src/HOL/Lifting_Set.thy
changeset 53012 cb82606b8215
child 53927 abe2b313f0e5
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Lifting_Set.thy	Tue Aug 13 15:59:22 2013 +0200
@@ -0,0 +1,273 @@
+(*  Title:      HOL/Lifting_Set.thy
+    Author:     Brian Huffman and Ondrej Kuncar
+*)
+
+header {* Setup for Lifting/Transfer for the set type *}
+
+theory Lifting_Set
+imports Lifting
+begin
+
+subsection {* Relator and predicator properties *}
+
+definition set_rel :: "('a \<Rightarrow> 'b \<Rightarrow> bool) \<Rightarrow> 'a set \<Rightarrow> 'b set \<Rightarrow> bool"
+  where "set_rel R = (\<lambda>A B. (\<forall>x\<in>A. \<exists>y\<in>B. R x y) \<and> (\<forall>y\<in>B. \<exists>x\<in>A. R x y))"
+
+lemma set_relI:
+  assumes "\<And>x. x \<in> A \<Longrightarrow> \<exists>y\<in>B. R x y"
+  assumes "\<And>y. y \<in> B \<Longrightarrow> \<exists>x\<in>A. R x y"
+  shows "set_rel R A B"
+  using assms unfolding set_rel_def by simp
+
+lemma set_rel_conversep: "set_rel (conversep R) = conversep (set_rel R)"
+  unfolding set_rel_def by auto
+
+lemma set_rel_eq [relator_eq]: "set_rel (op =) = (op =)"
+  unfolding set_rel_def fun_eq_iff by auto
+
+lemma set_rel_mono[relator_mono]:
+  assumes "A \<le> B"
+  shows "set_rel A \<le> set_rel B"
+using assms unfolding set_rel_def by blast
+
+lemma set_rel_OO[relator_distr]: "set_rel R OO set_rel S = set_rel (R OO S)"
+  apply (rule sym)
+  apply (intro ext, rename_tac X Z)
+  apply (rule iffI)
+  apply (rule_tac b="{y. (\<exists>x\<in>X. R x y) \<and> (\<exists>z\<in>Z. S y z)}" in relcomppI)
+  apply (simp add: set_rel_def, fast)
+  apply (simp add: set_rel_def, fast)
+  apply (simp add: set_rel_def, fast)
+  done
+
+lemma Domainp_set[relator_domain]:
+  assumes "Domainp T = R"
+  shows "Domainp (set_rel T) = (\<lambda>A. Ball A R)"
+using assms unfolding set_rel_def Domainp_iff[abs_def]
+apply (intro ext)
+apply (rule iffI) 
+apply blast
+apply (rename_tac A, rule_tac x="{y. \<exists>x\<in>A. T x y}" in exI, fast)
+done
+
+lemma reflp_set_rel[reflexivity_rule]: "reflp R \<Longrightarrow> reflp (set_rel R)"
+  unfolding reflp_def set_rel_def by fast
+
+lemma left_total_set_rel[reflexivity_rule]: 
+  "left_total A \<Longrightarrow> left_total (set_rel A)"
+  unfolding left_total_def set_rel_def
+  apply safe
+  apply (rename_tac X, rule_tac x="{y. \<exists>x\<in>X. A x y}" in exI, fast)
+done
+
+lemma left_unique_set_rel[reflexivity_rule]: 
+  "left_unique A \<Longrightarrow> left_unique (set_rel A)"
+  unfolding left_unique_def set_rel_def
+  by fast
+
+lemma right_total_set_rel [transfer_rule]:
+  "right_total A \<Longrightarrow> right_total (set_rel A)"
+  unfolding right_total_def set_rel_def
+  by (rule allI, rename_tac Y, rule_tac x="{x. \<exists>y\<in>Y. A x y}" in exI, fast)
+
+lemma right_unique_set_rel [transfer_rule]:
+  "right_unique A \<Longrightarrow> right_unique (set_rel A)"
+  unfolding right_unique_def set_rel_def by fast
+
+lemma bi_total_set_rel [transfer_rule]:
+  "bi_total A \<Longrightarrow> bi_total (set_rel A)"
+  unfolding bi_total_def set_rel_def
+  apply safe
+  apply (rename_tac X, rule_tac x="{y. \<exists>x\<in>X. A x y}" in exI, fast)
+  apply (rename_tac Y, rule_tac x="{x. \<exists>y\<in>Y. A x y}" in exI, fast)
+  done
+
+lemma bi_unique_set_rel [transfer_rule]:
+  "bi_unique A \<Longrightarrow> bi_unique (set_rel A)"
+  unfolding bi_unique_def set_rel_def by fast
+
+lemma set_invariant_commute [invariant_commute]:
+  "set_rel (Lifting.invariant P) = Lifting.invariant (\<lambda>A. Ball A P)"
+  unfolding fun_eq_iff set_rel_def Lifting.invariant_def Ball_def by fast
+
+subsection {* Quotient theorem for the Lifting package *}
+
+lemma Quotient_set[quot_map]:
+  assumes "Quotient R Abs Rep T"
+  shows "Quotient (set_rel R) (image Abs) (image Rep) (set_rel T)"
+  using assms unfolding Quotient_alt_def4
+  apply (simp add: set_rel_OO[symmetric] set_rel_conversep)
+  apply (simp add: set_rel_def, fast)
+  done
+
+subsection {* Transfer rules for the Transfer package *}
+
+subsubsection {* Unconditional transfer rules *}
+
+context
+begin
+interpretation lifting_syntax .
