thread \<notin> set (wq s cs)"
-  and s_i: "thread \<in> set (wq (e#s) cs)"
-  shows "e = P thread cs"
-proof(cases e)
-  -- {* This is the only non-trivial case: *}
-  case (V th cs1)
-  have False
-  proof(cases "cs1 = cs")
-    case True
-    show ?thesis
-    proof(cases "(wq s cs1)")
-      case (Cons w_hd w_tl)
-      have "set (wq (e#s) cs) \<subseteq> set (wq s cs)"
-      proof -
-        have "(wq (e#s) cs) = (SOME q. distinct q \<and> set q = set w_tl)"
-          using  Cons V by (auto simp:wq_def Let_def True split:if_splits)
-        moreover have "set ... \<subseteq> set (wq s cs)"
-        proof(rule someI2)
-          show "distinct w_tl \<and> set w_tl = set w_tl"
-            by (metis distinct.simps(2) local.Cons wq_distinct)
-        qed (insert Cons True, auto)
-        ultimately show ?thesis by simp
-      qed
-      with assms show ?thesis by auto
-    qed (insert assms V True, auto simp:wq_def Let_def split:if_splits)
-  qed (insert assms V, auto simp:wq_def Let_def split:if_splits)
-  thus ?thesis by auto
-qed (insert assms, auto simp:wq_def Let_def split:if_splits)
-
-lemma wq_out_inv: 
-  assumes s_in: "thread \<in> set (wq s cs)"
-  and s_hd: "thread = hd (wq s cs)"
-  and s_i: "thread \<noteq> hd (wq (e#s) cs)"
-  shows "e = V thread cs"
-proof(cases e)
--- {* There are only two non-trivial cases: *}
-  case (V th cs1)
-  show ?thesis
-  proof(cases "cs1 = cs")
-    case True
-    have "PIP s (V th cs)" using pip_e[unfolded V[unfolded True]] .
-    thus ?thesis
-    proof(cases)
-      case (thread_V)
-      moreover have "th = thread" using thread_V(2) s_hd
-          by (unfold s_holding_def wq_def, simp)
-      ultimately show ?thesis using V True by simp
-    qed
-  qed (insert assms V, auto simp:wq_def Let_def split:if_splits)
-next
-  case (P th cs1)
-  show ?thesis
-  proof(cases "cs1 = cs")
-    case True
-    with P have "wq (e#s) cs = wq_fun (schs s) cs @ [th]"
-      by (auto simp:wq_def Let_def split:if_splits)
-    with s_i s_hd s_in have False
-      by (metis empty_iff hd_append2 list.set(1) wq_def) 
-    thus ?thesis by simp
-  qed (insert assms P, auto simp:wq_def Let_def split:if_splits)
-qed (insert assms, auto simp:wq_def Let_def split:if_splits)
-
-end
-
-text {*
-  The following lemmas is also obvious and shallow. It says
-  that only running thread can request for a critical resource 
-  and that the requested resource must be one which is
-  not current held by the thread.
-*}
-
-lemma p_pre: "\<lbrakk>vt ((P thread cs)#s)\<rbrakk> \<Longrightarrow> 
-  thread \<in> runing s \<and> (Cs cs, Th thread)  \<notin> (RAG s)^+"
-apply (ind_cases "vt ((P thread cs)#s)")
-apply (ind_cases "step s (P thread cs)")
-by auto
-
-lemma abs1:
-  assumes ein: "e \<in> set es"
-  and neq: "hd es \<noteq> hd (es @ [x])"
-  shows "False"
-proof -
-  from ein have "es \<noteq> []" by auto
-  then obtain e ess where "es = e # ess" by (cases es, auto)
-  with neq show ?thesis by auto
-qed
-
-lemma q_head: "Q (hd es) \<Longrightarrow> hd es = hd [th\<leftarrow>es . Q th]"
-  by (cases es, auto)
-
-inductive_cases evt_cons: "vt (a#s)"
-
-context valid_trace_e
-begin
-
-lemma abs2:
-  assumes inq: "thread \<in> set (wq s cs)"
-  and nh: "thread = hd (wq s cs)"
-  and qt: "thread \<noteq> hd (wq (e#s) cs)"
-  and inq': "thread \<in> set (wq (e#s) cs)"
-  shows "False"
-proof -
-  from vt_e assms show "False"
-    apply (cases e)
-    apply ((simp split:if_splits add:Let_def wq_def)[1])+
-    apply (insert abs1, fast)[1]
-    apply (auto simp:wq_def simp:Let_def split:if_splits list.splits)
-  proof -
-    fix th qs
-    assume vt: "vt (V th cs # s)"
-      and th_in: "thread \<in> set (SOME q. distinct q \<and> set q = set qs)"
-      and eq_wq: "wq_fun (schs s) cs = thread # qs"
-    show "False"
-    proof -
-      from wq_distinct[of cs]
-        and eq_wq[folded wq_def] have "distinct (thread#qs)" by simp
-      moreover have "thread \<in> set qs"
-      proof -
-        have "set (SOME q. distinct q \<and> set q = set qs) = set qs"
-        proof(rule someI2)
-          from wq_distinct [of cs]
-          and eq_wq [folded wq_def]
-          show "distinct qs \<and> set qs = set qs" by auto
-        next
-          fix x assume "distinct x \<and> set x = set qs"
-          thus "set x = set qs" by auto
-        qed
-        with th_in show ?thesis by auto
-      qed
-      ultimately show ?thesis by auto
-    qed
-  qed
-qed
-
-end
-
-
-context valid_trace
-begin
-lemma  vt_moment: "\<And> t. vt (moment t s)"
-proof(induct rule:ind)
-  case Nil
-  thus ?case by (simp add:vt_nil)
-next
-  case (Cons s e t)
-  show ?case
-  proof(cases "t \<ge> length (e#s)")
-    case True
-    from True have "moment t (e#s) = e#s" by simp
-    thus ?thesis using Cons
-      by (simp add:valid_trace_def)
-  next
-    case False
-    from Cons have "vt (moment t s)" by simp
-    moreover have "moment t (e#s) = moment t s"
-    proof -
-      from False have "t \<le> length s" by simp
-      from moment_app [OF this, of "[e]"] 
-      show ?thesis by simp
-    qed
-    ultimately show ?thesis by simp
-  qed
-qed
-end
-
-
-locale valid_moment = valid_trace + 
-  fixes i :: nat
-
-sublocale valid_moment < vat_moment: valid_trace "(moment i s)"
-  by (unfold_locales, insert vt_moment, auto)
-
-context valid_trace
-begin
-
-
-text {* (* ddd *)
-  The nature of the work is like this: since it starts from a very simple and basic 
-  model, even intuitively very `basic` and `obvious` properties need to derived from scratch.
-  For instance, the fact 
-  that one thread can not be blocked by two critical resources at the same time
-  is obvious, because only running threads can make new requests, if one is waiting for 
-  a critical resource and get blocked, it can not make another resource request and get 
-  blocked the second time (because it is not running). 
-
-  To derive this fact, one needs to prove by contraction and 
-  reason about time (or @{text "moement"}). The reasoning is based on a generic theorem
-  named @{text "p_split"}, which is about status changing along the time axis. It says if 
-  a condition @{text "Q"} is @{text "True"} at a state @{text "s"},
-  but it was @{text "False"} at the very beginning, then there must exits a moment @{text "t"} 
-  in the history of @{text "s"} (notice that @{text "s"} itself is essentially the history 
-  of events leading to it), such that @{text "Q"} switched 
-  from being @{text "False"} to @{text "True"} and kept being @{text "True"}
-  till the last moment of @{text "s"}.
-
-  Suppose a thread @{text "th"} is blocked
-  on @{text "cs1"} and @{text "cs2"} in some state @{text "s"}, 
-  since no thread is blocked at the very beginning, by applying 
-  @{text "p_split"} to these two blocking facts, there exist 
-  two moments @{text "t1"} and @{text "t2"}  in @{text "s"}, such that 
-  @{text "th"} got blocked on @{text "cs1"} and @{text "cs2"} 
-  and kept on blocked on them respectively ever since.
- 
-  Without lost of generality, we assume @{text "t1"} is earlier than @{text "t2"}.
-  However, since @{text "th"} was blocked ever since memonent @{text "t1"}, so it was still
-  in blocked state at moment @{text "t2"} and could not
-  make any request and get blocked the second time: Contradiction.
-*}
-
-lemma waiting_unique_pre: (* ccc *)
-  assumes h11: "thread \<in> set (wq s cs1)"
-  and h12: "thread \<noteq> hd (wq s cs1)"
-  assumes h21: "thread \<in> set (wq s cs2)"
-  and h22: "thread \<noteq> hd (wq s cs2)"
-  and neq12: "cs1 \<noteq> cs2"
-  shows "False"
-proof -
-  let "?Q" = "\<lambda> cs s. thread \<in> set (wq s cs) \<and> thread \<noteq> hd (wq s cs)"
-  from h11 and h12 have q1: "?Q cs1 s" by simp
-  from h21 and h22 have q2: "?Q cs2 s" by simp
-  have nq1: "\<not> ?Q cs1 []" by (simp add:wq_def)
-  have nq2: "\<not> ?Q cs2 []" by (simp add:wq_def)
-  from p_split [of "?Q cs1", OF q1 nq1]
-  obtain t1 where lt1: "t1 < length s"
-    and np1: "\<not> ?Q cs1 (moment t1 s)"
-    and nn1: "(\<forall>i'>t1. ?Q cs1 (moment i' s))" by auto
-  from p_split [of "?Q cs2", OF q2 nq2]
-  obtain t2 where lt2: "t2 < length s"
-    and np2: "\<not> ?Q cs2 (moment t2 s)"
-    and nn2: "(\<forall>i'>t2. ?Q cs2 (moment i' s))" by auto
-  { fix s cs
-    assume q: "?Q cs s"
-    have "thread \<notin> runing s"
-    proof
-      assume "thread \<in> runing s"
-      hence " \<forall>cs. \<not> (thread \<in> set (wq_fun (schs s) cs) \<and> 
-                 thread \<noteq> hd (wq_fun (schs s) cs))"
-        by (unfold runing_def s_waiting_def readys_def, auto)
-      from this[rule_format, of cs] q 
-      show False by (simp add: wq_def) 
-    qed
-  } note q_not_runing = this
-  { fix i1 i2
-    let ?i3 = "Suc i2"
-    assume lt12: "i1 < i2"
-    and "i1 < length s" "i2 < length s"
-    hence le_i3: "?i3 \<le> length s" by auto
-    from moment_plus [OF this]
-    obtain e where eq_m: "moment ?i3 s = e#moment i2 s" by auto
-    have "i2 < ?i3" by simp
-    from nn2 [rule_format, OF this] and eq_m
-      have h1: "thread \<in> set (wq (e#moment t2 s) cs2)" and
-           h2: "thread \<noteq> hd (wq (e#moment t2 s) cs2)" by auto
-      have "vt (e#moment t2 s)"
-      proof -
-        from vt_moment 
-        have "vt (moment ?t3 s)" .
-        with eq_m show ?thesis by simp
-      qed
-      then interpret vt_e: valid_trace_e "moment t2 s" "e"
-        by (unfold_locales, auto, cases, simp)
-      have ?thesis
-      proof(cases "thread \<in> set (wq (moment t2 s) cs2)")
-        case True
-        from True and np2 have eq_th: "thread = hd (wq (moment t2 s) cs2)"
-          by auto 
-        from vt_e.abs2 [OF True eq_th h2 h1]
-        show ?thesis by auto
-      next
-        case False
-        from vt_e.block_pre[OF False h1]
-        have "e = P thread cs2" .
-        with vt_e.vt_e have "vt ((P thread cs2)# moment t2 s)" by simp
-        from p_pre [OF this] have "thread \<in> runing (moment t2 s)" by simp
-        with runing_ready have "thread \<in> readys (moment t2 s)" by auto
-        with nn1 [rule_format, OF lt12]
-        show ?thesis  by (simp add:readys_def wq_def s_waiting_def, auto)
-      qed
-  }
-  show ?thesis
-  proof -
-    { 
-      assume lt12: "t1 < t2"
-      let ?t3 = "Suc t2"
-      from lt2 have le_t3: "?t3 \<le> length s" by auto
-      from moment_plus [OF this] 
-      obtain e where eq_m: "moment ?t3 s = e#moment t2 s" by auto
-      have "t2 < ?t3" by simp
-      from nn2 [rule_format, OF this] and eq_m
-      have h1: "thread \<in> set (wq (e#moment t2 s) cs2)" and
-           h2: "thread \<noteq> hd (wq (e#moment t2 s) cs2)" by auto
-      have "vt (e#moment t2 s)"
-      proof -
-        from vt_moment 
-        have "vt (moment ?t3 s)" .
-        with eq_m show ?thesis by simp
-      qed
-      then interpret vt_e: valid_trace_e "moment t2 s" "e"
-        by (unfold_locales, auto, cases, simp)
-      have ?thesis
-      proof(cases "thread \<in> set (wq (moment t2 s) cs2)")
-        case True
-        from True and np2 have eq_th: "thread = hd (wq (moment t2 s) cs2)"
-          by auto 
-        from vt_e.abs2 [OF True eq_th h2 h1]
-        show ?thesis by auto
-      next
-        case False
-        from vt_e.block_pre[OF False h1]
-        have "e = P thread cs2" .
-        with vt_e.vt_e have "vt ((P thread cs2)# moment t2 s)" by simp
-        from p_pre [OF this] have "thread \<in> runing (moment t2 s)" by simp
-        with runing_ready have "thread \<in> readys (moment t2 s)" by auto
-        with nn1 [rule_format, OF lt12]
-        show ?thesis  by (simp add:readys_def wq_def s_waiting_def, auto)
-      qed
-    } moreover {
-      assume lt12: "t2 < t1"
-      let ?t3 = "Suc t1"
-      from lt1 have le_t3: "?t3 \<le> length s" by auto
-      from moment_plus [OF this] 
-      obtain e where eq_m: "moment ?t3 s = e#moment t1 s" by auto
-      have lt_t3: "t1 < ?t3" by simp
-      from nn1 [rule_format, OF this] and eq_m
-      have h1: "thread \<in> set (wq (e#moment t1 s) cs1)" and
-        h2: "thread \<noteq> hd (wq (e#moment t1 s) cs1)" by auto
-      have "vt  (e#moment t1 s)"
-      proof -
-        from vt_moment
-        have "vt (moment ?t3 s)" .
-        with eq_m show ?thesis by simp
-      qed
-      then interpret vt_e: valid_trace_e "moment t1 s" e
-        by (unfold_locales, auto, cases, auto)
-      have ?thesis
-      proof(cases "thread \<in> set (wq (moment t1 s) cs1)")
-        case True
-        from True and np1 have eq_th: "thread = hd (wq (moment t1 s) cs1)"
-          by auto
-        from vt_e.abs2 True eq_th h2 h1
-        show ?thesis by auto
-      next
-        case False
-        from vt_e.block_pre [OF False h1]
-        have "e = P thread cs1" .
-        with vt_e.vt_e have "vt ((P thread cs1)# moment t1 s)" by simp
-        from p_pre [OF this] have "thread \<in> runing (moment t1 s)" by simp
-        with runing_ready have "thread \<in> readys (moment t1 s)" by auto
-        with nn2 [rule_format, OF lt12]
-        show ?thesis  by (simp add:readys_def wq_def s_waiting_def, auto)
-      qed
-    } moreover {
-      assume eqt12: "t1 = t2"
-      let ?t3 = "Suc t1"
-      from lt1 have le_t3: "?t3 \<le> length s" by auto
-      from moment_plus [OF this] 
-      obtain e where eq_m: "moment ?t3 s = e#moment t1 s" by auto
-      have lt_t3: "t1 < ?t3" by simp
-      from nn1 [rule_format, OF this] and eq_m
-      have h1: "thread \<in> set (wq (e#moment t1 s) cs1)" and
-        h2: "thread \<noteq> hd (wq (e#moment t1 s) cs1)" by auto
-      have vt_e: "vt (e#moment t1 s)"
-      proof -
-        from vt_moment
-        have "vt (moment ?t3 s)" .
-        with eq_m show ?thesis by simp
-      qed
-      then interpret vt_e: valid_trace_e "moment t1 s" e
-        by (unfold_locales, auto, cases, auto)
-      have ?thesis
-      proof(cases "thread \<in> set (wq (moment t1 s) cs1)")
-        case True
-        from True and np1 have eq_th: "thread = hd (wq (moment t1 s) cs1)"
-          by auto
-        from vt_e.abs2 [OF True eq_th h2 h1]
-        show ?thesis by auto
-      next
-        case False
-        from vt_e.block_pre [OF False h1]
-        have eq_e1: "e = P thread cs1" .
-        have lt_t3: "t1 < ?t3" by simp
-        with eqt12 have "t2 < ?t3" by simp
-        from nn2 [rule_format, OF this] and eq_m and eqt12
-        have h1: "thread \<in> set (wq (e#moment t2 s) cs2)" and
-          h2: "thread \<noteq> hd (wq (e#moment t2 s) cs2)" by auto
-        show ?thesis
-        proof(cases "thread \<in> set (wq (moment t2 s) cs2)")
-          case True
-          from True and np2 have eq_th: "thread = hd (wq (moment t2 s) cs2)"
-            by auto
-          from vt_e and eqt12 have "vt (e#moment t2 s)" by simp 
-          then interpret vt_e2: valid_trace_e "moment t2 s" e
-            by (unfold_locales, auto, cases, auto)
-          from vt_e2.abs2 [OF True eq_th h2 h1]
-          show ?thesis .
-        next
-          case False
-          have "vt (e#moment t2 s)"
-          proof -
-            from vt_moment eqt12
-            have "vt (moment (Suc t2) s)" by auto
-            with eq_m eqt12 show ?thesis by simp
-          qed
-          then interpret vt_e2: valid_trace_e "moment t2 s" e
-            by (unfold_locales, auto, cases, auto)
-          from vt_e2.block_pre [OF False h1]
-          have "e = P thread cs2" .
-          with eq_e1 neq12 show ?thesis by auto
-        qed
-      qed
-    } ultimately show ?thesis by arith
-  qed
-qed
-
-text {*
-  This lemma is a simple corrolary of @{text "waiting_unique_pre"}.
-*}
-
-lemma waiting_unique:
-  assumes "waiting s th cs1"
-  and "waiting s th cs2"
-  shows "cs1 = cs2"
-using waiting_unique_pre assms
-unfolding wq_def s_waiting_def
-by auto
-
-end
-
-(* not used *)
-text {*
-  Every thread can only be blocked on one critical resource, 
-  symmetrically, every critical resource can only be held by one thread. 
-  This fact is much more easier according to our definition. 
-*}
-lemma held_unique:
-  assumes "holding (s::event list) th1 cs"
-  and "holding s th2 cs"
-  shows "th1 = th2"
- by (insert assms, unfold s_holding_def, auto)
-
-
-lemma last_set_lt: "th \<in> threads s \<Longrightarrow> last_set th s < length s"
-  apply (induct s, auto)
-  by (case_tac a, auto split:if_splits)
-
-lemma last_set_unique: 
-  "\<lbrakk>last_set th1 s = last_set th2 s; th1 \<in> threads s; th2 \<in> threads s\<rbrakk>
-          \<Longrightarrow> th1 = th2"
-  apply (induct s, auto)
-  by (case_tac a, auto split:if_splits dest:last_set_lt)
-
-lemma preced_unique : 
-  assumes pcd_eq: "preced th1 s = preced th2 s"
-  and th_in1: "th1 \<in> threads s"
-  and th_in2: " th2 \<in> threads s"
-  shows "th1 = th2"
-proof -
-  from pcd_eq have "last_set th1 s = last_set th2 s" by (simp add:preced_def)
-  from last_set_unique [OF this th_in1 th_in2]
-  show ?thesis .
-qed
-
-lemma preced_linorder: 
-  assumes neq_12: "th1 \<noteq> th2"
-  and th_in1: "th1 \<in> threads s"
-  and th_in2: " th2 \<in> threads s"
-  shows "preced th1 s < preced th2 s \<or> preced th1 s > preced th2 s"
-proof -
-  from preced_unique [OF _ th_in1 th_in2] and neq_12 
-  have "preced th1 s \<noteq> preced th2 s" by auto
-  thus ?thesis by auto
-qed
-
-(* An aux lemma used later *)
-lemma unique_minus:
-  assumes unique: "\<And> a b c. \<lbrakk>(a, b) \<in> r; (a, c) \<in> r\<rbrakk> \<Longrightarrow> b = c"
-  and xy: "(x, y) \<in> r"
-  and xz: "(x, z) \<in> r^+"
-  and neq: "y \<noteq> z"
-  shows "(y, z) \<in> r^+"
-proof -
- from xz and neq show ?thesis
- proof(induct)
-   case (base ya)
-   have "(x, ya) \<in> r" by fact
-   from unique [OF xy this] have "y = ya" .
