CpsG.thy updated. It is a copy of PIPBasics.thy under drastic improvement.
authorzhangx
Sat, 16 Jan 2016 10:59:03 +0800
changeset 77 d37703e0c5c4
parent 74 83ba2d8c859a
child 78 df0334468335
CpsG.thy updated. It is a copy of PIPBasics.thy under drastic improvement.
CpsG.thy~
PIPBasics.thy
PIPBasics.thy~
PIPDefs.thy~
--- a/CpsG.thy~	Thu Jan 14 00:55:54 2016 +0800
+++ b/CpsG.thy~	Sat Jan 16 10:59:03 2016 +0800
@@ -2,6 +2,19 @@
 imports PIPDefs 
 begin
 
+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
+
 (* I am going to use this file as a start point to retrofiting 
    PIPBasics.thy, which is originally called CpsG.ghy *)
 
@@ -9,6 +22,14 @@
   fixes s
   assumes vt : "vt s"
 
+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)
+
+thm s_waiting_def cs_waiting_def wq_def
+
 locale valid_trace_e = valid_trace +
   fixes e
   assumes vt_e: "vt (e#s)"
@@ -224,78 +245,6 @@
 
 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
@@ -369,7 +318,7 @@
   make any request and get blocked the second time: Contradiction.
 *}
 
-lemma waiting_unique_pre: (* ccc *)
+lemma waiting_unique_pre: (* ddd *)
   assumes h11: "thread \<in> set (wq s cs1)"
   and h12: "thread \<noteq> hd (wq s cs1)"
   assumes h21: "thread \<in> set (wq s cs2)"
@@ -402,55 +351,76 @@
       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
+  { fix t1 t2 cs1 cs2
+    assume  lt1: "t1 < length s"
+    and np1: "\<not> ?Q cs1 (moment t1 s)"
+    and nn1: "(\<forall>i'>t1. ?Q cs1 (moment i' s))"
+    and lt2: "t2 < length s"
+    and np2: "\<not> ?Q cs2 (moment t2 s)"
+    and nn2: "(\<forall>i'>t2. ?Q cs2 (moment i' s))"
+    and 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"
+    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
+    have ?thesis
+    proof -
+      have "thread \<in> runing (moment t2 s)"
       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
+        have "e = V thread cs2"
+        proof -
+          have eq_th: "thread = hd (wq (moment t2 s) cs2)" 
+              using True and np2  by auto 
+          from vt_e.wq_out_inv[OF True this h2]
+          show ?thesis .
+        qed
+        thus ?thesis using vt_e.actor_inv[OF vt_e.pip_e] 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)
+        have "e = P thread cs2" using vt_e.wq_in_inv[OF False h1] .
+        with vt_e.actor_inv[OF vt_e.pip_e]
+        show ?thesis by auto
       qed
-  }
+      moreover have "thread \<notin> runing (moment t2 s)"
+        by (rule q_not_runing[OF nn1[rule_format, OF lt12]])
+      ultimately show ?thesis by simp
+    qed
+  } note lt_case = this
   show ?thesis
   proof -
-    { 
-      assume lt12: "t1 < t2"
+    { assume "t1 < t2"
+      from lt_case[OF lt1 np1 nn1 lt2 np2 nn2 this]
+      have ?thesis .
+    } moreover {
+      assume "t2 < t1"
+      from lt_case[OF lt2 np2 nn2 lt1 np1 nn1 this]
+      have ?thesis .
+    } moreover {
+      assume eq_12: "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
+      have lt_2: "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
+      from nn1[rule_format, OF lt_2[folded eq_12]] eq_m[folded eq_12]
+      have g1: "thread \<in> set (wq (e#moment t1 s) cs1)" and
+           g2: "thread \<noteq> hd (wq (e#moment t1 s) cs1)" by auto
       have "vt (e#moment t2 s)"
       proof -
         from vt_moment 
@@ -458,119 +428,38 @@
         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
+          by (unfold_locales, auto, cases, simp)
+      have "e = V thread cs2 \<or> e = P thread cs2"
       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
+        have "e = V thread cs2"
+        proof -
+          have eq_th: "thread = hd (wq (moment t2 s) cs2)" 
+              using True and np2  by auto 
+          from vt_e.wq_out_inv[OF True this h2]
+          show ?thesis .
+        qed
+        thus ?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)
+        have "e = P thread cs2" using vt_e.wq_in_inv[OF False h1] .
+        thus ?thesis by 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
+      moreover have "e = V thread cs1 \<or> e = P thread cs1"
       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
+        have eq_th: "thread = hd (wq (moment t1 s) cs1)" 
+              using True and np1  by auto 
+        from vt_e.wq_out_inv[folded eq_12, OF True this g2]
+        have "e = V thread cs1" .
+        thus ?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
+        have "e = P thread cs1" using vt_e.wq_in_inv[folded eq_12, OF False g1] .
+        thus ?thesis by auto
       qed
-    } ultimately show ?thesis by arith
+      ultimately have ?thesis using neq12 by auto
+    } ultimately show ?thesis using nat_neq_iff by blast 
   qed
 qed
 
