--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/CpsG.thy_1_1 Wed Jan 27 19:28:42 2016 +0800
@@ -0,0 +1,1751 @@
+theory CpsG
+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
+
+
+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
+
+locale valid_trace_create = valid_trace_e +
+ fixes th prio
+ assumes is_create: "e = Create th prio"
+
+locale valid_trace_exit = valid_trace_e +
+ fixes th
+ assumes is_exit: "e = Exit th"
+
+locale valid_trace_p = valid_trace_e +
+ fixes th cs
+ assumes is_p: "e = P th cs"
+
+locale valid_trace_v = valid_trace_e +
+ fixes th cs
+ assumes is_v: "e = V th cs"
+begin
+ definition "rest = tl (wq s cs)"
+ definition "wq' = (SOME q. distinct q \<and> set q = set rest)"
+end
+
+locale valid_trace_v_n = valid_trace_v +
+ assumes rest_nnl: "rest \<noteq> []"
+
+locale valid_trace_v_e = valid_trace_v +
+ assumes rest_nil: "rest = []"
+
+locale valid_trace_set= valid_trace_e +
+ fixes th prio
+ assumes is_set: "e = Set th prio"
+
+context valid_trace
+begin
+
+lemma ind [consumes 0, case_names Nil Cons, induct type]:
+ assumes "PP []"
+ and "(\<And>s e. valid_trace_e s e \<Longrightarrow>
+ PP s \<Longrightarrow> PIP s e \<Longrightarrow> PP (e # s))"
+ shows "PP s"
+proof(induct rule:vt.induct[OF vt, case_names Init Step])
+ case Init
+ from assms(1) show ?case .
+next
+ case (Step s e)
+ show ?case
+ proof(rule assms(2))
+ show "valid_trace_e s e" using Step by (unfold_locales, auto)
+ next
+ show "PP s" using Step by simp
+ next
+ show "PIP s e" using Step by simp
+ qed
+qed
+
+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 valid_trace_e_def, auto)
+ 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
+
+lemma finite_threads:
+ shows "finite (threads s)"
+using vt by (induct) (auto elim: step.cases)
+
+end
+
+lemma cp_eq_cpreced: "cp s th = cpreced (wq s) s th"
+unfolding cp_def wq_def
+apply(induct s rule: schs.induct)
+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)
+
+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)
+
+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 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 runing_wqE:
+ assumes "th \<in> runing s"
+ and "th \<in> set (wq s cs)"
+ obtains rest where "wq s cs = th#rest"
+proof -
+ from assms(2) obtain th' rest where eq_wq: "wq s cs = th'#rest"
+ by (meson list.set_cases)
+ have "th' = th"
+ proof(rule ccontr)
+ assume "th' \<noteq> th"
+ hence "th \<noteq> hd (wq s cs)" using eq_wq by auto
+ with assms(2)
+ have "waiting s th cs"
+ by (unfold s_waiting_def, fold wq_def, auto)
+ with assms show False
+ by (unfold runing_def readys_def, auto)
+ qed
+ with eq_wq that show ?thesis by metis
+qed
+
+end
+
+context valid_trace_create
+begin
+
+lemma wq_neq_simp [simp]:
+ shows "wq (e#s) cs' = wq s cs'"
+ using assms unfolding is_create wq_def
+ by (auto simp:Let_def)
+
+lemma wq_distinct_kept:
+ assumes "distinct (wq s cs')"
+ shows "distinct (wq (e#s) cs')"
+ using assms by simp
+end
+
+context valid_trace_exit
+begin
+
+lemma wq_neq_simp [simp]:
+ shows "wq (e#s) cs' = wq s cs'"
+ using assms unfolding is_exit wq_def
+ by (auto simp:Let_def)
+
+lemma wq_distinct_kept:
+ assumes "distinct (wq s cs')"
+ shows "distinct (wq (e#s) cs')"
+ using assms by simp
+end
+
+context valid_trace_p
+begin
+
+lemma wq_neq_simp [simp]:
+ assumes "cs' \<noteq> cs"
+ shows "wq (e#s) cs' = wq s cs'"
+ using assms unfolding is_p wq_def
+ by (auto simp:Let_def)
+
+lemma runing_th_s:
+ shows "th \<in> runing s"
+proof -
+ from pip_e[unfolded is_p]
+ show ?thesis by (cases, simp)
+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 th_not_in_wq:
+ shows "th \<notin> set (wq s cs)"
+proof
+ assume otherwise: "th \<in> set (wq s cs)"
+ from runing_wqE[OF runing_th_s this]