-   with base show ?case by auto
- next
-   case (step ya z)
-   show ?case
-   proof(cases "y = ya")
-     case True
-     from step True show ?thesis by simp
-   next
-     case False
-     from step False
-     show ?thesis by auto
-   qed
- qed
-qed
-
-lemma unique_base:
-  assumes unique: "\<And> a b c. \<lbrakk>(a, b) \<in> r; (a, c) \<in> r\<rbrakk> \<Longrightarrow> b = c"
-  and xy: "(x, y) \<in> r"
-  and xz: "(x, z) \<in> r^+"
-  and neq_yz: "y \<noteq> z"
-  shows "(y, z) \<in> r^+"
-proof -
-  from xz neq_yz show ?thesis
-  proof(induct)
-    case (base ya)
-    from xy unique base show ?case by auto
-  next
-    case (step ya z)
-    show ?case
-    proof(cases "y = ya")
-      case True
-      from True step show ?thesis by auto
-    next
-      case False
-      from False step 
-      have "(y, ya) \<in> r\<^sup>+" by auto
-      with step show ?thesis by auto
-    qed
-  qed
-qed
-
-lemma unique_chain:
-  assumes unique: "\<And> a b c. \<lbrakk>(a, b) \<in> r; (a, c) \<in> r\<rbrakk> \<Longrightarrow> b = c"
-  and xy: "(x, y) \<in> r^+"
-  and xz: "(x, z) \<in> r^+"
-  and neq_yz: "y \<noteq> z"
-  shows "(y, z) \<in> r^+ \<or> (z, y) \<in> r^+"
-proof -
-  from xy xz neq_yz show ?thesis
-  proof(induct)
-    case (base y)
-    have h1: "(x, y) \<in> r" and h2: "(x, z) \<in> r\<^sup>+" and h3: "y \<noteq> z" using base by auto
-    from unique_base [OF _ h1 h2 h3] and unique show ?case by auto
-  next
-    case (step y za)
-    show ?case
-    proof(cases "y = z")
-      case True
-      from True step show ?thesis by auto
-    next
-      case False
-      from False step have "(y, z) \<in> r\<^sup>+ \<or> (z, y) \<in> r\<^sup>+" by auto
-      thus ?thesis
-      proof
-        assume "(z, y) \<in> r\<^sup>+"
-        with step have "(z, za) \<in> r\<^sup>+" by auto
-        thus ?thesis by auto
-      next
-        assume h: "(y, z) \<in> r\<^sup>+"
-        from step have yza: "(y, za) \<in> r" by simp
-        from step have "za \<noteq> z" by simp
-        from unique_minus [OF _ yza h this] and unique
-        have "(za, z) \<in> r\<^sup>+" by auto
-        thus ?thesis by auto
-      qed
-    qed
-  qed
-qed
-
-text {*
-  The following three lemmas show that @{text "RAG"} does not change
-  by the happening of @{text "Set"}, @{text "Create"} and @{text "Exit"}
-  events, respectively.
-*}
-
-lemma RAG_set_unchanged: "(RAG (Set th prio # s)) = RAG s"
-apply (unfold s_RAG_def s_waiting_def wq_def)
-by (simp add:Let_def)
-
-lemma RAG_create_unchanged: "(RAG (Create th prio # s)) = RAG s"
-apply (unfold s_RAG_def s_waiting_def wq_def)
-by (simp add:Let_def)
-
-lemma RAG_exit_unchanged: "(RAG (Exit th # s)) = RAG s"
-apply (unfold s_RAG_def s_waiting_def wq_def)
-by (simp add:Let_def)
-
-
-text {* 
-  The following lemmas are used in the proof of 
-  lemma @{text "step_RAG_v"}, which characterizes how the @{text "RAG"} is changed
-  by @{text "V"}-events. 
-  However, since our model is very concise, such  seemingly obvious lemmas need to be derived from scratch,
-  starting from the model definitions.
-*}
-lemma step_v_hold_inv[elim_format]:
-  "\<And>c t. \<lbrakk>vt (V th cs # s); 
-          \<not> holding (wq s) t c; holding (wq (V th cs # s)) t c\<rbrakk> \<Longrightarrow> 
-            next_th s th cs t \<and> c = cs"
-proof -
-  fix c t
-  assume vt: "vt (V th cs # s)"
-    and nhd: "\<not> holding (wq s) t c"
-    and hd: "holding (wq (V th cs # s)) t c"
-  show "next_th s th cs t \<and> c = cs"
-  proof(cases "c = cs")
-    case False
-    with nhd hd show ?thesis
-      by (unfold cs_holding_def wq_def, auto simp:Let_def)
-  next
-    case True
-    with step_back_step [OF vt] 
-    have "step s (V th c)" by simp
-    hence "next_th s th cs t"
-    proof(cases)
-      assume "holding s th c"
-      with nhd hd show ?thesis
-        apply (unfold s_holding_def cs_holding_def wq_def next_th_def,
-               auto simp:Let_def split:list.splits if_splits)
-        proof -
-          assume " hd (SOME q. distinct q \<and> q = []) \<in> set (SOME q. distinct q \<and> q = [])"
-          moreover have "\<dots> = set []"
-          proof(rule someI2)
-            show "distinct [] \<and> [] = []" by auto
-          next
-            fix x assume "distinct x \<and> x = []"
-            thus "set x = set []" by auto
-          qed
-          ultimately show False by auto
-        next
-          assume " hd (SOME q. distinct q \<and> q = []) \<in> set (SOME q. distinct q \<and> q = [])"
-          moreover have "\<dots> = set []"
-          proof(rule someI2)
-            show "distinct [] \<and> [] = []" by auto
-          next
-            fix x assume "distinct x \<and> x = []"
-            thus "set x = set []" by auto
-          qed
-          ultimately show False by auto
-        qed
-    qed
-    with True show ?thesis by auto
-  qed
-qed
-
-text {* 
-  The following @{text "step_v_wait_inv"} is also an obvious lemma, which, however, needs to be
-  derived from scratch, which confirms the correctness of the definition of @{text "next_th"}.
-*}
-lemma step_v_wait_inv[elim_format]:
-    "\<And>t c. \<lbrakk>vt (V th cs # s); \<not> waiting (wq (V th cs # s)) t c; waiting (wq s) t c
-           \<rbrakk>
-          \<Longrightarrow> (next_th s th cs t \<and> cs = c)"
-proof -
-  fix t c 
-  assume vt: "vt (V th cs # s)"
-    and nw: "\<not> waiting (wq (V th cs # s)) t c"
-    and wt: "waiting (wq s) t c"
-  from vt interpret vt_v: valid_trace_e s "V th cs" 
-    by  (cases, unfold_locales, simp)
-  show "next_th s th cs t \<and> cs = c"
-  proof(cases "cs = c")
-    case False
-    with nw wt show ?thesis
-      by (auto simp:cs_waiting_def wq_def Let_def)
-  next
-    case True
-    from nw[folded True] wt[folded True]
-    have "next_th s th cs t"
-      apply (unfold next_th_def, auto simp:cs_waiting_def wq_def Let_def split:list.splits)
-    proof -
-      fix a list
-      assume t_in: "t \<in> set list"
-        and t_ni: "t \<notin> set (SOME q. distinct q \<and> set q = set list)"
-        and eq_wq: "wq_fun (schs s) cs = a # list"
-      have " set (SOME q. distinct q \<and> set q = set list) = set list"
-      proof(rule someI2)
-        from vt_v.wq_distinct[of cs] and eq_wq[folded wq_def]
-        show "distinct list \<and> set list = set list" by auto
-      next
-        show "\<And>x. distinct x \<and> set x = set list \<Longrightarrow> set x = set list"
-          by auto
-      qed
-      with t_ni and t_in show "a = th" by auto
-    next
-      fix a list
-      assume t_in: "t \<in> set list"
-        and t_ni: "t \<notin> set (SOME q. distinct q \<and> set q = set list)"
-        and eq_wq: "wq_fun (schs s) cs = a # list"
-      have " set (SOME q. distinct q \<and> set q = set list) = set list"
-      proof(rule someI2)
-        from vt_v.wq_distinct[of cs] and eq_wq[folded wq_def]
-        show "distinct list \<and> set list = set list" by auto
-      next
-        show "\<And>x. distinct x \<and> set x = set list \<Longrightarrow> set x = set list"
-          by auto
-      qed
-      with t_ni and t_in show "t = hd (SOME q. distinct q \<and> set q = set list)" by auto
-    next
-      fix a list
-      assume eq_wq: "wq_fun (schs s) cs = a # list"
-      from step_back_step[OF vt]
-      show "a = th"
-      proof(cases)
-        assume "holding s th cs"
-        with eq_wq show ?thesis
-          by (unfold s_holding_def wq_def, auto)
-      qed
-    qed
-    with True show ?thesis by simp
-  qed
-qed
-
-lemma step_v_not_wait[consumes 3]:
-  "\<lbrakk>vt (V th cs # s); next_th s th cs t; waiting (wq (V th cs # s)) t cs\<rbrakk> \<Longrightarrow> False"
-  by (unfold next_th_def cs_waiting_def wq_def, auto simp:Let_def)
-
-lemma step_v_release:
-  "\<lbrakk>vt (V th cs # s); holding (wq (V th cs # s)) th cs\<rbrakk> \<Longrightarrow> False"
-proof -
-  assume vt: "vt (V th cs # s)"
-    and hd: "holding (wq (V th cs # s)) th cs"
-  from vt interpret vt_v: valid_trace_e s "V th cs"
-    by (cases, unfold_locales, simp+)
-  from step_back_step [OF vt] and hd
-  show "False"
-  proof(cases)
-    assume "holding (wq (V th cs # s)) th cs" and "holding s th cs"
-    thus ?thesis
-      apply (unfold s_holding_def wq_def cs_holding_def)
-      apply (auto simp:Let_def split:list.splits)
-    proof -
-      fix list
-      assume eq_wq[folded wq_def]: 
-        "wq_fun (schs s) cs = hd (SOME q. distinct q \<and> set q = set list) # list"
-      and hd_in: "hd (SOME q. distinct q \<and> set q = set list)
-            \<in> set (SOME q. distinct q \<and> set q = set list)"
-      have "set (SOME q. distinct q \<and> set q = set list) = set list"
-      proof(rule someI2)
-        from vt_v.wq_distinct[of cs] and eq_wq
-        show "distinct list \<and> set list = set list" by auto
-      next
-        show "\<And>x. distinct x \<and> set x = set list \<Longrightarrow> set x = set list"
-          by auto
-      qed
-      moreover have "distinct  (hd (SOME q. distinct q \<and> set q = set list) # list)"
-      proof -
-        from vt_v.wq_distinct[of cs] and eq_wq
-        show ?thesis by auto
-      qed
-      moreover note eq_wq and hd_in
-      ultimately show "False" by auto
-    qed
-  qed
-qed
-
-lemma step_v_get_hold:
-  "\<And>th'. \<lbrakk>vt (V th cs # s); \<not> holding (wq (V th cs # s)) th' cs; next_th s th cs th'\<rbrakk> \<Longrightarrow> False"
-  apply (unfold cs_holding_def next_th_def wq_def,
-         auto simp:Let_def)
-proof -
-  fix rest
-  assume vt: "vt (V th cs # s)"
-    and eq_wq[folded wq_def]: " wq_fun (schs s) cs = th # rest"
-    and nrest: "rest \<noteq> []"
-    and ni: "hd (SOME q. distinct q \<and> set q = set rest)
-            \<notin> set (SOME q. distinct q \<and> set q = set rest)"
-  from vt interpret vt_v: valid_trace_e s "V th cs"
-    by (cases, unfold_locales, simp+)
-  have "(SOME q. distinct q \<and> set q = set rest) \<noteq> []"
-  proof(rule someI2)
-    from vt_v.wq_distinct[of cs] and eq_wq
-    show "distinct rest \<and> set rest = set rest" by auto
-  next
-    fix x assume "distinct x \<and> set x = set rest"
-    hence "set x = set rest" by auto
-    with nrest
-    show "x \<noteq> []" by (case_tac x, auto)
-  qed
-  with ni show "False" by auto
-qed
-
-lemma step_v_release_inv[elim_format]:
-"\<And>c t. \<lbrakk>vt (V th cs # s); \<not> holding (wq (V th cs # s)) t c; holding (wq s) t c\<rbrakk> \<Longrightarrow> 
-  c = cs \<and> t = th"
-  apply (unfold cs_holding_def wq_def, auto simp:Let_def split:if_splits list.splits)
-  proof -
-    fix a list
-    assume vt: "vt (V th cs # s)" and eq_wq: "wq_fun (schs s) cs = a # list"
-    from step_back_step [OF vt] show "a = th"
-    proof(cases)
-      assume "holding s th cs" with eq_wq
-      show ?thesis
-        by (unfold s_holding_def wq_def, auto)
-    qed
-  next
-    fix a list
-    assume vt: "vt (V th cs # s)" and eq_wq: "wq_fun (schs s) cs = a # list"
-    from step_back_step [OF vt] show "a = th"
-    proof(cases)
-      assume "holding s th cs" with eq_wq
-      show ?thesis
-        by (unfold s_holding_def wq_def, auto)
-    qed
-  qed
-
-lemma step_v_waiting_mono:
-  "\<And>t c. \<lbrakk>vt (V th cs # s); waiting (wq (V th cs # s)) t c\<rbrakk> \<Longrightarrow> waiting (wq s) t c"
-proof -
-  fix t c
-  let ?s' = "(V th cs # s)"
-  assume vt: "vt ?s'" 
-    and wt: "waiting (wq ?s') t c"
-  from vt interpret vt_v: valid_trace_e s "V th cs"
-    by (cases, unfold_locales, simp+)
-  show "waiting (wq s) t c"
-  proof(cases "c = cs")
-    case False
-    assume neq_cs: "c \<noteq> cs"
-    hence "waiting (wq ?s') t c = waiting (wq s) t c"
-      by (unfold cs_waiting_def wq_def, auto simp:Let_def)
-    with wt show ?thesis by simp
-  next
-    case True
-    with wt show ?thesis
-      apply (unfold cs_waiting_def wq_def, auto simp:Let_def split:list.splits)
-    proof -
-      fix a list
-      assume not_in: "t \<notin> set list"
-        and is_in: "t \<in> set (SOME q. distinct q \<and> set q = set list)"
-        and eq_wq: "wq_fun (schs s) cs = a # list"
-      have "set (SOME q. distinct q \<and> set q = set list) = set list"
-      proof(rule someI2)
-        from vt_v.wq_distinct [of cs]
-        and eq_wq[folded wq_def]
-        show "distinct list \<and> set list = set list" by auto
-      next
-        fix x assume "distinct x \<and> set x = set list"
-        thus "set x = set list" by auto
-      qed
-      with not_in is_in show "t = a" by auto
-    next
-      fix list
-      assume is_waiting: "waiting (wq (V th cs # s)) t cs"
-      and eq_wq: "wq_fun (schs s) cs = t # list"
-      hence "t \<in> set list"
-        apply (unfold wq_def, auto simp:Let_def cs_waiting_def)
-      proof -
-        assume " t \<in> set (SOME q. distinct q \<and> set q = set list)"
-        moreover have "\<dots> = set list" 
-        proof(rule someI2)
-          from vt_v.wq_distinct [of cs]
-            and eq_wq[folded wq_def]
-          show "distinct list \<and> set list = set list" by auto
-        next
-          fix x assume "distinct x \<and> set x = set list" 
-          thus "set x = set list" by auto
-        qed
-        ultimately show "t \<in> set list" by simp
-      qed
-      with eq_wq and vt_v.wq_distinct [of cs, unfolded wq_def]
-      show False by auto
-    qed
-  qed
-qed
-
-text {* (* ddd *) 
-  The following @{text "step_RAG_v"} lemma charaterizes how @{text "RAG"} is changed
-  with the happening of @{text "V"}-events:
-*}
-lemma step_RAG_v:
-assumes vt:
-  "vt (V th cs#s)"
-shows "
-  RAG (V th cs # s) =
-  RAG s - {(Cs cs, Th th)} -
-  {(Th th', Cs cs) |th'. next_th s th cs th'} \<union>
-  {(Cs cs, Th th') |th'.  next_th s th cs th'}"
-  apply (insert vt, unfold s_RAG_def) 
-  apply (auto split:if_splits list.splits simp:Let_def)
-  apply (auto elim: step_v_waiting_mono step_v_hold_inv 
-              step_v_release step_v_wait_inv
-              step_v_get_hold step_v_release_inv)
-  apply (erule_tac step_v_not_wait, auto)
-  done
-
-text {* 
-  The following @{text "step_RAG_p"} lemma charaterizes how @{text "RAG"} is changed
-  with the happening of @{text "P"}-events:
-*}
-lemma step_RAG_p:
-  "vt (P th cs#s) \<Longrightarrow>
-  RAG (P th cs # s) =  (if (wq s cs = []) then RAG s \<union> {(Cs cs, Th th)}
-                                             else RAG s \<union> {(Th th, Cs cs)})"
-  apply(simp only: s_RAG_def wq_def)
-  apply (auto split:list.splits prod.splits simp:Let_def wq_def cs_waiting_def cs_holding_def)
-  apply(case_tac "csa = cs", auto)
-  apply(fold wq_def)
-  apply(drule_tac step_back_step)
-  apply(ind_cases " step s (P (hd (wq s cs)) cs)")
-  apply(simp add:s_RAG_def wq_def cs_holding_def)
-  apply(auto)
-  done
-
-
-lemma RAG_target_th: "(Th th, x) \<in> RAG (s::state) \<Longrightarrow> \<exists> cs. x = Cs cs"
-  by (unfold s_RAG_def, auto)
-
-context valid_trace
-begin
-
-text {*
-  The following lemma shows that @{text "RAG"} is acyclic.
-  The overall structure is by induction on the formation of @{text "vt s"}
-  and then case analysis on event @{text "e"}, where the non-trivial cases 
-  for those for @{text "V"} and @{text "P"} events.
-*}
-lemma acyclic_RAG:
-  shows "acyclic (RAG s)"
-using vt
-proof(induct)
-  case (vt_cons s e)
-  interpret vt_s: valid_trace s using vt_cons(1)
-    by (unfold_locales, simp)
-  assume ih: "acyclic (RAG s)"
-    and stp: "step s e"
-    and vt: "vt s"
-  show ?case
-  proof(cases e)
-    case (Create th prio)
-    with ih
-    show ?thesis by (simp add:RAG_create_unchanged)
-  next
-    case (Exit th)
-    with ih show ?thesis by (simp add:RAG_exit_unchanged)
-  next
-    case (V th cs)
-    from V vt stp have vtt: "vt (V th cs#s)" by auto
-    from step_RAG_v [OF this]
-    have eq_de: 
-      "RAG (e # s) = 
-      RAG s - {(Cs cs, Th th)} - {(Th th', Cs cs) |th'. next_th s th cs th'} \<union>
-      {(Cs cs, Th th') |th'. next_th s th cs th'}"
-      (is "?L = (?A - ?B - ?C) \<union> ?D") by (simp add:V)
-    from ih have ac: "acyclic (?A - ?B - ?C)" by (auto elim:acyclic_subset)
-    from step_back_step [OF vtt]
-    have "step s (V th cs)" .