@@ -582,9 +471,9 @@
   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
+  using waiting_unique_pre assms
+  unfolding wq_def s_waiting_def
+  by auto
 
 end
 
@@ -621,7 +510,7 @@
   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"
@@ -633,7 +522,7 @@
   thus ?thesis by auto
 qed
 
-(* An aux lemma used later *)
+(* 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"
@@ -743,284 +632,758 @@
 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"
+context valid_trace
+begin
+
+lemma finite_threads:
+  shows "finite (threads s)"
+using vt by (induct) (auto elim: step.cases)
+
+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
+
+lemma RAG_target_th: "(Th th, x) \<in> RAG (s::state) \<Longrightarrow> \<exists> cs. x = Cs cs"
+  by (unfold s_RAG_def, auto)
+
+lemma wq_threads: 
+  assumes h: "th \<in> set (wq s cs)"
+  shows "th \<in> threads s"
 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)
+ 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 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
+    case vt_nil
+    thus ?case by (auto simp:wq_def)
+  qed
+qed
+
+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
+
+
+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
 
-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")
+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
-    with nw wt show ?thesis
-      by (auto simp:cs_waiting_def wq_def Let_def)
+    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
-    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
+    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
-      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"
+      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
-      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)
+      next
+        from finite_threads
+        show "finite (cp s ` threads s)" by auto
       qed
     qed
-    with True show ?thesis by simp
+    ultimately show ?thesis by auto
+  qed
+  ultimately show ?thesis using eq_l by auto
+qed
+
+lemma max_cp_eq_the_preced:
+  shows "Max ((cp s) ` threads s) = Max (the_preced s ` threads s)"
+  using max_cp_eq using the_preced_def by presburger 
+
+end
+
+lemma preced_v [simp]: "preced th' (V th cs#s) = preced th' s"
+  by (unfold preced_def, simp)
+
+lemma the_preced_v[simp]: "the_preced (V th cs#s) = the_preced s"
+proof
+  fix th'
+  show "the_preced (V th cs # s) th' = the_preced s th'"
+    by (unfold the_preced_def preced_def, simp)
+qed
+
+locale valid_trace_v = valid_trace_e + 
+  fixes th cs
+  assumes is_v: "e = V th cs"
+
+context valid_trace_v
+begin
+
+definition "rest = tl (wq s cs)"
+
+definition "wq' = (SOME q. distinct q \<and> set q = set rest)"
+
+lemma distinct_rest: "distinct rest"
+  by (simp add: distinct_tl rest_def wq_distinct)
+
+lemma runing_th_s:
+  shows "th \<in> runing s"
+proof -
+  from pip_e[unfolded is_v]
+  show ?thesis by (cases, simp)
+qed
+
+lemma holding_cs_eq_th:
+  assumes "holding s t cs"
+  shows "t = th"
+proof -
+  from pip_e[unfolded is_v]
+  show ?thesis
+  proof(cases)
+    case (thread_V)
+    from held_unique[OF this(2) assms]
+    show ?thesis by simp
+  qed
+qed
+
+lemma th_not_waiting: 
+  "\<not> waiting s th c"
+proof -
+  have "th \<in> readys s"
+    using runing_ready runing_th_s by blast 
