--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/BNF/BNF_GFP.thy Fri Sep 21 16:45:06 2012 +0200
@@ -0,0 +1,331 @@
+(* Title: HOL/BNF/BNF_GFP.thy
+ Author: Dmitriy Traytel, TU Muenchen
+ Copyright 2012
+
+Greatest fixed point operation on bounded natural functors.
+*)
+
+header {* Greatest Fixed Point Operation on Bounded Natural Functors *}
+
+theory BNF_GFP
+imports BNF_FP Equiv_Relations_More "~~/src/HOL/Library/Prefix_Order"
+keywords
+ "codata_raw" :: thy_decl and
+ "codata" :: thy_decl
+begin
+
+lemma sum_case_comp_Inl:
+"sum_case f g \<circ> Inl = f"
+unfolding comp_def by simp
+
+lemma sum_case_expand_Inr: "f o Inl = g \<Longrightarrow> f x = sum_case g (f o Inr) x"
+by (auto split: sum.splits)
+
+lemma converse_Times: "(A \<times> B) ^-1 = B \<times> A"
+by auto
+
+lemma equiv_triv1:
+assumes "equiv A R" and "(a, b) \<in> R" and "(a, c) \<in> R"
+shows "(b, c) \<in> R"
+using assms unfolding equiv_def sym_def trans_def by blast
+
+lemma equiv_triv2:
+assumes "equiv A R" and "(a, b) \<in> R" and "(b, c) \<in> R"
+shows "(a, c) \<in> R"
+using assms unfolding equiv_def trans_def by blast
+
+lemma equiv_proj:
+ assumes e: "equiv A R" and "z \<in> R"
+ shows "(proj R o fst) z = (proj R o snd) z"
+proof -
+ from assms(2) have z: "(fst z, snd z) \<in> R" by auto
+ have P: "\<And>x. (fst z, x) \<in> R \<Longrightarrow> (snd z, x) \<in> R" by (erule equiv_triv1[OF e z])
+ have "\<And>x. (snd z, x) \<in> R \<Longrightarrow> (fst z, x) \<in> R" by (erule equiv_triv2[OF e z])
+ with P show ?thesis unfolding proj_def[abs_def] by auto
+qed
+
+(* Operators: *)
+definition diag where "diag A \<equiv> {(a,a) | a. a \<in> A}"
+definition image2 where "image2 A f g = {(f a, g a) | a. a \<in> A}"
+
+lemma diagI: "x \<in> A \<Longrightarrow> (x, x) \<in> diag A"
+unfolding diag_def by simp
+
+lemma diagE: "(a, b) \<in> diag A \<Longrightarrow> a = b"
+unfolding diag_def by simp
+
+lemma diagE': "x \<in> diag A \<Longrightarrow> fst x = snd x"
+unfolding diag_def by auto
+
+lemma diag_fst: "x \<in> diag A \<Longrightarrow> fst x \<in> A"
+unfolding diag_def by auto
+
+lemma diag_UNIV: "diag UNIV = Id"
+unfolding diag_def by auto
+
+lemma diag_converse: "diag A = (diag A) ^-1"
+unfolding diag_def by auto
+
+lemma diag_Comp: "diag A = diag A O diag A"
+unfolding diag_def by auto
+
+lemma diag_Gr: "diag A = Gr A id"
+unfolding diag_def Gr_def by simp
+
+lemma diag_UNIV_I: "x = y \<Longrightarrow> (x, y) \<in> diag UNIV"
+unfolding diag_def by auto
+
+lemma image2_eqI: "\<lbrakk>b = f x; c = g x; x \<in> A\<rbrakk> \<Longrightarrow> (b, c) \<in> image2 A f g"
+unfolding image2_def by auto
+
+lemma Id_subset: "Id \<subseteq> {(a, b). P a b \<or> a = b}"
+by auto
+
+lemma IdD: "(a, b) \<in> Id \<Longrightarrow> a = b"
+by auto
+
+lemma image2_Gr: "image2 A f g = (Gr A f)^-1 O (Gr A g)"
+unfolding image2_def Gr_def by auto
+
+lemma GrI: "\<lbrakk>x \<in> A; f x = fx\<rbrakk> \<Longrightarrow> (x, fx) \<in> Gr A f"
+unfolding Gr_def by simp
+
+lemma GrE: "(x, fx) \<in> Gr A f \<Longrightarrow> (x \<in> A \<Longrightarrow> f x = fx \<Longrightarrow> P) \<Longrightarrow> P"
+unfolding Gr_def by simp
+
+lemma GrD1: "(x, fx) \<in> Gr A f \<Longrightarrow> x \<in> A"
+unfolding Gr_def by simp
+
+lemma GrD2: "(x, fx) \<in> Gr A f \<Longrightarrow> f x = fx"
