diff -r 0b302c0b449a -r 469c26d19f8e uncomputable.thy --- a/uncomputable.thy Wed Feb 06 02:25:00 2013 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,1614 +0,0 @@ -(* Title: Turing machine's definition and its charater - Author: XuJian <xujian817@hotmail.com> - Maintainer: Xujian -*) - -header {* Undeciablity of the {\em Halting problem} *} - -theory uncomputable -imports Main turing_basic -begin - -text {* - The {\em Copying} TM, which duplicates its input. -*} -definition tcopy :: "tprog" -where -"tcopy \<equiv> [(W0, 0), (R, 2), (R, 3), (R, 2), - (W1, 3), (L, 4), (L, 4), (L, 5), (R, 11), (R, 6), - (R, 7), (W0, 6), (R, 7), (R, 8), (W1, 9), (R, 8), - (L, 10), (L, 9), (L, 10), (L, 5), (R, 12), (R, 12), - (W1, 13), (L, 14), (R, 12), (R, 12), (L, 15), (W0, 14), - (R, 0), (L, 15)]" - -text {* - @{text "wipeLastBs tp"} removes all blanks at the end of tape @{text "tp"}. -*} -fun wipeLastBs :: "block list \<Rightarrow> block list" - where - "wipeLastBs bl = rev (dropWhile (\<lambda>a. a = Bk) (rev bl))" - -fun isBk :: "block \<Rightarrow> bool" - where - "isBk b = (b = Bk)" - -text {* - The following functions are used to expression invariants of {\em Copying} TM. -*} -fun tcopy_F0 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F0 x (l, r) = (\<exists> i. l = Bk\<^bsup>i\<^esup> \<and> r = Oc\<^bsup>x\<^esup> @ Bk # Oc\<^bsup>x\<^esup>)" - -fun tcopy_F1 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F1 x (l, r) = (l = [] \<and> r = Oc\<^bsup>x\<^esup>)" - -fun tcopy_F2 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F2 x (l, r) = (\<exists> i j. i > 0 \<and> i + j = x \<and> l = Oc\<^bsup>i\<^esup> \<and> r = Oc\<^bsup>j\<^esup>)" - -fun tcopy_F3 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F3 x (l, r) = (x > 0 \<and> l = Bk # Oc\<^bsup>x\<^esup> \<and> tl r = [])" - -fun tcopy_F4 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F4 x (l, r) = (x > 0 \<and> ((l = Oc\<^bsup>x\<^esup> \<and> r = [Bk, Oc]) \<or> (l = Oc\<^bsup>x - 1\<^esup> \<and> r = [Oc, Bk, Oc])))" - -fun tcopy_F5_loop :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F5_loop x (l, r) = - (\<exists> i j. i + j + 1 = x \<and> l = Oc\<^bsup>i\<^esup> \<and> r = Oc # Oc # Bk\<^bsup>j\<^esup> @ Oc\<^bsup>j\<^esup> \<and> j > 0)" - -fun tcopy_F5_exit :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F5_exit x (l, r) = - (l = [] \<and> r = Bk # Oc # Bk\<^bsup>x\<^esup> @ Oc\<^bsup>x\<^esup> \<and> x > 0 )" - -fun tcopy_F5 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F5 x (l, r) = (tcopy_F5_loop x (l, r) \<or> tcopy_F5_exit x (l, r))" - -fun tcopy_F6 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F6 x (l, r) = - (\<exists> i j any. i + j = x \<and> x > 0 \<and> i > 0 \<and> j > 0 \<and> l = Oc\<^bsup>i\<^esup> \<and> r = any#Bk\<^bsup>j\<^esup> @ Oc\<^bsup>j\<^esup>)" - -fun tcopy_F7 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F7 x (l, r) = - (\<exists> i j k t. i + j = x \<and> i > 0 \<and> j > 0 \<and> k + t = Suc j \<and> l = Bk\<^bsup>k\<^esup> @ Oc\<^bsup>i\<^esup> \<and> r = Bk\<^bsup>t\<^esup> @ Oc\<^bsup>j\<^esup>)" - -fun tcopy_F8 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F8 x (l, r) = - (\<exists> i j k t. i + j = x \<and> i > 0 \<and> j > 0 \<and> k + t = j \<and> l = Oc\<^bsup>k\<^esup> @ Bk\<^bsup>Suc j\<^esup> @ Oc\<^bsup>i\<^esup> \<and> r = Oc\<^bsup>t\<^esup>)" - -fun tcopy_F9_loop :: "nat \<Rightarrow> tape \<Rightarrow> bool" -where - "tcopy_F9_loop x (l, r) = - (\<exists> i j k t. i + j = Suc x \<and> i > 0 \<and> j > 0 \<and> k + t = j \<and> t > 0\<and> l = Oc\<^bsup>k\<^esup> @ Bk\<^bsup>j\<^esup> @ Oc\<^bsup>i\<^esup> \<and> r = Oc\<^bsup>t\<^esup>)" - -fun tcopy_F9_exit :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F9_exit x (l, r) = (\<exists> i j. i + j = Suc x \<and> i > 0 \<and> j > 0 \<and> l = Bk\<^bsup>j - 1\<^esup> @ Oc\<^bsup>i\<^esup> \<and> r = Bk # Oc\<^bsup>j\<^esup>)" - -fun tcopy_F9 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F9 x (l, r) = (tcopy_F9_loop x (l, r) \<or> - tcopy_F9_exit x (l, r))" - -fun tcopy_F10_loop :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F10_loop x (l, r) = - (\<exists> i j k t. i + j = Suc x \<and> i > 0 \<and> k + t + 1 = j \<and> l = Bk\<^bsup>k\<^esup> @ Oc\<^bsup>i\<^esup> \<and> r = Bk\<^bsup>Suc t\<^esup> @ Oc\<^bsup>j\<^esup>)" - -fun tcopy_F10_exit :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F10_exit x (l, r) = - (\<exists> i j. i + j = x \<and> j > 0 \<and> l = Oc\<^bsup>i\<^esup> \<and> r = Oc # Bk\<^bsup>j\<^esup> @ Oc\<^bsup>j\<^esup>)" - -fun tcopy_F10 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F10 x (l, r) = (tcopy_F10_loop x (l, r) \<or> tcopy_F10_exit x (l, r))" - -fun tcopy_F11 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F11 x (l, r) = (x > 0 \<and> l = [Bk] \<and> r = Oc # Bk\<^bsup>x\<^esup> @ Oc\<^bsup>x\<^esup>)" - -fun tcopy_F12 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F12 x (l, r) = (\<exists> i j. i + j = Suc x \<and> x > 0 \<and> l = Oc\<^bsup>i\<^esup> @ [Bk] \<and> r = Bk\<^bsup>j\<^esup> @ Oc\<^bsup>x\<^esup>)" - -fun tcopy_F13 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F13 x (l, r) = - (\<exists> i j. x > 0 \<and> i + j = x \<and> l = Oc\<^bsup>i\<^esup> @ [Bk] \<and> r = Oc # Bk\<^bsup>j\<^esup> @ Oc\<^bsup>x\<^esup> )" - -fun tcopy_F14 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F14 x (l, r) = (\<exists> any. x > 0 \<and> l = Oc\<^bsup>x\<^esup> @ [Bk] \<and> r = any#Oc\<^bsup>x\<^esup>)" - -fun tcopy_F15_loop :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F15_loop x (l, r) = - (\<exists> i j. i + j = x \<and> x > 0 \<and> j > 0 \<and> l = Oc\<^bsup>i\<^esup> @ [Bk] \<and> r = Oc\<^bsup>j\<^esup> @ Bk # Oc\<^bsup>x\<^esup>)" - -fun tcopy_F15_exit :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F15_exit x (l, r) = (x > 0 \<and> l = [] \<and> r = Bk # Oc\<^bsup>x\<^esup> @ Bk # Oc\<^bsup>x\<^esup>)" - -fun tcopy_F15 :: "nat \<Rightarrow> tape \<Rightarrow> bool" - where - "tcopy_F15 x (l, r) = (tcopy_F15_loop x (l, r) \<or> tcopy_F15_exit x (l, r))" - -text {* - The following @{text "inv_tcopy"} is the invariant of the {\em Copying} TM. -*} -fun inv_tcopy :: "nat \<Rightarrow> t_conf \<Rightarrow> bool" - where - "inv_tcopy x c = (let (state, tp) = c in - if state = 0 then tcopy_F0 x tp - else if state = 1 then tcopy_F1 x tp - else if state = 2 then tcopy_F2 x tp - else if state = 3 then tcopy_F3 x tp - else if state = 4 then tcopy_F4 x tp - else if state = 5 then tcopy_F5 x tp - else if state = 6 then tcopy_F6 x tp - else if state = 7 then tcopy_F7 x tp - else if state = 8 then tcopy_F8 x tp - else if state = 9 then tcopy_F9 x tp - else if state = 10 then tcopy_F10 x tp - else if state = 11 then tcopy_F11 x tp - else if state = 12 then tcopy_F12 x tp - else if state = 13 then tcopy_F13 x tp - else if state = 14 then tcopy_F14 x tp - else if state = 15 then tcopy_F15 x tp - else False)" -declare tcopy_F0.simps [simp del] - tcopy_F1.simps [simp del] - tcopy_F2.simps [simp del] - tcopy_F3.simps [simp del] - tcopy_F4.simps [simp del] - tcopy_F5.simps [simp del] - tcopy_F6.simps [simp del] - tcopy_F7.simps [simp del] - tcopy_F8.simps [simp del] - tcopy_F9.simps [simp del] - tcopy_F10.simps [simp del] - tcopy_F11.simps [simp del] - tcopy_F12.simps [simp del] - tcopy_F13.simps [simp del] - tcopy_F14.simps [simp del] - tcopy_F15.simps [simp del] - -lemma exp_zero_simp: "(a\<^bsup>b\<^esup> = []) = (b = 0)" -apply(auto simp: exponent_def) -done - -lemma exp_zero_simp2: "([] = a\<^bsup>b\<^esup> ) = (b = 0)" -apply(auto simp: exponent_def) -done - -lemma [elim]: "\<lbrakk>tstep (0, a, b) tcopy = (s, l, r); s \<noteq> 0\<rbrakk> \<Longrightarrow> RR" -apply(simp add: tstep.simps tcopy_def fetch.simps) -done - -lemma [elim]: "\<lbrakk>tstep (Suc 0, a, b) tcopy = (s, l, r); s \<noteq> 0; s \<noteq> 2\<rbrakk> - \<Longrightarrow> RR" -apply(simp add: tstep.simps tcopy_def fetch.simps) -apply(simp split: block.splits list.splits) -done - -lemma [elim]: "\<lbrakk>tstep (2, a, b) tcopy = (s, l, r); s \<noteq> 2; s \<noteq> 3\<rbrakk> - \<Longrightarrow> RR" -apply(simp add: tstep.simps tcopy_def fetch.simps) -apply(simp split: block.splits list.splits) -done - -lemma [elim]: "\<lbrakk>tstep (3, a, b) tcopy = (s, l, r); s \<noteq> 3; s \<noteq> 4\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (4, a, b) tcopy = (s, l, r); s \<noteq> 4; s \<noteq> 5\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (5, a, b) tcopy = (s, l, r); s \<noteq> 6; s \<noteq> 11\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (6, a, b) tcopy = (s, l, r); s \<noteq> 6; s \<noteq> 7\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (7, a, b) tcopy = (s, l, r); s \<noteq> 7; s \<noteq> 8\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (8, a, b) tcopy = (s, l, r); s \<noteq> 8; s \<noteq> 9\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (9, a, b) tcopy = (s, l, r); s \<noteq> 9; s \<noteq> 10\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (10, a, b) tcopy = (s, l, r); s \<noteq> 10; s \<noteq> 5\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (11, a, b) tcopy = (s, l, r); s \<noteq> 12\<rbrakk> \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (12, a, b) tcopy = (s, l, r); s \<noteq> 13; s \<noteq> 14\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (13, a, b) tcopy = (s, l, r); s \<noteq> 12\<rbrakk> \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (14, a, b) tcopy = (s, l, r); s \<noteq> 14; s \<noteq> 15\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -lemma [elim]: "\<lbrakk>tstep (15, a, b) tcopy = (s, l, r); s \<noteq> 0; s \<noteq> 15\<rbrakk> - \<Longrightarrow> RR" -by(simp add: tstep.simps tcopy_def fetch.simps - split: block.splits list.splits) - -(* -lemma min_Suc4: "min (Suc (Suc x)) x = x" -by auto - -lemma takeWhile2replicate: - "\<exists>n. takeWhile (\<lambda>a. a = b) list = replicate n b" -apply(induct list) -apply(rule_tac x = 0 in exI, simp) -apply(auto) -apply(rule_tac x = "Suc n" in exI, simp) -done - -lemma rev_replicate_same: "rev (replicate x b) = replicate x b" -by(simp) - -lemma rev_equal: "a = b \<Longrightarrow> rev a = rev b" -by simp - -lemma rev_equal_rev: "rev a = rev b \<Longrightarrow> a = b" -by simp - -lemma rep_suc_rev[simp]:"replicate n b @ [b] = replicate (Suc n) b" -apply(rule rev_equal_rev) -apply(simp only: rev_append rev_replicate_same) -apply(auto) -done - -lemma replicate_Cons_simp: "b # replicate n b @ xs = - replicate n b @ b # xs" -apply(simp) -done -*) - -lemma [elim]: "\<lbrakk>tstep (14, b, c) tcopy = (15, ab, ba); - tcopy_F14 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F15 x (ab, ba)" -apply(auto simp: tstep.simps tcopy_def - tcopy_F14.simps tcopy_F15.simps fetch.simps new_tape.simps - split: if_splits list.splits block.splits) -apply(erule_tac [!] x = "x - 1" in allE) -apply(case_tac [!] x, simp_all add: exp_ind_def exp_zero) -apply(erule_tac [!] x = "Suc 0" in allE, simp_all) -done - -(* -lemma dropWhile_drophd: "\<not> p a \<Longrightarrow> - (dropWhile p xs @ (a # as)) = (dropWhile p (xs @ [a]) @ as)" -apply(induct xs) -apply(auto) -done -*) -(* -lemma dropWhile_append3: "\<lbrakk>\<not> p a; - listall ((dropWhile p xs) @ [a]) isBk\<rbrakk> \<Longrightarrow> - listall (dropWhile p (xs @ [a])) isBk" -apply(drule_tac p = p and xs = xs and a = a in dropWhile_drophd, simp) -done - -lemma takeWhile_append3: "\<lbrakk>\<not>p a; (takeWhile p xs) = b\<rbrakk> - \<Longrightarrow> takeWhile p (xs @ (a # as)) = b" -apply(drule_tac P = p and xs = xs and x = a and l = as in - takeWhile_tail) -apply(simp) -done - -lemma listall_append: "list_all p (xs @ ys) = - (list_all p xs \<and> list_all p ys)" -apply(induct xs) -apply(simp+) -done -*) -lemma false_case1: - "\<lbrakk>Oc\<^bsup>j\<^esup> @ Bk # Oc\<^bsup>i + j\<^esup> = Oc # list; - 0 < i; - \<forall>ia. tl (Oc\<^bsup>i\<^esup> @ [Bk]) = Oc\<^bsup>ia\<^esup> @ [Bk] \<longrightarrow> (\<forall>ja. ia + ja = i + j - \<longrightarrow> hd (Oc\<^bsup>i\<^esup> @ [Bk]) # Oc # list \<noteq> Oc\<^bsup>ja\<^esup> @ Bk # Oc\<^bsup>i + j\<^esup>)\<rbrakk> - \<Longrightarrow> RR" -apply(case_tac i, auto simp: exp_ind_def) -apply(erule_tac x = nat in allE, simp add:exp_ind_def) -apply(erule_tac x = "Suc j" in allE, simp) -done - -lemma false_case3:"\<forall>ja. ja \<noteq> i \<Longrightarrow> RR" -by auto - -lemma [elim]: "\<lbrakk>tstep (15, b, c) tcopy = (15, ab, ba); - tcopy_F15 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F15 x (ab, ba)" -apply(auto simp: tstep.simps tcopy_F15.simps - tcopy_def fetch.simps new_tape.simps - split: if_splits list.splits block.splits elim: false_case1) -apply(case_tac [!] i, simp_all add: exp_zero exp_ind_def) -apply(erule_tac [!] x = nat in allE, simp_all add: exp_ind_def) -apply(auto elim: false_case3) -done - -lemma [elim]: "\<lbrakk>tstep (14, b, c) tcopy = (14, ab, ba); - tcopy_F14 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F14 x (ab, ba)" -apply(auto simp: tcopy_F14.simps tcopy_def tstep.simps - tcopy_F14.simps fetch.simps new_tape.simps - split: if_splits list.splits block.splits) -done - - -lemma [elim]: "\<lbrakk>tstep (12, b, c) tcopy = (14, ab, ba); - tcopy_F12 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F14 x (ab, ba)" -apply(auto simp:tcopy_F12.simps tcopy_F14.simps - tcopy_def tstep.simps fetch.simps new_tape.simps - split: if_splits list.splits block.splits) -apply(case_tac [!] j, simp_all add: exp_zero exp_ind_def) -done - -lemma [elim]: "\<lbrakk>tstep (12, b, c) tcopy = (13, ab, ba); - tcopy_F12 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F13 x (ab, ba)" -apply(auto simp:tcopy_F12.simps tcopy_F13.simps - tcopy_def tstep.simps fetch.simps new_tape.simps - split: if_splits list.splits block.splits) -apply(case_tac x, simp_all add: exp_ind_def exp_zero) -apply(rule_tac [!] x = i in exI, simp_all) -apply(rule_tac [!] x = "j - 1" in exI) -apply(case_tac [!] j, simp_all add: exp_ind_def exp_zero) -apply(case_tac x, simp_all add: exp_ind_def exp_zero) -done - -lemma [elim]: "\<lbrakk>tstep (11, b, c) tcopy = (12, ab, ba); - tcopy_F11 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F12 x (ab, ba)" -apply(simp_all add:tcopy_F12.simps tcopy_F11.simps - tcopy_def tstep.simps fetch.simps new_tape.simps) -apply(auto) -apply(rule_tac x = "Suc 0" in exI, - rule_tac x = x in exI, simp add: exp_ind_def exp_zero) -done - - -lemma [elim]: "\<lbrakk>tstep (13, b, c) tcopy = (12, ab, ba); - tcopy_F13 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F12 x (ab, ba)" -apply(auto simp:tcopy_F12.simps tcopy_F13.simps - tcopy_def tstep.simps fetch.simps new_tape.simps - split: if_splits list.splits block.splits) -apply(rule_tac [!] x = "Suc i" in exI, simp_all add: exp_ind_def) -done - -lemma [elim]: "\<lbrakk>tstep (5, b, c) tcopy = (11, ab, ba); - tcopy_F5 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F11 x (ab, ba)" -apply(simp_all add:tcopy_F11.simps tcopy_F5.simps tcopy_def - tstep.simps fetch.simps new_tape.simps) -apply(simp split: if_splits list.splits block.splits) -done - -lemma F10_false: "tcopy_F10 x (b, []) = False" -apply(auto simp: tcopy_F10.simps exp_ind_def) -done - -lemma F10_false2: "tcopy_F10 x ([], Bk # list) = False" -apply(auto simp:tcopy_F10.simps) -apply(case_tac i, simp_all add: exp_ind_def exp_zero) -done - -lemma [simp]: "tcopy_F10_exit x (b, Bk # list) = False" -apply(auto simp: tcopy_F10.simps) -done - -declare tcopy_F10_loop.simps[simp del] tcopy_F10_exit.simps[simp del] - -lemma [simp]: "tcopy_F10_loop x (b, [Bk]) = False" -apply(auto simp: tcopy_F10_loop.simps) -apply(simp add: exp_ind_def) -done - -lemma [elim]: "\<lbrakk>tstep (10, b, c) tcopy = (10, ab, ba); - tcopy_F10 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F10 x (ab, ba)" -apply(simp add: tcopy_def tstep.simps fetch.simps - new_tape.simps exp_ind_def exp_zero_simp exp_zero_simp2 F10_false F10_false2 - split: if_splits list.splits block.splits) -apply(simp add: tcopy_F10.simps del: tcopy_F10_loop.simps tcopy_F10_exit.simps) -apply(case_tac b, simp, case_tac aa) -apply(rule_tac disjI1) -apply(simp only: tcopy_F10_loop.simps) -apply(erule_tac exE)+ -apply(rule_tac x = i in exI, rule_tac x = j in exI, - rule_tac x = "k - 1" in exI, rule_tac x = "Suc t" in exI, simp) -apply(case_tac k, simp_all add: exp_ind_def exp_zero) -apply(case_tac i, simp_all add: exp_ind_def exp_zero) -apply(rule_tac disjI2) -apply(simp only: tcopy_F10_loop.simps tcopy_F10_exit.simps) -apply(erule_tac exE)+ -apply(rule_tac x = "i - 1" in exI, rule_tac x = "j" in exI) -apply(case_tac k, simp_all add: exp_ind_def exp_zero) -apply(case_tac i, simp_all add: exp_ind_def exp_zero) -apply(auto) -apply(simp add: exp_ind_def) -done - -(* -lemma false_case4: "\<lbrakk>i + (k + t) = Suc x; - 0 < i; - Bk # list = Oc\<^bsup>t\<^esup>; - \<forall>ia j. ia + j = Suc x \<longrightarrow> ia = 0 \<or> (\<forall>ka. tl (Oc\<^bsup>k\<^esup>) @ Bk\<^bsup>k + t\<^esup> @ Oc\<^bsup>i\<^esup> = Bk\<^bsup>ka\<^esup> @ Oc\<^bsup>ia\<^esup> \<longrightarrow> (\<forall>ta. Suc (ka + ta) = j \<longrightarrow> Oc # Oc\<^bsup>t\<^esup> \<noteq> Bk\<^bsup>Suc ta\<^esup> @ Oc\<^bsup>j\<^esup>)); - 0 < k\<rbrakk> - \<Longrightarrow> RR" -apply(case_tac t, simp_all add: exp_ind_def exp_zero) -done - -lemma false_case5: " - \<lbrakk>Suc (i + nata) = x; - 0 < i; - \<forall>ia j. ia + j = Suc x \<longrightarrow> ia = 0 \<or> (\<forall>k. Bk\<^bsup>nata\<^esup> @ Oc\<^bsup>i\<^esup> = Bk\<^bsup>k\<^esup> @ Oc\<^bsup>ia\<^esup> \<longrightarrow> (\<forall>t. Suc (k + t) = j \<longrightarrow> Bk # Oc # Oc # Oc\<^bsup>nata\<^esup> \<noteq> Bk\<^bsup>t\<^esup> @ Oc\<^bsup>j\<^esup>))\<rbrakk> - \<Longrightarrow> False" -apply(erule_tac x = i in allE, simp) -apply(erule_tac x = "Suc (Suc nata)" in allE, simp) -apply(erule_tac x = nata in allE, simp, simp add: exp_ind_def exp_zero) -done - -lemma false_case6: "\<lbrakk>0 < x; \<forall>i. tl (Oc\<^bsup>x\<^esup>) = Oc\<^bsup>i\<^esup> \<longrightarrow> (\<forall>j. i + j = x \<longrightarrow> j = 0 \<or> [Bk, Oc] \<noteq> Bk\<^bsup>j\<^esup> @ Oc\<^bsup>j\<^esup>)\<rbrakk> - \<Longrightarrow> False" -apply(erule_tac x = "x - 1" in allE) -apply(case_tac x, simp_all add: exp_ind_def exp_zero) -apply(erule_tac x = "Suc 0" in allE, simp) -done -*) - -lemma [simp]: "tcopy_F9 x ([], b) = False" -apply(auto simp: tcopy_F9.simps) -apply(case_tac [!] i, simp_all add: exp_ind_def exp_zero) -done - -lemma [simp]: "tcopy_F9 x (b, []) = False" -apply(auto simp: tcopy_F9.simps) -apply(case_tac [!] t, simp_all add: exp_ind_def exp_zero) -done - -declare tcopy_F9_loop.simps[simp del] tcopy_F9_exit.simps[simp del] -lemma [simp]: "tcopy_F9_loop x (b, Bk # list) = False" -apply(auto simp: tcopy_F9_loop.simps) -apply(case_tac [!] t, simp_all add: exp_ind_def exp_zero) -done - -lemma [elim]: "\<lbrakk>tstep (9, b, c) tcopy = (10, ab, ba); - tcopy_F9 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F10 x (ab, ba)" -apply(auto simp:tcopy_def - tstep.simps fetch.simps new_tape.simps exp_zero_simp - exp_zero_simp2 - split: if_splits list.splits block.splits) -apply(case_tac "hd b", simp add:tcopy_F9.simps tcopy_F10.simps ) -apply(simp only: tcopy_F9_exit.simps tcopy_F10_loop.simps) -apply(erule_tac exE)+ -apply(rule_tac x = i in exI, rule_tac x = j in exI, simp) -apply(rule_tac x = "j - 2" in exI, simp add: exp_ind_def) -apply(case_tac j, simp, simp) -apply(case_tac nat, simp_all add: exp_zero exp_ind_def) -apply(case_tac x, simp_all add: exp_ind_def exp_zero) -apply(simp add: tcopy_F9.simps tcopy_F10.simps) -apply(rule_tac disjI2) -apply(simp only: tcopy_F10_exit.simps tcopy_F9_exit.simps) -apply(erule_tac exE)+ -apply(simp) -apply(case_tac j, simp_all, case_tac nat, simp_all add: exp_ind_def exp_zero) -apply(case_tac x, simp_all add: exp_ind_def exp_zero) -apply(rule_tac x = nata in exI, rule_tac x = 1 in exI, simp add: exp_ind_def exp_zero) -done - -lemma false_case7: - "\<lbrakk>i + (n + t) = x; 0 < i; 0 < t; Oc # list = Oc\<^bsup>t\<^esup>; k = Suc n; - \<forall>j. i + j = Suc x \<longrightarrow> (\<forall>k. Oc\<^bsup>n\<^esup> @ Bk # Bk\<^bsup>n + t\<^esup> = Oc\<^bsup>k\<^esup> @ Bk\<^bsup>j\<^esup> \<longrightarrow> - (\<forall>ta. k + ta = j \<longrightarrow> ta = 0 \<or> Oc # Oc\<^bsup>t\<^esup> \<noteq> Oc\<^bsup>ta\<^esup>))\<rbrakk> - \<Longrightarrow> RR" -apply(erule_tac x = "k + t" in allE, simp) -apply(erule_tac x = n in allE, simp add: exp_ind_def) -apply(erule_tac x = "Suc t" in allE, simp) -done - -lemma false_case8: - "\<lbrakk>i + t = Suc x; - 0 < i; - 0 < t; - \<forall>ia j. tl (Bk\<^bsup>t\<^esup> @ Oc\<^bsup>i\<^esup>) = Bk\<^bsup>j - Suc 0\<^esup> @ Oc\<^bsup>ia\<^esup> \<longrightarrow> - ia + j = Suc x \<longrightarrow> ia = 0 \<or> j = 0 \<or> Oc\<^bsup>t\<^esup> \<noteq> Oc\<^bsup>j\<^esup>\<rbrakk> \<Longrightarrow> - RR" -apply(erule_tac x = i in allE, simp) -apply(erule_tac x = t in allE, simp) -apply(case_tac t, simp_all add: exp_ind_def exp_zero) -done - -lemma [elim]: "\<lbrakk>tstep (9, b, c) tcopy = (9, ab, ba); - tcopy_F9 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F9 x (ab, ba)" -apply(auto simp: tcopy_F9.simps tcopy_def - tstep.simps fetch.simps new_tape.simps exp_zero_simp exp_zero_simp2 - tcopy_F9_exit.simps tcopy_F9_loop.simps - split: if_splits list.splits block.splits) -apply(case_tac [!] k, simp_all add: exp_ind_def exp_zero) -apply(erule_tac [!] x = i in allE, simp) -apply(erule_tac false_case7, simp_all)+ -apply(case_tac t, simp_all add: exp_zero exp_ind_def) -apply(erule_tac false_case7, simp_all)+ -apply(erule_tac false_case8, simp_all) -apply(erule_tac false_case7, simp_all)+ -apply(case_tac t, simp_all add: exp_ind_def exp_zero) -apply(erule_tac false_case7, simp_all) -apply(erule_tac false_case8, simp_all) -apply(erule_tac false_case7, simp_all) -done - -lemma [elim]: "\<lbrakk>tstep (8, b, c) tcopy = (9, ab, ba); - tcopy_F8 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F9 x (ab, ba)" -apply(auto simp:tcopy_F8.simps tcopy_F9.simps tcopy_def - tstep.simps fetch.simps new_tape.simps tcopy_F9_loop.simps - tcopy_F9_exit.simps - split: if_splits list.splits block.splits) -apply(case_tac [!] t, simp_all add: exp_ind_def exp_zero) -apply(rule_tac x = i in exI) -apply(rule_tac x = "Suc k" in exI, simp) -apply(rule_tac x = "k" in exI, simp add: exp_ind_def exp_zero) -done - - -lemma [elim]: "\<lbrakk>tstep (8, b, c) tcopy = (8, ab, ba); - tcopy_F8 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F8 x (ab, ba)" -apply(auto simp:tcopy_F8.simps tcopy_def tstep.simps - fetch.simps new_tape.simps exp_zero_simp exp_zero split: if_splits list.splits - - block.splits) -apply(rule_tac x = i in exI, rule_tac x = "k + t" in exI, simp) -apply(rule_tac x = "Suc k" in exI, simp) -apply(rule_tac x = "t - 1" in exI, simp) -apply(case_tac t, simp_all add: exp_zero exp_ind_def) -done - - -lemma [elim]: "\<lbrakk>tstep (7, b, c) tcopy = (7, ab, ba); - tcopy_F7 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F7 x (ab, ba)" -apply(auto simp:tcopy_F7.simps tcopy_def tstep.simps fetch.simps - new_tape.simps exp_ind_def exp_zero_simp - split: if_splits list.splits block.splits) -apply(rule_tac x = i in exI) -apply(rule_tac x = j in exI, simp) -apply(rule_tac x = "Suc k" in exI, simp) -apply(rule_tac x = "t - 1" in exI) -apply(case_tac t, simp_all add: exp_zero exp_ind_def) -apply(case_tac j, simp_all add: exp_zero exp_ind_def) -done - -lemma [elim]: "\<lbrakk>tstep (7, b, c) tcopy = (8, ab, ba); - tcopy_F7 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F8 x (ab, ba)" -apply(auto simp:tcopy_F7.simps tcopy_def tstep.simps tcopy_F8.simps - fetch.simps new_tape.simps exp_zero_simp - split: if_splits list.splits block.splits) -apply(rule_tac x = i in exI, simp) -apply(rule_tac x = "Suc 0" in exI, simp add: exp_ind_def exp_zero) -apply(rule_tac x = "j - 1" in exI, simp) -apply(case_tac t, simp_all add: exp_ind_def ) -apply(case_tac j, simp_all add: exp_ind_def exp_zero) -done - -lemma [elim]: "\<lbrakk>tstep (6, b, c) tcopy = (7, ab, ba); - tcopy_F6 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F7 x (ab, ba)" -apply(case_tac x) -apply(auto simp:tcopy_F7.simps tcopy_F6.simps - tcopy_def tstep.simps fetch.simps new_tape.simps exp_zero_simp - split: if_splits list.splits block.splits) -apply(case_tac i, simp_all add: exp_ind_def exp_zero) -apply(rule_tac x = i in exI, simp) -apply(rule_tac x = j in exI, simp) -apply(rule_tac x = "Suc 0" in exI, simp add: exp_ind_def exp_zero) -done - -lemma [elim]: "\<lbrakk>tstep (6, b, c) tcopy = (6, ab, ba); - tcopy_F6 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F6 x (ab, ba)" -apply(auto simp:tcopy_F6.simps tcopy_def tstep.simps - new_tape.simps fetch.simps - split: if_splits list.splits block.splits) -done - -lemma [elim]: "\<lbrakk>tstep (5, b, c) tcopy = (6, ab, ba); - tcopy_F5 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F6 x (ab, ba)" -apply(auto simp:tcopy_F5.simps tcopy_F6.simps tcopy_def - tstep.simps fetch.simps new_tape.simps exp_zero_simp2 - split: if_splits list.splits block.splits) -apply(rule_tac x = "Suc 0" in exI, simp add: exp_ind_def exp_zero) -apply(rule_tac x = "Suc i" in exI, simp add: exp_ind_def) -done - -lemma [elim]: "\<lbrakk>tstep (10, b, c) tcopy = (5, ab, ba); - tcopy_F10 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F5 x (ab, ba)" -apply(auto simp:tcopy_F5.simps tcopy_F10.simps tcopy_def - tstep.simps fetch.simps new_tape.simps exp_zero_simp exp_zero_simp2 - exp_ind_def tcopy_F10.simps tcopy_F10_loop.simps tcopy_F10_exit.simps - split: if_splits list.splits block.splits ) -apply(erule_tac [!] x = "i - 1" in allE) -apply(erule_tac [!] x = j in allE, simp_all) -apply(case_tac [!] i, simp_all add: exp_ind_def) -done - -lemma [elim]: "\<lbrakk>tstep (4, b, c) tcopy = (5, ab, ba); - tcopy_F4 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F5 x (ab, ba)" -apply(auto simp:tcopy_F5.simps tcopy_F4.simps tcopy_def - tstep.simps fetch.simps new_tape.simps exp_zero_simp exp_zero_simp2 - split: if_splits list.splits block.splits) -apply(case_tac x, simp, simp add: exp_ind_def exp_zero) -apply(erule_tac [!] x = "x - 2" in allE) -apply(erule_tac [!] x = "Suc 0" in allE) -apply(case_tac [!] x, simp_all add: exp_ind_def exp_zero) -apply(case_tac [!] nat, simp_all add: exp_ind_def exp_zero) -done - -lemma [elim]: "\<lbrakk>tstep (3, b, c) tcopy = (4, ab, ba); - tcopy_F3 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F4 x (ab, ba)" -apply(auto simp:tcopy_F3.simps tcopy_F4.simps - tcopy_def tstep.simps fetch.simps new_tape.simps - split: if_splits list.splits block.splits) -done - -lemma [elim]: "\<lbrakk>tstep (4, b, c) tcopy = (4, ab, ba); - tcopy_F4 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F4 x (ab, ba)" -apply(case_tac x) -apply(auto simp:tcopy_F3.simps tcopy_F4.simps - tcopy_def tstep.simps fetch.simps new_tape.simps exp_zero_simp exp_zero_simp2 exp_ind_def - split: if_splits list.splits block.splits) -done - -lemma [elim]: "\<lbrakk>tstep (3, b, c) tcopy = (3, ab, ba); - tcopy_F3 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F3 x (ab, ba)" -apply(auto simp:tcopy_F3.simps tcopy_F4.simps - tcopy_def tstep.simps fetch.simps new_tape.simps - split: if_splits list.splits block.splits) -done - -lemma [elim]: "\<lbrakk>tstep (2, b, c) tcopy = (3, ab, ba); - tcopy_F2 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F3 x (ab, ba)" -apply(case_tac x) -apply(auto simp:tcopy_F3.simps tcopy_F2.simps - tcopy_def tstep.simps fetch.simps new_tape.simps - exp_zero_simp exp_zero_simp2 exp_zero - split: if_splits list.splits block.splits) -apply(case_tac [!] j, simp_all add: exp_zero exp_ind_def) -done - -lemma [elim]: "\<lbrakk>tstep (2, b, c) tcopy = (2, ab, ba); - tcopy_F2 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F2 x (ab, ba)" -apply(auto simp:tcopy_F3.simps tcopy_F2.simps - tcopy_def tstep.simps fetch.simps new_tape.simps - exp_zero_simp exp_zero_simp2 exp_zero - split: if_splits list.splits block.splits) -apply(rule_tac x = "Suc i" in exI, simp add: exp_ind_def exp_zero) -apply(rule_tac x = "j - 1" in exI, simp) -apply(case_tac j, simp_all add: exp_ind_def exp_zero) -done - -lemma [elim]: "\<lbrakk>tstep (Suc 0, b, c) tcopy = (2, ab, ba); - tcopy_F1 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F2 x (ab, ba)" -apply(auto simp:tcopy_F1.simps tcopy_F2.simps - tcopy_def tstep.simps fetch.simps new_tape.simps - exp_zero_simp exp_zero_simp2 exp_zero - split: if_splits list.splits block.splits) -apply(rule_tac x = "Suc 0" in exI, simp) -apply(rule_tac x = "x - 1" in exI, simp) -apply(case_tac x, simp_all add: exp_ind_def exp_zero) -done - -lemma [elim]: "\<lbrakk>tstep (Suc 0, b, c) tcopy = (0, ab, ba); - tcopy_F1 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F0 x (ab, ba)" -apply(simp_all add:tcopy_F0.simps tcopy_F1.simps - tcopy_def tstep.simps fetch.simps new_tape.simps - exp_zero_simp exp_zero_simp2 exp_zero - split: if_splits list.splits block.splits ) -apply(case_tac x, simp_all add: exp_ind_def exp_zero, auto) -done - -lemma [elim]: "\<lbrakk>tstep (15, b, c) tcopy = (0, ab, ba); - tcopy_F15 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F0 x (ab, ba)" -apply(auto simp: tcopy_F15.simps tcopy_F0.simps - tcopy_def tstep.simps new_tape.simps fetch.simps - split: if_splits list.splits block.splits) -apply(rule_tac x = "Suc 0" in exI, simp add: exp_ind_def exp_zero) -apply(case_tac [!] j, simp_all add: exp_ind_def exp_zero) -done - - -lemma [elim]: "\<lbrakk>tstep (0, b, c) tcopy = (0, ab, ba); - tcopy_F0 x (b, c)\<rbrakk> \<Longrightarrow> tcopy_F0 x (ab, ba)" -apply(case_tac x) -apply(simp_all add: tcopy_F0.simps tcopy_def - tstep.simps new_tape.simps fetch.simps) -done - -declare tstep.simps[simp del] - -text {* - Finally establishes the invariant of Copying TM, which is used to dervie - the parital correctness of Copying TM. -*} -lemma inv_tcopy_step:"inv_tcopy x c \<Longrightarrow> inv_tcopy x (tstep c tcopy)" -apply(induct c) -apply(auto split: if_splits block.splits list.splits taction.splits) -apply(auto simp: tstep.simps tcopy_def fetch.simps new_tape.simps - split: if_splits list.splits block.splits taction.splits) -done - -declare inv_tcopy.simps[simp del] - -text {* - Invariant under mult-step execution. - *} -lemma inv_tcopy_steps: - "inv_tcopy x (steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy stp) " -apply(induct stp) -apply(simp add: tstep.simps tcopy_def steps.simps - tcopy_F1.simps