-    thus ?thesis
-    proof(cases)
-      assume "holding s th cs"
-      hence th_in: "th \<in> set (wq s cs)" and
-        eq_hd: "th = hd (wq s cs)" unfolding s_holding_def wq_def by auto
-      then obtain rest where
-        eq_wq: "wq s cs = th#rest"
-        by (cases "wq s cs", auto)
-      show ?thesis
-      proof(cases "rest = []")
-        case False
-        let ?th' = "hd (SOME q. distinct q \<and> set q = set rest)"
-        from eq_wq False have eq_D: "?D = {(Cs cs, Th ?th')}"
-          by (unfold next_th_def, auto)
-        let ?E = "(?A - ?B - ?C)"
-        have "(Th ?th', Cs cs) \<notin> ?E\<^sup>*"
-        proof
-          assume "(Th ?th', Cs cs) \<in> ?E\<^sup>*"
-          hence " (Th ?th', Cs cs) \<in> ?E\<^sup>+" by (simp add: rtrancl_eq_or_trancl)
-          from tranclD [OF this]
-          obtain x where th'_e: "(Th ?th', x) \<in> ?E" by blast
-          hence th_d: "(Th ?th', x) \<in> ?A" by simp
-          from RAG_target_th [OF this]
-          obtain cs' where eq_x: "x = Cs cs'" by auto
-          with th_d have "(Th ?th', Cs cs') \<in> ?A" by simp
-          hence wt_th': "waiting s ?th' cs'"
-            unfolding s_RAG_def s_waiting_def cs_waiting_def wq_def by simp
-          hence "cs' = cs"
-          proof(rule vt_s.waiting_unique)
-            from eq_wq vt_s.wq_distinct[of cs]
-            show "waiting s ?th' cs" 
-              apply (unfold s_waiting_def wq_def, auto)
-            proof -
-              assume hd_in: "hd (SOME q. distinct q \<and> set q = set rest) \<notin> set rest"
-                and eq_wq: "wq_fun (schs s) cs = th # rest"
-              have "(SOME q. distinct q \<and> set q = set rest) \<noteq> []"
-              proof(rule someI2)
-                from vt_s.wq_distinct[of cs] and eq_wq
-                show "distinct rest \<and> set rest = set rest" unfolding wq_def by auto
-              next
-                fix x assume "distinct x \<and> set x = set rest"
-                with False show "x \<noteq> []" by auto
-              qed
-              hence "hd (SOME q. distinct q \<and> set q = set rest) \<in> 
-                set (SOME q. distinct q \<and> set q = set rest)" by auto
-              moreover have "\<dots> = set rest" 
-              proof(rule someI2)
-                from vt_s.wq_distinct[of cs] and eq_wq
-                show "distinct rest \<and> set rest = set rest" unfolding wq_def by auto
-              next
-                show "\<And>x. distinct x \<and> set x = set rest \<Longrightarrow> set x = set rest" by auto
-              qed
-              moreover note hd_in
-              ultimately show "hd (SOME q. distinct q \<and> set q = set rest) = th" by auto
-            next
-              assume hd_in: "hd (SOME q. distinct q \<and> set q = set rest) \<notin> set rest"
-                and eq_wq: "wq s cs = hd (SOME q. distinct q \<and> set q = set rest) # rest"
-              have "(SOME q. distinct q \<and> set q = set rest) \<noteq> []"
-              proof(rule someI2)
-                from vt_s.wq_distinct[of cs] and eq_wq
-                show "distinct rest \<and> set rest = set rest" by auto
-              next
-                fix x assume "distinct x \<and> set x = set rest"
-                with False show "x \<noteq> []" by auto
-              qed
-              hence "hd (SOME q. distinct q \<and> set q = set rest) \<in> 
-                set (SOME q. distinct q \<and> set q = set rest)" by auto
-              moreover have "\<dots> = set rest" 
-              proof(rule someI2)
-                from vt_s.wq_distinct[of cs] and eq_wq
-                show "distinct rest \<and> set rest = set rest" by auto
-              next
-                show "\<And>x. distinct x \<and> set x = set rest \<Longrightarrow> set x = set rest" by auto
-              qed
-              moreover note hd_in
-              ultimately show False by auto
-            qed
-          qed
-          with th'_e eq_x have "(Th ?th', Cs cs) \<in> ?E" by simp
-          with False
-          show "False" by (auto simp: next_th_def eq_wq)
-        qed
-        with acyclic_insert[symmetric] and ac
-          and eq_de eq_D show ?thesis by auto
-      next
-        case True
-        with eq_wq
-        have eq_D: "?D = {}"
-          by (unfold next_th_def, auto)
-        with eq_de ac
-        show ?thesis by auto
-      qed 
-    qed
-  next
-    case (P th cs)
-    from P vt stp have vtt: "vt (P th cs#s)" by auto
-    from step_RAG_p [OF this] P
-    have "RAG (e # s) = 
-      (if wq s cs = [] then RAG s \<union> {(Cs cs, Th th)} else 
-      RAG s \<union> {(Th th, Cs cs)})" (is "?L = ?R")
-      by simp
-    moreover have "acyclic ?R"
-    proof(cases "wq s cs = []")
-      case True
-      hence eq_r: "?R =  RAG s \<union> {(Cs cs, Th th)}" by simp
-      have "(Th th, Cs cs) \<notin> (RAG s)\<^sup>*"
-      proof
-        assume "(Th th, Cs cs) \<in> (RAG s)\<^sup>*"
-        hence "(Th th, Cs cs) \<in> (RAG s)\<^sup>+" by (simp add: rtrancl_eq_or_trancl)
-        from tranclD2 [OF this]
-        obtain x where "(x, Cs cs) \<in> RAG s" by auto
-        with True show False by (auto simp:s_RAG_def cs_waiting_def)
-      qed
-      with acyclic_insert ih eq_r show ?thesis by auto
-    next
-      case False
-      hence eq_r: "?R =  RAG s \<union> {(Th th, Cs cs)}" by simp
-      have "(Cs cs, Th th) \<notin> (RAG s)\<^sup>*"
-      proof
-        assume "(Cs cs, Th th) \<in> (RAG s)\<^sup>*"
-        hence "(Cs cs, Th th) \<in> (RAG s)\<^sup>+" by (simp add: rtrancl_eq_or_trancl)
-        moreover from step_back_step [OF vtt] have "step s (P th cs)" .
-        ultimately show False
-        proof -
-          show " \<lbrakk>(Cs cs, Th th) \<in> (RAG s)\<^sup>+; step s (P th cs)\<rbrakk> \<Longrightarrow> False"
-            by (ind_cases "step s (P th cs)", simp)
-        qed
-      qed
-      with acyclic_insert ih eq_r show ?thesis by auto
-      qed
-      ultimately show ?thesis by simp
-    next
-      case (Set thread prio)
-      with ih
-      thm RAG_set_unchanged
-      show ?thesis by (simp add:RAG_set_unchanged)
-    qed
-  next
-    case vt_nil
-    show "acyclic (RAG ([]::state))"
-      by (auto simp: s_RAG_def cs_waiting_def 
-        cs_holding_def wq_def acyclic_def)
-qed
-
-
-lemma finite_RAG:
-  shows "finite (RAG s)"
-proof -
-  from vt show ?thesis
-  proof(induct)
-    case (vt_cons s e)
-    interpret vt_s: valid_trace s using vt_cons(1)
-      by (unfold_locales, simp)
-    assume ih: "finite (RAG s)"
-      and stp: "step s e"
-      and vt: "vt s"
-    show ?case
-    proof(cases e)
-      case (Create th prio)
-      with ih
-      show ?thesis by (simp add:RAG_create_unchanged)
-    next
-      case (Exit th)
-      with ih show ?thesis by (simp add:RAG_exit_unchanged)
-    next
-      case (V th cs)
-      from V vt stp have vtt: "vt (V th cs#s)" by auto
-      from step_RAG_v [OF this]
-      have eq_de: "RAG (e # s) = 
-                   RAG s - {(Cs cs, Th th)} - {(Th th', Cs cs) |th'. next_th s th cs th'} \<union>
-                      {(Cs cs, Th th') |th'. next_th s th cs th'}
-"
-        (is "?L = (?A - ?B - ?C) \<union> ?D") by (simp add:V)
-      moreover from ih have ac: "finite (?A - ?B - ?C)" by simp
-      moreover have "finite ?D"
-      proof -
-        have "?D = {} \<or> (\<exists> a. ?D = {a})" 
-          by (unfold next_th_def, auto)
-        thus ?thesis
-        proof
-          assume h: "?D = {}"
-          show ?thesis by (unfold h, simp)
-        next
-          assume "\<exists> a. ?D = {a}"
-          thus ?thesis
-            by (metis finite.simps)
-        qed
-      qed
-      ultimately show ?thesis by simp
-    next
-      case (P th cs)
-      from P vt stp have vtt: "vt (P th cs#s)" by auto
-      from step_RAG_p [OF this] P
-      have "RAG (e # s) = 
-              (if wq s cs = [] then RAG s \<union> {(Cs cs, Th th)} else 
-                                    RAG s \<union> {(Th th, Cs cs)})" (is "?L = ?R")
-        by simp
-      moreover have "finite ?R"
-      proof(cases "wq s cs = []")
-        case True
-        hence eq_r: "?R =  RAG s \<union> {(Cs cs, Th th)}" by simp
-        with True and ih show ?thesis by auto
-      next
-        case False
-        hence "?R = RAG s \<union> {(Th th, Cs cs)}" by simp
-        with False and ih show ?thesis by auto
-      qed
-      ultimately show ?thesis by auto
-    next
-      case (Set thread prio)
-      with ih
-      show ?thesis by (simp add:RAG_set_unchanged)
-    qed
-  next
-    case vt_nil
-    show "finite (RAG ([]::state))"
-      by (auto simp: s_RAG_def cs_waiting_def 
-                   cs_holding_def wq_def acyclic_def)
-  qed
-qed
-
-text {* Several useful lemmas *}
-
-lemma wf_dep_converse: 
-  shows "wf ((RAG s)^-1)"
-proof(rule finite_acyclic_wf_converse)
-  from finite_RAG 
-  show "finite (RAG s)" .
-next
-  from acyclic_RAG
-  show "acyclic (RAG s)" .
-qed
-
-end
-
-lemma hd_np_in: "x \<in> set l \<Longrightarrow> hd l \<in> set l"
-  by (induct l, auto)
-
-lemma th_chasing: "(Th th, Cs cs) \<in> RAG (s::state) \<Longrightarrow> \<exists> th'. (Cs cs, Th th') \<in> RAG s"
-  by (auto simp:s_RAG_def s_holding_def cs_holding_def cs_waiting_def wq_def dest:hd_np_in)
-
-context valid_trace
-begin
-
-lemma wq_threads: 
-  assumes h: "th \<in> set (wq s cs)"
-  shows "th \<in> threads s"
-proof -
- from vt and h show ?thesis
-  proof(induct arbitrary: th cs)
-    case (vt_cons s e)
-    interpret vt_s: valid_trace s
-      using vt_cons(1) by (unfold_locales, auto)
-    assume ih: "\<And>th cs. th \<in> set (wq s cs) \<Longrightarrow> th \<in> threads s"
-      and stp: "step s e"
-      and vt: "vt s"
-      and h: "th \<in> set (wq (e # s) cs)"
-    show ?case
-    proof(cases e)
-      case (Create th' prio)
-      with ih h show ?thesis
-        by (auto simp:wq_def Let_def)
-    next
-      case (Exit th')
-      with stp ih h show ?thesis
-        apply (auto simp:wq_def Let_def)
-        apply (ind_cases "step s (Exit th')")
-        apply (auto simp:runing_def readys_def s_holding_def s_waiting_def holdents_def
-               s_RAG_def s_holding_def cs_holding_def)
-        done
-    next
-      case (V th' cs')
-      show ?thesis
-      proof(cases "cs' = cs")
-        case False
-        with h
-        show ?thesis
-          apply(unfold wq_def V, auto simp:Let_def V split:prod.splits, fold wq_def)
-          by (drule_tac ih, simp)
-      next
-        case True
-        from h
-        show ?thesis
-        proof(unfold V wq_def)
-          assume th_in: "th \<in> set (wq_fun (schs (V th' cs' # s)) cs)" (is "th \<in> set ?l")
-          show "th \<in> threads (V th' cs' # s)"
-          proof(cases "cs = cs'")
-            case False
-            hence "?l = wq_fun (schs s) cs" by (simp add:Let_def)
-            with th_in have " th \<in> set (wq s cs)" 
-              by (fold wq_def, simp)
-            from ih [OF this] show ?thesis by simp
-          next
-            case True
-            show ?thesis
-            proof(cases "wq_fun (schs s) cs'")
-              case Nil
-              with h V show ?thesis
-                apply (auto simp:wq_def Let_def split:if_splits)
-                by (fold wq_def, drule_tac ih, simp)
-            next
-              case (Cons a rest)
-              assume eq_wq: "wq_fun (schs s) cs' = a # rest"
-              with h V show ?thesis
-                apply (auto simp:Let_def wq_def split:if_splits)
-              proof -
-                assume th_in: "th \<in> set (SOME q. distinct q \<and> set q = set rest)"
-                have "set (SOME q. distinct q \<and> set q = set rest) = set rest" 
-                proof(rule someI2)
-                  from vt_s.wq_distinct[of cs'] and eq_wq[folded wq_def]
-                  show "distinct rest \<and> set rest = set rest" by auto
-                next
-                  show "\<And>x. distinct x \<and> set x = set rest \<Longrightarrow> set x = set rest"
-                    by auto
-                qed
-                with eq_wq th_in have "th \<in> set (wq_fun (schs s) cs')" by auto
-                from ih[OF this[folded wq_def]] show "th \<in> threads s" .
-              next
-                assume th_in: "th \<in> set (wq_fun (schs s) cs)"
-                from ih[OF this[folded wq_def]]
-                show "th \<in> threads s" .
-              qed
-            qed
-          qed
-        qed
-      qed
-    next
-      case (P th' cs')
-      from h stp
-      show ?thesis
-        apply (unfold P wq_def)
-        apply (auto simp:Let_def split:if_splits, fold wq_def)
-        apply (auto intro:ih)
-        apply(ind_cases "step s (P th' cs')")
-        by (unfold runing_def readys_def, auto)
-    next
-      case (Set thread prio)
-      with ih h show ?thesis
-        by (auto simp:wq_def Let_def)
-    qed
-  next
-    case vt_nil
-    thus ?case by (auto simp:wq_def)
-  qed
-qed
-
-lemma range_in: "\<lbrakk>(Th th) \<in> Range (RAG (s::state))\<rbrakk> \<Longrightarrow> th \<in> threads s"
-  apply(unfold s_RAG_def cs_waiting_def cs_holding_def)
-  by (auto intro:wq_threads)
-
-lemma readys_v_eq:
-  assumes neq_th: "th \<noteq> thread"
-  and eq_wq: "wq s cs = thread#rest"
-  and not_in: "th \<notin>  set rest"
-  shows "(th \<in> readys (V thread cs#s)) = (th \<in> readys s)"
-proof -
-  from assms show ?thesis
-    apply (auto simp:readys_def)
-    apply(simp add:s_waiting_def[folded wq_def])
-    apply (erule_tac x = csa in allE)
-    apply (simp add:s_waiting_def wq_def Let_def split:if_splits)
-    apply (case_tac "csa = cs", simp)
-    apply (erule_tac x = cs in allE)
-    apply(auto simp add: s_waiting_def[folded wq_def] Let_def split: list.splits)
-    apply(auto simp add: wq_def)
-    apply (auto simp:s_waiting_def wq_def Let_def split:list.splits)
-    proof -
-       assume th_nin: "th \<notin> set rest"
-        and th_in: "th \<in> set (SOME q. distinct q \<and> set q = set rest)"
-        and eq_wq: "wq_fun (schs s) cs = thread # rest"
-      have "set (SOME q. distinct q \<and> set q = set rest) = set rest"
-      proof(rule someI2)
-        from wq_distinct[of cs, unfolded wq_def] and eq_wq[unfolded wq_def]
-        show "distinct rest \<and> set rest = set rest" by auto
-      next
-        show "\<And>x. distinct x \<and> set x = set rest \<Longrightarrow> set x = set rest" by auto
-      qed
-      with th_nin th_in show False by auto
-    qed
-qed
-
-text {* \noindent
-  The following lemmas shows that: starting from any node in @{text "RAG"}, 
-  by chasing out-going edges, it is always possible to reach a node representing a ready
-  thread. In this lemma, it is the @{text "th'"}.
-*}
-
-lemma chain_building:
-  shows "node \<in> Domain (RAG s) \<longrightarrow> (\<exists> th'. th' \<in> readys s \<and> (node, Th th') \<in> (RAG s)^+)"
-proof -
-  from wf_dep_converse
-  have h: "wf ((RAG s)\<inverse>)" .
-  show ?thesis
-  proof(induct rule:wf_induct [OF h])
-    fix x
-    assume ih [rule_format]: 
-      "\<forall>y. (y, x) \<in> (RAG s)\<inverse> \<longrightarrow> 
-           y \<in> Domain (RAG s) \<longrightarrow> (\<exists>th'. th' \<in> readys s \<and> (y, Th th') \<in> (RAG s)\<^sup>+)"
-    show "x \<in> Domain (RAG s) \<longrightarrow> (\<exists>th'. th' \<in> readys s \<and> (x, Th th') \<in> (RAG s)\<^sup>+)"
-    proof
-      assume x_d: "x \<in> Domain (RAG s)"
-      show "\<exists>th'. th' \<in> readys s \<and> (x, Th th') \<in> (RAG s)\<^sup>+"
-      proof(cases x)
-        case (Th th)
-        from x_d Th obtain cs where x_in: "(Th th, Cs cs) \<in> RAG s" by (auto simp:s_RAG_def)
-        with Th have x_in_r: "(Cs cs, x) \<in> (RAG s)^-1" by simp
-        from th_chasing [OF x_in] obtain th' where "(Cs cs, Th th') \<in> RAG s" by blast
-        hence "Cs cs \<in> Domain (RAG s)" by auto
-        from ih [OF x_in_r this] obtain th'
-          where th'_ready: " th' \<in> readys s" and cs_in: "(Cs cs, Th th') \<in> (RAG s)\<^sup>+" by auto
-        have "(x, Th th') \<in> (RAG s)\<^sup>+" using Th x_in cs_in by auto
-        with th'_ready show ?thesis by auto
-      next
-        case (Cs cs)
-        from x_d Cs obtain th' where th'_d: "(Th th', x) \<in> (RAG s)^-1" by (auto simp:s_RAG_def)
-        show ?thesis
-        proof(cases "th' \<in> readys s")
-          case True
-          from True and th'_d show ?thesis by auto
-        next
-          case False
-          from th'_d and range_in  have "th' \<in> threads s" by auto
-          with False have "Th th' \<in> Domain (RAG s)" 
-            by (auto simp:readys_def wq_def s_waiting_def s_RAG_def cs_waiting_def Domain_def)
-          from ih [OF th'_d this]
-          obtain th'' where 
-            th''_r: "th'' \<in> readys s" and 
-            th''_in: "(Th th', Th th'') \<in> (RAG s)\<^sup>+" by auto
-          from th'_d and th''_in 
-          have "(x, Th th'') \<in> (RAG s)\<^sup>+" by auto
-          with th''_r show ?thesis by auto
-        qed
-      qed
-    qed
-  qed
-qed
-
-text {* \noindent
-  The following is just an instance of @{text "chain_building"}.
-*}
-lemma th_chain_to_ready:
-  assumes th_in: "th \<in> threads s"
-  shows "th \<in> readys s \<or> (\<exists> th'. th' \<in> readys s \<and> (Th th, Th th') \<in> (RAG s)^+)"
-proof(cases "th \<in> readys s")
-  case True
-  thus ?thesis by auto
-next
-  case False
-  from False and th_in have "Th th \<in> Domain (RAG s)" 
-    by (auto simp:readys_def s_waiting_def s_RAG_def wq_def cs_waiting_def Domain_def)
-  from chain_building [rule_format, OF this]
-  show ?thesis by auto
-qed
-
-end
-
-lemma waiting_eq: "waiting s th cs = waiting (wq s) th cs"
-  by  (unfold s_waiting_def cs_waiting_def wq_def, auto)
-
-lemma holding_eq: "holding (s::state) th cs = holding (wq s) th cs"
-  by (unfold s_holding_def wq_def cs_holding_def, simp)
-
-lemma holding_unique: "\<lbrakk>holding (s::state) th1 cs; holding s th2 cs\<rbrakk> \<Longrightarrow> th1 = th2"
-  by (unfold s_holding_def cs_holding_def, auto)
-
-context valid_trace
-begin
-
-lemma unique_RAG: "\<lbrakk>(n, n1) \<in> RAG s; (n, n2) \<in> RAG s\<rbrakk> \<Longrightarrow> n1 = n2"
-  apply(unfold s_RAG_def, auto, fold waiting_eq holding_eq)
-  by(auto elim:waiting_unique holding_unique)
-
-end
-
-
-lemma trancl_split: "(a, b) \<in> r^+ \<Longrightarrow> \<exists> c. (a, c) \<in> r"
-by (induct rule:trancl_induct, auto)
-
-context valid_trace
-begin
-
-lemma dchain_unique:
-  assumes th1_d: "(n, Th th1) \<in> (RAG s)^+"
-  and th1_r: "th1 \<in> readys s"
-  and th2_d: "(n, Th th2) \<in> (RAG s)^+"
-  and th2_r: "th2 \<in> readys s"
-  shows "th1 = th2"
-proof -
-  { assume neq: "th1 \<noteq> th2"
-    hence "Th th1 \<noteq> Th th2" by simp
-    from unique_chain [OF _ th1_d th2_d this] and unique_RAG 
-    have "(Th th1, Th th2) \<in> (RAG s)\<^sup>+ \<or> (Th th2, Th th1) \<in> (RAG s)\<^sup>+" by auto
-    hence "False"
-    proof
-      assume "(Th th1, Th th2) \<in> (RAG s)\<^sup>+"
-      from trancl_split [OF this]
-      obtain n where dd: "(Th th1, n) \<in> RAG s" by auto
-      then obtain cs where eq_n: "n = Cs cs"
-        by (auto simp:s_RAG_def s_holding_def cs_holding_def cs_waiting_def wq_def dest:hd_np_in)
-      from dd eq_n have "th1 \<notin> readys s"
-        by (auto simp:readys_def s_RAG_def wq_def s_waiting_def cs_waiting_def)
-      with th1_r show ?thesis by auto
-    next
-      assume "(Th th2, Th th1) \<in> (RAG s)\<^sup>+"
-      from trancl_split [OF this]
-      obtain n where dd: "(Th th2, n) \<in> RAG s" by auto
-      then obtain cs where eq_n: "n = Cs cs"
-        by (auto simp:s_RAG_def s_holding_def cs_holding_def cs_waiting_def wq_def dest:hd_np_in)
-      from dd eq_n have "th2 \<notin> readys s"
-        by (auto simp:readys_def wq_def s_RAG_def s_waiting_def cs_waiting_def)
-      with th2_r show ?thesis by auto
-    qed
-  } thus ?thesis by auto
-qed
-
-end
-             
-
-lemma step_holdents_p_add:
-  assumes vt: "vt (P th cs#s)"
-  and "wq s cs = []"
-  shows "holdents (P th cs#s) th = holdents s th \<union> {cs}"
-proof -
-  from assms show ?thesis
-  unfolding  holdents_test step_RAG_p[OF vt] by (auto)
-qed
-
-lemma step_holdents_p_eq:
-  assumes vt: "vt (P th cs#s)"
-  and "wq s cs \<noteq> []"
-  shows "holdents (P th cs#s) th = holdents s th"
-proof -
-  from assms show ?thesis
-  unfolding  holdents_test step_RAG_p[OF vt] by auto
-qed
-
-
-lemma (in valid_trace) finite_holding :
-  shows "finite (holdents s th)"
-proof -
-  let ?F = "\<lambda> (x, y). the_cs x"
-  from finite_RAG 
-  have "finite (RAG s)" .