+
+lemma empty_transfer [transfer_rule]: "(set_rel A) {} {}"
+  unfolding set_rel_def by simp
+
+lemma insert_transfer [transfer_rule]:
+  "(A ===> set_rel A ===> set_rel A) insert insert"
+  unfolding fun_rel_def set_rel_def by auto
+
+lemma union_transfer [transfer_rule]:
+  "(set_rel A ===> set_rel A ===> set_rel A) union union"
+  unfolding fun_rel_def set_rel_def by auto
+
+lemma Union_transfer [transfer_rule]:
+  "(set_rel (set_rel A) ===> set_rel A) Union Union"
+  unfolding fun_rel_def set_rel_def by simp fast
+
+lemma image_transfer [transfer_rule]:
+  "((A ===> B) ===> set_rel A ===> set_rel B) image image"
+  unfolding fun_rel_def set_rel_def by simp fast
+
+lemma UNION_transfer [transfer_rule]:
+  "(set_rel A ===> (A ===> set_rel B) ===> set_rel B) UNION UNION"
+  unfolding SUP_def [abs_def] by transfer_prover
+
+lemma Ball_transfer [transfer_rule]:
+  "(set_rel A ===> (A ===> op =) ===> op =) Ball Ball"
+  unfolding set_rel_def fun_rel_def by fast
+
+lemma Bex_transfer [transfer_rule]:
+  "(set_rel A ===> (A ===> op =) ===> op =) Bex Bex"
+  unfolding set_rel_def fun_rel_def by fast
+
+lemma Pow_transfer [transfer_rule]:
+  "(set_rel A ===> set_rel (set_rel A)) Pow Pow"
+  apply (rule fun_relI, rename_tac X Y, rule set_relI)
+  apply (rename_tac X', rule_tac x="{y\<in>Y. \<exists>x\<in>X'. A x y}" in rev_bexI, clarsimp)
+  apply (simp add: set_rel_def, fast)
+  apply (rename_tac Y', rule_tac x="{x\<in>X. \<exists>y\<in>Y'. A x y}" in rev_bexI, clarsimp)
+  apply (simp add: set_rel_def, fast)
+  done
+
+lemma set_rel_transfer [transfer_rule]:
+  "((A ===> B ===> op =) ===> set_rel A ===> set_rel B ===> op =)
+    set_rel set_rel"
+  unfolding fun_rel_def set_rel_def by fast
+
+
+subsubsection {* Rules requiring bi-unique, bi-total or right-total relations *}
+
+lemma member_transfer [transfer_rule]:
+  assumes "bi_unique A"
+  shows "(A ===> set_rel A ===> op =) (op \<in>) (op \<in>)"
+  using assms unfolding fun_rel_def set_rel_def bi_unique_def by fast
+
+lemma right_total_Collect_transfer[transfer_rule]:
+  assumes "right_total A"
+  shows "((A ===> op =) ===> set_rel A) (\<lambda>P. Collect (\<lambda>x. P x \<and> Domainp A x)) Collect"
+  using assms unfolding right_total_def set_rel_def fun_rel_def Domainp_iff by fast
+
+lemma Collect_transfer [transfer_rule]:
+  assumes "bi_total A"
+  shows "((A ===> op =) ===> set_rel A) Collect Collect"
+  using assms unfolding fun_rel_def set_rel_def bi_total_def by fast
+
+lemma inter_transfer [transfer_rule]:
+  assumes "bi_unique A"
+  shows "(set_rel A ===> set_rel A ===> set_rel A) inter inter"
+  using assms unfolding fun_rel_def set_rel_def bi_unique_def by fast
+
+lemma Diff_transfer [transfer_rule]:
+  assumes "bi_unique A"
+  shows "(set_rel A ===> set_rel A ===> set_rel A) (op -) (op -)"
+  using assms unfolding fun_rel_def set_rel_def bi_unique_def
+  unfolding Ball_def Bex_def Diff_eq
+  by (safe, simp, metis, simp, metis)
+
+lemma subset_transfer [transfer_rule]:
+  assumes [transfer_rule]: "bi_unique A"
+  shows "(set_rel A ===> set_rel A ===> op =) (op \<subseteq>) (op \<subseteq>)"
+  unfolding subset_eq [abs_def] by transfer_prover
+
