thys/Spec.thy
changeset 267 32b222d77fa0
parent 266 fff2e1b40dfc
child 268 6746f5e1f1f8
--- a/thys/Spec.thy	Wed Jul 19 14:55:46 2017 +0100
+++ b/thys/Spec.thy	Fri Aug 11 20:29:01 2017 +0100
@@ -1,9 +1,8 @@
    
 theory Spec
-  imports Main 
+  imports Main "~~/src/HOL/Library/Sublist"
 begin
 
-
 section {* Sequential Composition of Languages *}
 
 definition
@@ -172,13 +171,15 @@
 
 lemma ders_correctness:
   shows "L (ders s r) = Ders s (L r)"
-apply(induct s arbitrary: r)
-apply(simp_all add: Ders_def der_correctness Der_def)
-done
+by (induct s arbitrary: r)
+   (simp_all add: Ders_def der_correctness Der_def)
+
 
 
 section {* Lemmas about ders *}
 
+(* not really needed *)
+
 lemma ders_ZERO:
   shows "ders s (ZERO) = ZERO"
 apply(induct s)
@@ -201,9 +202,8 @@
 
 lemma  ders_ALT:
   shows "ders s (ALT r1 r2) = ALT (ders s r1) (ders s r2)"
-apply(induct s arbitrary: r1 r2)
-apply(simp_all)
-done
+by (induct s arbitrary: r1 r2)(simp_all)
+
 
 section {* Values *}
 
@@ -229,8 +229,11 @@
 | "flat (Stars []) = []"
 | "flat (Stars (v#vs)) = (flat v) @ (flat (Stars vs))" 
 
+abbreviation
+  "flats vs \<equiv> concat (map flat vs)"
+
 lemma flat_Stars [simp]:
- "flat (Stars vs) = concat (map flat vs)"
+ "flat (Stars vs) = flats vs"
 by (induct vs) (auto)
 
 
@@ -273,7 +276,7 @@
 
 lemma Star_val:
   assumes "\<forall>s\<in>set ss. \<exists>v. s = flat v \<and> \<turnstile> v : r"
-  shows "\<exists>vs. concat (map flat vs) = concat ss \<and> (\<forall>v\<in>set vs. \<turnstile> v : r)"
+  shows "\<exists>vs. flats vs = concat ss \<and> (\<forall>v\<in>set vs. \<turnstile> v : r)"
 using assms
 apply(induct ss)
 apply(auto)
@@ -313,7 +316,7 @@
   have "s \<in> L (STAR r)" by fact
   then obtain ss where "concat ss = s" "\<forall>s \<in> set ss. s \<in> L r"
   using Star_string by auto
-  then obtain vs where "concat (map flat vs) = s" "\<forall>v\<in>set vs. \<turnstile> v : r"
+  then obtain vs where "flats vs = s" "\<forall>v\<in>set vs. \<turnstile> v : r"
   using IH Star_val by blast
   then show "\<exists>v. \<turnstile> v : STAR r \<and> flat v = s"
   using Prf.intros(6) flat_Stars by blast
@@ -331,8 +334,8 @@
   shows "L(r) = {flat v | v. \<turnstile> v : r}"
 using L_flat_Prf1 L_flat_Prf2 by blast
 
-section {* CPT and CPTpre *}
 
+section {* Canonical Values *}
 
 inductive 
   CPrf :: "val \<Rightarrow> rexp \<Rightarrow> bool" ("\<Turnstile> _ : _" [100, 100] 100)
@@ -350,71 +353,153 @@
 using assms
 by (induct)(auto intro: Prf.intros)
 