-  hence "finite (?F `(RAG s))" by simp
-  moreover have "{cs . (Cs cs, Th th) \<in> RAG s} \<subseteq> \<dots>" 
-  proof -
-    { have h: "\<And> a A f. a \<in> A \<Longrightarrow> f a \<in> f ` A" by auto
-      fix x assume "(Cs x, Th th) \<in> RAG s"
-      hence "?F (Cs x, Th th) \<in> ?F `(RAG s)" by (rule h)
-      moreover have "?F (Cs x, Th th) = x" by simp
-      ultimately have "x \<in> (\<lambda>(x, y). the_cs x) ` RAG s" by simp 
-    } thus ?thesis by auto
-  qed
-  ultimately show ?thesis by (unfold holdents_test, auto intro:finite_subset)
-qed
-
-lemma cntCS_v_dec: 
-  assumes vtv: "vt (V thread cs#s)"
-  shows "(cntCS (V thread cs#s) thread + 1) = cntCS s thread"
-proof -
-  from vtv interpret vt_s: valid_trace s
-    by (cases, unfold_locales, simp)
-  from vtv interpret vt_v: valid_trace "V thread cs#s"
-     by (unfold_locales, simp)
-  from step_back_step[OF vtv]
-  have cs_in: "cs \<in> holdents s thread" 
-    apply (cases, unfold holdents_test s_RAG_def, simp)
-    by (unfold cs_holding_def s_holding_def wq_def, auto)
-  moreover have cs_not_in: 
-    "(holdents (V thread cs#s) thread) = holdents s thread - {cs}"
-    apply (insert vt_s.wq_distinct[of cs])
-    apply (unfold holdents_test, unfold step_RAG_v[OF vtv],
-            auto simp:next_th_def)
-  proof -
-    fix rest
-    assume dst: "distinct (rest::thread list)"
-      and ne: "rest \<noteq> []"
-    and hd_ni: "hd (SOME q. distinct q \<and> set q = set rest) \<notin> set rest"
-    moreover have "set (SOME q. distinct q \<and> set q = set rest) = set rest"
-    proof(rule someI2)
-      from dst show "distinct rest \<and> set rest = set rest" by auto
-    next
-      show "\<And>x. distinct x \<and> set x = set rest \<Longrightarrow> set x = set rest" by auto
-    qed
-    ultimately have "hd (SOME q. distinct q \<and> set q = set rest) \<notin> 
-                     set (SOME q. distinct q \<and> set q = set rest)" by simp
-    moreover have "(SOME q. distinct q \<and> set q = set rest) \<noteq> []"
-    proof(rule someI2)
-      from dst show "distinct rest \<and> set rest = set rest" by auto
-    next
-      fix x assume " distinct x \<and> set x = set rest" with ne
-      show "x \<noteq> []" by auto
-    qed
-    ultimately 
-    show "(Cs cs, Th (hd (SOME q. distinct q \<and> set q = set rest))) \<in> RAG s"
-      by auto
-  next
-    fix rest
-    assume dst: "distinct (rest::thread list)"
-      and ne: "rest \<noteq> []"
-    and hd_ni: "hd (SOME q. distinct q \<and> set q = set rest) \<notin> set rest"
-    moreover have "set (SOME q. distinct q \<and> set q = set rest) = set rest"
-    proof(rule someI2)
-      from dst show "distinct rest \<and> set rest = set rest" by auto
-    next
-      show "\<And>x. distinct x \<and> set x = set rest \<Longrightarrow> set x = set rest" by auto
-    qed
-    ultimately have "hd (SOME q. distinct q \<and> set q = set rest) \<notin> 
-                     set (SOME q. distinct q \<and> set q = set rest)" by simp
-    moreover have "(SOME q. distinct q \<and> set q = set rest) \<noteq> []"
-    proof(rule someI2)
-      from dst show "distinct rest \<and> set rest = set rest" by auto
-    next
-      fix x assume " distinct x \<and> set x = set rest" with ne
-      show "x \<noteq> []" by auto
-    qed
-    ultimately show "False" by auto 
-  qed
-  ultimately 
-  have "holdents s thread = insert cs (holdents (V thread cs#s) thread)"
-    by auto
-  moreover have "card \<dots> = 
-                    Suc (card ((holdents (V thread cs#s) thread) - {cs}))"
-  proof(rule card_insert)
-    from vt_v.finite_holding
-    show " finite (holdents (V thread cs # s) thread)" .
-  qed
-  moreover from cs_not_in 
-  have "cs \<notin> (holdents (V thread cs#s) thread)" by auto
-  ultimately show ?thesis by (simp add:cntCS_def)
-qed 
-
-lemma count_rec1 [simp]: 
-  assumes "Q e"
-  shows "count Q (e#es) = Suc (count Q es)"
-  using assms
-  by (unfold count_def, auto)
-
-lemma count_rec2 [simp]: 
-  assumes "\<not>Q e"
-  shows "count Q (e#es) = (count Q es)"
-  using assms
-  by (unfold count_def, auto)
-
-lemma count_rec3 [simp]: 
-  shows "count Q [] =  0"
-  by (unfold count_def, auto)
-
-lemma cntP_diff_inv:
-  assumes "cntP (e#s) th \<noteq> cntP s th"
-  shows "isP e \<and> actor e = th"
-proof(cases e)
-  case (P th' pty)
-  show ?thesis
-  by (cases "(\<lambda>e. \<exists>cs. e = P th cs) (P th' pty)", 
-        insert assms P, auto simp:cntP_def)
-qed (insert assms, auto simp:cntP_def)
-  
-lemma cntV_diff_inv:
-  assumes "cntV (e#s) th \<noteq> cntV s th"
-  shows "isV e \<and> actor e = th"
-proof(cases e)
-  case (V th' pty)
-  show ?thesis
-  by (cases "(\<lambda>e. \<exists>cs. e = V th cs) (V th' pty)", 
-        insert assms V, auto simp:cntV_def)
-qed (insert assms, auto simp:cntV_def)
-
-context valid_trace
-begin
-
-text {* (* ddd *) \noindent
-  The relationship between @{text "cntP"}, @{text "cntV"} and @{text "cntCS"} 
-  of one particular thread. 
-*} 
-
-lemma cnp_cnv_cncs:
-  shows "cntP s th = cntV s th + (if (th \<in> readys s \<or> th \<notin> threads s) 
-                                       then cntCS s th else cntCS s th + 1)"
-proof -
-  from vt show ?thesis
-  proof(induct arbitrary:th)
-    case (vt_cons s e)
-    interpret vt_s: valid_trace s using vt_cons(1) by (unfold_locales, simp)
-    assume vt: "vt s"
-    and ih: "\<And>th. cntP s th  = cntV s th +
-               (if (th \<in> readys s \<or> th \<notin> threads s) then cntCS s th else cntCS s th + 1)"
-    and stp: "step s e"
-    from stp show ?case
-    proof(cases)
-      case (thread_create thread prio)
-      assume eq_e: "e = Create thread prio"
-        and not_in: "thread \<notin> threads s"
-      show ?thesis
-      proof -
-        { fix cs 
-          assume "thread \<in> set (wq s cs)"
-          from vt_s.wq_threads [OF this] have "thread \<in> threads s" .
-          with not_in have "False" by simp
-        } with eq_e have eq_readys: "readys (e#s) = readys s \<union> {thread}"
-          by (auto simp:readys_def threads.simps s_waiting_def 
-            wq_def cs_waiting_def Let_def)
-        from eq_e have eq_cnp: "cntP (e#s) th = cntP s th" by (simp add:cntP_def count_def)
-        from eq_e have eq_cnv: "cntV (e#s) th = cntV s th" by (simp add:cntV_def count_def)
-        have eq_cncs: "cntCS (e#s) th = cntCS s th"
-          unfolding cntCS_def holdents_test
-          by (simp add:RAG_create_unchanged eq_e)
-        { assume "th \<noteq> thread"
-          with eq_readys eq_e
-          have "(th \<in> readys (e # s) \<or> th \<notin> threads (e # s)) = 
-                      (th \<in> readys (s) \<or> th \<notin> threads (s))" 
-            by (simp add:threads.simps)
-          with eq_cnp eq_cnv eq_cncs ih not_in
-          have ?thesis by simp
-        } moreover {
-          assume eq_th: "th = thread"
-          with not_in ih have " cntP s th  = cntV s th + cntCS s th" by simp
-          moreover from eq_th and eq_readys have "th \<in> readys (e#s)" by simp
-          moreover note eq_cnp eq_cnv eq_cncs
-          ultimately have ?thesis by auto
-        } ultimately show ?thesis by blast
-      qed
-    next
-      case (thread_exit thread)
-      assume eq_e: "e = Exit thread" 
-      and is_runing: "thread \<in> runing s"
-      and no_hold: "holdents s thread = {}"
-      from eq_e have eq_cnp: "cntP (e#s) th = cntP s th" by (simp add:cntP_def count_def)
-      from eq_e have eq_cnv: "cntV (e#s) th = cntV s th" by (simp add:cntV_def count_def)
-      have eq_cncs: "cntCS (e#s) th = cntCS s th"
-        unfolding cntCS_def holdents_test
-        by (simp add:RAG_exit_unchanged eq_e)
-      { assume "th \<noteq> thread"
-        with eq_e
-        have "(th \<in> readys (e # s) \<or> th \<notin> threads (e # s)) = 
-          (th \<in> readys (s) \<or> th \<notin> threads (s))" 
-          apply (simp add:threads.simps readys_def)
-          apply (subst s_waiting_def)
-          apply (simp add:Let_def)
-          apply (subst s_waiting_def, simp)
-          done
-        with eq_cnp eq_cnv eq_cncs ih
-        have ?thesis by simp
-      } moreover {
-        assume eq_th: "th = thread"
-        with ih is_runing have " cntP s th = cntV s th + cntCS s th" 
-          by (simp add:runing_def)
-        moreover from eq_th eq_e have "th \<notin> threads (e#s)"
-          by simp
-        moreover note eq_cnp eq_cnv eq_cncs
-        ultimately have ?thesis by auto
-      } ultimately show ?thesis by blast
-    next
-      case (thread_P thread cs)
-      assume eq_e: "e = P thread cs"
-        and is_runing: "thread \<in> runing s"
-        and no_dep: "(Cs cs, Th thread) \<notin> (RAG s)\<^sup>+"
-      from thread_P vt stp ih  have vtp: "vt (P thread cs#s)" by auto
-      then interpret vt_p: valid_trace "(P thread cs#s)"
-        by (unfold_locales, simp)
-      show ?thesis 
-      proof -
-        { have hh: "\<And> A B C. (B = C) \<Longrightarrow> (A \<and> B) = (A \<and> C)" by blast
-          assume neq_th: "th \<noteq> thread"
-          with eq_e
-          have eq_readys: "(th \<in> readys (e#s)) = (th \<in> readys (s))"
-            apply (simp add:readys_def s_waiting_def wq_def Let_def)
-            apply (rule_tac hh)
-             apply (intro iffI allI, clarify)
-            apply (erule_tac x = csa in allE, auto)
-            apply (subgoal_tac "wq_fun (schs s) cs \<noteq> []", auto)
-            apply (erule_tac x = cs in allE, auto)
-            by (case_tac "(wq_fun (schs s) cs)", auto)
-          moreover from neq_th eq_e have "cntCS (e # s) th = cntCS s th"
-            apply (simp add:cntCS_def holdents_test)
-            by (unfold  step_RAG_p [OF vtp], auto)
-          moreover from eq_e neq_th have "cntP (e # s) th = cntP s th"
-            by (simp add:cntP_def count_def)
-          moreover from eq_e neq_th have "cntV (e#s) th = cntV s th"
-            by (simp add:cntV_def count_def)
-          moreover from eq_e neq_th have "threads (e#s) = threads s" by simp
-          moreover note ih [of th] 
-          ultimately have ?thesis by simp
-        } moreover {
-          assume eq_th: "th = thread"
-          have ?thesis
-          proof -
-            from eq_e eq_th have eq_cnp: "cntP (e # s) th  = 1 + (cntP s th)" 
-              by (simp add:cntP_def count_def)
-            from eq_e eq_th have eq_cnv: "cntV (e#s) th = cntV s th"
-              by (simp add:cntV_def count_def)
-            show ?thesis
-            proof (cases "wq s cs = []")
-              case True
-              with is_runing
-              have "th \<in> readys (e#s)"
-                apply (unfold eq_e wq_def, unfold readys_def s_RAG_def)
-                apply (simp add: wq_def[symmetric] runing_def eq_th s_waiting_def)
-                by (auto simp:readys_def wq_def Let_def s_waiting_def wq_def)
-              moreover have "cntCS (e # s) th = 1 + cntCS s th"
-              proof -
-                have "card {csa. csa = cs \<or> (Cs csa, Th thread) \<in> RAG s} =
-                  Suc (card {cs. (Cs cs, Th thread) \<in> RAG s})" (is "card ?L = Suc (card ?R)")
-                proof -
-                  have "?L = insert cs ?R" by auto
-                  moreover have "card \<dots> = Suc (card (?R - {cs}))" 
-                  proof(rule card_insert)
-                    from vt_s.finite_holding [of thread]
-                    show " finite {cs. (Cs cs, Th thread) \<in> RAG s}"
-                      by (unfold holdents_test, simp)
-                  qed
-                  moreover have "?R - {cs} = ?R"
-                  proof -
-                    have "cs \<notin> ?R"
-                    proof
-                      assume "cs \<in> {cs. (Cs cs, Th thread) \<in> RAG s}"
-                      with no_dep show False by auto
-                    qed
-                    thus ?thesis by auto
-                  qed
-                  ultimately show ?thesis by auto
-                qed
-                thus ?thesis
-                  apply (unfold eq_e eq_th cntCS_def)
-                  apply (simp add: holdents_test)
-                  by (unfold step_RAG_p [OF vtp], auto simp:True)
-              qed
-              moreover from is_runing have "th \<in> readys s"
-                by (simp add:runing_def eq_th)
-              moreover note eq_cnp eq_cnv ih [of th]
-              ultimately show ?thesis by auto
-            next
-              case False
-              have eq_wq: "wq (e#s) cs = wq s cs @ [th]"
-                    by (unfold eq_th eq_e wq_def, auto simp:Let_def)
-              have "th \<notin> readys (e#s)"
-              proof
-                assume "th \<in> readys (e#s)"
-                hence "\<forall>cs. \<not> waiting (e # s) th cs" by (simp add:readys_def)
-                from this[rule_format, of cs] have " \<not> waiting (e # s) th cs" .
-                hence "th \<in> set (wq (e#s) cs) \<Longrightarrow> th = hd (wq (e#s) cs)" 
-                  by (simp add:s_waiting_def wq_def)
-                moreover from eq_wq have "th \<in> set (wq (e#s) cs)" by auto
-                ultimately have "th = hd (wq (e#s) cs)" by blast
-                with eq_wq have "th = hd (wq s cs @ [th])" by simp
-                hence "th = hd (wq s cs)" using False by auto
-                with False eq_wq vt_p.wq_distinct [of cs]
-                show False by (fold eq_e, auto)
-              qed
-              moreover from is_runing have "th \<in> threads (e#s)" 
-                by (unfold eq_e, auto simp:runing_def readys_def eq_th)
-              moreover have "cntCS (e # s) th = cntCS s th"
-                apply (unfold cntCS_def holdents_test eq_e step_RAG_p[OF vtp])
-                by (auto simp:False)
-              moreover note eq_cnp eq_cnv ih[of th]
-              moreover from is_runing have "th \<in> readys s"
-                by (simp add:runing_def eq_th)
-              ultimately show ?thesis by auto
-            qed
-          qed
-        } ultimately show ?thesis by blast
-      qed
-    next
-      case (thread_V thread cs)
-      from assms vt stp ih thread_V have vtv: "vt (V thread cs # s)" by auto
-      then interpret vt_v: valid_trace "(V thread cs # s)" by (unfold_locales, simp)
-      assume eq_e: "e = V thread cs"
-        and is_runing: "thread \<in> runing s"
-        and hold: "holding s thread cs"
-      from hold obtain rest 
-        where eq_wq: "wq s cs = thread # rest"
-        by (case_tac "wq s cs", auto simp: wq_def s_holding_def)
-      have eq_threads: "threads (e#s) = threads s" by (simp add: eq_e)
-      have eq_set: "set (SOME q. distinct q \<and> set q = set rest) = set rest"
-      proof(rule someI2)
-        from vt_v.wq_distinct[of cs] and eq_wq
-        show "distinct rest \<and> set rest = set rest"
-          by (metis distinct.simps(2) vt_s.wq_distinct)
-      next
-        show "\<And>x. distinct x \<and> set x = set rest \<Longrightarrow> set x = set rest"
-          by auto
-      qed
-      show ?thesis
-      proof -
-        { assume eq_th: "th = thread"
-          from eq_th have eq_cnp: "cntP (e # s) th = cntP s th"
-            by (unfold eq_e, simp add:cntP_def count_def)
-          moreover from eq_th have eq_cnv: "cntV (e#s) th = 1 + cntV s th"
-            by (unfold eq_e, simp add:cntV_def count_def)
-          moreover from cntCS_v_dec [OF vtv] 
-          have "cntCS (e # s) thread + 1 = cntCS s thread"
-            by (simp add:eq_e)
-          moreover from is_runing have rd_before: "thread \<in> readys s"
-            by (unfold runing_def, simp)
-          moreover have "thread \<in> readys (e # s)"
-          proof -
-            from is_runing
-            have "thread \<in> threads (e#s)" 
-              by (unfold eq_e, auto simp:runing_def readys_def)
-            moreover have "\<forall> cs1. \<not> waiting (e#s) thread cs1"
-            proof
-              fix cs1
-              { assume eq_cs: "cs1 = cs" 
-                have "\<not> waiting (e # s) thread cs1"
-                proof -
-                  from eq_wq
-                  have "thread \<notin> set (wq (e#s) cs1)"
-                    apply(unfold eq_e wq_def eq_cs s_holding_def)
-                    apply (auto simp:Let_def)
-                  proof -
-                    assume "thread \<in> set (SOME q. distinct q \<and> set q = set rest)"
-                    with eq_set have "thread \<in> set rest" by simp
-                    with vt_v.wq_distinct[of cs]
-                    and eq_wq show False
-                        by (metis distinct.simps(2) vt_s.wq_distinct)
-                  qed
-                  thus ?thesis by (simp add:wq_def s_waiting_def)
-                qed
-              } moreover {
-                assume neq_cs: "cs1 \<noteq> cs"
-                  have "\<not> waiting (e # s) thread cs1" 
-                  proof -
-                    from wq_v_neq [OF neq_cs[symmetric]]
-                    have "wq (V thread cs # s) cs1 = wq s cs1" .