+  thus ?thesis
+    by (unfold readys_def, auto)
+qed
+
+lemma waiting_neq_th: 
+  assumes "waiting s t c"
+  shows "t \<noteq> th"
+  using assms using th_not_waiting by blast 
+
+lemma wq_s_cs:
+  "wq s cs = th#rest"
+proof -
+  from pip_e[unfolded is_v]
+  show ?thesis
+  proof(cases)
+    case (thread_V)
+    from this(2) show ?thesis
+      by (unfold rest_def s_holding_def, fold wq_def,
+                 metis empty_iff list.collapse list.set(1))
+  qed
+qed
+
+lemma wq_es_cs:
+  "wq (e#s) cs = wq'"
+ using wq_s_cs[unfolded wq_def]
+ by (auto simp:Let_def wq_def rest_def wq'_def is_v, simp) 
+
+lemma distinct_wq': "distinct wq'"
+  by (metis (mono_tags, lifting) distinct_rest  some_eq_ex wq'_def)
+  
+lemma th'_in_inv:
+  assumes "th' \<in> set wq'"
+  shows "th' \<in> set rest"
+  using assms
+  by (metis (mono_tags, lifting) distinct.simps(2) 
+        rest_def some_eq_ex wq'_def wq_distinct wq_s_cs) 
+
+lemma neq_t_th: 
+  assumes "waiting (e#s) t c"
+  shows "t \<noteq> th"
+proof
+  assume otherwise: "t = th"
+  show False
+  proof(cases "c = cs")
+    case True
+    have "t \<in> set wq'" 
+     using assms[unfolded True s_waiting_def, folded wq_def, unfolded wq_es_cs]
+     by simp 
+    from th'_in_inv[OF this] have "t \<in> set rest" .
+    with wq_s_cs[folded otherwise] wq_distinct[of cs]
+    show ?thesis by simp
+  next
+    case False
+    have "wq (e#s) c = wq s c" using False
+        by (unfold is_v, simp)
+    hence "waiting s t c" using assms 
+        by (simp add: cs_waiting_def waiting_eq)
+    hence "t \<notin> readys s" by (unfold readys_def, auto)
+    hence "t \<notin> runing s" using runing_ready by auto 
+    with runing_th_s[folded otherwise] show ?thesis by auto
   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"
+lemma waiting_esI1:
+  assumes "waiting s t c"
+      and "c \<noteq> cs" 
+  shows "waiting (e#s) t c" 
+proof -
+  have "wq (e#s) c = wq s c" 
+    using assms(2) is_v by auto
+  with assms(1) show ?thesis 
+    using cs_waiting_def waiting_eq by auto 
+qed
+
+lemma holding_esI2:
+  assumes "c \<noteq> cs" 
+  and "holding s t c"
+  shows "holding (e#s) t c"
+proof -
+  from assms(1) have "wq (e#s) c = wq s c" using is_v by auto
+  from assms(2)[unfolded s_holding_def, folded wq_def, 
+                folded this, unfolded wq_def, folded s_holding_def]
+  show ?thesis .
+qed
+
+end
+
+locale valid_trace_v_n = valid_trace_v +
+  assumes rest_nnl: "rest \<noteq> []"
+begin
+
+lemma neq_wq': "wq' \<noteq> []" 
+proof (unfold wq'_def, rule someI2)
+  show "distinct rest \<and> set rest = set rest"
+    by (simp add: distinct_rest) 
+next
+  fix x
+  assume " distinct x \<and> set x = set rest" 
+  thus "x \<noteq> []" using rest_nnl by auto
+qed 
+
+definition "taker = hd wq'"
+
+definition "rest' = tl wq'"
+
+lemma eq_wq': "wq' = taker # rest'"
+  by (simp add: neq_wq' rest'_def taker_def)
+
+lemma next_th_taker: 
+  shows "next_th s th cs taker"
+  using rest_nnl taker_def wq'_def wq_s_cs 
+  by (auto simp:next_th_def)
+
+lemma taker_unique: 
+  assumes "next_th s th cs taker'"
+  shows "taker' = taker"
+proof -
+  from assms
+  obtain rest' where 
+    h: "wq s cs = th # rest'" 
+       "taker' = hd (SOME q. distinct q \<and> set q = set rest')"