+ obtain rest where eq_wq: "wq s cs = th#rest" by blast
+ with otherwise
+ have "holding s th cs"
+ by (unfold s_holding_def, fold wq_def, simp)
+ hence cs_th_RAG: "(Cs cs, Th th) \<in> RAG s"
+ by (unfold s_RAG_def, fold holding_eq, auto)
+ from pip_e[unfolded is_p]
+ show False
+ proof(cases)
+ case (thread_P)
+ with cs_th_RAG show ?thesis by auto
+ qed
+qed
+
+lemma wq_es_cs:
+ "wq (e#s) cs = wq s cs @ [th]"
+ by (unfold is_p wq_def, auto simp:Let_def)
+
+lemma wq_distinct_kept:
+ assumes "distinct (wq s cs')"
+ shows "distinct (wq (e#s) cs')"
+proof(cases "cs' = cs")
+ case True
+ show ?thesis using True assms th_not_in_wq
+ by (unfold True wq_es_cs, auto)
+qed (insert assms, simp)
+
+end
+
+context valid_trace_v
+begin
+
+lemma wq_neq_simp [simp]:
+ assumes "cs' \<noteq> cs"
+ shows "wq (e#s) cs' = wq s cs'"
+ using assms unfolding is_v wq_def
+ by (auto simp:Let_def)
+
+lemma runing_th_s:
+ shows "th \<in> runing s"
+proof -
+ from pip_e[unfolded is_v]
+ show ?thesis by (cases, simp)
+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 wq_distinct_kept:
+ assumes "distinct (wq s cs')"
+ shows "distinct (wq (e#s) cs')"
+proof(cases "cs' = cs")
+ case True
+ show ?thesis
+ proof(unfold True wq_es_cs wq'_def, rule someI2)
+ show "distinct rest \<and> set rest = set rest"
+ using assms[unfolded True wq_s_cs] by auto
+ qed simp
+qed (insert assms, simp)
+
+end
+
+context valid_trace_set
+begin
+
+lemma wq_neq_simp [simp]:
+ shows "wq (e#s) cs' = wq s cs'"
+ using assms unfolding is_set wq_def
+ by (auto simp:Let_def)
+
+lemma wq_distinct_kept:
+ assumes "distinct (wq s cs')"
+ shows "distinct (wq (e#s) cs')"
+ using assms by simp
+end
+
+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 wq_distinct: "distinct (wq s cs)"
+proof(induct rule:ind)
+ case (Cons s e)
+ interpret vt_e: valid_trace_e s e using Cons by simp
+ show ?case
+ proof(cases e)
+ case (Create th prio)
+ interpret vt_create: valid_trace_create s e th prio
+ using Create by (unfold_locales, simp)
+ show ?thesis using Cons by (simp add: vt_create.wq_distinct_kept)
+ next
+ case (Exit th)
+ interpret vt_exit: valid_trace_exit s e th
+ using Exit by (unfold_locales, simp)
+ show ?thesis using Cons by (simp add: vt_exit.wq_distinct_kept)
+ next
+ case (P th cs)
+ interpret vt_p: valid_trace_p s e th cs using P by (unfold_locales, simp)
+ show ?thesis using Cons by (simp add: vt_p.wq_distinct_kept)
+ next
+ case (V th cs)
+ interpret vt_v: valid_trace_v s e th cs using V by (unfold_locales, simp)
+ show ?thesis using Cons by (simp add: vt_v.wq_distinct_kept)
+ next
+ case (Set th prio)
+ interpret vt_set: valid_trace_set s e th prio
+ using Set by (unfold_locales, simp)
+ show ?thesis using Cons by (simp add: vt_set.wq_distinct_kept)
+ qed
+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
+
+
+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: (* 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)"
+ 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 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"
+ by (unfold_locales, auto, cases, simp)
+ have ?thesis
+ proof -
+ have "thread \<in> runing (moment t2 s)"
+ proof(cases "thread \<in> set (wq (moment t2 s) cs2)")
+ case True
+ 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
+ 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 "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 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
+ 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 "e = V thread cs2 \<or> e = P thread cs2"
+ proof(cases "thread \<in> set (wq (moment t2 s) cs2)")
+ case True
+ 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
+ have "e = P thread cs2" using vt_e.wq_in_inv[OF False h1] .