-                    moreover have "\<not> waiting s thread cs1" 
-                    proof -
-                      from runing_ready and is_runing
-                      have "thread \<in> readys s" by auto
-                      thus ?thesis by (simp add:readys_def)
-                    qed
-                    ultimately show ?thesis 
-                      by (auto simp:wq_def s_waiting_def eq_e)
-                  qed
-              } ultimately show "\<not> waiting (e # s) thread cs1" by blast
-            qed
-            ultimately show ?thesis by (simp add:readys_def)
-          qed
-          moreover note eq_th ih
-          ultimately have ?thesis by auto
-        } moreover {
-          assume neq_th: "th \<noteq> thread"
-          from neq_th eq_e have eq_cnp: "cntP (e # s) th = cntP s th" 
-            by (simp add:cntP_def count_def)
-          from neq_th eq_e have eq_cnv: "cntV (e # s) th = cntV s th" 
-            by (simp add:cntV_def count_def)
-          have ?thesis
-          proof(cases "th \<in> set rest")
-            case False
-            have "(th \<in> readys (e # s)) = (th \<in> readys s)"
-              apply (insert step_back_vt[OF vtv])
-              by (simp add: False eq_e eq_wq neq_th vt_s.readys_v_eq)
-            moreover have "cntCS (e#s) th = cntCS s th"
-              apply (insert neq_th, unfold eq_e cntCS_def holdents_test step_RAG_v[OF vtv], auto)
-              proof -
-                have "{csa. (Cs csa, Th th) \<in> RAG s \<or> csa = cs \<and> next_th s thread cs th} =
-                      {cs. (Cs cs, Th th) \<in> RAG s}"
-                proof -
-                  from False eq_wq
-                  have " next_th s thread cs th \<Longrightarrow> (Cs cs, Th th) \<in> RAG s"
-                    apply (unfold next_th_def, auto)
-                  proof -
-                    assume ne: "rest \<noteq> []"
-                      and ni: "hd (SOME q. distinct q \<and> set q = set rest) \<notin> set rest"
-                      and eq_wq: "wq s cs = thread # rest"
-                    from eq_set ni have "hd (SOME q. distinct q \<and> set q = set rest) \<notin> 
-                                  set (SOME q. distinct q \<and> set q = set rest)
-                                  " by simp
-                    moreover have "(SOME q. distinct q \<and> set q = set rest) \<noteq> []"
-                    proof(rule someI2)
-                      from vt_s.wq_distinct[ of cs] and eq_wq
-                      show "distinct rest \<and> set rest = set rest" by auto
-                    next
-                      fix x assume "distinct x \<and> set x = set rest"
-                      with ne show "x \<noteq> []" by auto
-                    qed
-                    ultimately show 
-                      "(Cs cs, Th (hd (SOME q. distinct q \<and> set q = set rest))) \<in> RAG s"
-                      by auto
-                  qed    
-                  thus ?thesis by auto
-                qed
-                thus "card {csa. (Cs csa, Th th) \<in> RAG s \<or> csa = cs \<and> next_th s thread cs th} =
-                             card {cs. (Cs cs, Th th) \<in> RAG s}" by simp 
-              qed
-            moreover note ih eq_cnp eq_cnv eq_threads
-            ultimately show ?thesis by auto
-          next
-            case True
-            assume th_in: "th \<in> set rest"
-            show ?thesis
-            proof(cases "next_th s thread cs th")
-              case False
-              with eq_wq and th_in have 
-                neq_hd: "th \<noteq> hd (SOME q. distinct q \<and> set q = set rest)" (is "th \<noteq> hd ?rest")
-                by (auto simp:next_th_def)
-              have "(th \<in> readys (e # s)) = (th \<in> readys s)"
-              proof -
-                from eq_wq and th_in
-                have "\<not> th \<in> readys s"
-                  apply (auto simp:readys_def s_waiting_def)
-                  apply (rule_tac x = cs in exI, auto)
-                  by (insert vt_s.wq_distinct[of cs], auto simp add: wq_def)
-                moreover 
-                from eq_wq and th_in and neq_hd
-                have "\<not> (th \<in> readys (e # s))"
-                  apply (auto simp:readys_def s_waiting_def eq_e wq_def Let_def split:list.splits)
-                  by (rule_tac x = cs in exI, auto simp:eq_set)
-                ultimately show ?thesis by auto
-              qed
-              moreover have "cntCS (e#s) th = cntCS s th" 
-              proof -
-                from eq_wq and  th_in and neq_hd
-                have "(holdents (e # s) th) = (holdents s th)"
-                  apply (unfold eq_e step_RAG_v[OF vtv], 
-                         auto simp:next_th_def eq_set s_RAG_def holdents_test wq_def
-                                   Let_def cs_holding_def)
-                  by (insert vt_s.wq_distinct[of cs], auto simp:wq_def)
-                thus ?thesis by (simp add:cntCS_def)
-              qed
-              moreover note ih eq_cnp eq_cnv eq_threads
-              ultimately show ?thesis by auto
-            next
-              case True
-              let ?rest = " (SOME q. distinct q \<and> set q = set rest)"
-              let ?t = "hd ?rest"
-              from True eq_wq th_in neq_th
-              have "th \<in> readys (e # s)"
-                apply (auto simp:eq_e readys_def s_waiting_def wq_def
-                        Let_def next_th_def)
-              proof -
-                assume eq_wq: "wq_fun (schs s) cs = thread # rest"
-                  and t_in: "?t \<in> set rest"
-                show "?t \<in> threads s"
-                proof(rule vt_s.wq_threads)
-                  from eq_wq and t_in
-                  show "?t \<in> set (wq s cs)" by (auto simp:wq_def)
-                qed
-              next
-                fix csa
-                assume eq_wq: "wq_fun (schs s) cs = thread # rest"
-                  and t_in: "?t \<in> set rest"
-                  and neq_cs: "csa \<noteq> cs"
-                  and t_in': "?t \<in>  set (wq_fun (schs s) csa)"
-                show "?t = hd (wq_fun (schs s) csa)"
-                proof -
-                  { assume neq_hd': "?t \<noteq> hd (wq_fun (schs s) csa)"
-                    from vt_s.wq_distinct[of cs] and 
-                    eq_wq[folded wq_def] and t_in eq_wq
-                    have "?t \<noteq> thread" by auto
-                    with eq_wq and t_in
-                    have w1: "waiting s ?t cs"
-                      by (auto simp:s_waiting_def wq_def)
-                    from t_in' neq_hd'
-                    have w2: "waiting s ?t csa"
-                      by (auto simp:s_waiting_def wq_def)
-                    from vt_s.waiting_unique[OF w1 w2]
-                    and neq_cs have "False" by auto
-                  } thus ?thesis by auto
-                qed
-              qed
-              moreover have "cntP s th = cntV s th + cntCS s th + 1"
-              proof -
-                have "th \<notin> readys s" 
-                proof -
-                  from True eq_wq neq_th th_in
-                  show ?thesis
-                    apply (unfold readys_def s_waiting_def, auto)
-                    by (rule_tac x = cs in exI, auto simp add: wq_def)
-                qed
-                moreover have "th \<in> threads s"
-                proof -
-                  from th_in eq_wq
-                  have "th \<in> set (wq s cs)" by simp
-                  from vt_s.wq_threads [OF this] 
-                  show ?thesis .
-                qed
-                ultimately show ?thesis using ih by auto
-              qed
-              moreover from True neq_th have "cntCS (e # s) th = 1 + cntCS s th"
-                apply (unfold cntCS_def holdents_test eq_e step_RAG_v[OF vtv], auto)
-              proof -
-                show "card {csa. (Cs csa, Th th) \<in> RAG s \<or> csa = cs} =
-                               Suc (card {cs. (Cs cs, Th th) \<in> RAG s})"
-                  (is "card ?A = Suc (card ?B)")
-                proof -
-                  have "?A = insert cs ?B" by auto
-                  hence "card ?A = card (insert cs ?B)" by simp
-                  also have "\<dots> = Suc (card ?B)"
-                  proof(rule card_insert_disjoint)
-                    have "?B \<subseteq> ((\<lambda> (x, y). the_cs x) ` RAG s)" 
-                      apply (auto simp:image_def)
-                      by (rule_tac x = "(Cs x, Th th)" in bexI, auto)
-                    with vt_s.finite_RAG
-                    show "finite {cs. (Cs cs, Th th) \<in> RAG s}" by (auto intro:finite_subset)
-                  next
-                    show "cs \<notin> {cs. (Cs cs, Th th) \<in> RAG s}"
-                    proof
-                      assume "cs \<in> {cs. (Cs cs, Th th) \<in> RAG s}"
-                      hence "(Cs cs, Th th) \<in> RAG s" by simp
-                      with True neq_th eq_wq show False
-                        by (auto simp:next_th_def s_RAG_def cs_holding_def)
-                    qed
-                  qed
-                  finally show ?thesis .
-                qed
-              qed
-              moreover note eq_cnp eq_cnv
-              ultimately show ?thesis by simp
-            qed
-          qed
-        } ultimately show ?thesis by blast
-      qed
-    next
-      case (thread_set thread prio)
-      assume eq_e: "e = Set thread prio"
-        and is_runing: "thread \<in> runing s"
-      show ?thesis
-      proof -
-        from eq_e have eq_cnp: "cntP (e#s) th = cntP s th" by (simp add:cntP_def count_def)
-        from eq_e have eq_cnv: "cntV (e#s) th = cntV s th" by (simp add:cntV_def count_def)
-        have eq_cncs: "cntCS (e#s) th = cntCS s th"
-          unfolding cntCS_def holdents_test
-          by (simp add:RAG_set_unchanged eq_e)
-        from eq_e have eq_readys: "readys (e#s) = readys s" 
-          by (simp add:readys_def cs_waiting_def s_waiting_def wq_def,
-                  auto simp:Let_def)
-        { assume "th \<noteq> thread"
-          with eq_readys eq_e
-          have "(th \<in> readys (e # s) \<or> th \<notin> threads (e # s)) = 
-                      (th \<in> readys (s) \<or> th \<notin> threads (s))" 
-            by (simp add:threads.simps)
-          with eq_cnp eq_cnv eq_cncs ih is_runing
-          have ?thesis by simp
-        } moreover {
-          assume eq_th: "th = thread"
-          with is_runing ih have " cntP s th  = cntV s th + cntCS s th" 
-            by (unfold runing_def, auto)
-          moreover from eq_th and eq_readys is_runing have "th \<in> readys (e#s)"
-            by (simp add:runing_def)
-          moreover note eq_cnp eq_cnv eq_cncs
-          ultimately have ?thesis by auto
-        } ultimately show ?thesis by blast
-      qed   
-    qed
-  next
-    case vt_nil
-    show ?case 
-      by (unfold cntP_def cntV_def cntCS_def, 
-        auto simp:count_def holdents_test s_RAG_def wq_def cs_holding_def)
-  qed
-qed
-
-lemma not_thread_cncs:
-  assumes not_in: "th \<notin> threads s" 
-  shows "cntCS s th = 0"
-proof -
-  from vt not_in show ?thesis
-  proof(induct arbitrary:th)
-    case (vt_cons s e th)
-    interpret vt_s: valid_trace s using vt_cons(1)
-       by (unfold_locales, simp)
-    assume vt: "vt s"
-      and ih: "\<And>th. th \<notin> threads s \<Longrightarrow> cntCS s th = 0"
-      and stp: "step s e"
-      and not_in: "th \<notin> threads (e # s)"
-    from stp show ?case
-    proof(cases)
-      case (thread_create thread prio)
-      assume eq_e: "e = Create thread prio"
-        and not_in': "thread \<notin> threads s"
-      have "cntCS (e # s) th = cntCS s th"
-        apply (unfold eq_e cntCS_def holdents_test)
-        by (simp add:RAG_create_unchanged)
-      moreover have "th \<notin> threads s" 
-      proof -
-        from not_in eq_e show ?thesis by simp
-      qed
-      moreover note ih ultimately show ?thesis by auto
-    next
-      case (thread_exit thread)
-      assume eq_e: "e = Exit thread"
-      and nh: "holdents s thread = {}"
-      have eq_cns: "cntCS (e # s) th = cntCS s th"
-        apply (unfold eq_e cntCS_def holdents_test)
-        by (simp add:RAG_exit_unchanged)
-      show ?thesis
-      proof(cases "th = thread")
-        case True
-        have "cntCS s th = 0" by (unfold cntCS_def, auto simp:nh True)
-        with eq_cns show ?thesis by simp
-      next
-        case False
-        with not_in and eq_e
-        have "th \<notin> threads s" by simp
-        from ih[OF this] and eq_cns show ?thesis by simp
-      qed
-    next
-      case (thread_P thread cs)
-      assume eq_e: "e = P thread cs"
-      and is_runing: "thread \<in> runing s"
-      from assms thread_P ih vt stp thread_P have vtp: "vt (P thread cs#s)" by auto
-      have neq_th: "th \<noteq> thread" 
-      proof -
-        from not_in eq_e have "th \<notin> threads s" by simp
-        moreover from is_runing have "thread \<in> threads s"
-          by (simp add:runing_def readys_def)
-        ultimately show ?thesis by auto
-      qed
-      hence "cntCS (e # s) th  = cntCS s th "
-        apply (unfold cntCS_def holdents_test eq_e)
-        by (unfold step_RAG_p[OF vtp], auto)
-      moreover have "cntCS s th = 0"
-      proof(rule ih)
-        from not_in eq_e show "th \<notin> threads s" by simp
-      qed
-      ultimately show ?thesis by simp
-    next
-      case (thread_V thread cs)
-      assume eq_e: "e = V thread cs"
-        and is_runing: "thread \<in> runing s"
-        and hold: "holding s thread cs"
-      have neq_th: "th \<noteq> thread" 
-      proof -
-        from not_in eq_e have "th \<notin> threads s" by simp
-        moreover from is_runing have "thread \<in> threads s"
-          by (simp add:runing_def readys_def)
-        ultimately show ?thesis by auto
-      qed
-      from assms thread_V vt stp ih 
-      have vtv: "vt (V thread cs#s)" by auto
-      then interpret vt_v: valid_trace "(V thread cs#s)"
-        by (unfold_locales, simp)
-      from hold obtain rest 
-        where eq_wq: "wq s cs = thread # rest"
-        by (case_tac "wq s cs", auto simp: wq_def s_holding_def)
-      from not_in eq_e eq_wq
-      have "\<not> next_th s thread cs th"
-        apply (auto simp:next_th_def)
-      proof -
-        assume ne: "rest \<noteq> []"
-          and ni: "hd (SOME q. distinct q \<and> set q = set rest) \<notin> threads s" (is "?t \<notin> threads s")
-        have "?t \<in> set rest"
-        proof(rule someI2)
-          from vt_v.wq_distinct[of cs] and eq_wq
-          show "distinct rest \<and> set rest = set rest"
-            by (metis distinct.simps(2) vt_s.wq_distinct) 
-        next
-          fix x assume "distinct x \<and> set x = set rest" with ne
-          show "hd x \<in> set rest" by (cases x, auto)
-        qed
-        with eq_wq have "?t \<in> set (wq s cs)" by simp
-        from vt_s.wq_threads[OF this] and ni
-        show False
-          using `hd (SOME q. distinct q \<and> set q = set rest) \<in> set (wq s cs)` 
-            ni vt_s.wq_threads by blast 
-      qed
-      moreover note neq_th eq_wq
-      ultimately have "cntCS (e # s) th  = cntCS s th"
-        by (unfold eq_e cntCS_def holdents_test step_RAG_v[OF vtv], auto)
-      moreover have "cntCS s th = 0"
-      proof(rule ih)
-        from not_in eq_e show "th \<notin> threads s" by simp
-      qed
-      ultimately show ?thesis by simp
-    next
-      case (thread_set thread prio)
-      print_facts
-      assume eq_e: "e = Set thread prio"
-        and is_runing: "thread \<in> runing s"
-      from not_in and eq_e have "th \<notin> threads s" by auto
-      from ih [OF this] and eq_e
-      show ?thesis 
-        apply (unfold eq_e cntCS_def holdents_test)
-        by (simp add:RAG_set_unchanged)
-    qed
-    next
-      case vt_nil
-      show ?case
-      by (unfold cntCS_def, 
-        auto simp:count_def holdents_test s_RAG_def wq_def cs_holding_def)
-  qed
-qed
-
-end
-
-lemma eq_waiting: "waiting (wq (s::state)) th cs = waiting s th cs"
-  by (auto simp:s_waiting_def cs_waiting_def wq_def)
-
-context valid_trace
-begin
-
-lemma dm_RAG_threads:
-  assumes in_dom: "(Th th) \<in> Domain (RAG s)"
-  shows "th \<in> threads s"
-proof -
-  from in_dom obtain n where "(Th th, n) \<in> RAG s" by auto
-  moreover from RAG_target_th[OF this] obtain cs where "n = Cs cs" by auto
-  ultimately have "(Th th, Cs cs) \<in> RAG s" by simp
-  hence "th \<in> set (wq s cs)"
-    by (unfold s_RAG_def, auto simp:cs_waiting_def)
-  from wq_threads [OF this] show ?thesis .
-qed
-
-end
-
-lemma cp_eq_cpreced: "cp s th = cpreced (wq s) s th"
-unfolding cp_def wq_def
-apply(induct s rule: schs.induct)
-thm cpreced_initial
-apply(simp add: Let_def cpreced_initial)
-apply(simp add: Let_def)
-apply(simp add: Let_def)
-apply(simp add: Let_def)
-apply(subst (2) schs.simps)
-apply(simp add: Let_def)
-apply(subst (2) schs.simps)
-apply(simp add: Let_def)
-done
-
-context valid_trace
-begin
-
-lemma runing_unique:
-  assumes runing_1: "th1 \<in> runing s"
-  and runing_2: "th2 \<in> runing s"
-  shows "th1 = th2"
-proof -
-  from runing_1 and runing_2 have "cp s th1 = cp s th2"
-    unfolding runing_def
-    apply(simp)
-    done
-  hence eq_max: "Max ((\<lambda>th. preced th s) ` ({th1} \<union> dependants (wq s) th1)) =
-                 Max ((\<lambda>th. preced th s) ` ({th2} \<union> dependants (wq s) th2))"
-    (is "Max (?f ` ?A) = Max (?f ` ?B)")
-    unfolding cp_eq_cpreced 
-    unfolding cpreced_def .
-  obtain th1' where th1_in: "th1' \<in> ?A" and eq_f_th1: "?f th1' = Max (?f ` ?A)"
-  proof -
-    have h1: "finite (?f ` ?A)"
-    proof -
-      have "finite ?A" 
-      proof -
-        have "finite (dependants (wq s) th1)"
-        proof-
-          have "finite {th'. (Th th', Th th1) \<in> (RAG (wq s))\<^sup>+}"
-          proof -
-            let ?F = "\<lambda> (x, y). the_th x"
-            have "{th'. (Th th', Th th1) \<in> (RAG (wq s))\<^sup>+} \<subseteq> ?F ` ((RAG (wq s))\<^sup>+)"
-              apply (auto simp:image_def)
-              by (rule_tac x = "(Th x, Th th1)" in bexI, auto)
-            moreover have "finite \<dots>"
-            proof -
-              from finite_RAG have "finite (RAG s)" .
-              hence "finite ((RAG (wq s))\<^sup>+)"
-                apply (unfold finite_trancl)
-                by (auto simp: s_RAG_def cs_RAG_def wq_def)
-              thus ?thesis by auto
-            qed
-            ultimately show ?thesis by (auto intro:finite_subset)
-          qed
-          thus ?thesis by (simp add:cs_dependants_def)
-        qed
-        thus ?thesis by simp
-      qed
-      thus ?thesis by auto
-    qed
-    moreover have h2: "(?f ` ?A) \<noteq> {}"
-    proof -
-      have "?A \<noteq> {}" by simp
-      thus ?thesis by simp
-    qed
-    from Max_in [OF h1 h2]
-    have "Max (?f ` ?A) \<in> (?f ` ?A)" .
-    thus ?thesis 
-      thm cpreced_def
-      unfolding cpreced_def[symmetric] 
-      unfolding cp_eq_cpreced[symmetric] 
-      unfolding cpreced_def 
-      using that[intro] by (auto)
-  qed
-  obtain th2' where th2_in: "th2' \<in> ?B" and eq_f_th2: "?f th2' = Max (?f ` ?B)"
-  proof -
-    have h1: "finite (?f ` ?B)"
-    proof -
-      have "finite ?B" 
-      proof -
-        have "finite (dependants (wq s) th2)"
-        proof-
-          have "finite {th'. (Th th', Th th2) \<in> (RAG (wq s))\<^sup>+}"
-          proof -
-            let ?F = "\<lambda> (x, y). the_th x"
-            have "{th'. (Th th', Th th2) \<in> (RAG (wq s))\<^sup>+} \<subseteq> ?F ` ((RAG (wq s))\<^sup>+)"
-              apply (auto simp:image_def)
-              by (rule_tac x = "(Th x, Th th2)" in bexI, auto)
-            moreover have "finite \<dots>"
-            proof -
-              from finite_RAG have "finite (RAG s)" .
-              hence "finite ((RAG (wq s))\<^sup>+)"
-                apply (unfold finite_trancl)
-                by (auto simp: s_RAG_def cs_RAG_def wq_def)
-              thus ?thesis by auto
-            qed
-            ultimately show ?thesis by (auto intro:finite_subset)
-          qed
-          thus ?thesis by (simp add:cs_dependants_def)
-        qed
-        thus ?thesis by simp
-      qed
-      thus ?thesis by auto
-    qed
-    moreover have h2: "(?f ` ?B) \<noteq> {}"
-    proof -
-      have "?B \<noteq> {}" by simp
-      thus ?thesis by simp
-    qed
-    from Max_in [OF h1 h2]
-    have "Max (?f ` ?B) \<in> (?f ` ?B)" .