+          by (unfold next_th_def, auto)
+  with wq_s_cs have "rest' = rest" by auto
+  thus ?thesis using h(2) taker_def wq'_def by auto 
+qed
+
+lemma waiting_set_eq:
+  "{(Th th', Cs cs) |th'. next_th s th cs th'} = {(Th taker, Cs cs)}"
+  by (smt all_not_in_conv bot.extremum insertI1 insert_subset 
+      mem_Collect_eq next_th_taker subsetI subset_antisym taker_def taker_unique)
+
+lemma holding_set_eq:
+  "{(Cs cs, Th th') |th'.  next_th s th cs th'} = {(Cs cs, Th taker)}"
+  using next_th_taker taker_def waiting_set_eq 
+  by fastforce
+   
+lemma holding_taker:
+  shows "holding (e#s) taker cs"
+    by (unfold s_holding_def, fold wq_def, unfold wq_es_cs, 
+        auto simp:neq_wq' taker_def)
+
+lemma waiting_esI2:
+  assumes "waiting s t cs"
+      and "t \<noteq> taker"
+  shows "waiting (e#s) t cs" 
+proof -
+  have "t \<in> set wq'" 
+  proof(unfold wq'_def, rule someI2)
+    show "distinct rest \<and> set rest = set rest"
+          by (simp add: distinct_rest)
+  next
+    fix x
+    assume "distinct x \<and> set x = set rest"
+    moreover have "t \<in> set rest"
+        using assms(1) cs_waiting_def waiting_eq wq_s_cs by auto 
+    ultimately show "t \<in> set x" by simp
+  qed
+  moreover have "t \<noteq> hd wq'"
+    using assms(2) taker_def by auto 
+  ultimately show ?thesis
+    by (unfold s_waiting_def, fold wq_def, unfold wq_es_cs, simp)
+qed
+
+lemma waiting_esE:
+  assumes "waiting (e#s) t c" 
+  obtains "c \<noteq> cs" "waiting s t c"
+     |    "c = cs" "t \<noteq> taker" "waiting s t cs" "t \<in> set rest'"
+proof(cases "c = cs")
+  case False
+  hence "wq (e#s) c = wq s c" using is_v by auto
+  with assms have "waiting s t c" using cs_waiting_def waiting_eq by auto 
+  from that(1)[OF False this] show ?thesis .
+next
+  case True
+  from assms[unfolded s_waiting_def True, folded wq_def, unfolded wq_es_cs]
+  have "t \<noteq> hd wq'" "t \<in> set wq'" by auto
+  hence "t \<noteq> taker" by (simp add: taker_def) 
+  moreover hence "t \<noteq> th" using assms neq_t_th by blast 
+  moreover have "t \<in> set rest" by (simp add: `t \<in> set wq'` th'_in_inv) 
+  ultimately have "waiting s t cs"
+    by (metis cs_waiting_def list.distinct(2) list.sel(1) 
+                list.set_sel(2) rest_def waiting_eq wq_s_cs)  
+  show ?thesis using that(2)
+  using True `t \<in> set wq'` `t \<noteq> taker` `waiting s t cs` eq_wq' by auto   
+qed
+
+lemma holding_esI1:
+  assumes "c = cs"
+  and "t = taker"
+  shows "holding (e#s) t c"
+  by (unfold assms, simp add: holding_taker)
+
+lemma holding_esE:
+  assumes "holding (e#s) t c" 
+  obtains "c = cs" "t = taker"
+      | "c \<noteq> cs" "holding s t c"
+proof(cases "c = cs")
+  case True
+  from assms[unfolded True, unfolded s_holding_def, 
+             folded wq_def, unfolded wq_es_cs]
+  have "t = taker" by (simp add: taker_def) 
+  from that(1)[OF True this] show ?thesis .
+next
+  case False
+  hence "wq (e#s) c = wq s c" using is_v by auto
+  from assms[unfolded s_holding_def, folded wq_def, 
+             unfolded this, unfolded wq_def, folded s_holding_def]
+  have "holding s t c"  .
+  from that(2)[OF False this] show ?thesis .
+qed
+
+end 
+
+locale valid_trace_v_e = valid_trace_v +
+  assumes rest_nil: "rest = []"
+begin
+
+lemma nil_wq': "wq' = []" 