inv_tcopy.simps) -apply(drule_tac inv_tcopy_step, simp add: tstep_red) -done - - - - -(*----------halt problem of tcopy----------------------------------------*) - -section {* - The following definitions are used to construct the measure function used to show - the termnation of Copying TM. -*} - -definition lex_pair :: "((nat \<times> nat) \<times> nat \<times> nat) set" - where - "lex_pair \<equiv> less_than <*lex*> less_than" - -definition lex_triple :: - "((nat \<times> (nat \<times> nat)) \<times> (nat \<times> (nat \<times> nat))) set" - where -"lex_triple \<equiv> less_than <*lex*> lex_pair" - -definition lex_square :: - "((nat \<times> nat \<times> nat \<times> nat) \<times> (nat \<times> nat \<times> nat \<times> nat)) set" - where -"lex_square \<equiv> less_than <*lex*> lex_triple" - -lemma wf_lex_triple: "wf lex_triple" - by (auto intro:wf_lex_prod simp:lex_triple_def lex_pair_def) - -lemma wf_lex_square: "wf lex_square" - by (auto intro:wf_lex_prod - simp:lex_triple_def lex_square_def lex_pair_def) - -text {* - A measurement functions used to show the termination of copying machine: -*} -fun tcopy_phase :: "t_conf \<Rightarrow> nat" - where - "tcopy_phase c = (let (state, tp) = c in - if state > 0 & state <= 4 then 5 - else if state >=5 & state <= 10 then 4 - else if state = 11 then 3 - else if state = 12 | state = 13 then 2 - else if state = 14 | state = 15 then 1 - else 0)" - -fun tcopy_phase4_stage :: "tape \<Rightarrow> nat" - where - "tcopy_phase4_stage (ln, rn) = - (let lrn = (rev ln) @ rn - in length (takeWhile (\<lambda>a. a = Oc) lrn))" - -fun tcopy_stage :: "t_conf \<Rightarrow> nat" - where - "tcopy_stage c = (let (state, ln, rn) = c in - if tcopy_phase c = 5 then 0 - else if tcopy_phase c = 4 then - tcopy_phase4_stage (ln, rn) - else if tcopy_phase c = 3 then 0 - else if tcopy_phase c = 2 then length rn - else if tcopy_phase c = 1 then 0 - else 0)" - -fun tcopy_phase4_state :: "t_conf \<Rightarrow> nat" - where - "tcopy_phase4_state c = (let (state, ln, rn) = c in - if state = 6 & hd rn = Oc then 0 - else if state = 5 then 1 - else 12 - state)" - -fun tcopy_state :: "t_conf \<Rightarrow> nat" - where - "tcopy_state c = (let (state, ln, rn) = c in - if tcopy_phase c = 5 then 4 - state - else if tcopy_phase c = 4 then - tcopy_phase4_state c - else if tcopy_phase c = 3 then 0 - else if tcopy_phase c = 2 then 13 - state - else if tcopy_phase c = 1 then 15 - state - else 0)" - -fun tcopy_step2 :: "t_conf \<Rightarrow> nat" - where - "tcopy_step2 (s, l, r) = length r" - -fun tcopy_step3 :: "t_conf \<Rightarrow> nat" - where - "tcopy_step3 (s, l, r) = (if r = [] | r = [Bk] then Suc 0 else 0)" - -fun tcopy_step4 :: "t_conf \<Rightarrow> nat" - where - "tcopy_step4 (s, l, r) = length l" - -fun tcopy_step7 :: "t_conf \<Rightarrow> nat" - where - "tcopy_step7 (s, l, r) = length r" - -fun tcopy_step8 :: "t_conf \<Rightarrow> nat" - where - "tcopy_step8 (s, l, r) = length r" - -fun tcopy_step9 :: "t_conf \<Rightarrow> nat" - where - "tcopy_step9 (s, l, r) = length l" - -fun tcopy_step10 :: "t_conf \<Rightarrow> nat" - where - "tcopy_step10 (s, l, r) = length l" - -fun tcopy_step14 :: "t_conf \<Rightarrow> nat" - where - "tcopy_step14 (s, l, r) = (case hd r of - Oc \<Rightarrow> 1 | - Bk \<Rightarrow> 0)" - -fun tcopy_step15 :: "t_conf \<Rightarrow> nat" - where - "tcopy_step15 (s, l, r) = length l" - -fun tcopy_step :: "t_conf \<Rightarrow> nat" - where - "tcopy_step c = (let (state, ln, rn) = c in - if state = 0 | state = 1 | state = 11 | - state = 5 | state = 6 | state = 12 | state = 13 then 0 - else if state = 2 then tcopy_step2 c - else if state = 3 then tcopy_step3 c - else if state = 4 then tcopy_step4 c - else if state = 7 then tcopy_step7 c - else if state = 8 then tcopy_step8 c - else if state = 9 then tcopy_step9 c - else if state = 10 then tcopy_step10 c - else if state = 14 then tcopy_step14 c - else if state = 15 then tcopy_step15 c - else 0)" - -text {* - The measure function used to show the termination of Copying TM. -*} -fun tcopy_measure :: "t_conf \<Rightarrow> (nat * nat * nat * nat)" - where - "tcopy_measure c = - (tcopy_phase c, tcopy_stage c, tcopy_state c, tcopy_step c)" - -definition tcopy_LE :: "((nat \<times> block list \<times> block list) \<times> - (nat \<times> block list \<times> block list)) set" - where - "tcopy_LE \<equiv> (inv_image lex_square tcopy_measure)" - -lemma wf_tcopy_le: "wf tcopy_LE" -by(auto intro:wf_inv_image wf_lex_square simp:tcopy_LE_def) - - -declare steps.simps[simp del] - -declare tcopy_phase.simps[simp del] tcopy_stage.simps[simp del] - tcopy_state.simps[simp del] tcopy_step.simps[simp del] - inv_tcopy.simps[simp del] -declare tcopy_F0.simps [simp] - tcopy_F1.simps [simp] - tcopy_F2.simps [simp] - tcopy_F3.simps [simp] - tcopy_F4.simps [simp] - tcopy_F5.simps [simp] - tcopy_F6.simps [simp] - tcopy_F7.simps [simp] - tcopy_F8.simps [simp] - tcopy_F9.simps [simp] - tcopy_F10.simps [simp] - tcopy_F11.simps [simp] - tcopy_F12.simps [simp] - tcopy_F13.simps [simp] - tcopy_F14.simps [simp] - tcopy_F15.simps [simp] - fetch.simps[simp] - new_tape.simps[simp] -lemma [elim]: "tcopy_F1 x (b, c) \<Longrightarrow> - (tstep (Suc 0, b, c) tcopy, Suc 0, b, c) \<in> tcopy_LE" -apply(simp add: tcopy_F1.simps tstep.simps tcopy_def tcopy_LE_def - lex_square_def lex_triple_def lex_pair_def tcopy_phase.simps - tcopy_stage.simps tcopy_state.simps tcopy_step.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -done - -lemma [elim]: "tcopy_F2 x (b, c) \<Longrightarrow> - (tstep (2, b, c) tcopy, 2, b, c) \<in> tcopy_LE" -apply(simp add:tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps tcopy_stage.simps - tcopy_state.simps tcopy_step.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -done - -lemma [elim]: "tcopy_F3 x (b, c) \<Longrightarrow> - (tstep (3, b, c) tcopy, 3, b, c) \<in> tcopy_LE" -apply(simp add: tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps tcopy_stage.simps - tcopy_state.simps tcopy_step.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto) -done - -lemma [elim]: "tcopy_F4 x (b, c) \<Longrightarrow> - (tstep (4, b, c) tcopy, 4, b, c) \<in> tcopy_LE" -apply(case_tac x, simp) -apply(simp add: tcopy_F4.simps tstep.simps tcopy_def tcopy_LE_def - lex_square_def lex_triple_def lex_pair_def tcopy_phase.simps - tcopy_stage.simps tcopy_state.simps tcopy_step.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto simp: exp_ind_def) -done - -lemma[simp]: "takeWhile (\<lambda>a. a = b) (replicate x b @ ys) = - replicate x b @ (takeWhile (\<lambda>a. a = b) ys)" -apply(induct x) -apply(simp+) -done - -lemma [elim]: "tcopy_F5 x (b, c) \<Longrightarrow> - (tstep (5, b, c) tcopy, 5, b, c) \<in> tcopy_LE" -apply(case_tac x, simp) -apply(simp add: tstep.simps tcopy_def tcopy_LE_def - lex_square_def lex_triple_def lex_pair_def tcopy_phase.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto) -apply(simp_all add: tcopy_phase.simps - tcopy_stage.simps tcopy_state.simps) -done - -lemma [elim]: "\<lbrakk>replicate n x = []; n > 0\<rbrakk> \<Longrightarrow> RR" -apply(case_tac n, simp+) -done - -lemma [elim]: "tcopy_F6 x (b, c) \<Longrightarrow> - (tstep (6, b, c) tcopy, 6, b, c) \<in> tcopy_LE" -apply(case_tac x, simp) -apply(simp add: tstep.simps tcopy_def tcopy_LE_def - lex_square_def lex_triple_def lex_pair_def - tcopy_phase.