+ thus ?thesis by auto
+ qed
+ moreover have "e = V thread cs1 \<or> e = P thread cs1"
+ proof(cases "thread \<in> set (wq (moment t1 s) cs1)")
+ case True
+ 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
+ have "e = P thread cs1" using vt_e.wq_in_inv[folded eq_12, OF False g1] .
+ thus ?thesis by auto
+ qed
+ ultimately have ?thesis using neq12 by auto
+ } ultimately show ?thesis using nat_neq_iff by blast
+ 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
+
+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)
+
+
+context valid_trace_v
+begin
+
+lemma distinct_rest: "distinct rest"
+ by (simp add: distinct_tl rest_def wq_distinct)
+
+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 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 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
+
+lemma holding_esI1:
+ assumes "holding s t c"
+ and "t \<noteq> th"
+ shows "holding (e#s) t c"
+proof -
+ have "c \<noteq> cs" using assms using holding_cs_eq_th by blast
+ from holding_esI2[OF this assms(1)]
+ show ?thesis .
+qed
+
+end
+
+context valid_trace_v_n
+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
+
+
+context valid_trace_v_e
+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 -
+ 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_esI2:
+ assumes "waiting s t c"
+ shows "waiting (e#s) t c"
+proof -
+ have "c \<noteq> cs" using assms
+ using cs_waiting_def rest_nil waiting_eq wq_s_cs by auto
+ from waiting_esI1[OF assms this]
+ show ?thesis .
+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
+
+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_es:
+ "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
+ proof(cases rule:in_RAG_E)
+ case (waiting th' cs')
+ from h and this(1,2)
+ have "th' \<noteq> h_n.taker \<or> cs' \<noteq> cs" by auto
+ hence "waiting (e#s) th' cs'"
+ proof
+ assume "cs' \<noteq> cs"
+ from waiting_esI1[OF waiting(3) this]
+ show ?thesis .
+ next
+ assume neq_th': "th' \<noteq> h_n.taker"
+ show ?thesis
+ proof(cases "cs' = cs")
+ case False
+ from waiting_esI1[OF waiting(3) this]
+ show ?thesis .
+ next
+ case True
+ from h_n.waiting_esI2[OF waiting(3)[unfolded True] neq_th', folded True]
+ show ?thesis .
+ qed
+ qed
+ thus ?thesis using waiting(1,2)
+ by (unfold s_RAG_def, fold waiting_eq, auto)
+ next
+ case (holding th' cs')
+ from h this(1,2)
+ have "cs' \<noteq> cs \<or> th' \<noteq> th" by auto
+ hence "holding (e#s) th' cs'"
+ proof
+ assume "cs' \<noteq> cs"
+ from holding_esI2[OF this holding(3)]
+ show ?thesis .