+unfolding Gr_def by simp
+
+lemma Gr_incl: "Gr A f \<subseteq> A <*> B \<longleftrightarrow> f ` A \<subseteq> B"
+unfolding Gr_def by auto
+
+definition relImage where
+"relImage R f \<equiv> {(f a1, f a2) | a1 a2. (a1,a2) \<in> R}"
+
+definition relInvImage where
+"relInvImage A R f \<equiv> {(a1, a2) | a1 a2. a1 \<in> A \<and> a2 \<in> A \<and> (f a1, f a2) \<in> R}"
+
+lemma relImage_Gr:
+"\<lbrakk>R \<subseteq> A \<times> A\<rbrakk> \<Longrightarrow> relImage R f = (Gr A f)^-1 O R O Gr A f"
+unfolding relImage_def Gr_def relcomp_def by auto
+
+lemma relInvImage_Gr: "\<lbrakk>R \<subseteq> B \<times> B\<rbrakk> \<Longrightarrow> relInvImage A R f = Gr A f O R O (Gr A f)^-1"
+unfolding Gr_def relcomp_def image_def relInvImage_def by auto
+
+lemma relImage_mono:
+"R1 \<subseteq> R2 \<Longrightarrow> relImage R1 f \<subseteq> relImage R2 f"
+unfolding relImage_def by auto
+
+lemma relInvImage_mono:
+"R1 \<subseteq> R2 \<Longrightarrow> relInvImage A R1 f \<subseteq> relInvImage A R2 f"
+unfolding relInvImage_def by auto
+
+lemma relInvImage_diag:
+"(\<And>a1 a2. f a1 = f a2 \<longleftrightarrow> a1 = a2) \<Longrightarrow> relInvImage A (diag B) f \<subseteq> Id"
+unfolding relInvImage_def diag_def by auto
+
+lemma relInvImage_UNIV_relImage:
+"R \<subseteq> relInvImage UNIV (relImage R f) f"
+unfolding relInvImage_def relImage_def by auto
+
+lemma equiv_Image: "equiv A R \<Longrightarrow> (\<And>a b. (a, b) \<in> R \<Longrightarrow> a \<in> A \<and> b \<in> A \<and> R `` {a} = R `` {b})"
+unfolding equiv_def refl_on_def Image_def by (auto intro: transD symD)
+
+lemma relImage_proj:
+assumes "equiv A R"
+shows "relImage R (proj R) \<subseteq> diag (A//R)"
+unfolding relImage_def diag_def apply safe
+using proj_iff[OF assms]
+by (metis assms equiv_Image proj_def proj_preserves)
+
+lemma relImage_relInvImage:
+assumes "R \<subseteq> f ` A <*> f ` A"
+shows "relImage (relInvImage A R f) f = R"
+using assms unfolding relImage_def relInvImage_def by fastforce
+
+lemma subst_Pair: "P x y \<Longrightarrow> a = (x, y) \<Longrightarrow> P (fst a) (snd a)"
+by simp
+
+lemma fst_diag_id: "(fst \<circ> (%x. (x, x))) z = id z"
+by simp
+
+lemma snd_diag_id: "(snd \<circ> (%x. (x, x))) z = id z"
+by simp
+
+lemma Collect_restrict': "{(x, y) | x y. phi x y \<and> P x y} \<subseteq> {(x, y) | x y. phi x y}"
+by auto
+
+lemma image_convolD: "\<lbrakk>(a, b) \<in> <f, g> ` X\<rbrakk> \<Longrightarrow> \<exists>x. x \<in> X \<and> a = f x \<and> b = g x"
+unfolding convol_def by auto
+
+(*Extended Sublist*)
+
+definition prefCl where
+ "prefCl Kl = (\<forall> kl1 kl2. kl1 \<le> kl2 \<and> kl2 \<in> Kl \<longrightarrow> kl1 \<in> Kl)"
+definition PrefCl where
+ "PrefCl A n = (\<forall>kl kl'. kl \<in> A n \<and> kl' \<le> kl \<longrightarrow> (\<exists>m\<le>n. kl' \<in> A m))"
+
+lemma prefCl_UN:
+ "\<lbrakk>\<And>n. PrefCl A n\<rbrakk> \<Longrightarrow> prefCl (\<Union>n. A n)"
+unfolding prefCl_def PrefCl_def by fastforce
+
+definition Succ where "Succ Kl kl = {k . kl @ [k] \<in> Kl}"
+definition Shift where "Shift Kl k = {kl. k # kl \<in> Kl}"
+definition shift where "shift lab k = (\<lambda>kl. lab (k # kl))"
+
+lemma empty_Shift: "\<lbrakk>[] \<in> Kl; k \<in> Succ Kl []\<rbrakk> \<Longrightarrow> [] \<in> Shift Kl k"