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto) -apply(simp_all add: tcopy_phase.simps tcopy_stage.simps - tcopy_state.simps tcopy_step.simps exponent_def) -done - -lemma [elim]: "tcopy_F7 x (b, c) \<Longrightarrow> - (tstep (7, b, c) tcopy, 7, b, c) \<in> tcopy_LE" -apply(case_tac x, simp) -apply(simp add: tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto simp: exp_zero_simp) -apply(simp_all add: tcopy_phase.simps tcopy_stage.simps - tcopy_state.simps tcopy_step.simps) -done - -lemma [elim]: "tcopy_F8 x (b, c) \<Longrightarrow> - (tstep (8, b, c) tcopy, 8, b, c) \<in> tcopy_LE" -apply(case_tac x, simp) -apply(simp add: tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto simp: exp_zero_simp) -apply(simp_all add: tcopy_phase.simps tcopy_stage.simps - tcopy_state.simps tcopy_step.simps exponent_def) -done - -lemma rev_equal_rev: "rev a = rev b \<Longrightarrow> a = b" -by simp - -lemma app_app_app_equal: "xs @ ys @ zs = (xs @ ys) @ zs" -by simp - -lemma append_cons_assoc: "as @ b # bs = (as @ [b]) @ bs" -apply(rule rev_equal_rev) -apply(simp) -done - -lemma rev_tl_hd_merge: "bs \<noteq> [] \<Longrightarrow> - rev (tl bs) @ hd bs # as = rev bs @ as" -apply(rule rev_equal_rev) -apply(simp) -done - -lemma[simp]: "takeWhile (\<lambda>a. a = b) (replicate x b @ ys) = - replicate x b @ (takeWhile (\<lambda>a. a = b) ys)" -apply(induct x) -apply(simp+) -done - -lemma [elim]: "tcopy_F9 x (b, c) \<Longrightarrow> - (tstep (9, b, c) tcopy, 9, b, c) \<in> tcopy_LE" -apply(simp add: tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps tcopy_F9.simps - tcopy_F9_loop.simps tcopy_F9_exit.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto) -apply(simp_all add: tcopy_phase.simps tcopy_stage.simps tcopy_F9_loop.simps - tcopy_state.simps tcopy_step.simps tstep.simps exp_zero_simp - exponent_def) -apply(case_tac [1-2] t, simp_all add: rev_tl_hd_merge) -apply(case_tac j, simp, simp) -apply(case_tac nat, simp_all) -apply(case_tac nata, simp_all) -done - -lemma [elim]: "tcopy_F10 x (b, c) \<Longrightarrow> - (tstep (10, b, c) tcopy, 10, b, c) \<in> tcopy_LE" -apply(simp add: tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps tcopy_F10_loop.simps - tcopy_F10_exit.simps exp_zero_simp) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto simp: exp_zero_simp) -apply(simp_all add: tcopy_phase.simps tcopy_stage.simps - tcopy_state.simps tcopy_step.simps exponent_def - rev_tl_hd_merge) -apply(case_tac k, simp_all) -apply(case_tac nat, simp_all) -done - -lemma [elim]: "tcopy_F11 x (b, c) \<Longrightarrow> - (tstep (11, b, c) tcopy, 11, b, c) \<in> tcopy_LE" -apply(case_tac x, simp) -apply(simp add: tstep.simps tcopy_def tcopy_LE_def - lex_square_def lex_triple_def lex_pair_def - tcopy_phase.simps) -done - -lemma [elim]: "tcopy_F12 x (b, c) \<Longrightarrow> - (tstep (12, b, c) tcopy, 12, b, c) \<in> tcopy_LE" -apply(case_tac x, simp) -apply(simp add: tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto) -apply(simp_all add: tcopy_phase.simps tcopy_stage.simps - tcopy_state.simps tcopy_step.simps) -apply(simp_all add: exp_ind_def) -done - -lemma [elim]: "tcopy_F13 x (b, c) \<Longrightarrow> - (tstep (13, b, c) tcopy, 13, b, c) \<in> tcopy_LE" -apply(case_tac x, simp) -apply(simp add: tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto) -apply(simp_all add: tcopy_phase.simps tcopy_stage.simps - tcopy_state.simps tcopy_step.simps) -done - -lemma [elim]: "tcopy_F14 x (b, c) \<Longrightarrow> - (tstep (14, b, c) tcopy, 14, b, c) \<in> tcopy_LE" -apply(case_tac x, simp) -apply(simp add: tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto) -apply(simp_all add: tcopy_phase.simps tcopy_stage.simps - tcopy_state.simps tcopy_step.simps) -done - -lemma [elim]: "tcopy_F15 x (b, c) \<Longrightarrow> - (tstep (15, b, c) tcopy, 15, b, c) \<in> tcopy_LE" -apply(case_tac x, simp) -apply(simp add: tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps ) -apply(simp split: if_splits list.splits block.splits taction.splits) -apply(auto) -apply(simp_all add: tcopy_phase.simps tcopy_stage.simps - tcopy_state.simps tcopy_step.simps) -done - -lemma exp_length: "length (a\<^bsup>b\<^esup>) = b" -apply(induct b, simp_all add: exp_zero exp_ind_def) -done - -declare tcopy_F9.simps[simp del] tcopy_F10.simps[simp del] - -lemma length_eq: "xs = ys \<Longrightarrow> length xs = length ys" -by simp - -lemma tcopy_wf_step:"\<lbrakk>a > 0; inv_tcopy x (a, b, c)\<rbrakk> \<Longrightarrow> - (tstep (a, b, c) tcopy, (a, b, c)) \<in> tcopy_LE" -apply(simp add:inv_tcopy.simps split: if_splits, auto) -apply(auto simp: tstep.simps tcopy_def tcopy_LE_def lex_square_def - lex_triple_def lex_pair_def tcopy_phase.simps - tcopy_stage.simps tcopy_state.simps tcopy_step.simps - exp_length exp_zero_simp exponent_def - split: if_splits list.splits block.splits taction.splits) -apply(case_tac [!] t, simp_all) -apply(case_tac j, simp_all) -apply(drule_tac length_eq, simp) -done - -lemma tcopy_wf: -"\<forall>n. let nc = steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy n in - let Sucnc = steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy (Suc n) in - \<not> isS0 nc \<longrightarrow> ((Sucnc, nc) \<in> tcopy_LE)" -proof(rule allI, case_tac - "steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy n", auto simp: tstep_red) - fix n a b c - assume h: "\<not> isS0 (a, b, c)" - "steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy n = (a, b, c)" - hence "inv_tcopy x (a, b, c)" - using inv_tcopy_steps[of x n] by(simp) - thus "(tstep (a, b, c) tcopy, a, b, c) \<in> tcopy_LE" - using h - by(rule_tac tcopy_wf_step, auto simp: isS0_def) -qed - -text {* - The termination of Copying TM: -*} -lemma tcopy_halt: - "\<exists>n. isS0 (steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy n)" -apply(insert halt_lemma - [of tcopy_LE isS0 "steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy"]) -apply(insert tcopy_wf [of x]) -apply(simp only: Let_def) -apply(insert wf_tcopy_le) -apply(simp) -done - -text {* - The total correntess of Copying TM: -*} -theorem tcopy_halt_rs: - "\<exists>stp m. - steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy stp = - (0, Bk\<^bsup>m\<^esup>, Oc\<^bsup>x\<^esup> @ Bk # Oc\<^bsup>x\<^esup>)" -using tcopy_halt[of x] -proof(erule_tac exE) - fix n - assume h: "isS0 (steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy n)" - have "inv_tcopy x (steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy n)" - using inv_tcopy_steps[of x n] by simp - thus "?thesis" - using h - apply(cases "(steps (Suc 0, [], Oc\<^bsup>x\<^esup>) tcopy n)", - auto simp: isS0_def inv_tcopy.simps) - done -qed - -section {* - The {\em Dithering} Turing Machine -*} - -text {* - The {\em Dithering} TM, when the input is @{text "1"}, it will loop forever, otherwise, it will - terminate. -*} -definition dither :: "tprog" - where - "dither \<equiv> [(W0, 1), (R, 2), (L, 1), (L, 0)] " - -lemma dither_halt_rs: - "\<exists> stp. steps (Suc 0, Bk\<^bsup>m\<^esup>, [Oc, Oc]) dither stp = - (0, Bk\<^bsup>m\<^esup>, [Oc, Oc])" -apply(rule_tac x = "Suc (Suc (Suc 0))" in exI) -apply(simp add: dither_def steps.simps - tstep.simps fetch.simps new_tape.simps) -done - -lemma dither_unhalt_state: - "(steps (Suc 0, Bk\<^bsup>m\<^esup>, [Oc]) dither stp = - (Suc 0, Bk\<^bsup>m\<^esup>, [Oc])) \<or> - (steps (Suc 0, Bk\<^bsup>m\<^esup>, [Oc]) dither stp = (2, Oc # Bk\<^bsup>m\<^esup>, []))" - apply(induct stp, simp add: steps.simps) - apply(simp add: tstep_red, auto) - apply(auto simp: tstep.simps fetch.simps dither_def new_tape.simps) - done - -lemma dither_unhalt_rs: - "\<not> (\<exists> stp. isS0 (steps (Suc 0, Bk\<^bsup>m\<^esup>, [Oc]) dither stp))" -proof(auto) - fix stp - assume h1: "isS0 (steps (Suc 0, Bk\<^bsup>m\<^esup>, [Oc]) dither stp)" - have "\<not> isS0 ((steps (Suc 0, Bk\<^bsup>m\<^esup>, [Oc]) dither stp))" - using dither_unhalt_state[of m stp] - by(auto simp: isS0_def) - from