+ next
+ assume "th' \<noteq> th"
+ from holding_esI1[OF holding(3) this]
+ show ?thesis .
+ qed
+ thus ?thesis using holding(1,2)
+ by (unfold s_RAG_def, fold holding_eq, auto)
+ qed
+ qed
+ next
+ case True
+ interpret h_e: valid_trace_v_e s e th cs
+ by (unfold_locales, insert True, simp)
+ from h[unfolded h_e.waiting_set_eq h_e.holding_set_eq]
+ have h_s: "(n1, n2) \<in> RAG s" "(n1, n2) \<noteq> (Cs cs, Th th)"
+ by auto
+ from h_s(1)
+ show ?thesis
+ proof(cases rule:in_RAG_E)
+ case (waiting th' cs')
+ from h_e.waiting_esI2[OF this(3)]
+ show ?thesis using waiting(1,2)
+ by (unfold s_RAG_def, fold waiting_eq, auto)
+ next
+ case (holding th' cs')
+ with h_s(2)
+ have "cs' \<noteq> cs \<or> th' \<noteq> th" by auto
+ thus ?thesis
+ proof
+ assume neq_cs: "cs' \<noteq> cs"
+ from holding_esI2[OF this holding(3)]
+ show ?thesis using holding(1,2)
+ by (unfold s_RAG_def, fold holding_eq, auto)
+ next
+ assume "th' \<noteq> th"
+ from holding_esI1[OF holding(3) this]
+ show ?thesis using holding(1,2)
+ by (unfold s_RAG_def, fold holding_eq, auto)
+ qed
+ qed
+ qed
+qed
+
+end
+
+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'}" (is "?L = ?R")
+proof -
+ interpret vt_v: valid_trace_v s "V th cs"
+ using assms step_back_vt by (unfold_locales, auto)
+ show ?thesis using vt_v.RAG_es .
+qed
+
+lemma (in valid_trace_create)
+ th_not_in_threads: "th \<notin> threads s"
+proof -
+ from pip_e[unfolded is_create]
+ show ?thesis by (cases, simp)
+qed
+
+lemma (in valid_trace_create)
+ threads_es [simp]: "threads (e#s) = threads s \<union> {th}"
+ by (unfold is_create, simp)
+
+lemma (in valid_trace_exit)
+ threads_es [simp]: "threads (e#s) = threads s - {th}"
+ by (unfold is_exit, simp)
+
+lemma (in valid_trace_p)
+ threads_es [simp]: "threads (e#s) = threads s"
+ by (unfold is_p, simp)
+
+lemma (in valid_trace_v)
+ threads_es [simp]: "threads (e#s) = threads s"
+ by (unfold is_v, simp)
+
+lemma (in valid_trace_v)
+ th_not_in_rest[simp]: "th \<notin> set rest"
+proof
+ assume otherwise: "th \<in> set rest"
+ have "distinct (wq s cs)" by (simp add: wq_distinct)
+ from this[unfolded wq_s_cs] and otherwise
+ show False by auto
+qed
+
+lemma (in valid_trace_v)
+ set_wq_es_cs [simp]: "set (wq (e#s) cs) = set (wq s cs) - {th}"
+proof(unfold wq_es_cs 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 "set x = set (wq s cs) - {th}"
+ by (unfold wq_s_cs, simp)
+qed
+
+lemma (in valid_trace_exit)
+ th_not_in_wq: "th \<notin> set (wq s cs)"
+proof -
+ from pip_e[unfolded is_exit]
+ show ?thesis
+ by (cases, unfold holdents_def s_holding_def, fold wq_def,
+ auto elim!:runing_wqE)
+qed
+
+lemma (in valid_trace) wq_threads:
+ assumes "th \<in> set (wq s cs)"
+ shows "th \<in> threads s"
+ using assms
+proof(induct rule:ind)
+ case (Nil)
+ thus ?case by (auto simp:wq_def)
+next