-    thus ?thesis by (auto intro:that)
-  qed
-  from eq_f_th1 eq_f_th2 eq_max 
-  have eq_preced: "preced th1' s = preced th2' s" by auto
-  hence eq_th12: "th1' = th2'"
-  proof (rule preced_unique)
-    from th1_in have "th1' = th1 \<or> (th1' \<in> dependants (wq s) th1)" by simp
-    thus "th1' \<in> threads s"
-    proof
-      assume "th1' \<in> dependants (wq s) th1"
-      hence "(Th th1') \<in> Domain ((RAG s)^+)"
-        apply (unfold cs_dependants_def cs_RAG_def s_RAG_def)
-        by (auto simp:Domain_def)
-      hence "(Th th1') \<in> Domain (RAG s)" by (simp add:trancl_domain)
-      from dm_RAG_threads[OF this] show ?thesis .
-    next
-      assume "th1' = th1"
-      with runing_1 show ?thesis
-        by (unfold runing_def readys_def, auto)
-    qed
-  next
-    from th2_in have "th2' = th2 \<or> (th2' \<in> dependants (wq s) th2)" by simp
-    thus "th2' \<in> threads s"
-    proof
-      assume "th2' \<in> dependants (wq s) th2"
-      hence "(Th th2') \<in> Domain ((RAG s)^+)"
-        apply (unfold cs_dependants_def cs_RAG_def s_RAG_def)
-        by (auto simp:Domain_def)
-      hence "(Th th2') \<in> Domain (RAG s)" by (simp add:trancl_domain)
-      from dm_RAG_threads[OF this] show ?thesis .
-    next
-      assume "th2' = th2"
-      with runing_2 show ?thesis
-        by (unfold runing_def readys_def, auto)
-    qed
-  qed
-  from th1_in have "th1' = th1 \<or> th1' \<in> dependants (wq s) th1" by simp
-  thus ?thesis
-  proof
-    assume eq_th': "th1' = th1"
-    from th2_in have "th2' = th2 \<or> th2' \<in> dependants (wq s) th2" by simp
-    thus ?thesis
-    proof
-      assume "th2' = th2" thus ?thesis using eq_th' eq_th12 by simp
-    next
-      assume "th2' \<in> dependants (wq s) th2"
-      with eq_th12 eq_th' have "th1 \<in> dependants (wq s) th2" by simp
-      hence "(Th th1, Th th2) \<in> (RAG s)^+"
-        by (unfold cs_dependants_def s_RAG_def cs_RAG_def, simp)
-      hence "Th th1 \<in> Domain ((RAG s)^+)" 
-        apply (unfold cs_dependants_def cs_RAG_def s_RAG_def)
-        by (auto simp:Domain_def)
-      hence "Th th1 \<in> Domain (RAG s)" by (simp add:trancl_domain)
-      then obtain n where d: "(Th th1, n) \<in> RAG s" by (auto simp:Domain_def)
-      from RAG_target_th [OF this]
-      obtain cs' where "n = Cs cs'" by auto
-      with d have "(Th th1, Cs cs') \<in> RAG s" by simp
-      with runing_1 have "False"
-        apply (unfold runing_def readys_def s_RAG_def)
-        by (auto simp:eq_waiting)
-      thus ?thesis by simp
-    qed
-  next
-    assume th1'_in: "th1' \<in> dependants (wq s) th1"
-    from th2_in have "th2' = th2 \<or> th2' \<in> dependants (wq s) th2" by simp
-    thus ?thesis 
-    proof
-      assume "th2' = th2"
-      with th1'_in eq_th12 have "th2 \<in> dependants (wq s) th1" by simp
-      hence "(Th th2, Th th1) \<in> (RAG s)^+"
-        by (unfold cs_dependants_def s_RAG_def cs_RAG_def, simp)
-      hence "Th th2 \<in> Domain ((RAG s)^+)" 
-        apply (unfold cs_dependants_def cs_RAG_def s_RAG_def)
-        by (auto simp:Domain_def)
-      hence "Th th2 \<in> Domain (RAG s)" by (simp add:trancl_domain)
-      then obtain n where d: "(Th th2, n) \<in> RAG s" by (auto simp:Domain_def)
-      from RAG_target_th [OF this]
-      obtain cs' where "n = Cs cs'" by auto
-      with d have "(Th th2, Cs cs') \<in> RAG s" by simp
-      with runing_2 have "False"
-        apply (unfold runing_def readys_def s_RAG_def)
-        by (auto simp:eq_waiting)
-      thus ?thesis by simp
-    next
-      assume "th2' \<in> dependants (wq s) th2"
-      with eq_th12 have "th1' \<in> dependants (wq s) th2" by simp
-      hence h1: "(Th th1', Th th2) \<in> (RAG s)^+"
-        by (unfold cs_dependants_def s_RAG_def cs_RAG_def, simp)
-      from th1'_in have h2: "(Th th1', Th th1) \<in> (RAG s)^+"
-        by (unfold cs_dependants_def s_RAG_def cs_RAG_def, simp)
-      show ?thesis
-      proof(rule dchain_unique[OF h1 _ h2, symmetric])
-        from runing_1 show "th1 \<in> readys s" by (simp add:runing_def)
-        from runing_2 show "th2 \<in> readys s" by (simp add:runing_def) 
-      qed
-    qed
-  qed
-qed
-
-
-lemma "card (runing s) \<le> 1"
-apply(subgoal_tac "finite (runing s)")
-prefer 2
-apply (metis finite_nat_set_iff_bounded lessI runing_unique)
-apply(rule ccontr)
-apply(simp)
-apply(case_tac "Suc (Suc 0) \<le> card (runing s)")
-apply(subst (asm) card_le_Suc_iff)
-apply(simp)
-apply(auto)[1]
-apply (metis insertCI runing_unique)
-apply(auto) 
-done
-
-end
-
-
-lemma create_pre:
-  assumes stp: "step s e"
-  and not_in: "th \<notin> threads s"
-  and is_in: "th \<in> threads (e#s)"
-  obtains prio where "e = Create th prio"
-proof -
-  from assms  
-  show ?thesis
-  proof(cases)
-    case (thread_create thread prio)
-    with is_in not_in have "e = Create th prio" by simp
-    from that[OF this] show ?thesis .
-  next
-    case (thread_exit thread)
-    with assms show ?thesis by (auto intro!:that)
-  next
-    case (thread_P thread)
-    with assms show ?thesis by (auto intro!:that)
-  next
-    case (thread_V thread)
-    with assms show ?thesis by (auto intro!:that)
-  next 
-    case (thread_set thread)
-    with assms show ?thesis by (auto intro!:that)
-  qed
-qed
-
-lemma length_down_to_in: 
-  assumes le_ij: "i \<le> j"
-    and le_js: "j \<le> length s"
-  shows "length (down_to j i s) = j - i"
-proof -
-  have "length (down_to j i s) = length (from_to i j (rev s))"
-    by (unfold down_to_def, auto)
-  also have "\<dots> = j - i"
-  proof(rule length_from_to_in[OF le_ij])
-    from le_js show "j \<le> length (rev s)" by simp
-  qed
-  finally show ?thesis .
-qed
-
-
-lemma moment_head: 
-  assumes le_it: "Suc i \<le> length t"
-  obtains e where "moment (Suc i) t = e#moment i t"
-proof -
-  have "i \<le> Suc i" by simp
-  from length_down_to_in [OF this le_it]
-  have "length (down_to (Suc i) i t) = 1" by auto
-  then obtain e where "down_to (Suc i) i t = [e]"
-    apply (cases "(down_to (Suc i) i t)") by auto
-  moreover have "down_to (Suc i) 0 t = down_to (Suc i) i t @ down_to i 0 t"
-    by (rule down_to_conc[symmetric], auto)
-  ultimately have eq_me: "moment (Suc i) t = e#(moment i t)"
-    by (auto simp:down_to_moment)
-  from that [OF this] show ?thesis .
-qed
-
-context valid_trace
-begin
-
-lemma cnp_cnv_eq:
-  assumes "th \<notin> threads s"
-  shows "cntP s th = cntV s th"
-  using assms
-  using cnp_cnv_cncs not_thread_cncs by auto
-
-end
-
-
-lemma Max_UNION: 
-  assumes "finite A"
-  and "A \<noteq> {}"
-  and "\<forall> M \<in> f ` A. finite M"
-  and "\<forall> M \<in> f ` A. M \<noteq> {}"
-  shows "Max (\<Union>x\<in> A. f x) = Max (Max ` f ` A)" (is "?L = ?R")
-  using assms[simp]
-proof -
-  have "?L = Max (\<Union>(f ` A))"
-    by (fold Union_image_eq, simp)
-  also have "... = ?R"
-    by (subst Max_Union, simp+)
-  finally show ?thesis .
-qed
-
-lemma max_Max_eq:
-  assumes "finite A"
-    and "A \<noteq> {}"
-    and "x = y"
-  shows "max x (Max A) = Max ({y} \<union> A)" (is "?L = ?R")
-proof -
-  have "?R = Max (insert y A)" by simp
-  also from assms have "... = ?L"
-      by (subst Max.insert, simp+)
-  finally show ?thesis by simp
-qed
-
-lemma birth_time_lt:  
-  assumes "s \<noteq> []"
-  shows "last_set th s < length s"
-  using assms
-proof(induct s)
-  case (Cons a s)
-  show ?case
-  proof(cases "s \<noteq> []")
-    case False
-    thus ?thesis
-      by (cases a, auto)
-  next
-    case True
-    show ?thesis using Cons(1)[OF True]
-      by (cases a, auto)
-  qed
-qed simp
-
-lemma th_in_ne: "th \<in> threads s \<Longrightarrow> s \<noteq> []"
-  by (induct s, auto)
-
-lemma preced_tm_lt: "th \<in> threads s \<Longrightarrow> preced th s = Prc x y \<Longrightarrow> y < length s"
-  by (drule_tac th_in_ne, unfold preced_def, auto intro: birth_time_lt)
-
-lemma eq_RAG: 
-  "RAG (wq s) = RAG s"
-by (unfold cs_RAG_def s_RAG_def, auto)
-
-context valid_trace
-begin
-
-lemma count_eq_dependants:
-  assumes eq_pv: "cntP s th = cntV s th"
-  shows "dependants (wq s) th = {}"
-proof -
-  from cnp_cnv_cncs and eq_pv
-  have "cntCS s th = 0" 
-    by (auto split:if_splits)
-  moreover have "finite {cs. (Cs cs, Th th) \<in> RAG s}"
-  proof -
-    from finite_holding[of th] show ?thesis
-      by (simp add:holdents_test)
-  qed
-  ultimately have h: "{cs. (Cs cs, Th th) \<in> RAG s} = {}"
-    by (unfold cntCS_def holdents_test cs_dependants_def, auto)
-  show ?thesis
-  proof(unfold cs_dependants_def)
-    { assume "{th'. (Th th', Th th) \<in> (RAG (wq s))\<^sup>+} \<noteq> {}"
-      then obtain th' where "(Th th', Th th) \<in> (RAG (wq s))\<^sup>+" by auto
-      hence "False"
-      proof(cases)
-        assume "(Th th', Th th) \<in> RAG (wq s)"
-        thus "False" by (auto simp:cs_RAG_def)
-      next
-        fix c
-        assume "(c, Th th) \<in> RAG (wq s)"
-        with h and eq_RAG show "False"
-          by (cases c, auto simp:cs_RAG_def)
-      qed
-    } thus "{th'. (Th th', Th th) \<in> (RAG (wq s))\<^sup>+} = {}" by auto
-  qed
-qed
-
-lemma dependants_threads:
-  shows "dependants (wq s) th \<subseteq> threads s"
-proof
-  { fix th th'
-    assume h: "th \<in> {th'a. (Th th'a, Th th') \<in> (RAG (wq s))\<^sup>+}"
-    have "Th th \<in> Domain (RAG s)"
-    proof -
-      from h obtain th' where "(Th th, Th th') \<in> (RAG (wq s))\<^sup>+" by auto
-      hence "(Th th) \<in> Domain ( (RAG (wq s))\<^sup>+)" by (auto simp:Domain_def)
-      with trancl_domain have "(Th th) \<in> Domain (RAG (wq s))" by simp
-      thus ?thesis using eq_RAG by simp
-    qed
-    from dm_RAG_threads[OF this]
-    have "th \<in> threads s" .
-  } note hh = this
-  fix th1 
-  assume "th1 \<in> dependants (wq s) th"
-  hence "th1 \<in> {th'a. (Th th'a, Th th) \<in> (RAG (wq s))\<^sup>+}"
-    by (unfold cs_dependants_def, simp)
-  from hh [OF this] show "th1 \<in> threads s" .
-qed
-
-lemma finite_threads:
-  shows "finite (threads s)"
-using vt by (induct) (auto elim: step.cases)
-
-end
-
-lemma Max_f_mono:
-  assumes seq: "A \<subseteq> B"
-  and np: "A \<noteq> {}"
-  and fnt: "finite B"
-  shows "Max (f ` A) \<le> Max (f ` B)"
-proof(rule Max_mono)
-  from seq show "f ` A \<subseteq> f ` B" by auto
-next
-  from np show "f ` A \<noteq> {}" by auto
-next
-  from fnt and seq show "finite (f ` B)" by auto
-qed
-
-context valid_trace
-begin
-
-lemma cp_le:
-  assumes th_in: "th \<in> threads s"
-  shows "cp s th \<le> Max ((\<lambda> th. (preced th s)) ` threads s)"
-proof(unfold cp_eq_cpreced cpreced_def cs_dependants_def)
-  show "Max ((\<lambda>th. preced th s) ` ({th} \<union> {th'. (Th th', Th th) \<in> (RAG (wq s))\<^sup>+}))
-         \<le> Max ((\<lambda>th. preced th s) ` threads s)"
-    (is "Max (?f ` ?A) \<le> Max (?f ` ?B)")
-  proof(rule Max_f_mono)
-    show "{th} \<union> {th'. (Th th', Th th) \<in> (RAG (wq s))\<^sup>+} \<noteq> {}" by simp
-  next
-    from finite_threads
-    show "finite (threads s)" .
-  next
-    from th_in
-    show "{th} \<union> {th'. (Th th', Th th) \<in> (RAG (wq s))\<^sup>+} \<subseteq> threads s"
-      apply (auto simp:Domain_def)
-      apply (rule_tac dm_RAG_threads)
-      apply (unfold trancl_domain [of "RAG s", symmetric])
-      by (unfold cs_RAG_def s_RAG_def, auto simp:Domain_def)
-  qed
-qed
-
-lemma le_cp:
-  shows "preced th s \<le> cp s th"
-proof(unfold cp_eq_cpreced preced_def cpreced_def, simp)
-  show "Prc (priority th s) (last_set th s)
-    \<le> Max (insert (Prc (priority th s) (last_set th s))
-            ((\<lambda>th. Prc (priority th s) (last_set th s)) ` dependants (wq s) th))"
-    (is "?l \<le> Max (insert ?l ?A)")
-  proof(cases "?A = {}")
-    case False
-    have "finite ?A" (is "finite (?f ` ?B)")
-    proof -
-      have "finite ?B" 
-      proof-
-        have "finite {th'. (Th th', Th th) \<in> (RAG (wq s))\<^sup>+}"
-        proof -
-          let ?F = "\<lambda> (x, y). the_th x"
-          have "{th'. (Th th', Th th) \<in> (RAG (wq s))\<^sup>+} \<subseteq> ?F ` ((RAG (wq s))\<^sup>+)"
-            apply (auto simp:image_def)
-            by (rule_tac x = "(Th x, Th th)" in bexI, auto)
-          moreover have "finite \<dots>"
-          proof -
-            from finite_RAG have "finite (RAG s)" .
-            hence "finite ((RAG (wq s))\<^sup>+)"
-              apply (unfold finite_trancl)
-              by (auto simp: s_RAG_def cs_RAG_def wq_def)
-            thus ?thesis by auto
-          qed
-          ultimately show ?thesis by (auto intro:finite_subset)
-        qed
-        thus ?thesis by (simp add:cs_dependants_def)
-      qed
-      thus ?thesis by simp
-    qed
-    from Max_insert [OF this False, of ?l] show ?thesis by auto
-  next
-    case True
-    thus ?thesis by auto
-  qed
-qed
-
-lemma max_cp_eq: 
-  shows "Max ((cp s) ` threads s) = Max ((\<lambda> th. (preced th s)) ` threads s)"
-  (is "?l = ?r")
-proof(cases "threads s = {}")
-  case True
-  thus ?thesis by auto
-next
-  case False
-  have "?l \<in> ((cp s) ` threads s)"
-  proof(rule Max_in)
-    from finite_threads
-    show "finite (cp s ` threads s)" by auto
-  next
-    from False show "cp s ` threads s \<noteq> {}" by auto
-  qed
-  then obtain th 
-    where th_in: "th \<in> threads s" and eq_l: "?l = cp s th" by auto
-  have "\<dots> \<le> ?r" by (rule cp_le[OF th_in])
-  moreover have "?r \<le> cp s th" (is "Max (?f ` ?A) \<le> cp s th")
-  proof -
-    have "?r \<in> (?f ` ?A)"
-    proof(rule Max_in)
-      from finite_threads
-      show " finite ((\<lambda>th. preced th s) ` threads s)" by auto
-    next
-      from False show " (\<lambda>th. preced th s) ` threads s \<noteq> {}" by auto
-    qed
-    then obtain th' where 
-      th_in': "th' \<in> ?A " and eq_r: "?r = ?f th'" by auto
-    from le_cp [of th']  eq_r
-    have "?r \<le> cp s th'" by auto
-    moreover have "\<dots> \<le> cp s th"
-    proof(fold eq_l)
-      show " cp s th' \<le> Max (cp s ` threads s)"
-      proof(rule Max_ge)
-        from th_in' show "cp s th' \<in> cp s ` threads s"
-          by auto
-      next
-        from finite_threads
-        show "finite (cp s ` threads s)" by auto
-      qed
-    qed
-    ultimately show ?thesis by auto
-  qed
-  ultimately show ?thesis using eq_l by auto
-qed
-
-lemma max_cp_readys_threads_pre:
-  assumes np: "threads s \<noteq> {}"
-  shows "Max (cp s ` readys s) = Max (cp s ` threads s)"
-proof(unfold max_cp_eq)
-  show "Max (cp s ` readys s) = Max ((\<lambda>th. preced th s) ` threads s)"
-  proof -
-    let ?p = "Max ((\<lambda>th. preced th s) ` threads s)" 
-    let ?f = "(\<lambda>th. preced th s)"
-    have "?p \<in> ((\<lambda>th. preced th s) ` threads s)"
-    proof(rule Max_in)
-      from finite_threads show "finite (?f ` threads s)" by simp
-    next
-      from np show "?f ` threads s \<noteq> {}" by simp
-    qed
-    then obtain tm where tm_max: "?f tm = ?p" and tm_in: "tm \<in> threads s"
-      by (auto simp:Image_def)
-    from th_chain_to_ready [OF tm_in]
-    have "tm \<in> readys s \<or> (\<exists>th'. th' \<in> readys s \<and> (Th tm, Th th') \<in> (RAG s)\<^sup>+)" .
-    thus ?thesis
-    proof
-      assume "\<exists>th'. th' \<in> readys s \<and> (Th tm, Th th') \<in> (RAG s)\<^sup>+ "
-      then obtain th' where th'_in: "th' \<in> readys s" 
-        and tm_chain:"(Th tm, Th th') \<in> (RAG s)\<^sup>+" by auto
-      have "cp s th' = ?f tm"
-      proof(subst cp_eq_cpreced, subst cpreced_def, rule Max_eqI)
-        from dependants_threads finite_threads
-        show "finite ((\<lambda>th. preced th s) ` ({th'} \<union> dependants (wq s) th'))" 
-          by (auto intro:finite_subset)
-      next
-        fix p assume p_in: "p \<in> (\<lambda>th. preced th s) ` ({th'} \<union> dependants (wq s) th')"
-        from tm_max have " preced tm s = Max ((\<lambda>th. preced th s) ` threads s)" .