+unfolding Shift_def Succ_def by simp
+
+lemma Shift_clists: "Kl \<subseteq> Field (clists r) \<Longrightarrow> Shift Kl k \<subseteq> Field (clists r)"
+unfolding Shift_def clists_def Field_card_of by auto
+
+lemma Shift_prefCl: "prefCl Kl \<Longrightarrow> prefCl (Shift Kl k)"
+unfolding prefCl_def Shift_def
+proof safe
+ fix kl1 kl2
+ assume "\<forall>kl1 kl2. kl1 \<le> kl2 \<and> kl2 \<in> Kl \<longrightarrow> kl1 \<in> Kl"
+ "kl1 \<le> kl2" "k # kl2 \<in> Kl"
+ thus "k # kl1 \<in> Kl" using Cons_prefix_Cons[of k kl1 k kl2] by blast
+qed
+
+lemma not_in_Shift: "kl \<notin> Shift Kl x \<Longrightarrow> x # kl \<notin> Kl"
+unfolding Shift_def by simp
+
+lemma prefCl_Succ: "\<lbrakk>prefCl Kl; k # kl \<in> Kl\<rbrakk> \<Longrightarrow> k \<in> Succ Kl []"
+unfolding Succ_def proof
+ assume "prefCl Kl" "k # kl \<in> Kl"
+ moreover have "k # [] \<le> k # kl" by auto
+ ultimately have "k # [] \<in> Kl" unfolding prefCl_def by blast
+ thus "[] @ [k] \<in> Kl" by simp
+qed
+
+lemma SuccD: "k \<in> Succ Kl kl \<Longrightarrow> kl @ [k] \<in> Kl"
+unfolding Succ_def by simp
+
+lemmas SuccE = SuccD[elim_format]
+
+lemma SuccI: "kl @ [k] \<in> Kl \<Longrightarrow> k \<in> Succ Kl kl"
+unfolding Succ_def by simp
+
+lemma ShiftD: "kl \<in> Shift Kl k \<Longrightarrow> k # kl \<in> Kl"
+unfolding Shift_def by simp
+
+lemma Succ_Shift: "Succ (Shift Kl k) kl = Succ Kl (k # kl)"
+unfolding Succ_def Shift_def by auto
+
+lemma ShiftI: "k # kl \<in> Kl \<Longrightarrow> kl \<in> Shift Kl k"
+unfolding Shift_def by simp
+
+lemma Func_cexp: "|Func A B| =o |B| ^c |A|"
+unfolding cexp_def Field_card_of by (simp only: card_of_refl)
+
+lemma clists_bound: "A \<in> Field (cpow (clists r)) - {{}} \<Longrightarrow> |A| \<le>o clists r"
+unfolding cpow_def clists_def Field_card_of by (auto simp: card_of_mono1)
+
+lemma cpow_clists_czero: "\<lbrakk>A \<in> Field (cpow (clists r)) - {{}}; |A| =o czero\<rbrakk> \<Longrightarrow> False"
+unfolding cpow_def clists_def
+by (auto simp add: card_of_ordIso_czero_iff_empty[symmetric])
+ (erule notE, erule ordIso_transitive, rule czero_ordIso)
+
+lemma incl_UNION_I:
+assumes "i \<in> I" and "A \<subseteq> F i"
+shows "A \<subseteq> UNION I F"
+using assms by auto
+
+lemma Nil_clists: "{[]} \<subseteq> Field (clists r)"
+unfolding clists_def Field_card_of by auto
+
+lemma Cons_clists:
+ "\<lbrakk>x \<in> Field r; xs \<in> Field (clists r)\<rbrakk> \<Longrightarrow> x # xs \<in> Field (clists r)"
+unfolding clists_def Field_card_of by auto
+
+lemma length_Cons: "length (x # xs) = Suc (length xs)"
+by simp
+
+lemma length_append_singleton: "length (xs @ [x]) = Suc (length xs)"
+by simp
+
+(*injection into the field of a cardinal*)
+definition "toCard_pred A r f \<equiv> inj_on f A \<and> f ` A \<subseteq> Field r \<and> Card_order r"
+definition "toCard A r \<equiv> SOME f. toCard_pred A r f"
+
+lemma ex_toCard_pred:
+"\<lbrakk>|A| \<le>o r; Card_order r\<rbrakk> \<Longrightarrow> \<exists> f. toCard_pred A r f"
+unfolding toCard_pred_def
+using card_of_ordLeq[of A "Field r"]
+ ordLeq_ordIso_trans[OF _ card_of_unique[of "Field r" r], of "|A|"]
+by blast
+
+lemma toCard_pred_toCard:
+ "\<lbrakk>|A| \<le>o r; Card_order r\<rbrakk> \<Longrightarrow> toCard_pred A r (toCard A r)"
+unfolding toCard_def using someI_ex[OF ex_toCard_pred] .