+ case (Cons s e)
+ interpret vt_e: valid_trace_e s e using Cons by simp
+ show ?case
+ proof(cases e)
+ case (Create th' prio')
+ interpret vt: valid_trace_create s e th' prio'
+ using Create by (unfold_locales, simp)
+ show ?thesis
+ using Cons.hyps(2) Cons.prems by auto
+ next
+ case (Exit th')
+ interpret vt: valid_trace_exit s e th'
+ using Exit by (unfold_locales, simp)
+ show ?thesis
+ using Cons.hyps(2) Cons.prems vt.th_not_in_wq by auto
+ next
+ case (P th' cs')
+ interpret vt: valid_trace_p s e th' cs'
+ using P by (unfold_locales, simp)
+ show ?thesis
+ using Cons.hyps(2) Cons.prems readys_threads
+ runing_ready vt.is_p vt.runing_th_s vt_e.wq_in_inv
+ by fastforce
+ next
+ case (V th' cs')
+ interpret vt: valid_trace_v s e th' cs'
+ using V by (unfold_locales, simp)
+ show ?thesis using Cons
+ using vt.is_v vt.threads_es vt_e.wq_in_inv by blast
+ next
+ case (Set th' prio)
+ interpret vt: valid_trace_set s e th' prio
+ using Set by (unfold_locales, simp)
+ show ?thesis using Cons.hyps(2) Cons.prems vt.is_set
+ by (auto simp:wq_def Let_def)
+ qed
+qed
+
+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
+
+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 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'"
+ 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_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 (in valid_trace_v)
+ preced_es: "preced th (e#s) = preced th s"
+ by (unfold is_v 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
+
+lemma (in valid_trace_v)
+ the_preced_es: "the_preced (e#s) = the_preced s"
+ by (unfold is_v preced_def, simp)
+
+context valid_trace_p
+begin
+
+lemma not_holding_es_th_cs: "\<not> holding s th cs"
+proof
+ assume otherwise: "holding s th cs"
+ from pip_e[unfolded is_p]
+ show False
+ proof(cases)
+ case (thread_P)
+ moreover have "(Cs cs, Th th) \<in> RAG s"
+ using otherwise cs_holding_def
+ holding_eq th_not_in_wq by auto
+ ultimately show ?thesis by auto
+ qed
+qed
+
+lemma waiting_kept:
+ assumes "waiting s th' cs'"
+ shows "waiting (e#s) th' cs'"
+ using assms
+ by (metis cs_waiting_def hd_append2 list.sel(1) list.set_intros(2)
+ rotate1.simps(2) self_append_conv2 set_rotate1
+ th_not_in_wq waiting_eq wq_es_cs wq_neq_simp)
+
+lemma holding_kept:
+ assumes "holding s th' cs'"
+ shows "holding (e#s) th' cs'"
+proof(cases "cs' = cs")
+ case False
+ hence "wq (e#s) cs' = wq s cs'" by simp
+ with assms show ?thesis using cs_holding_def holding_eq by auto
+next
+ case True
+ from assms[unfolded s_holding_def, folded wq_def]
+ obtain rest where eq_wq: "wq s cs' = th'#rest"
+ by (metis empty_iff list.collapse list.set(1))
+ hence "wq (e#s) cs' = th'#(rest@[th])"
+ by (simp add: True wq_es_cs)
+ thus ?thesis
+ by (simp add: cs_holding_def holding_eq)
+qed
+
+end
+
+locale valid_trace_p_h = valid_trace_p +