-        moreover have "p \<le> \<dots>"
-        proof(rule Max_ge)
-          from finite_threads
-          show "finite ((\<lambda>th. preced th s) ` threads s)" by simp
-        next
-          from p_in and th'_in and dependants_threads[of th']
-          show "p \<in> (\<lambda>th. preced th s) ` threads s"
-            by (auto simp:readys_def)
-        qed
-        ultimately show "p \<le> preced tm s" by auto
-      next
-        show "preced tm s \<in> (\<lambda>th. preced th s) ` ({th'} \<union> dependants (wq s) th')"
-        proof -
-          from tm_chain
-          have "tm \<in> dependants (wq s) th'"
-            by (unfold cs_dependants_def s_RAG_def cs_RAG_def, auto)
-          thus ?thesis by auto
-        qed
-      qed
-      with tm_max
-      have h: "cp s th' = Max ((\<lambda>th. preced th s) ` threads s)" by simp
-      show ?thesis
-      proof (fold h, rule Max_eqI)
-        fix q 
-        assume "q \<in> cp s ` readys s"
-        then obtain th1 where th1_in: "th1 \<in> readys s"
-          and eq_q: "q = cp s th1" by auto
-        show "q \<le> cp s th'"
-          apply (unfold h eq_q)
-          apply (unfold cp_eq_cpreced cpreced_def)
-          apply (rule Max_mono)
-        proof -
-          from dependants_threads [of th1] th1_in
-          show "(\<lambda>th. preced th s) ` ({th1} \<union> dependants (wq s) th1) \<subseteq> 
-                 (\<lambda>th. preced th s) ` threads s"
-            by (auto simp:readys_def)
-        next
-          show "(\<lambda>th. preced th s) ` ({th1} \<union> dependants (wq s) th1) \<noteq> {}" by simp
-        next
-          from finite_threads 
-          show " finite ((\<lambda>th. preced th s) ` threads s)" by simp
-        qed
-      next
-        from finite_threads
-        show "finite (cp s ` readys s)" by (auto simp:readys_def)
-      next
-        from th'_in
-        show "cp s th' \<in> cp s ` readys s" by simp
-      qed
-    next
-      assume tm_ready: "tm \<in> readys s"
-      show ?thesis
-      proof(fold tm_max)
-        have cp_eq_p: "cp s tm = preced tm s"
-        proof(unfold cp_eq_cpreced cpreced_def, rule Max_eqI)
-          fix y 
-          assume hy: "y \<in> (\<lambda>th. preced th s) ` ({tm} \<union> dependants (wq s) tm)"
-          show "y \<le> preced tm s"
-          proof -
-            { fix y'
-              assume hy' : "y' \<in> ((\<lambda>th. preced th s) ` dependants (wq s) tm)"
-              have "y' \<le> preced tm s"
-              proof(unfold tm_max, rule Max_ge)
-                from hy' dependants_threads[of tm]
-                show "y' \<in> (\<lambda>th. preced th s) ` threads s" by auto
-              next
-                from finite_threads
-                show "finite ((\<lambda>th. preced th s) ` threads s)" by simp
-              qed
-            } with hy show ?thesis by auto
-          qed
-        next
-          from dependants_threads[of tm] finite_threads
-          show "finite ((\<lambda>th. preced th s) ` ({tm} \<union> dependants (wq s) tm))"
-            by (auto intro:finite_subset)
-        next
-          show "preced tm s \<in> (\<lambda>th. preced th s) ` ({tm} \<union> dependants (wq s) tm)"
-            by simp
-        qed 
-        moreover have "Max (cp s ` readys s) = cp s tm"
-        proof(rule Max_eqI)
-          from tm_ready show "cp s tm \<in> cp s ` readys s" by simp
-        next
-          from finite_threads
-          show "finite (cp s ` readys s)" by (auto simp:readys_def)
-        next
-          fix y assume "y \<in> cp s ` readys s"
-          then obtain th1 where th1_readys: "th1 \<in> readys s"
-            and h: "y = cp s th1" by auto
-          show "y \<le> cp s tm"
-            apply(unfold cp_eq_p h)
-            apply(unfold cp_eq_cpreced cpreced_def tm_max, rule Max_mono)
-          proof -
-            from finite_threads
-            show "finite ((\<lambda>th. preced th s) ` threads s)" by simp
-          next
-            show "(\<lambda>th. preced th s) ` ({th1} \<union> dependants (wq s) th1) \<noteq> {}"
-              by simp
-          next
-            from dependants_threads[of th1] th1_readys
-            show "(\<lambda>th. preced th s) ` ({th1} \<union> dependants (wq s) th1) 
-                    \<subseteq> (\<lambda>th. preced th s) ` threads s"
-              by (auto simp:readys_def)
-          qed
-        qed
-        ultimately show " Max (cp s ` readys s) = preced tm s" by simp
-      qed 
-    qed
-  qed
-qed
-
-text {* (* ccc *) \noindent
-  Since the current precedence of the threads in ready queue will always be boosted,
-  there must be one inside it has the maximum precedence of the whole system. 
-*}
-lemma max_cp_readys_threads:
-  shows "Max (cp s ` readys s) = Max (cp s ` threads s)"
-proof(cases "threads s = {}")
-  case True
-  thus ?thesis 
-    by (auto simp:readys_def)
-next
-  case False
-  show ?thesis by (rule max_cp_readys_threads_pre[OF False])
-qed
-
-end
-
-lemma eq_holding: "holding (wq s) th cs = holding s th cs"
-  apply (unfold s_holding_def cs_holding_def wq_def, simp)
-  done
-
-lemma f_image_eq:
-  assumes h: "\<And> a. a \<in> A \<Longrightarrow> f a = g a"
-  shows "f ` A = g ` A"
-proof
-  show "f ` A \<subseteq> g ` A"
-    by(rule image_subsetI, auto intro:h)
-next
-  show "g ` A \<subseteq> f ` A"
-   by (rule image_subsetI, auto intro:h[symmetric])
-qed
-
-
-definition detached :: "state \<Rightarrow> thread \<Rightarrow> bool"
-  where "detached s th \<equiv> (\<not>(\<exists> cs. holding s th cs)) \<and> (\<not>(\<exists>cs. waiting s th cs))"
-
-
-lemma detached_test:
-  shows "detached s th = (Th th \<notin> Field (RAG s))"
-apply(simp add: detached_def Field_def)
-apply(simp add: s_RAG_def)
-apply(simp add: s_holding_abv s_waiting_abv)
-apply(simp add: Domain_iff Range_iff)
-apply(simp add: wq_def)
-apply(auto)
-done
-
-context valid_trace
-begin
-
-lemma detached_intro:
-  assumes eq_pv: "cntP s th = cntV s th"
-  shows "detached s th"
-proof -
- from cnp_cnv_cncs
-  have eq_cnt: "cntP s th =
-    cntV s th + (if th \<in> readys s \<or> th \<notin> threads s then cntCS s th else cntCS s th + 1)" .
-  hence cncs_zero: "cntCS s th = 0"
-    by (auto simp:eq_pv split:if_splits)
-  with eq_cnt
-  have "th \<in> readys s \<or> th \<notin> threads s" by (auto simp:eq_pv)
-  thus ?thesis
-  proof
-    assume "th \<notin> threads s"
-    with range_in dm_RAG_threads
-    show ?thesis
-      by (auto simp add: detached_def s_RAG_def s_waiting_abv s_holding_abv wq_def Domain_iff Range_iff)
-  next
-    assume "th \<in> readys s"
-    moreover have "Th th \<notin> Range (RAG s)"
-    proof -
-      from card_0_eq [OF finite_holding] and cncs_zero
-      have "holdents s th = {}"
-        by (simp add:cntCS_def)
-      thus ?thesis
-        apply(auto simp:holdents_test)
-        apply(case_tac a)
-        apply(auto simp:holdents_test s_RAG_def)
-        done
-    qed
-    ultimately show ?thesis
-      by (auto simp add: detached_def s_RAG_def s_waiting_abv s_holding_abv wq_def readys_def)
-  qed
-qed
-
-lemma detached_elim:
-  assumes dtc: "detached s th"
-  shows "cntP s th = cntV s th"
-proof -
-  from cnp_cnv_cncs
-  have eq_pv: " cntP s th =
-    cntV s th + (if th \<in> readys s \<or> th \<notin> threads s then cntCS s th else cntCS s th + 1)" .
-  have cncs_z: "cntCS s th = 0"
-  proof -
-    from dtc have "holdents s th = {}"
-      unfolding detached_def holdents_test s_RAG_def
-      by (simp add: s_waiting_abv wq_def s_holding_abv Domain_iff Range_iff)
-    thus ?thesis by (auto simp:cntCS_def)
-  qed
-  show ?thesis
-  proof(cases "th \<in> threads s")
-    case True
-    with dtc 
-    have "th \<in> readys s"
-      by (unfold readys_def detached_def Field_def Domain_def Range_def, 
-           auto simp:eq_waiting s_RAG_def)
-    with cncs_z and eq_pv show ?thesis by simp
-  next
-    case False
-    with cncs_z and eq_pv show ?thesis by simp
-  qed
-qed
-
-lemma detached_eq:
-  shows "(detached s th) = (cntP s th = cntV s th)"
-  by (insert vt, auto intro:detached_intro detached_elim)
-
-end
-
-text {* 
-  The lemmas in this .thy file are all obvious lemmas, however, they still needs to be derived
-  from the concise and miniature model of PIP given in PrioGDef.thy.
-*}
-
-lemma eq_dependants: "dependants (wq s) = dependants s"
-  by (simp add: s_dependants_abv wq_def)
-
-lemma next_th_unique: 
-  assumes nt1: "next_th s th cs th1"
-  and nt2: "next_th s th cs th2"
-  shows "th1 = th2"
-using assms by (unfold next_th_def, auto)
-
-lemma birth_time_lt:  "s \<noteq> [] \<Longrightarrow> last_set th s < length s"
-  apply (induct s, simp)
-proof -
-  fix a s
-  assume ih: "s \<noteq> [] \<Longrightarrow> last_set th s < length s"
-    and eq_as: "a # s \<noteq> []"
-  show "last_set th (a # s) < length (a # s)"
-  proof(cases "s \<noteq> []")
-    case False
-    from False show ?thesis
-      by (cases a, auto simp:last_set.simps)
-  next
-    case True
-    from ih [OF True] show ?thesis
-      by (cases a, auto simp:last_set.simps)
-  qed
-qed
-
-lemma th_in_ne: "th \<in> threads s \<Longrightarrow> s \<noteq> []"
-  by (induct s, auto simp:threads.simps)
-
-lemma preced_tm_lt: "th \<in> threads s \<Longrightarrow> preced th s = Prc x y \<Longrightarrow> y < length s"
-  apply (drule_tac th_in_ne)
-  by (unfold preced_def, auto intro: birth_time_lt)
-
-lemma inj_the_preced: 
-  "inj_on (the_preced s) (threads s)"
-  by (metis inj_onI preced_unique the_preced_def)
-
-lemma tRAG_alt_def: 
-  "tRAG s = {(Th th1, Th th2) | th1 th2. 
-                  \<exists> cs. (Th th1, Cs cs) \<in> RAG s \<and> (Cs cs, Th th2) \<in> RAG s}"
- by (auto simp:tRAG_def RAG_split wRAG_def hRAG_def)
-
-lemma tRAG_Field:
-  "Field (tRAG s) \<subseteq> Field (RAG s)"
-  by (unfold tRAG_alt_def Field_def, auto)
-
-lemma tRAG_ancestorsE:
-  assumes "x \<in> ancestors (tRAG s) u"
-  obtains th where "x = Th th"
-proof -
-  from assms have "(u, x) \<in> (tRAG s)^+" 
-      by (unfold ancestors_def, auto)
-  from tranclE[OF this] obtain c where "(c, x) \<in> tRAG s" by auto
-  then obtain th where "x = Th th"
-    by (unfold tRAG_alt_def, auto)
-  from that[OF this] show ?thesis .
-qed
-
-lemma tRAG_mono:
-  assumes "RAG s' \<subseteq> RAG s"
-  shows "tRAG s' \<subseteq> tRAG s"
-  using assms 
-  by (unfold tRAG_alt_def, auto)
-
-lemma holding_next_thI:
-  assumes "holding s th cs"
-  and "length (wq s cs) > 1"
-  obtains th' where "next_th s th cs th'"
-proof -
-  from assms(1)[folded eq_holding, unfolded cs_holding_def]
-  have " th \<in> set (wq s cs) \<and> th = hd (wq s cs)" .
-  then obtain rest where h1: "wq s cs = th#rest" 
-    by (cases "wq s cs", auto)
-  with assms(2) have h2: "rest \<noteq> []" by auto
-  let ?th' = "hd (SOME q. distinct q \<and> set q = set rest)"
-  have "next_th s th cs ?th'" using  h1(1) h2 
-    by (unfold next_th_def, auto)
-  from that[OF this] show ?thesis .
-qed
-
-lemma RAG_tRAG_transfer:
-  assumes "vt s'"
-  assumes "RAG s = RAG s' \<union> {(Th th, Cs cs)}"
-  and "(Cs cs, Th th'') \<in> RAG s'"
-  shows "tRAG s = tRAG s' \<union> {(Th th, Th th'')}" (is "?L = ?R")
-proof -
-  interpret vt_s': valid_trace "s'" using assms(1)
-    by (unfold_locales, simp)
-  interpret rtree: rtree "RAG s'"
-  proof
-  show "single_valued (RAG s')"
-  apply (intro_locales)
-    by (unfold single_valued_def, 
-        auto intro:vt_s'.unique_RAG)
-
-  show "acyclic (RAG s')"
-     by (rule vt_s'.acyclic_RAG)
-  qed
-  { fix n1 n2
-    assume "(n1, n2) \<in> ?L"
-    from this[unfolded tRAG_alt_def]
-    obtain th1 th2 cs' where 
-      h: "n1 = Th th1" "n2 = Th th2" 
-         "(Th th1, Cs cs') \<in> RAG s"
-         "(Cs cs', Th th2) \<in> RAG s" by auto
-    from h(4) and assms(2) have cs_in: "(Cs cs', Th th2) \<in> RAG s'" by auto
-    from h(3) and assms(2) 
-    have "(Th th1, Cs cs') = (Th th, Cs cs) \<or> 
-          (Th th1, Cs cs') \<in> RAG s'" by auto
-    hence "(n1, n2) \<in> ?R"
-    proof
-      assume h1: "(Th th1, Cs cs') = (Th th, Cs cs)"
-      hence eq_th1: "th1 = th" by simp
-      moreover have "th2 = th''"
-      proof -
-        from h1 have "cs' = cs" by simp
-        from assms(3) cs_in[unfolded this] rtree.sgv
-        show ?thesis
-          by (unfold single_valued_def, auto)
-      qed
-      ultimately show ?thesis using h(1,2) by auto
-    next
-      assume "(Th th1, Cs cs') \<in> RAG s'"
-      with cs_in have "(Th th1, Th th2) \<in> tRAG s'"
-        by (unfold tRAG_alt_def, auto)
-      from this[folded h(1, 2)] show ?thesis by auto
-    qed
-  } moreover {
-    fix n1 n2
-    assume "(n1, n2) \<in> ?R"
-    hence "(n1, n2) \<in>tRAG s' \<or> (n1, n2) = (Th th, Th th'')" by auto
-    hence "(n1, n2) \<in> ?L" 
-    proof
-      assume "(n1, n2) \<in> tRAG s'"
-      moreover have "... \<subseteq> ?L"
-      proof(rule tRAG_mono)
-        show "RAG s' \<subseteq> RAG s" by (unfold assms(2), auto)
-      qed
-      ultimately show ?thesis by auto
-    next
-      assume eq_n: "(n1, n2) = (Th th, Th th'')"
-      from assms(2, 3) have "(Cs cs, Th th'') \<in> RAG s" by auto
-      moreover have "(Th th, Cs cs) \<in> RAG s" using assms(2) by auto
-      ultimately show ?thesis 
-        by (unfold eq_n tRAG_alt_def, auto)
-    qed
-  } ultimately show ?thesis by auto
-qed
-
-context valid_trace
-begin
-
-lemmas RAG_tRAG_transfer = RAG_tRAG_transfer[OF vt]
-
-end
-
-lemma cp_alt_def:
-  "cp s th =  
-           Max ((the_preced s) ` {th'. Th th' \<in> (subtree (RAG s) (Th th))})"
-proof -
-  have "Max (the_preced s ` ({th} \<union> dependants (wq s) th)) =
-        Max (the_preced s ` {th'. Th th' \<in> subtree (RAG s) (Th th)})" 
-          (is "Max (_ ` ?L) = Max (_ ` ?R)")
-  proof -
-    have "?L = ?R" 
-    by (auto dest:rtranclD simp:cs_dependants_def cs_RAG_def s_RAG_def subtree_def)
-    thus ?thesis by simp
-  qed
-  thus ?thesis by (unfold cp_eq_cpreced cpreced_def, fold the_preced_def, simp)
-qed
-
-lemma cp_gen_alt_def:
-  "cp_gen s = (Max \<circ> (\<lambda>x. (the_preced s \<circ> the_thread) ` subtree (tRAG s) x))"
-    by (auto simp:cp_gen_def)
-
-lemma tRAG_nodeE:
-  assumes "(n1, n2) \<in> tRAG s"
-  obtains th1 th2 where "n1 = Th th1" "n2 = Th th2"
-  using assms
-  by (auto simp: tRAG_def wRAG_def hRAG_def tRAG_def)
-
-lemma subtree_nodeE:
-  assumes "n \<in> subtree (tRAG s) (Th th)"
-  obtains th1 where "n = Th th1"
-proof -
-  show ?thesis
-  proof(rule subtreeE[OF assms])
-    assume "n = Th th"
-    from that[OF this] show ?thesis .
-  next
-    assume "Th th \<in> ancestors (tRAG s) n"
-    hence "(n, Th th) \<in> (tRAG s)^+" by (auto simp:ancestors_def)
-    hence "\<exists> th1. n = Th th1"
-    proof(induct)
-      case (base y)
-      from tRAG_nodeE[OF this] show ?case by metis
-    next
-      case (step y z)
-      thus ?case by auto
-    qed
-    with that show ?thesis by auto
-  qed
-qed
-
-lemma tRAG_star_RAG: "(tRAG s)^* \<subseteq> (RAG s)^*"
-proof -
-  have "(wRAG s O hRAG s)^* \<subseteq> (RAG s O RAG s)^*" 
-    by (rule rtrancl_mono, auto simp:RAG_split)
-  also have "... \<subseteq> ((RAG s)^*)^*"
-    by (rule rtrancl_mono, auto)
-  also have "... = (RAG s)^*" by simp
-  finally show ?thesis by (unfold tRAG_def, simp)
-qed
-
-lemma tRAG_subtree_RAG: "subtree (tRAG s) x \<subseteq> subtree (RAG s) x"
-proof -
-  { fix a
-    assume "a \<in> subtree (tRAG s) x"
-    hence "(a, x) \<in> (tRAG s)^*" by (auto simp:subtree_def)
-    with tRAG_star_RAG[of s]
-    have "(a, x) \<in> (RAG s)^*" by auto
-    hence "a \<in> subtree (RAG s) x" by (auto simp:subtree_def)
-  } thus ?thesis by auto
-qed
-
-lemma tRAG_trancl_eq:
-   "{th'. (Th th', Th th)  \<in> (tRAG s)^+} = 
-    {th'. (Th th', Th th)  \<in> (RAG s)^+}"
-   (is "?L = ?R")
-proof -
-  { fix th'
-    assume "th' \<in> ?L"
-    hence "(Th th', Th th) \<in> (tRAG s)^+" by auto
-    from tranclD[OF this]
-    obtain z where h: "(Th th', z) \<in> tRAG s" "(z, Th th) \<in> (tRAG s)\<^sup>*" by auto
-    from tRAG_subtree_RAG[of s] and this(2)
-    have "(z, Th th) \<in> (RAG s)^*" by (meson subsetCE tRAG_star_RAG) 
-    moreover from h(1) have "(Th th', z) \<in> (RAG s)^+" using tRAG_alt_def by auto 
-    ultimately have "th' \<in> ?R"  by auto 
-  } moreover 
-  { fix th'
-    assume "th' \<in> ?R"
-    hence "(Th th', Th th) \<in> (RAG s)^+" by (auto)
-    from plus_rpath[OF this]
-    obtain xs where rp: "rpath (RAG s) (Th th') xs (Th th)" "xs \<noteq> []" by auto
-    hence "(Th th', Th th) \<in> (tRAG s)^+"
-    proof(induct xs arbitrary:th' th rule:length_induct)
-      case (1 xs th' th)
-      then obtain x1 xs1 where Cons1: "xs = x1#xs1" by (cases xs, auto)
-      show ?case
-      proof(cases "xs1")
-        case Nil
-        from 1(2)[unfolded Cons1 Nil]
-        have rp: "rpath (RAG s) (Th th') [x1] (Th th)" .
-        hence "(Th th', x1) \<in> (RAG s)" by (cases, simp)
-        then obtain cs where "x1 = Cs cs" 
-              by (unfold s_RAG_def, auto)
-        from rpath_nnl_lastE[OF rp[unfolded this]]
-        show ?thesis by auto
-      next
-        case (Cons x2 xs2)
-        from 1(2)[unfolded Cons1[unfolded this]]
-        have rp: "rpath (RAG s) (Th th') (x1 # x2 # xs2) (Th th)" .
-        from rpath_edges_on[OF this]
-        have eds: "edges_on (Th th' # x1 # x2 # xs2) \<subseteq> RAG s" .