+proof (unfold wq'_def, rule someI2)
+  show "distinct rest \<and> set rest = set rest"
+    by (simp add: distinct_rest) 
+next
+  fix x
+  assume " distinct x \<and> set x = set rest" 
+  thus "x = []" using rest_nil by auto
+qed 
+
+lemma no_taker: 
+  assumes "next_th s th cs taker"
+  shows "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"
+  from assms[unfolded next_th_def]
+  obtain rest' where "wq s cs = th # rest'" "rest' \<noteq> []"
+    by auto
+  thus ?thesis using rest_def rest_nil by auto 
+qed
+
+lemma waiting_set_eq:
+  "{(Th th', Cs cs) |th'. next_th s th cs th'} = {}"
+  using no_taker by auto
+
+lemma holding_set_eq:
+  "{(Cs cs, Th th') |th'.  next_th s th cs th'} = {}"
+  using no_taker by auto
+   
+lemma no_holding:
+  assumes "holding (e#s) taker cs"
+  shows False
+proof -
+  from wq_es_cs[unfolded nil_wq']
+  have " wq (e # s) cs = []" .
+  from assms[unfolded s_holding_def, folded wq_def, unfolded this]
+  show ?thesis by auto
+qed
+
+lemma no_waiting:
+  assumes "waiting (e#s) t cs"
+  shows False
+proof -
+  from wq_es_cs[unfolded nil_wq']
+  have " wq (e # s) cs = []" .
+  from assms[unfolded s_waiting_def, folded wq_def, unfolded this]
+  show ?thesis by auto
+qed
+
+lemma waiting_esE:
+  assumes "waiting (e#s) t c" 
+  obtains "c \<noteq> cs" "waiting s t c"
+proof(cases "c = cs")
+  case False
+  hence "wq (e#s) c = wq s c" using is_v by auto
+  with assms have "waiting s t c" using cs_waiting_def waiting_eq by auto 
+  from that(1)[OF False this] show ?thesis .
+next
+  case True
+  from no_waiting[OF assms[unfolded True]]
+  show ?thesis by auto
+qed
+
+lemma holding_esE:
+  assumes "holding (e#s) t c" 
+  obtains "c \<noteq> cs" "holding s t c"
+proof(cases "c = cs")
+  case True
+  from no_holding[OF assms[unfolded True]] 
+  show ?thesis by auto
+next
+  case False
+  hence "wq (e#s) c = wq s c" using is_v by auto
+  from assms[unfolded s_holding_def, folded wq_def, 
+             unfolded this, unfolded wq_def, folded s_holding_def]
+  have "holding s t c"  .
+  from that[OF False this] show ?thesis .
+qed
+
+end (* ccc *)
+
+lemma rel_eqI:
+  assumes "\<And> x y. (x,y) \<in> A \<Longrightarrow> (x,y) \<in> B"
+  and "\<And> x y. (x,y) \<in> B \<Longrightarrow> (x, y) \<in> A"
+  shows "A = B"
+  using assms by auto
+
+lemma in_RAG_E:
+  assumes "(n1, n2) \<in> RAG (s::state)"
+  obtains (waiting) th cs where "n1 = Th th" "n2 = Cs cs" "waiting s th cs"
+      | (holding) th cs where "n1 = Cs cs" "n2 = Th th" "holding s th cs"
+  using assms[unfolded s_RAG_def, folded waiting_eq holding_eq]
+  by auto
+  
+context valid_trace_v
+begin
+
+lemma
+  "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 = ?R")
+proof(rule rel_eqI)
+  fix n1 n2
+  assume "(n1, n2) \<in> ?L"
+  thus "(n1, n2) \<in> ?R"
+  proof(cases rule:in_RAG_E)
+    case (waiting th' cs')
+    show ?thesis
+    proof(cases "rest = []")
+      case False
+      interpret h_n: valid_trace_v_n s e th cs
+        by (unfold_locales, insert False, simp)
+      from waiting(3)
+      show ?thesis
+      proof(cases rule:h_n.waiting_esE)
+        case 1
+        with waiting(1,2)
+        show ?thesis
+        by (unfold h_n.waiting_set_eq h_n.holding_set_eq s_RAG_def, 
+             fold waiting_eq, auto)
+      next