+ assumes we: "wq s cs = []"
+
+locale valid_trace_p_w = valid_trace_p +
+ assumes wne: "wq s cs \<noteq> []"
+begin
+
+definition "holder = hd (wq s cs)"
+definition "waiters = tl (wq s cs)"
+definition "waiters' = waiters @ [th]"
+
+lemma wq_s_cs: "wq s cs = holder#waiters"
+ by (simp add: holder_def waiters_def wne)
+
+lemma wq_es_cs': "wq (e#s) cs = holder#waiters@[th]"
+ by (simp add: wq_es_cs wq_s_cs)
+
+lemma waiting_es_th_cs: "waiting (e#s) th cs"
+ using cs_waiting_def th_not_in_wq waiting_eq wq_es_cs' wq_s_cs by auto
+
+lemma RAG_edge: "(Th th, Cs cs) \<in> RAG (e#s)"
+ by (unfold s_RAG_def, fold waiting_eq, insert waiting_es_th_cs, auto)
+
+lemma holding_esE:
+ assumes "holding (e#s) th' cs'"
+ obtains "holding s th' cs'"
+ using assms
+proof(cases "cs' = cs")
+ case False
+ hence "wq (e#s) cs' = wq s cs'" by simp
+ with assms show ?thesis
+ using cs_holding_def holding_eq that by auto
+next
+ case True
+ with assms show ?thesis
+ by (metis cs_holding_def holding_eq list.sel(1) list.set_intros(1) that
+ wq_es_cs' wq_s_cs)
+qed
+
+lemma waiting_esE:
+ assumes "waiting (e#s) th' cs'"
+ obtains "th' \<noteq> th" "waiting s th' cs'"
+ | "th' = th" "cs' = cs"
+proof(cases "waiting s th' cs'")
+ case True
+ have "th' \<noteq> th"
+ proof
+ assume otherwise: "th' = th"
+ from True[unfolded this]
+ show False by (simp add: th_not_waiting)
+ qed
+ from that(1)[OF this True] show ?thesis .
+next
+ case False
+ hence "th' = th \<and> cs' = cs"
+ by (metis assms cs_waiting_def holder_def list.sel(1) rotate1.simps(2)
+ set_ConsD set_rotate1 waiting_eq wq_es_cs wq_es_cs' wq_neq_simp)
+ with that(2) show ?thesis by metis
+qed
+
+lemma RAG_es: "RAG (e # s) = RAG s \<union> {(Th th, Cs cs)}" (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')
+ from this(3)
+ show ?thesis
+ proof(cases rule:waiting_esE)
+ case 1
+ thus ?thesis using waiting(1,2)
+ by (unfold s_RAG_def, fold waiting_eq, auto)
+ next
+ case 2
+ thus ?thesis using waiting(1,2) by auto
+ qed
+ next
+ case (holding th' cs')
+ from this(3)
+ show ?thesis
+ proof(cases rule:holding_esE)
+ case 1
+ with holding(1,2)
+ show ?thesis by (unfold s_RAG_def, fold holding_eq, auto)
+ qed
+ qed
+next
+ fix n1 n2
+ assume "(n1, n2) \<in> ?R"
+ hence "(n1, n2) \<in> RAG s \<or> (n1 = Th th \<and> n2 = Cs cs)" by auto
+ thus "(n1, n2) \<in> ?L"
+ proof
+ assume "(n1, n2) \<in> RAG s"
+ thus ?thesis
+ proof(cases rule:in_RAG_E)
+ case (waiting th' cs')
+ from waiting_kept[OF this(3)]
+ show ?thesis using waiting(1,2)
+ by (unfold s_RAG_def, fold waiting_eq, auto)
+ next
+ case (holding th' cs')
+ from holding_kept[OF this(3)]
+ show ?thesis using holding(1,2)
+ by (unfold s_RAG_def, fold holding_eq, auto)
+ qed
+ next
+ assume "n1 = Th th \<and> n2 = Cs cs"
+ thus ?thesis using RAG_edge by auto
+ qed
+qed
+
+end