-        have "(Th th', x1) \<in> edges_on (Th th' # x1 # x2 # xs2)"
-            by (simp add: edges_on_unfold)
-        with eds have rg1: "(Th th', x1) \<in> RAG s" by auto
-        then obtain cs1 where eq_x1: "x1 = Cs cs1" by (unfold s_RAG_def, auto)
-        have "(x1, x2) \<in> edges_on (Th th' # x1 # x2 # xs2)"
-            by (simp add: edges_on_unfold)
-        from this eds
-        have rg2: "(x1, x2) \<in> RAG s" by auto
-        from this[unfolded eq_x1] 
-        obtain th1 where eq_x2: "x2 = Th th1" by (unfold s_RAG_def, auto)
-        from rg1[unfolded eq_x1] rg2[unfolded eq_x1 eq_x2]
-        have rt1: "(Th th', Th th1) \<in> tRAG s" by (unfold tRAG_alt_def, auto)
-        from rp have "rpath (RAG s) x2 xs2 (Th th)"
-           by  (elim rpath_ConsE, simp)
-        from this[unfolded eq_x2] have rp': "rpath (RAG s) (Th th1) xs2 (Th th)" .
-        show ?thesis
-        proof(cases "xs2 = []")
-          case True
-          from rpath_nilE[OF rp'[unfolded this]]
-          have "th1 = th" by auto
-          from rt1[unfolded this] show ?thesis by auto
-        next
-          case False
-          from 1(1)[rule_format, OF _ rp' this, unfolded Cons1 Cons]
-          have "(Th th1, Th th) \<in> (tRAG s)\<^sup>+" by simp
-          with rt1 show ?thesis by auto
-        qed
-      qed
-    qed
-    hence "th' \<in> ?L" by auto
-  } ultimately show ?thesis by blast
-qed
-
-lemma tRAG_trancl_eq_Th:
-   "{Th th' | th'. (Th th', Th th)  \<in> (tRAG s)^+} = 
-    {Th th' | th'. (Th th', Th th)  \<in> (RAG s)^+}"
-    using tRAG_trancl_eq by auto
-
-lemma dependants_alt_def:
-  "dependants s th = {th'. (Th th', Th th) \<in> (tRAG s)^+}"
-  by (metis eq_RAG s_dependants_def tRAG_trancl_eq)
-  
-context valid_trace
-begin
-
-lemma count_eq_tRAG_plus:
-  assumes "cntP s th = cntV s th"
-  shows "{th'. (Th th', Th th) \<in> (tRAG s)^+} = {}"
-  using assms count_eq_dependants dependants_alt_def eq_dependants by auto 
-
-lemma count_eq_RAG_plus:
-  assumes "cntP s th = cntV s th"
-  shows "{th'. (Th th', Th th) \<in> (RAG s)^+} = {}"
-  using assms count_eq_dependants cs_dependants_def eq_RAG by auto
-
-lemma count_eq_RAG_plus_Th:
-  assumes "cntP s th = cntV s th"
-  shows "{Th th' | th'. (Th th', Th th) \<in> (RAG s)^+} = {}"
-  using count_eq_RAG_plus[OF assms] by auto
-
-lemma count_eq_tRAG_plus_Th:
-  assumes "cntP s th = cntV s th"
-  shows "{Th th' | th'. (Th th', Th th) \<in> (tRAG s)^+} = {}"
-   using count_eq_tRAG_plus[OF assms] by auto
-
-end
-
-lemma tRAG_subtree_eq: 
-   "(subtree (tRAG s) (Th th)) = {Th th' | th'. Th th'  \<in> (subtree (RAG s) (Th th))}"
-   (is "?L = ?R")
-proof -
-  { fix n 
-    assume h: "n \<in> ?L"
-    hence "n \<in> ?R"
-    by (smt mem_Collect_eq subsetCE subtree_def subtree_nodeE tRAG_subtree_RAG) 
-  } moreover {
-    fix n
-    assume "n \<in> ?R"
-    then obtain th' where h: "n = Th th'" "(Th th', Th th) \<in> (RAG s)^*"
-      by (auto simp:subtree_def)
-    from rtranclD[OF this(2)]
-    have "n \<in> ?L"
-    proof
-      assume "Th th' \<noteq> Th th \<and> (Th th', Th th) \<in> (RAG s)\<^sup>+"
-      with h have "n \<in> {Th th' | th'. (Th th', Th th)  \<in> (RAG s)^+}" by auto
-      thus ?thesis using subtree_def tRAG_trancl_eq by fastforce
-    qed (insert h, auto simp:subtree_def)
-  } ultimately show ?thesis by auto
-qed
-
-lemma threads_set_eq: 
-   "the_thread ` (subtree (tRAG s) (Th th)) = 
-                  {th'. Th th' \<in> (subtree (RAG s) (Th th))}" (is "?L = ?R")
-   by (auto intro:rev_image_eqI simp:tRAG_subtree_eq)
-
-lemma cp_alt_def1: 
-  "cp s th = Max ((the_preced s o the_thread) ` (subtree (tRAG s) (Th th)))"
-proof -
-  have "(the_preced s ` the_thread ` subtree (tRAG s) (Th th)) =
-       ((the_preced s \<circ> the_thread) ` subtree (tRAG s) (Th th))"
-       by auto
-  thus ?thesis by (unfold cp_alt_def, fold threads_set_eq, auto)
-qed
-
-lemma cp_gen_def_cond: 
-  assumes "x = Th th"
-  shows "cp s th = cp_gen s (Th th)"
-by (unfold cp_alt_def1 cp_gen_def, simp)
-
-lemma cp_gen_over_set:
-  assumes "\<forall> x \<in> A. \<exists> th. x = Th th"
-  shows "cp_gen s ` A = (cp s \<circ> the_thread) ` A"
-proof(rule f_image_eq)
-  fix a
-  assume "a \<in> A"
-  from assms[rule_format, OF this]
-  obtain th where eq_a: "a = Th th" by auto
-  show "cp_gen s a = (cp s \<circ> the_thread) a"
-    by  (unfold eq_a, simp, unfold cp_gen_def_cond[OF refl[of "Th th"]], simp)
-qed
-
-
-context valid_trace
-begin
-
-lemma RAG_threads:
-  assumes "(Th th) \<in> Field (RAG s)"
-  shows "th \<in> threads s"
-  using assms
-  by (metis Field_def UnE dm_RAG_threads range_in vt)
-
-lemma subtree_tRAG_thread:
-  assumes "th \<in> threads s"
-  shows "subtree (tRAG s) (Th th) \<subseteq> Th ` threads s" (is "?L \<subseteq> ?R")
-proof -
-  have "?L = {Th th' |th'. Th th' \<in> subtree (RAG s) (Th th)}"
-    by (unfold tRAG_subtree_eq, simp)
-  also have "... \<subseteq> ?R"
-  proof
-    fix x
-    assume "x \<in> {Th th' |th'. Th th' \<in> subtree (RAG s) (Th th)}"
-    then obtain th' where h: "x = Th th'" "Th th' \<in> subtree (RAG s) (Th th)" by auto
-    from this(2)
-    show "x \<in> ?R"
-    proof(cases rule:subtreeE)
-      case 1
-      thus ?thesis by (simp add: assms h(1)) 
-    next
-      case 2
-      thus ?thesis by (metis ancestors_Field dm_RAG_threads h(1) image_eqI) 
-    qed
-  qed
-  finally show ?thesis .
-qed
-
-lemma readys_root:
-  assumes "th \<in> readys s"
-  shows "root (RAG s) (Th th)"
-proof -
-  { fix x
-    assume "x \<in> ancestors (RAG s) (Th th)"
-    hence h: "(Th th, x) \<in> (RAG s)^+" by (auto simp:ancestors_def)
-    from tranclD[OF this]
-    obtain z where "(Th th, z) \<in> RAG s" by auto
-    with assms(1) have False
-         apply (case_tac z, auto simp:readys_def s_RAG_def s_waiting_def cs_waiting_def)
-         by (fold wq_def, blast)
-  } thus ?thesis by (unfold root_def, auto)
-qed
-
-lemma readys_in_no_subtree:
-  assumes "th \<in> readys s"
-  and "th' \<noteq> th"
-  shows "Th th \<notin> subtree (RAG s) (Th th')" 
-proof
-   assume "Th th \<in> subtree (RAG s) (Th th')"
-   thus False
-   proof(cases rule:subtreeE)
-      case 1
-      with assms show ?thesis by auto
-   next
-      case 2
-      with readys_root[OF assms(1)]
-      show ?thesis by (auto simp:root_def)
-   qed
-qed
-
-lemma not_in_thread_isolated:
-  assumes "th \<notin> threads s"
-  shows "(Th th) \<notin> Field (RAG s)"
-proof
-  assume "(Th th) \<in> Field (RAG s)"
-  with dm_RAG_threads and range_in assms
-  show False by (unfold Field_def, blast)
-qed
-
-lemma wf_RAG: "wf (RAG s)"
-proof(rule finite_acyclic_wf)
-  from finite_RAG show "finite (RAG s)" .
-next
-  from acyclic_RAG show "acyclic (RAG s)" .
-qed
-
-lemma sgv_wRAG: "single_valued (wRAG s)"
-  using waiting_unique
-  by (unfold single_valued_def wRAG_def, auto)
-
-lemma sgv_hRAG: "single_valued (hRAG s)"
-  using holding_unique 
-  by (unfold single_valued_def hRAG_def, auto)
-
-lemma sgv_tRAG: "single_valued (tRAG s)"
-  by (unfold tRAG_def, rule single_valued_relcomp, 
-              insert sgv_wRAG sgv_hRAG, auto)
-
-lemma acyclic_tRAG: "acyclic (tRAG s)"
-proof(unfold tRAG_def, rule acyclic_compose)
-  show "acyclic (RAG s)" using acyclic_RAG .
-next
-  show "wRAG s \<subseteq> RAG s" unfolding RAG_split by auto
-next
-  show "hRAG s \<subseteq> RAG s" unfolding RAG_split by auto
-qed
-
-lemma sgv_RAG: "single_valued (RAG s)"
-  using unique_RAG by (auto simp:single_valued_def)
-
-lemma rtree_RAG: "rtree (RAG s)"
-  using sgv_RAG acyclic_RAG
-  by (unfold rtree_def rtree_axioms_def sgv_def, auto)
-
-end
-
-sublocale valid_trace < rtree_RAG: rtree "RAG s"
-proof
-  show "single_valued (RAG s)"
-  apply (intro_locales)
-    by (unfold single_valued_def, 
-        auto intro:unique_RAG)
-
-  show "acyclic (RAG s)"
-     by (rule acyclic_RAG)
-qed
-
-sublocale valid_trace < rtree_s: rtree "tRAG s"
-proof(unfold_locales)
-  from sgv_tRAG show "single_valued (tRAG s)" .
-next
-  from acyclic_tRAG show "acyclic (tRAG s)" .
-qed
-
-sublocale valid_trace < fsbtRAGs : fsubtree "RAG s"
-proof -
-  show "fsubtree (RAG s)"
-  proof(intro_locales)
-    show "fbranch (RAG s)" using finite_fbranchI[OF finite_RAG] .
-  next
-    show "fsubtree_axioms (RAG s)"
-    proof(unfold fsubtree_axioms_def)
-      from wf_RAG show "wf (RAG s)" .
-    qed
-  qed
-qed
-
-sublocale valid_trace < fsbttRAGs: fsubtree "tRAG s"
-proof -
-  have "fsubtree (tRAG s)"
-  proof -
-    have "fbranch (tRAG s)"
-    proof(unfold tRAG_def, rule fbranch_compose)
-        show "fbranch (wRAG s)"
-        proof(rule finite_fbranchI)
-           from finite_RAG show "finite (wRAG s)"
-           by (unfold RAG_split, auto)
-        qed
-    next
-        show "fbranch (hRAG s)"
-        proof(rule finite_fbranchI)
-           from finite_RAG 
-           show "finite (hRAG s)" by (unfold RAG_split, auto)
-        qed
-    qed
-    moreover have "wf (tRAG s)"
-    proof(rule wf_subset)
-      show "wf (RAG s O RAG s)" using wf_RAG
-        by (fold wf_comp_self, simp)
-    next
-      show "tRAG s \<subseteq> (RAG s O RAG s)"
-        by (unfold tRAG_alt_def, auto)
-    qed
-    ultimately show ?thesis
-      by (unfold fsubtree_def fsubtree_axioms_def,auto)
-  qed
-  from this[folded tRAG_def] show "fsubtree (tRAG s)" .
-qed
-
-lemma Max_UNION: 
-  assumes "finite A"
-  and "A \<noteq> {}"
-  and "\<forall> M \<in> f ` A. finite M"
-  and "\<forall> M \<in> f ` A. M \<noteq> {}"
-  shows "Max (\<Union>x\<in> A. f x) = Max (Max ` f ` A)" (is "?L = ?R")
-  using assms[simp]
-proof -
-  have "?L = Max (\<Union>(f ` A))"
-    by (fold Union_image_eq, simp)
-  also have "... = ?R"
-    by (subst Max_Union, simp+)
-  finally show ?thesis .
-qed
-
-lemma max_Max_eq:
-  assumes "finite A"
-    and "A \<noteq> {}"
-    and "x = y"
-  shows "max x (Max A) = Max ({y} \<union> A)" (is "?L = ?R")
-proof -
-  have "?R = Max (insert y A)" by simp
-  also from assms have "... = ?L"
-      by (subst Max.insert, simp+)
-  finally show ?thesis by simp
-qed
-
-context valid_trace
-begin
-
-(* ddd *)
-lemma cp_gen_rec:
-  assumes "x = Th th"
-  shows "cp_gen s x = Max ({the_preced s th} \<union> (cp_gen s) ` children (tRAG s) x)"
-proof(cases "children (tRAG s) x = {}")
-  case True
-  show ?thesis
-    by (unfold True cp_gen_def subtree_children, simp add:assms)
-next
-  case False
-  hence [simp]: "children (tRAG s) x \<noteq> {}" by auto
-  note fsbttRAGs.finite_subtree[simp]
-  have [simp]: "finite (children (tRAG s) x)"
-     by (intro rev_finite_subset[OF fsbttRAGs.finite_subtree], 
-            rule children_subtree)
-  { fix r x
-    have "subtree r x \<noteq> {}" by (auto simp:subtree_def)
-  } note this[simp]
-  have [simp]: "\<exists>x\<in>children (tRAG s) x. subtree (tRAG s) x \<noteq> {}"
-  proof -
-    from False obtain q where "q \<in> children (tRAG s) x" by blast
-    moreover have "subtree (tRAG s) q \<noteq> {}" by simp
-    ultimately show ?thesis by blast
-  qed
-  have h: "Max ((the_preced s \<circ> the_thread) `
-                ({x} \<union> \<Union>(subtree (tRAG s) ` children (tRAG s) x))) =
-        Max ({the_preced s th} \<union> cp_gen s ` children (tRAG s) x)"
-                     (is "?L = ?R")
-  proof -
-    let "Max (?f ` (?A \<union> \<Union> (?g ` ?B)))" = ?L
-    let "Max (_ \<union> (?h ` ?B))" = ?R
-    let ?L1 = "?f ` \<Union>(?g ` ?B)"
-    have eq_Max_L1: "Max ?L1 = Max (?h ` ?B)"
-    proof -
-      have "?L1 = ?f ` (\<Union> x \<in> ?B.(?g x))" by simp
-      also have "... =  (\<Union> x \<in> ?B. ?f ` (?g x))" by auto
-      finally have "Max ?L1 = Max ..." by simp
-      also have "... = Max (Max ` (\<lambda>x. ?f ` subtree (tRAG s) x) ` ?B)"
-        by (subst Max_UNION, simp+)
-      also have "... = Max (cp_gen s ` children (tRAG s) x)"
-          by (unfold image_comp cp_gen_alt_def, simp)
-      finally show ?thesis .
-    qed
-    show ?thesis
-    proof -
-      have "?L = Max (?f ` ?A \<union> ?L1)" by simp
-      also have "... = max (the_preced s (the_thread x)) (Max ?L1)"
-            by (subst Max_Un, simp+)
-      also have "... = max (?f x) (Max (?h ` ?B))"
-        by (unfold eq_Max_L1, simp)
-      also have "... =?R"
-        by (rule max_Max_eq, (simp)+, unfold assms, simp)
-      finally show ?thesis .
-    qed
-  qed  thus ?thesis 
-          by (fold h subtree_children, unfold cp_gen_def, simp) 
-qed
-
-lemma cp_rec:
-  "cp s th = Max ({the_preced s th} \<union> 
-                     (cp s o the_thread) ` children (tRAG s) (Th th))"
-proof -
-  have "Th th = Th th" by simp
-  note h =  cp_gen_def_cond[OF this] cp_gen_rec[OF this]
-  show ?thesis 
-  proof -
-    have "cp_gen s ` children (tRAG s) (Th th) = 
-                (cp s \<circ> the_thread) ` children (tRAG s) (Th th)"
-    proof(rule cp_gen_over_set)
-      show " \<forall>x\<in>children (tRAG s) (Th th). \<exists>th. x = Th th"
-        by (unfold tRAG_alt_def, auto simp:children_def)
-    qed
-    thus ?thesis by (subst (1) h(1), unfold h(2), simp)
-  qed
-qed
-
-end
-
-(* keep *)
-lemma next_th_holding:
-  assumes vt: "vt s"
-  and nxt: "next_th s th cs th'"
-  shows "holding (wq s) th cs"
-proof -
-  from nxt[unfolded next_th_def]
-  obtain rest where h: "wq s cs = th # rest"
-                       "rest \<noteq> []" 
-                       "th' = hd (SOME q. distinct q \<and> set q = set rest)" by auto
-  thus ?thesis
-    by (unfold cs_holding_def, auto)
-qed
-
-lemma tRAG_alt_def: 
-  "tRAG s = {(Th th1, Th th2) | th1 th2. 
-                  \<exists> cs. (Th th1, Cs cs) \<in> RAG s \<and> (Cs cs, Th th2) \<in> RAG s}"
- by (auto simp:tRAG_def RAG_split wRAG_def hRAG_def)
-
-sublocale valid_trace < fsbttRAGs: fsubtree "tRAG s"
-proof -
-  have "fsubtree (tRAG s)"
-  proof -
-    have "fbranch (tRAG s)"
-    proof(unfold tRAG_def, rule fbranch_compose)
-        show "fbranch (wRAG s)"
-        proof(rule finite_fbranchI)
-           from finite_RAG show "finite (wRAG s)"
-           by (unfold RAG_split, auto)
-        qed
-    next
-        show "fbranch (hRAG s)"
-        proof(rule finite_fbranchI)
-           from finite_RAG 
-           show "finite (hRAG s)" by (unfold RAG_split, auto)
-        qed
-    qed
-    moreover have "wf (tRAG s)"
-    proof(rule wf_subset)
-      show "wf (RAG s O RAG s)" using wf_RAG
-        by (fold wf_comp_self, simp)
-    next
-      show "tRAG s \<subseteq> (RAG s O RAG s)"
-        by (unfold tRAG_alt_def, auto)
-    qed
-    ultimately show ?thesis
-      by (unfold fsubtree_def fsubtree_axioms_def,auto)
-  qed
-  from this[folded tRAG_def] show "fsubtree (tRAG s)" .
-qed
-
-
-context valid_trace
-begin
-
-lemma next_th_waiting:
-  assumes nxt: "next_th s th cs th'"
-  shows "waiting (wq s) th' cs"
-proof -
-  from nxt[unfolded next_th_def]
-  obtain rest where h: "wq s cs = th # rest"
-                       "rest \<noteq> []" 
-                       "th' = hd (SOME q. distinct q \<and> set q = set rest)" by auto
-  from wq_distinct[of cs, unfolded h]
-  have dst: "distinct (th # rest)" .
-  have in_rest: "th' \<in> set rest"
-  proof(unfold h, rule someI2)
-    show "distinct rest \<and> set rest = set rest" using dst by auto
-  next
-    fix x assume "distinct x \<and> set x = set rest"
-    with h(2)
-    show "hd x \<in> set (rest)" by (cases x, auto)
-  qed
-  hence "th' \<in> set (wq s cs)" by (unfold h(1), auto)
-  moreover have "th' \<noteq> hd (wq s cs)"
-    by (unfold h(1), insert in_rest dst, auto)
-  ultimately show ?thesis by (auto simp:cs_waiting_def)
-qed
-
-lemma next_th_RAG:
-  assumes nxt: "next_th (s::event list) th cs th'"
-  shows "{(Cs cs, Th th), (Th th', Cs cs)} \<subseteq> RAG s"
-  using vt assms next_th_holding next_th_waiting
-  by (unfold s_RAG_def, simp)
-
-end
-
--- {* A useless definition *}
-definition cps:: "state \<Rightarrow> (thread \<times> precedence) set"
-where "cps s = {(th, cp s th) | th . th \<in> threads s}"
-
-end