+
+lemma toCard_inj: "\<lbrakk>|A| \<le>o r; Card_order r; x \<in> A; y \<in> A\<rbrakk> \<Longrightarrow>
+ toCard A r x = toCard A r y \<longleftrightarrow> x = y"
+using toCard_pred_toCard unfolding inj_on_def toCard_pred_def by blast
+
+lemma toCard: "\<lbrakk>|A| \<le>o r; Card_order r; b \<in> A\<rbrakk> \<Longrightarrow> toCard A r b \<in> Field r"
+using toCard_pred_toCard unfolding toCard_pred_def by blast
+
+definition "fromCard A r k \<equiv> SOME b. b \<in> A \<and> toCard A r b = k"
+
+lemma fromCard_toCard:
+"\<lbrakk>|A| \<le>o r; Card_order r; b \<in> A\<rbrakk> \<Longrightarrow> fromCard A r (toCard A r b) = b"
+unfolding fromCard_def by (rule some_equality) (auto simp add: toCard_inj)
+
+(* pick according to the weak pullback *)
+definition pickWP_pred where
+"pickWP_pred A p1 p2 b1 b2 a \<equiv> a \<in> A \<and> p1 a = b1 \<and> p2 a = b2"
+
+definition pickWP where
+"pickWP A p1 p2 b1 b2 \<equiv> SOME a. pickWP_pred A p1 p2 b1 b2 a"
+
+lemma pickWP_pred:
+assumes "wpull A B1 B2 f1 f2 p1 p2" and
+"b1 \<in> B1" and "b2 \<in> B2" and "f1 b1 = f2 b2"
+shows "\<exists> a. pickWP_pred A p1 p2 b1 b2 a"
+using assms unfolding wpull_def pickWP_pred_def by blast
+
+lemma pickWP_pred_pickWP:
+assumes "wpull A B1 B2 f1 f2 p1 p2" and
+"b1 \<in> B1" and "b2 \<in> B2" and "f1 b1 = f2 b2"
+shows "pickWP_pred A p1 p2 b1 b2 (pickWP A p1 p2 b1 b2)"
+unfolding pickWP_def using assms by(rule someI_ex[OF pickWP_pred])
+
+lemma pickWP:
+assumes "wpull A B1 B2 f1 f2 p1 p2" and
+"b1 \<in> B1" and "b2 \<in> B2" and "f1 b1 = f2 b2"
+shows "pickWP A p1 p2 b1 b2 \<in> A"
+ "p1 (pickWP A p1 p2 b1 b2) = b1"
+ "p2 (pickWP A p1 p2 b1 b2) = b2"
+using assms pickWP_pred_pickWP unfolding pickWP_pred_def by fastforce+
+
+lemma Inl_Field_csum: "a \<in> Field r \<Longrightarrow> Inl a \<in> Field (r +c s)"
+unfolding Field_card_of csum_def by auto
+
+lemma Inr_Field_csum: "a \<in> Field s \<Longrightarrow> Inr a \<in> Field (r +c s)"
+unfolding Field_card_of csum_def by auto
+
+lemma nat_rec_0: "f = nat_rec f1 (%n rec. f2 n rec) \<Longrightarrow> f 0 = f1"
+by auto
+
+lemma nat_rec_Suc: "f = nat_rec f1 (%n rec. f2 n rec) \<Longrightarrow> f (Suc n) = f2 n (f n)"
+by auto
+
+lemma list_rec_Nil: "f = list_rec f1 (%x xs rec. f2 x xs rec) \<Longrightarrow> f [] = f1"
+by auto
+
+lemma list_rec_Cons: "f = list_rec f1 (%x xs rec. f2 x xs rec) \<Longrightarrow> f (x # xs) = f2 x xs (f xs)"
+by auto
+
+lemma not_arg_cong_Inr: "x \<noteq> y \<Longrightarrow> Inr x \<noteq> Inr y"
+by simp
+
+ML_file "Tools/bnf_gfp_util.ML"
+ML_file "Tools/bnf_gfp_tactics.ML"
+ML_file "Tools/bnf_gfp.ML"
+
+end