-lemma CPrf_stars:
-  assumes "\<Turnstile> Stars vs : STAR r"
-  shows "\<forall>v \<in> set vs. flat v \<noteq> [] \<and> \<Turnstile> v : r"
-using assms
-apply(erule_tac CPrf.cases)
-apply(simp_all)
-done
-
 lemma CPrf_Stars_appendE:
   assumes "\<Turnstile> Stars (vs1 @ vs2) : STAR r"
   shows "\<Turnstile> Stars vs1 : STAR r \<and> \<Turnstile> Stars vs2 : STAR r" 
 using assms
 apply(erule_tac CPrf.cases)
-apply(auto intro: CPrf.intros elim: Prf.cases)
+apply(auto intro: CPrf.intros)
 done
 
-definition PT :: "rexp \<Rightarrow> string \<Rightarrow> val set"
-where "PT r s \<equiv> {v. flat v = s \<and> \<turnstile> v : r}"
+
+section {* Sets of Lexical and Canonical Values *}
 
-definition
-  "CPT r s = {v. flat v = s \<and> \<Turnstile> v : r}"
+definition 
+  LV :: "rexp \<Rightarrow> string \<Rightarrow> val set"
+where "LV r s \<equiv> {v.  \<turnstile> v : r \<and> flat v = s}"
 
 definition
-  "CPTpre r s = {v. \<exists>s'. flat v @ s' = s \<and> \<Turnstile> v : r}"
+  CV :: "rexp \<Rightarrow> string \<Rightarrow> val set"
+where  "CV r s \<equiv> {v. \<Turnstile> v : r \<and> flat v = s}"
+
+lemma LV_CV_subset:
+  shows "CV r s \<subseteq> LV r s"
+unfolding CV_def LV_def by(auto simp add: Prf_CPrf)
+
+abbreviation
+  "Prefixes s \<equiv> {s'. prefixeq s' s}"
+
+abbreviation
+  "Suffixes s \<equiv> {s'. suffixeq s' s}"
+
+abbreviation
+  "SSuffixes s \<equiv> {s'. suffix s' s}"
 
-lemma CPT_CPTpre_subset:
-  shows "CPT r s \<subseteq> CPTpre r s"
-by(auto simp add: CPT_def CPTpre_def)
+lemma Suffixes_cons [simp]:
+  shows "Suffixes (c # s) = Suffixes s \<union> {c # s}"
+by (auto simp add: suffixeq_def Cons_eq_append_conv)
+
+lemma CV_simps:
+  shows "CV ZERO s = {}"
+  and   "CV ONE s = (if s = [] then {Void} else {})"
+  and   "CV (CHAR c) s = (if s = [c] then {Char c} else {})"
+  and   "CV (ALT r1 r2) s = Left ` CV r1 s \<union> Right ` CV r2 s"
+unfolding CV_def
+by (auto intro: CPrf.intros elim: CPrf.cases)
+
+lemma finite_Suffixes: 
+  shows "finite (Suffixes s)"
+by (induct s) (simp_all)
 