h1 and this show False by (auto) -qed - -section {* - The final diagnal arguments to show the undecidability of Halting problem. -*} - -text {* - @{text "haltP tp x"} means TM @{text "tp"} terminates on input @{text "x"} - and the final configuration is standard. -*} -definition haltP :: "tprog \<Rightarrow> nat \<Rightarrow> bool" - where - "haltP t x = (\<exists>n a b c. steps (Suc 0, [], Oc\<^bsup>x\<^esup>) t n = (0, Bk\<^bsup>a\<^esup>, Oc\<^bsup>b\<^esup> @ Bk\<^bsup>c\<^esup>))" - -lemma [simp]: "length (A |+| B) = length A + length B" -by(auto simp: t_add.simps tshift.simps) - -lemma [intro]: "\<lbrakk>iseven (x::nat); iseven y\<rbrakk> \<Longrightarrow> iseven (x + y)" -apply(auto simp: iseven_def) -apply(rule_tac x = "x + xa" in exI, simp) -done - -lemma t_correct_add[intro]: - "\<lbrakk>t_correct A; t_correct B\<rbrakk> \<Longrightarrow> t_correct (A |+| B)" -apply(auto simp: t_correct.simps tshift.simps t_add.simps - change_termi_state.simps list_all_iff) -apply(erule_tac x = "(a, b)" in ballE, auto) -apply(case_tac "ba = 0", auto) -done - -lemma [intro]: "t_correct tcopy" -apply(simp add: t_correct.simps tcopy_def iseven_def) -apply(rule_tac x = 15 in exI, simp) -done - -lemma [intro]: "t_correct dither" -apply(simp add: t_correct.simps dither_def iseven_def) -apply(rule_tac x = 2 in exI, simp) -done - -text {* - The following locale specifies that TM @{text "H"} can be used to solve - the {\em Halting Problem} and @{text "False"} is going to be derived - under this locale. Therefore, the undecidability of {\em Halting Problem} - is established. -*} -locale uncomputable = - -- {* The coding function of TM, interestingly, the detailed definition of this - funciton @{text "code"} does not affect the final result. *} - fixes code :: "tprog \<Rightarrow> nat" - -- {* - The TM @{text "H"} is the one which is assummed being able to solve the Halting problem. - *} - and H :: "tprog" - assumes h_wf[intro]: "t_correct H" - -- {* - The following two assumptions specifies that @{text "H"} does solve the Halting problem. - *} - and h_case: - "\<And> M n. \<lbrakk>(haltP M n)\<rbrakk> \<Longrightarrow> - \<exists> na nb. (steps (Suc 0, [], Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na = (0, Bk\<^bsup>nb\<^esup>, [Oc]))" - and nh_case: - "\<And> M n. \<lbrakk>(\<not> haltP M n)\<rbrakk> \<Longrightarrow> - \<exists> na nb. (steps (Suc 0, [], Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na = (0, Bk\<^bsup>nb\<^esup>, [Oc, Oc]))" -begin - -term t_correct -declare haltP_def[simp del] -definition tcontra :: "tprog \<Rightarrow> tprog" - where - "tcontra h \<equiv> ((tcopy |+| h) |+| dither)" - -lemma [simp]: "a\<^bsup>0\<^esup> = []" - by(simp add: exponent_def) - -lemma tinres_ex1: - "tinres (Bk\<^bsup>nb\<^esup>) b \<Longrightarrow> \<exists>nb. b = Bk\<^bsup>nb\<^esup>" -apply(auto simp: tinres_def) -proof - - fix n - assume "Bk\<^bsup>nb\<^esup> = b @ Bk\<^bsup>n\<^esup>" - thus "\<exists>nb. b = Bk\<^bsup>nb\<^esup>" - proof(induct b arbitrary: nb) - show "\<exists>nb. [] = Bk\<^bsup>nb\<^esup>" - by(rule_tac x = 0 in exI, simp add: exp_zero) - next - fix a b nb - assume ind: "\<And>nb. Bk\<^bsup>nb\<^esup> = b @ Bk\<^bsup>n\<^esup> \<Longrightarrow> \<exists>nb. b = Bk\<^bsup>nb\<^esup>" - and h: "Bk\<^bsup>nb\<^esup> = (a # b) @ Bk\<^bsup>n\<^esup>" - from h show "\<exists>nb. a # b = Bk\<^bsup>nb\<^esup>" - proof(case_tac a, case_tac nb, simp_all add: exp_ind_def) - fix nat - assume "Bk\<^bsup>nat\<^esup> = b @ Bk\<^bsup>n\<^esup>" - thus "\<exists>nb. Bk # b = Bk\<^bsup>nb\<^esup>" - using ind[of nat] - apply(auto) - apply(rule_tac x = "Suc nb" in exI, simp add: exp_ind_def) - done - next - assume "Bk\<^bsup>nb\<^esup> = Oc # b @ Bk\<^bsup>n\<^esup>" - thus "\<exists>nb. Oc # b = Bk\<^bsup>nb\<^esup>" - apply(case_tac nb, simp_all add: exp_ind_def) - done - qed - qed -next - fix n - show "\<exists>nba. Bk\<^bsup>nb\<^esup> @ Bk\<^bsup>n\<^esup> = Bk\<^bsup>nba\<^esup>" - apply(rule_tac x = "nb + n" in exI) - apply(simp add: exponent_def replicate_add) - done -qed - -lemma h_newcase: "\<And> M n. \<lbrakk>(haltP M n)\<rbrakk> \<Longrightarrow> - \<exists> na nb. (steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na = (0, Bk\<^bsup>nb\<^esup>, [Oc]))" -proof - - fix M n x - assume "haltP M n" - hence " \<exists> na nb. (steps (Suc 0, [], Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na - = (0, Bk\<^bsup>nb\<^esup>, [Oc]))" - apply(erule_tac h_case) - done - from this obtain na nb where - cond1:"(steps (Suc 0, [], Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na - = (0, Bk\<^bsup>nb\<^esup>, [Oc]))" by blast - thus "\<exists> na nb. (steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na = (0, Bk\<^bsup>nb\<^esup>, [Oc]))" - proof(rule_tac x = na in exI, case_tac "steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na", simp) - fix a b c - assume cond2: "steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na = (a, b, c)" - have "tinres (Bk\<^bsup>nb\<^esup>) b \<and> [Oc] = c \<and> 0 = a" - proof(rule_tac tinres_steps) - show "tinres [] (Bk\<^bsup>x\<^esup>)" - apply(simp add: tinres_def) - apply(auto) - done - next - show "(steps (Suc 0, [], Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na - = (0, Bk\<^bsup>nb\<^esup>, [Oc]))" - by(simp add: cond1) - next - show "steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na = (a, b, c)" - by(simp add: cond2) - qed - thus "a = 0 \<and> (\<exists>nb. b = Bk\<^bsup>nb\<^esup>) \<and> c = [Oc]" - apply(auto simp: tinres_ex1) - done - qed -qed - -lemma nh_newcase: "\<And> M n. \<lbrakk>\<not> (haltP M n)\<rbrakk> \<Longrightarrow> - \<exists> na nb. (steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na = (0, Bk\<^bsup>nb\<^esup>, [Oc, Oc]))" -proof - - fix M n - assume "\<not> haltP M n" - hence "\<exists> na nb. (steps (Suc 0, [], Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na - = (0, Bk\<^bsup>nb\<^esup>, [Oc, Oc]))" - apply(erule_tac nh_case) - done - from this obtain na nb where - cond1: "(steps (Suc 0, [], Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na - = (0, Bk\<^bsup>nb\<^esup>, [Oc, Oc]))" by blast - thus "\<exists> na nb. (steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na = (0, Bk\<^bsup>nb\<^esup>, [Oc, Oc]))" - proof(rule_tac x = na in exI, case_tac "steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na", simp) - fix a b c - assume cond2: "steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na = (a, b, c)" - have "tinres (Bk\<^bsup>nb\<^esup>) b \<and> [Oc, Oc] = c \<and> 0 = a" - proof(rule_tac tinres_steps) - show "tinres [] (Bk\<^bsup>x\<^esup>)" - apply(simp add: tinres_def) - apply(auto) - done - next - show "(steps (Suc 0, [], Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na - = (0, Bk\<^bsup>nb\<^esup>, [Oc, Oc]))" - by(simp add: cond1) - next - show "steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code M\<^esup> @ Bk # Oc\<^bsup>n\<^esup>) H na = (a, b, c)" - by(simp add: cond2) - qed - thus "a = 0 \<and> (\<exists>nb. b = Bk\<^bsup>nb\<^esup>) \<and> c = [Oc, Oc]" - apply(auto simp: tinres_ex1) - done - qed -qed - -lemma haltP_weaking: - "haltP (tcontra H) (code (tcontra H)) \<Longrightarrow> - \<exists>stp. isS0 (steps (Suc 0, [], Oc\<^bsup>code (tcontra H)\<^esup>) - ((tcopy |+| H) |+| dither) stp)" - apply(simp add: haltP_def, auto) - apply(rule_tac x = n in exI, simp add: isS0_def tcontra_def) - done - -lemma h_uh: "haltP (tcontra H) (code (tcontra H)) - \<Longrightarrow> \<not> haltP (tcontra H) (code (tcontra H))" -proof - - let ?cn = "code (tcontra H)" - let ?P1 = "\<lambda> tp. let (l, r) = tp in (l = [] \<and> - (r::block list) = Oc\<^bsup>(?cn)\<^esup>)" - let ?Q1 = "\<lambda> (l, r).