+
+context valid_trace_p_h
+begin
+
+lemma wq_es_cs': "wq (e#s) cs = [th]"
+ using wq_es_cs[unfolded we] by simp
+
+lemma holding_es_th_cs:
+ shows "holding (e#s) th cs"
+proof -
+ from wq_es_cs'
+ have "th \<in> set (wq (e#s) cs)" "th = hd (wq (e#s) cs)" by auto
+ thus ?thesis using cs_holding_def holding_eq by blast
+qed
+
+lemma RAG_edge: "(Cs cs, Th th) \<in> RAG (e#s)"
+ by (unfold s_RAG_def, fold holding_eq, insert holding_es_th_cs, auto)
+
+lemma waiting_esE:
+ assumes "waiting (e#s) th' cs'"
+ obtains "waiting s th' cs'"
+ using assms
+ by (metis cs_waiting_def event.distinct(15) is_p list.sel(1)
+ set_ConsD waiting_eq we wq_es_cs' wq_neq_simp wq_out_inv)
+
+lemma holding_esE:
+ assumes "holding (e#s) th' cs'"
+ obtains "cs' \<noteq> cs" "holding s th' cs'"
+ | "cs' = cs" "th' = th"
+proof(cases "cs' = cs")
+ case True
+ from held_unique[OF holding_es_th_cs assms[unfolded True]]
+ have "th' = th" by simp
+ from that(2)[OF True this] show ?thesis .
+next
+ case False
+ have "holding s th' cs'" using assms
+ using False cs_holding_def holding_eq by auto
+ from that(1)[OF False this] show ?thesis .
+qed
+
+lemma RAG_es: "RAG (e # s) = RAG s \<union> {(Cs cs, Th 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')
+ from this(3)
+ show ?thesis
+ proof(cases rule:waiting_esE)
+ case 1
+ thus ?thesis using waiting(1,2)
+ by (unfold s_RAG_def, fold waiting_eq, auto)
+ qed
+ next
+ case (holding th' cs')
+ from this(3)
+ show ?thesis
+ proof(cases rule:holding_esE)
+ case 1
+ with holding(1,2)
+ show ?thesis by (unfold s_RAG_def, fold holding_eq, auto)
+ next
+ case 2
+ with holding(1,2) show ?thesis by auto
+ qed
+ qed
+next
+ fix n1 n2
+ assume "(n1, n2) \<in> ?R"
+ hence "(n1, n2) \<in> RAG s \<or> (n1 = Cs cs \<and> n2 = Th th)" by auto
+ thus "(n1, n2) \<in> ?L"
+ proof
+ assume "(n1, n2) \<in> RAG s"
+ thus ?thesis
+ proof(cases rule:in_RAG_E)
+ case (waiting th' cs')
+ from waiting_kept[OF this(3)]
+ show ?thesis using waiting(1,2)
+ by (unfold s_RAG_def, fold waiting_eq, auto)
+ next
+ case (holding th' cs')
+ from holding_kept[OF this(3)]
+ show ?thesis using holding(1,2)
+ by (unfold s_RAG_def, fold holding_eq, auto)
+ qed
+ next
+ assume "n1 = Cs cs \<and> n2 = Th th"
+ with holding_es_th_cs
+ show ?thesis
+ by (unfold s_RAG_def, fold holding_eq, auto)
+ qed
+qed
+
+end
+
+context valid_trace_p
+begin
+
+lemma RAG_es': "RAG (e # s) = (if (wq s cs = []) then RAG s \<union> {(Cs cs, Th th)}
+ else RAG s \<union> {(Th th, Cs cs)})"
+proof(cases "wq s cs = []")
+ case True
+ interpret vt_p: valid_trace_p_h using True
+ by (unfold_locales, simp)
+ show ?thesis by (simp add: vt_p.RAG_es vt_p.we)
+next
+ case False
+ interpret vt_p: valid_trace_p_w using False
+ by (unfold_locales, simp)
+ show ?thesis by (simp add: vt_p.RAG_es vt_p.wne)
+qed
+
+end
+
+
+end