-lemma CPT_simps:
-  shows "CPT ZERO s = {}"
-  and   "CPT ONE s = (if s = [] then {Void} else {})"
-  and   "CPT (CHAR c) s = (if s = [c] then {Char c} else {})"
-  and   "CPT (ALT r1 r2) s = Left ` CPT r1 s \<union> Right ` CPT r2 s"
-  and   "CPT (SEQ r1 r2) s = 
-          {Seq v1 v2 | v1 v2. flat v1 @ flat v2 = s \<and> v1 \<in> CPT r1 (flat v1) \<and> v2 \<in> CPT r2 (flat v2)}"
-  and   "CPT (STAR r) s = 
-          Stars ` {vs. concat (map flat vs) = s \<and> (\<forall>v \<in> set vs. v \<in> CPT r (flat v) \<and> flat v \<noteq> [])}"
-apply -
-apply(auto simp add: CPT_def intro: CPrf.intros)[1]
+lemma finite_SSuffixes: 
+  shows "finite (SSuffixes s)"
+proof -
+  have "SSuffixes s \<subseteq> Suffixes s"
+   unfolding suffix_def suffixeq_def by auto
+  then show "finite (SSuffixes s)"
+   using finite_Suffixes finite_subset by blast
+qed
+
+lemma finite_Prefixes: 
+  shows "finite (Prefixes s)"
+proof -
+  have "finite (Suffixes (rev s))" 
+    by (rule finite_Suffixes)
+  then have "finite (rev ` Suffixes (rev s))" by simp
+  moreover
+  have "rev ` (Suffixes (rev s)) = Prefixes s"
+  unfolding suffixeq_def prefixeq_def image_def
+   by (auto)(metis rev_append rev_rev_ident)+
+  ultimately show "finite (Prefixes s)" by simp
+qed
+
+lemma CV_SEQ_subset:
+  "CV (SEQ r1 r2) s \<subseteq> (\<lambda>(v1,v2). Seq v1 v2) ` ((\<Union>s' \<in> Prefixes s. CV r1 s') \<times> (\<Union>s' \<in> Suffixes s. CV r2 s'))"
+unfolding image_def CV_def prefixeq_def suffixeq_def
+by (auto elim: CPrf.cases)
+
+lemma CV_STAR_subset:
+  "CV (STAR r) s \<subseteq> {Stars []} \<union>
+      (\<lambda>(v,vs). Stars (v#vs)) ` ((\<Union>s' \<in> Prefixes s. CV r s') \<times> (\<Union>s2 \<in> SSuffixes s. Stars -` (CV (STAR r) s2)))"
+unfolding image_def CV_def prefixeq_def suffix_def
+apply(auto)
 apply(erule CPrf.cases)
-apply(simp_all)[6]
-apply(auto simp add: CPT_def intro: CPrf.intros)[1]
-apply(erule CPrf.cases)
-apply(simp_all)[6]
-apply(erule CPrf.cases)
-apply(simp_all)[6]
-apply(auto simp add: CPT_def intro: CPrf.intros)[1]
-apply(erule CPrf.cases)
-apply(simp_all)[6]
-apply(erule CPrf.cases)
-apply(simp_all)[6]
-apply(auto simp add: CPT_def intro: CPrf.intros)[1]
-apply(erule CPrf.cases)
-apply(simp_all)[6]
-apply(auto simp add: CPT_def intro: CPrf.intros)[1]
-apply(erule CPrf.cases)
-apply(simp_all)[6]
-(* STAR case *)
-apply(auto simp add: CPT_def intro: CPrf.intros)[1]
-apply(erule CPrf.cases)
-apply(simp_all)[6]
+apply(auto)
+apply(case_tac vs)
+apply(auto intro: CPrf.intros)
 done
 