+        case 2
+        with waiting(1,2)
+        show ?thesis
+         by (unfold h_n.waiting_set_eq h_n.holding_set_eq s_RAG_def, 
+             fold waiting_eq, auto)
+      qed
+    next
+      case True
+      interpret h_e: valid_trace_v_e s e th cs
+        by (unfold_locales, insert True, simp)
+      from waiting(3)
+      show ?thesis
+      proof(cases rule:h_e.waiting_esE)
+        case 1
+        with waiting(1,2)
+        show ?thesis
+        by (unfold h_e.waiting_set_eq h_e.holding_set_eq s_RAG_def, 
+             fold waiting_eq, auto)
+      qed
+    qed
+  next
+    case (holding th' cs')
+    show ?thesis
+    proof(cases "rest = []")
+      case False
+      interpret h_n: valid_trace_v_n s e th cs
+        by (unfold_locales, insert False, simp)
+      from holding(3)
+      show ?thesis
+      proof(cases rule:h_n.holding_esE)
+        case 1
+        with holding(1,2)
+        show ?thesis
+        by (unfold h_n.waiting_set_eq h_n.holding_set_eq s_RAG_def, 
+             fold waiting_eq, auto)
+      next
+        case 2
+        with holding(1,2)
+        show ?thesis
+         by (unfold h_n.waiting_set_eq h_n.holding_set_eq s_RAG_def, 
+             fold holding_eq, auto)
+      qed
+    next
+      case True
+      interpret h_e: valid_trace_v_e s e th cs
+        by (unfold_locales, insert True, simp)
+      from holding(3)
+      show ?thesis
+      proof(cases rule:h_e.holding_esE)
+        case 1
+        with holding(1,2)
+        show ?thesis
+        by (unfold h_e.waiting_set_eq h_e.holding_set_eq s_RAG_def, 
+             fold holding_eq, auto)
+      qed
+    qed
+  qed
+next
+  fix n1 n2
+  assume h: "(n1, n2) \<in> ?R"
+  show "(n1, n2) \<in> ?L"
+  proof(cases "rest = []")
+    case False
+    interpret h_n: valid_trace_v_n s e th cs
+        by (unfold_locales, insert False, simp)
+    from h[unfolded h_n.waiting_set_eq h_n.holding_set_eq]
+    have "((n1, n2) \<in> RAG s \<and> (n1 \<noteq> Cs cs \<or> n2 \<noteq> Th th)
+                            \<and> (n1 \<noteq> Th h_n.taker \<or> n2 \<noteq> Cs cs)) \<or> 
+          (n2 = Th h_n.taker \<and> n1 = Cs cs)" 
+      by auto
+   thus ?thesis
+   proof
+      assume "n2 = Th h_n.taker \<and> n1 = Cs cs"
+      with h_n.holding_taker
+      show ?thesis 
+        by (unfold s_RAG_def, fold holding_eq, auto)
+   next
+    assume h: "(n1, n2) \<in> RAG s \<and>
+        (n1 \<noteq> Cs cs \<or> n2 \<noteq> Th th) \<and> (n1 \<noteq> Th h_n.taker \<or> n2 \<noteq> Cs cs)"
+    hence "(n1, n2) \<in> RAG s" by simp
     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
+    proof(cases rule:in_RAG_E)
+      case (waiting th' cs')
+      thus ?thesis
     qed
+   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
+end
+
+
+lemma step_RAG_v: (* ccc *)
+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'}" (is "?L = ?R")
+proof(rule rel_eqI)
+  fix n1 n2
+  assume "(n1, n2) \<in> ?L"
+  show "(n1, n2) \<in> ?R" sorry
+next
+  fix n1 n2
+  assume "(n1, n2) \<in> ?R"
+  show "(n1, n2) \<in> ?L" sorry
 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
@@ -1036,7 +1399,7 @@
   {(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 
+  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)
@@ -1559,11 +1922,7 @@
 