(\<exists> nb. l = Bk\<^bsup>nb\<^esup> \<and> - r = Oc\<^bsup>(?cn)\<^esup> @ Bk # Oc\<^bsup>(?cn)\<^esup>)" - let ?P2 = ?Q1 - let ?Q2 = "\<lambda> (l, r). (\<exists> nd. l = Bk\<^bsup>nd \<^esup>\<and> r = [Oc])" - let ?P3 = "\<lambda> tp. False" - assume h: "haltP (tcontra H) (code (tcontra H))" - hence h1: "\<And> x. \<exists> na nb. steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>code (tcontra H)\<^esup> @ Bk # - Oc\<^bsup>code (tcontra H)\<^esup>) H na = (0, Bk\<^bsup>nb\<^esup>, [Oc])" - by(drule_tac x = x in h_newcase, simp) - have "?P1 \<turnstile>-> \<lambda> tp. (\<exists> stp tp'. steps (Suc 0, tp) (tcopy |+| H) stp = (0, tp') \<and> ?Q2 tp')" - proof(rule_tac turing_merge.t_merge_halt[of tcopy H "?P1" "?P2" "?P3" - "?P3" "?Q1" "?Q2"], auto simp: turing_merge_def) - show "\<exists>stp. case steps (Suc 0, [], Oc\<^bsup>?cn\<^esup>) tcopy stp of (s, tp') \<Rightarrow> - s = 0 \<and> (case tp' of (l, r) \<Rightarrow> (\<exists>nb. l = Bk\<^bsup>nb\<^esup>) \<and> r = Oc\<^bsup>?cn\<^esup> @ Bk # Oc\<^bsup>?cn\<^esup>)" - using tcopy_halt_rs[of "?cn"] - apply(auto) - apply(rule_tac x = stp in exI, auto simp: exponent_def) - done - next - fix nb - show "\<exists>stp. case steps (Suc 0, Bk\<^bsup>nb\<^esup>, Oc\<^bsup>code (tcontra H)\<^esup> @ Bk # Oc\<^bsup>code (tcontra H)\<^esup>) H stp of - (s, tp') \<Rightarrow> s = 0 \<and> (case tp' of (l, r) \<Rightarrow> (\<exists>nd. l = Bk\<^bsup>nd\<^esup>) \<and> r = [Oc])" - using h1[of nb] - apply(auto) - apply(rule_tac x = na in exI, auto) - done - next - show "\<lambda>(l, r). ((\<exists>nb. l = Bk\<^bsup>nb\<^esup>) \<and> r = Oc\<^bsup>code (tcontra H)\<^esup> @ Bk # Oc\<^bsup>code (tcontra H)\<^esup>) \<turnstile>-> - \<lambda>(l, r). ((\<exists>nb. l = Bk\<^bsup>nb\<^esup>) \<and> r = Oc\<^bsup>code (tcontra H)\<^esup> @ Bk # Oc\<^bsup>code (tcontra H)\<^esup>)" - apply(simp add: t_imply_def) - done - qed - hence "\<exists>stp tp'. steps (Suc 0, [], Oc\<^bsup>?cn\<^esup>) (tcopy |+| H) stp = (0, tp') \<and> - (case tp' of (l, r) \<Rightarrow> \<exists>nd. l = Bk\<^bsup>nd\<^esup> \<and> r = [Oc])" - apply(simp add: t_imply_def) - done - hence "?P1 \<turnstile>-> \<lambda> tp. \<not> (\<exists> stp. isS0 (steps (Suc 0, tp) ((tcopy |+| H) |+| dither) stp))" - proof(rule_tac turing_merge.t_merge_uhalt[of "tcopy |+| H" dither "?P1" "?P3" "?P3" - "?Q2" "?Q2" "?Q2"], simp add: turing_merge_def, auto) - fix stp nd - assume "steps (Suc 0, [], Oc\<^bsup>code (tcontra H)\<^esup>) (tcopy |+| H) stp = (0, Bk\<^bsup>nd\<^esup>, [Oc])" - thus "\<exists>stp. case steps (Suc 0, [], Oc\<^bsup>code (tcontra H)\<^esup>) (tcopy |+| H) stp of (s, tp') - \<Rightarrow> s = 0 \<and> (case tp' of (l, r) \<Rightarrow> (\<exists>nd. l = Bk\<^bsup>nd\<^esup>) \<and> r = [Oc])" - apply(rule_tac x = stp in exI, auto) - done - next - fix stp nd nda stpa - assume "isS0 (steps (Suc 0, Bk\<^bsup>nda\<^esup>, [Oc]) dither stpa)" - thus "False" - using dither_unhalt_rs[of nda] - apply auto - done - next - fix stp nd - show "\<lambda>(l, r). ((\<exists>nd. l = Bk\<^bsup>nd\<^esup>) \<and> r = [Oc]) \<turnstile>-> - \<lambda>(l, r). ((\<exists>nd. l = Bk\<^bsup>nd\<^esup>) \<and> r = [Oc])" - by (simp add: t_imply_def) - qed - thus "\<not> haltP (tcontra H) (code (tcontra H))" - apply(simp add: t_imply_def haltP_def tcontra_def, auto) - apply(erule_tac x = n in allE, simp add: isS0_def) - done -qed - -lemma uh_h: - assumes uh: "\<not> haltP (tcontra H) (code (tcontra H))" - shows "haltP (tcontra H) (code (tcontra H))" -proof - - let ?cn = "code (tcontra H)" - have h1: "\<And> x. \<exists> na nb. steps (Suc 0, Bk\<^bsup>x\<^esup>, Oc\<^bsup>?cn\<^esup> @ Bk # Oc\<^bsup>?cn\<^esup>) - H na = (0, Bk\<^bsup>nb\<^esup>, [Oc, Oc])" - using uh - by(drule_tac x = x in nh_newcase, simp) - let ?P1 = "\<lambda> tp. let (l, r) = tp in (l = [] \<and> - (r::block list) = Oc\<^bsup>(?cn)\<^esup>)" - let ?Q1 = "\<lambda> (l, r).(\<exists> na. l = Bk\<^bsup>na\<^esup> \<and> r = [Oc, Oc])" - let ?P2 = ?Q1 - let ?Q2 = ?Q1 - let ?P3 = "\<lambda> tp. False" - have "?P1 \<turnstile>-> \<lambda> tp. (\<exists> stp tp'. steps (Suc 0, tp) ((tcopy |+| H ) |+| dither) - stp = (0, tp') \<and> ?Q2 tp')" - proof(rule_tac turing_merge.t_merge_halt[of "tcopy |+| H" dither ?P1 ?P2 ?P3 ?P3 - ?Q1 ?Q2], auto simp: turing_merge_def) - show "\<exists>stp. case steps (Suc 0, [], Oc\<^bsup>code (tcontra H)\<^esup>) (tcopy |+| H) stp of (s, tp') \<Rightarrow> - - s = 0 \<and> (case tp' of (l, r) \<Rightarrow> (\<exists>na. l = Bk\<^bsup>na\<^esup>) \<and> r = [Oc, Oc])" - proof - - let ?Q1 = "\<lambda> (l, r).(\<exists> nb. l = Bk\<^bsup>nb\<^esup> \<and> r = Oc\<^bsup>(?cn)\<^esup> @ Bk # Oc\<^bsup>(?cn)\<^esup>)" - let ?P2 = "?Q1" - let ?Q2 = "\<lambda> (l, r).(\<exists> na. l = Bk\<^bsup>na\<^esup> \<and> r = [Oc, Oc])" - have "?P1 \<turnstile>-> \<lambda> tp. (\<exists> stp tp'. steps (Suc 0, tp) (tcopy |+| H ) - stp = (0, tp') \<and> ?Q2 tp')" - proof(rule_tac turing_merge.t_merge_halt[of tcopy H ?P1 ?P2 ?P3 ?P3 - ?Q1 ?Q2], auto simp: turing_merge_def) - show "\<exists>stp. case steps (Suc 0, [], Oc\<^bsup>code (tcontra H)\<^esup>) tcopy stp of (s, tp') \<Rightarrow> s = 0 - \<and> (case tp' of (l, r) \<Rightarrow> (\<exists>nb. l = Bk\<^bsup>nb\<^esup>) \<and> r = Oc\<^bsup>code (tcontra H)\<^esup> @ Bk # Oc\<^bsup>code (tcontra H)\<^esup>)" - using tcopy_halt_rs[of "?cn"] - apply(auto) - apply(rule_tac x = stp in exI, simp add: exponent_def) - done - next - fix nb - show "\<exists>stp. case steps (Suc 0, Bk\<^bsup>nb\<^esup>, Oc\<^bsup>code (tcontra H)\<^esup> @ Bk # Oc\<^bsup>code (tcontra H)\<^esup>) H stp of - (s, tp') \<Rightarrow> s = 0 \<and> (case tp' of (l, r) \<Rightarrow> (\<exists>na. l = Bk\<^bsup>na\<^esup>) \<and> r = [Oc, Oc])" - using h1[of nb] - apply(auto) - apply(rule_tac x = na in exI, auto) - done - next - show "\<lambda>(l, r). ((\<exists>nb. l = Bk\<^bsup>nb\<^esup>) \<and> r = Oc\<^bsup>code (tcontra H)\<^esup> @ Bk # Oc\<^bsup>code (tcontra H)\<^esup>) \<turnstile>-> - \<lambda>(l, r). ((\<exists>nb. l = Bk\<^bsup>nb\<^esup>) \<and> r = Oc\<^bsup>code (tcontra H)\<^esup> @ Bk # Oc\<^bsup>code (tcontra H)\<^esup>)" - by(simp add: t_imply_def) - qed - hence "(\<exists> stp tp'. steps (Suc 0, [], Oc\<^bsup>?cn\<^esup>) (tcopy |+| H ) stp = (0, tp') \<and> ?Q2 tp')" - apply(simp add: t_imply_def) - done - thus "?thesis" - apply(auto) - apply(rule_tac x = stp in exI, auto) - done - qed - next - fix na - show "\<exists>stp. case steps (Suc 0, Bk\<^bsup>na\<^esup>, [Oc, Oc]) dither stp of (s, tp') - \<Rightarrow> s = 0 \<and> (case tp' of (l, r) \<Rightarrow> (\<exists>na. l = Bk\<^bsup>na\<^esup>) \<and> r = [Oc, Oc])" - using dither_halt_rs[of na] - apply(auto) - apply(rule_tac x = stp in exI, auto) - done - next - show "\<lambda>(l, r). ((\<exists>na. l = Bk\<^bsup>na\<^esup>) \<and> r = [Oc, Oc]) \<turnstile>-> - (\<lambda>(l, r). (\<exists>na. l = Bk\<^bsup>na\<^esup>) \<and> r = [Oc, Oc])" - by (simp add: t_imply_def) - qed - hence "\<exists> stp tp'. steps (Suc 0, [], Oc\<^bsup>?cn\<^esup>) ((tcopy |+| H ) |+| dither) - stp = (0, tp') \<and> ?Q2 tp'" - apply(simp add: t_imply_def) - done - thus "haltP (tcontra H) (code (tcontra H))" - apply(auto simp: haltP_def tcontra_def) - apply(rule_tac x = stp in exI, - rule_tac x = na in exI, - rule_tac x = "Suc (Suc 0)" in exI, - rule_tac x = "0" in exI, simp add: exp_ind_def) - done -qed - -text {* - @{text "False"} is finally derived. -*} - -lemma "False" -using uh_h h_uh -by auto -end - -end -