 
+lemma CV_STAR_finite:
+  assumes "\<forall>s. finite (CV r s)"
+  shows "finite (CV (STAR r) s)"
+proof(induct s rule: length_induct)
+  fix s::"char list"
+  assume "\<forall>s'. length s' < length s \<longrightarrow> finite (CV (STAR r) s')"
+  then have IH: "\<forall>s' \<in> SSuffixes s. finite (CV (STAR r) s')"
+    by (auto simp add: suffix_def) 
+  def f \<equiv> "\<lambda>(v, vs). Stars (v # vs)"
+  def S1 \<equiv> "\<Union>s' \<in> Prefixes s. CV r s'"
+  def S2 \<equiv> "\<Union>s2 \<in> SSuffixes s. Stars -` (CV (STAR r) s2)"
+  have "finite S1" using assms
+    unfolding S1_def by (simp_all add: finite_Prefixes)
+  moreover 
+  with IH have "finite S2" unfolding S2_def
+    by (auto simp add: finite_SSuffixes inj_on_def finite_vimageI)
+  ultimately 
+  have "finite ({Stars []} \<union> f ` (S1 \<times> S2))" by simp
+  moreover 
+  have "CV (STAR r) s \<subseteq> {Stars []} \<union> f ` (S1 \<times> S2)" unfolding S1_def S2_def f_def
+     by (rule CV_STAR_subset)
+  ultimately
+  show "finite (CV (STAR r) s)" by (simp add: finite_subset)
+qed  
+    
+
+lemma CV_finite:
+  shows "finite (CV r s)"
+proof(induct r arbitrary: s)
+  case (ZERO s) 
+  show "finite (CV ZERO s)" by (simp add: CV_simps)
+next
+  case (ONE s)
+  show "finite (CV ONE s)" by (simp add: CV_simps)
+next
+  case (CHAR c s)
+  show "finite (CV (CHAR c) s)" by (simp add: CV_simps)
+next 
+  case (ALT r1 r2 s)
+  then show "finite (CV (ALT r1 r2) s)" by (simp add: CV_simps)
+next 
+  case (SEQ r1 r2 s)
+  def f \<equiv> "\<lambda>(v1, v2). Seq v1 v2"
+  def S1 \<equiv> "\<Union>s' \<in> Prefixes s. CV r1 s'"
+  def S2 \<equiv> "\<Union>s' \<in> Suffixes s. CV r2 s'"
+  have IHs: "\<And>s. finite (CV r1 s)" "\<And>s. finite (CV r2 s)" by fact+
+  then have "finite S1" "finite S2" unfolding S1_def S2_def
+    by (simp_all add: finite_Prefixes finite_Suffixes)
+  moreover
+  have "CV (SEQ r1 r2) s \<subseteq> f ` (S1 \<times> S2)"
+    unfolding f_def S1_def S2_def by (auto simp add: CV_SEQ_subset)
+  ultimately 
+  show "finite (CV (SEQ r1 r2) s)"
+    by (simp add: finite_subset)
+next
+  case (STAR r s)
+  then show "finite (CV (STAR r) s)" by (simp add: CV_STAR_finite)
+qed
+
+
 
 section {* Our POSIX Definition *}
 
@@ -531,12 +616,12 @@
   Our POSIX value is a canonical value.
 *}
 
-lemma Posix_CPT:
+lemma Posix_CV:
   assumes "s \<in> r \<rightarrow> v"
-  shows "v \<in> CPT r s"
+  shows "v \<in> CV r s"
 using assms
 apply(induct rule: Posix.induct)
-apply(auto simp add: CPT_def intro: CPrf.intros elim: CPrf.cases)
+apply(auto simp add: CV_def intro: CPrf.intros elim: CPrf.cases)
 apply(rotate_tac 5)
 apply(erule CPrf.cases)
 apply(simp_all)
@@ -544,203 +629,17 @@
 apply(simp_all)
 done
 