 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)
@@ -2388,8 +2747,6 @@
 
 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
@@ -2579,7 +2936,7 @@
       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)
+        by (auto simp:waiting_eq)
       thus ?thesis by simp
     qed
   next
@@ -2601,7 +2958,7 @@
       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)
+        by (auto simp:waiting_eq)
       thus ?thesis by simp
     next
       assume "th2' \<in> dependants (wq s) th2"
@@ -2664,37 +3021,6 @@
   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
 
@@ -3077,7 +3403,6 @@
 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)
@@ -3146,7 +3471,7 @@
     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)
+           auto simp:waiting_eq s_RAG_def)
     with cncs_z and eq_pv show ?thesis by simp
   next
     case False
@@ -3888,4 +4213,10 @@
 definition cps:: "state \<Rightarrow> (thread \<times> precedence) set"
 where "cps s = {(th, cp s th) | th . th \<in> threads s}"
 
+find_theorems release
+
+lemma "wq (V th cs # s) cs1 = ttt"
+  apply (unfold wq_def, auto simp:Let_def)
+
 end
+
--- a/PIPBasics.thy	Thu Jan 14 00:55:54 2016 +0800
+++ b/PIPBasics.thy	Sat Jan 16 10:59:03 2016 +0800
@@ -3775,4 +3775,6 @@
 definition cps:: "state \<Rightarrow> (thread \<times> precedence) set"
 where "cps s = {(th, cp s th) | th . th \<in> threads s}"
 
+find_theorems holding wq
+
 end
--- a/PIPBasics.thy~	Thu Jan 14 00:55:54 2016 +0800
+++ b/PIPBasics.thy~	Sat Jan 16 10:59:03 2016 +0800
@@ -30,6 +30,13 @@
    "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
 
@@ -60,39 +67,70 @@
 qed
 
 lemma wq_distinct: "distinct (wq s cs)"
-proof(rule ind, simp add:wq_def)
-  fix s e
-  assume h1: "step s e"
-  and h2: "distinct (wq s cs)"
-  thus "distinct (wq (e # s) cs)"
-  proof(induct rule:step.induct, auto simp: wq_def Let_def split:list.splits)
-    fix thread s
-    assume h1: "(Cs cs, Th thread) \<notin> (RAG s)\<^sup>+"
-      and h2: "thread \<in> set (wq_fun (schs s) cs)"
-      and h3: "thread \<in> runing s"
-    show "False" 
-    proof -
-      from h3 have "\<And> cs. thread \<in>  set (wq_fun (schs s) cs) \<Longrightarrow> 
-                             thread = hd ((wq_fun (schs s) cs))" 
-        by (simp add:runing_def readys_def s_waiting_def wq_def)
-      from this [OF h2] have "thread = hd (wq_fun (schs s) cs)" .
-      with h2
-      have "(Cs cs, Th thread) \<in> (RAG s)"
-        by (simp add:s_RAG_def s_holding_def wq_def cs_holding_def)
-      with h1 show False by auto
+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
-    fix thread s a list
-    assume dst: "distinct list"
-    show "distinct (SOME q. distinct q \<and> set q = set list)"
-    proof(rule someI2)
-      from dst show  "distinct list \<and> set list = set list" by auto
+    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
-      fix q assume "distinct q \<and> set q = set list"
-      thus "distinct q" by auto
+      case False
+      with thread_V(3)
+      show ?thesis
+        by (auto simp:wq_def wf_def Let_def split:list.splits)
     qed
-  qed
-qed
+  qed (insert Cons, auto simp: wq_def Let_def split:list.splits)
+qed (unfold wq_def Let_def, simp)
 
 end
 
@@ -108,56 +146,34 @@
 *}
 
 lemma block_pre: 
-  assumes s_ni: "thread \<notin>  set (wq s cs)"
+  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 -
-  show ?thesis
-  proof(cases e)
-    case (P th cs)
-    with assms
+proof(cases e)
+  -- {* This is the only non-trivial case: *}
+  case (V th cs1)
+  have False
+  proof(cases "cs1 = cs")
+    case True
     show ?thesis
-      by (auto simp:wq_def Let_def split:if_splits)
-  next
-    case (Create th prio)
-    with assms show ?thesis
-      by (auto simp:wq_def Let_def split:if_splits)
-  next
-    case (Exit th)
-    with assms show ?thesis
-      by (auto simp:wq_def Let_def split:if_splits)
-  next
-    case (Set th prio)
-    with assms show ?thesis
-      by (auto simp:wq_def Let_def split:if_splits)
-  next
-    case (V th cs)
-    with vt_e assms show ?thesis
-      apply (auto simp:wq_def Let_def split:if_splits)
-    proof -
-      fix q qs
-      assume h1: "thread \<notin> set (wq_fun (schs s) cs)"
-        and h2: "q # qs = wq_fun (schs s) cs"
-        and h3: "thread \<in> set (SOME q. distinct q \<and> set q = set qs)"
-        and vt: "vt (V th cs # s)"
-      from h1 and h2[symmetric] have "thread \<notin> set (q # qs)" by simp
-      moreover have "thread \<in> set qs"
+    proof(cases "(wq s cs1)")
+      case (Cons w_hd w_tl)
+      have "set (wq (e#s) cs) \<subseteq> set (wq s cs)"
       proof -
-        have "set (SOME q. distinct q \<and> set q = set qs) = set qs"
+        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)
-          from wq_distinct [of cs]
-          and h2[symmetric, 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 h3 show ?thesis by simp
+          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
-      ultimately show "False" by auto
-      qed
-  qed
-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)
 
 end
 
@@ -233,10 +249,10 @@
 
 end
 
+
 context valid_trace
 begin
-
-lemma vt_moment: "\<And> t. vt (moment t s)"
+lemma  vt_moment: "\<And> t. vt (moment t s)"
 proof(induct rule:ind)
   case Nil
   thus ?case by (simp add:vt_nil)
@@ -260,10 +276,17 @@
     ultimately show ?thesis by simp
   qed
 qed
+end
 