+lemma right_total_UNIV_transfer[transfer_rule]: 
+  assumes "right_total A"
+  shows "(set_rel A) (Collect (Domainp A)) UNIV"
+  using assms unfolding right_total_def set_rel_def Domainp_iff by blast
+
+lemma UNIV_transfer [transfer_rule]:
+  assumes "bi_total A"
+  shows "(set_rel A) UNIV UNIV"
+  using assms unfolding set_rel_def bi_total_def by simp
+
+lemma right_total_Compl_transfer [transfer_rule]:
+  assumes [transfer_rule]: "bi_unique A" and [transfer_rule]: "right_total A"
+  shows "(set_rel A ===> set_rel A) (\<lambda>S. uminus S \<inter> Collect (Domainp A)) uminus"
+  unfolding Compl_eq [abs_def]
+  by (subst Collect_conj_eq[symmetric]) transfer_prover
+
+lemma Compl_transfer [transfer_rule]:
+  assumes [transfer_rule]: "bi_unique A" and [transfer_rule]: "bi_total A"
+  shows "(set_rel A ===> set_rel A) uminus uminus"
+  unfolding Compl_eq [abs_def] by transfer_prover
+
+lemma right_total_Inter_transfer [transfer_rule]:
+  assumes [transfer_rule]: "bi_unique A" and [transfer_rule]: "right_total A"
+  shows "(set_rel (set_rel A) ===> set_rel A) (\<lambda>S. Inter S \<inter> Collect (Domainp A)) Inter"
+  unfolding Inter_eq[abs_def]
+  by (subst Collect_conj_eq[symmetric]) transfer_prover
+
+lemma Inter_transfer [transfer_rule]:
+  assumes [transfer_rule]: "bi_unique A" and [transfer_rule]: "bi_total A"
+  shows "(set_rel (set_rel A) ===> set_rel A) Inter Inter"
+  unfolding Inter_eq [abs_def] by transfer_prover
+
+lemma filter_transfer [transfer_rule]:
+  assumes [transfer_rule]: "bi_unique A"
+  shows "((A ===> op=) ===> set_rel A ===> set_rel A) Set.filter Set.filter"
+  unfolding Set.filter_def[abs_def] fun_rel_def set_rel_def by blast
+
+lemma bi_unique_set_rel_lemma:
+  assumes "bi_unique R" and "set_rel R X Y"
+  obtains f where "Y = image f X" and "inj_on f X" and "\<forall>x\<in>X. R x (f x)"
+proof
+  let ?f = "\<lambda>x. THE y. R x y"
+  from assms show f: "\<forall>x\<in>X. R x (?f x)"
+    apply (clarsimp simp add: set_rel_def)
+    apply (drule (1) bspec, clarify)
+    apply (rule theI2, assumption)
+    apply (simp add: bi_unique_def)
+    apply assumption
+    done
+  from assms show "Y = image ?f X"
+    apply safe
+    apply (clarsimp simp add: set_rel_def)
+    apply (drule (1) bspec, clarify)
+    apply (rule image_eqI)
+    apply (rule the_equality [symmetric], assumption)
+    apply (simp add: bi_unique_def)
+    apply assumption
+    apply (clarsimp simp add: set_rel_def)
+    apply (frule (1) bspec, clarify)
+    apply (rule theI2, assumption)
+    apply (clarsimp simp add: bi_unique_def)
+    apply (simp add: bi_unique_def, metis)
+    done
+  show "inj_on ?f X"
+    apply (rule inj_onI)
+    apply (drule f [rule_format])
+    apply (drule f [rule_format])
+    apply (simp add: assms(1) [unfolded bi_unique_def])
+    done
+qed
+
+lemma finite_transfer [transfer_rule]:
+  "bi_unique A \<Longrightarrow> (set_rel A ===> op =) finite finite"
+  by (rule fun_relI, erule (1) bi_unique_set_rel_lemma,
+    auto dest: finite_imageD)
+
+lemma card_transfer [transfer_rule]:
+  "bi_unique A \<Longrightarrow> (set_rel A ===> op =) card card"
+  by (rule fun_relI, erule (1) bi_unique_set_rel_lemma, simp add: card_image)
+
+end
+
+end