-
-
-(*
-lemma CPTpre_STAR_finite:
-  assumes "\<And>s. finite (CPT r s)"
-  shows "finite (CPT (STAR r) s)"
-apply(induct s rule: length_induct)
-apply(case_tac xs)
-apply(simp)
-apply(simp add: CPT_simps)
-apply(auto)
-apply(rule finite_imageI)
-using assms
-thm finite_Un
-prefer 2
-apply(simp add: CPT_simps)
-apply(rule finite_imageI)
-apply(rule finite_subset)
-apply(rule CPTpre_subsets)
-apply(simp)
-apply(rule_tac B="(\<lambda>(v, vs). Stars (v#vs)) ` {(v, vs). v \<in> CPTpre r (a#list) \<and> flat v \<noteq> [] \<and> Stars vs \<in> CPTpre (STAR r) (drop (length (flat v)) (a#list))}" in finite_subset)
-apply(auto)[1]
-apply(rule finite_imageI)
-apply(simp add: Collect_case_prod_Sigma)
-apply(rule finite_SigmaI)
-apply(rule assms)
-apply(case_tac "flat v = []")
-apply(simp)
-apply(drule_tac x="drop (length (flat v)) (a # list)" in spec)
-apply(simp)
-apply(auto)[1]
-apply(rule test)
-apply(simp)
-done
-
-lemma CPTpre_subsets:
-  "CPTpre ZERO s = {}"
-  "CPTpre ONE s \<subseteq> {Void}"
-  "CPTpre (CHAR c) s \<subseteq> {Char c}"
-  "CPTpre (ALT r1 r2) s \<subseteq> Left ` CPTpre r1 s \<union> Right ` CPTpre r2 s"
-  "CPTpre (SEQ r1 r2) s \<subseteq> {Seq v1 v2 | v1 v2. v1 \<in> CPTpre r1 s \<and> v2 \<in> CPTpre r2 (drop (length (flat v1)) s)}"
-  "CPTpre (STAR r) s \<subseteq> {Stars []} \<union>
-    {Stars (v#vs) | v vs. v \<in> CPTpre r s \<and> flat v \<noteq> [] \<and> Stars vs \<in> CPTpre (STAR r) (drop (length (flat v)) s)}"
-  "CPTpre (STAR r) [] = {Stars []}"
-apply(auto simp add: CPTpre_def)
-apply(erule CPrf.cases)
-apply(simp_all)
-apply(erule CPrf.cases)
-apply(simp_all)
-apply(erule CPrf.cases)
-apply(simp_all)
-apply(erule CPrf.cases)
-apply(simp_all)
-apply(erule CPrf.cases)
-apply(simp_all)
-
-apply(erule CPrf.cases)
-apply(simp_all)
-apply(erule CPrf.cases)
-apply(simp_all)
-apply(rule CPrf.intros)
-done
-
-
-lemma CPTpre_simps:
-  shows "CPTpre ONE s = {Void}"
-  and   "CPTpre (CHAR c) (d#s) = (if c = d then {Char c} else {})"
-  and   "CPTpre (ALT r1 r2) s = Left ` CPTpre r1 s \<union> Right ` CPTpre r2 s"
-  and   "CPTpre (SEQ r1 r2) s = 
-          {Seq v1 v2 | v1 v2. v1 \<in> CPTpre r1 s \<and> v2 \<in> CPTpre r2 (drop (length (flat v1)) s)}"
-apply -
-apply(rule subset_antisym)
-apply(rule CPTpre_subsets)
-apply(auto simp add: CPTpre_def intro: "CPrf.intros")[1]
-apply(case_tac "c = d")
-apply(simp)
-apply(rule subset_antisym)
-apply(rule CPTpre_subsets)
-apply(auto simp add: CPTpre_def intro: CPrf.intros)[1]
-apply(simp)
-apply(auto simp add: CPTpre_def intro: CPrf.intros)[1]
-apply(erule CPrf.cases)
-apply(simp_all)
-apply(rule subset_antisym)
-apply(rule CPTpre_subsets)
-apply(auto simp add: CPTpre_def intro: CPrf.intros)[1]
-apply(rule subset_antisym)
-apply(rule CPTpre_subsets)
-apply(auto simp add: CPTpre_def intro: CPrf.intros)[1]
-done
-
-lemma CPT_simps:
-  shows "CPT ONE s = (if s = [] then {Void} else {})"
-  and   "CPT (CHAR c) [d] = (if c = d then {Char c} else {})"
-  and   "CPT (ALT r1 r2) s = Left ` CPT r1 s \<union> Right ` CPT r2 s"
-  and   "CPT (SEQ r1 r2) s = 