-(* Wrong:
-    lemma \<lbrakk>thread \<in> set (wq_fun cs1 s); thread \<in> set (wq_fun cs2 s)\<rbrakk> \<Longrightarrow> cs1 = cs2"
-*)
+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 
@@ -292,13 +315,13 @@
   @{text "th"} got blocked on @{text "cs1"} and @{text "cs2"} 
   and kept on blocked on them respectively ever since.
  
-  Without lose of generality, we assume @{text "t1"} is earlier than @{text "t2"}.
+  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:
+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)"
@@ -519,7 +542,6 @@
 
 (* An aux lemma used later *)
 lemma unique_minus:
-  fixes x y z r
   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^+"
@@ -547,7 +569,6 @@
 qed
 
 lemma unique_base:
-  fixes r x y z
   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^+"
@@ -574,7 +595,6 @@
 qed
 
 lemma unique_chain:
-  fixes r x y z
   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^+"
@@ -914,7 +934,6 @@
   with the happening of @{text "V"}-events:
 *}
 lemma step_RAG_v:
-fixes th::thread
 assumes vt:
   "vt (V th cs#s)"
 shows "
@@ -1342,7 +1361,6 @@
   by (auto intro:wq_threads)
 
 lemma readys_v_eq:
-  fixes th thread cs rest
   assumes neq_th: "th \<noteq> thread"
   and eq_wq: "wq s cs = thread#rest"
   and not_in: "th \<notin>  set rest"
@@ -1511,7 +1529,6 @@
              
 
 lemma step_holdents_p_add:
-  fixes th cs s
   assumes vt: "vt (P th cs#s)"
   and "wq s cs = []"
   shows "holdents (P th cs#s) th = holdents s th \<union> {cs}"
@@ -1521,7 +1538,6 @@
 qed
 
 lemma step_holdents_p_eq:
-  fixes th cs s
   assumes vt: "vt (P th cs#s)"
   and "wq s cs \<noteq> []"
   shows "holdents (P th cs#s) th = holdents s th"
@@ -1551,7 +1567,6 @@
 qed
 
 lemma cntCS_v_dec: 
-  fixes s thread cs
   assumes vtv: "vt (V thread cs#s)"
   shows "(cntCS (V thread cs#s) thread + 1) = cntCS s thread"
 proof -
@@ -2566,36 +2581,6 @@
   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
@@ -3790,4 +3775,6 @@
 definition cps:: "state \<Rightarrow> (thread \<times> precedence) set"
 where "cps s = {(th, cp s th) | th . th \<in> threads s}"
 
+find_theorems readys runing
+
 end
--- a/PIPDefs.thy~	Thu Jan 14 00:55:54 2016 +0800
+++ b/PIPDefs.thy~	Sat Jan 16 10:59:03 2016 +0800
@@ -37,6 +37,24 @@
   V thread cs | -- {* Thread @{text "thread"}  releasing critical resource @{text "cs"}. *}
   Set thread priority -- {* Thread @{text "thread"} resets its priority to @{text "priority"}. *}
 
+fun actor :: "event \<Rightarrow> thread" where
+  "actor (Create th pty) = th" |
+  "actor (Exit th) = th" |
+  "actor (P th cs) = th" |
+  "actor (V th cs) = th" |
+  "actor (Set th pty) = th"
+
+fun isCreate :: "event \<Rightarrow> bool" where
+  "isCreate (Create th pty) = True" |
+  "isCreate _ = False"
+
+fun isP :: "event \<Rightarrow> bool" where
+  "isP (P th cs) = True" |
+  "isP _ = False"
+
+fun isV :: "event \<Rightarrow> bool" where
+  "isV (V th cs) = True" |
+  "isV _ = False"
 
 text {* 
   As mentioned earlier, in Paulson's inductive method, the states of system are represented as lists of events,