-          {Seq v1 v2 | v1 v2 s1 s2. s1 @ s2 = s \<and> v1 \<in> CPT r1 s1 \<and> v2 \<in> CPT r2 s2}"
-apply -
-apply(rule subset_antisym)
-apply(auto simp add: CPT_def)[1]
-apply(erule CPrf.cases)
-apply(simp_all)[7]
-apply(erule CPrf.cases)
-apply(simp_all)[7]
-apply(auto simp add: CPT_def intro: CPrf.intros)[1]
-apply(auto simp add: CPT_def intro: CPrf.intros)[1]
-apply(erule CPrf.cases)
-apply(simp_all)[7]
-apply(erule CPrf.cases)
-apply(simp_all)[7]
-apply(auto simp add: CPT_def image_def intro: CPrf.intros)[1]
-apply(erule CPrf.cases)
-apply(simp_all)[7]
-apply(clarify)
-apply blast
-apply(auto simp add: CPT_def image_def intro: CPrf.intros)[1]
-apply(erule CPrf.cases)
-apply(simp_all)[7]
-done
-
-lemma test: 
-  assumes "finite A"
-  shows "finite {vs. Stars vs \<in> A}"
-using assms
-apply(induct A)
-apply(simp)
-apply(auto)
-apply(case_tac x)
-apply(simp_all)
-done
-
-lemma CPTpre_STAR_finite:
-  assumes "\<And>s. finite (CPTpre r s)"
-  shows "finite (CPTpre (STAR r) s)"
-apply(induct s rule: length_induct)
-apply(case_tac xs)
-apply(simp)
-apply(simp add: CPTpre_subsets)
-apply(rule finite_subset)
-apply(rule CPTpre_subsets)
-apply(simp)
-apply(rule_tac B="(\<lambda>(v, vs). Stars (v#vs)) ` {(v, vs). v \<in> CPTpre r (a#list) \<and> flat v \<noteq> [] \<and> Stars vs \<in> CPTpre (STAR r) (drop (length (flat v)) (a#list))}" in finite_subset)
-apply(auto)[1]
-apply(rule finite_imageI)
-apply(simp add: Collect_case_prod_Sigma)
-apply(rule finite_SigmaI)
-apply(rule assms)
-apply(case_tac "flat v = []")
-apply(simp)
-apply(drule_tac x="drop (length (flat v)) (a # list)" in spec)
-apply(simp)
-apply(auto)[1]
-apply(rule test)
-apply(simp)
-done
-
-lemma CPTpre_finite:
-  shows "finite (CPTpre r s)"
-apply(induct r arbitrary: s)
-apply(simp add: CPTpre_subsets)
-apply(rule finite_subset)
-apply(rule CPTpre_subsets)
-apply(simp)
-apply(rule finite_subset)
-apply(rule CPTpre_subsets)
-apply(simp)
-apply(rule finite_subset)
-apply(rule CPTpre_subsets)
-apply(rule_tac B="(\<lambda>(v1, v2). Seq v1 v2) ` {(v1, v2).  v1 \<in> CPTpre r1 s \<and> v2 \<in> CPTpre r2 (drop (length (flat v1)) s)}" in finite_subset)
-apply(auto)[1]
-apply(rule finite_imageI)
-apply(simp add: Collect_case_prod_Sigma)
-apply(rule finite_subset)
-apply(rule CPTpre_subsets)
-apply(simp)
-by (simp add: CPTpre_STAR_finite)
-
-
-lemma CPT_finite:
-  shows "finite (CPT r s)"
-apply(rule finite_subset)
-apply(rule CPT_CPTpre_subset)
-apply(rule CPTpre_finite)
-done
-*)
-
 lemma test2: 
   assumes "\<forall>v \<in> set vs. flat v \<in> r \<rightarrow> v \<and> flat v \<noteq> []"
-  shows "(Stars vs) \<in> CPT (STAR r) (flat (Stars vs))" 
+  shows "(Stars vs) \<in> CV (STAR r) (flat (Stars vs))" 
 using assms
 apply(induct vs)
-apply(auto simp add: CPT_def)
+apply(auto simp add: CV_def)
 apply(rule CPrf.intros)
 apply(simp)
 apply(rule CPrf.intros)
 apply(simp_all)
-by (metis (no_types, lifting) CPT_def Posix_CPT mem_Collect_eq)
+by (metis (no_types, lifting) CV_def Posix_CV mem_Collect_eq)
 
 
 end
\ No newline at end of file