diff -r b1281a0051ae -r b611aee9f8e7 Attic/Quot/Examples/IntEx2.thy --- a/Attic/Quot/Examples/IntEx2.thy Thu Apr 29 09:13:18 2010 +0200 +++ b/Attic/Quot/Examples/IntEx2.thy Thu Apr 29 09:14:16 2010 +0200 @@ -1,361 +1,7 @@ theory IntEx2 -imports "../Quotient" "../Quotient_Product" Nat -(*uses - ("Tools/numeral.ML") - ("Tools/numeral_syntax.ML") - ("Tools/int_arith.ML")*) -begin - -fun - intrel :: "(nat \ nat) \ (nat \ nat) \ bool" (infix "\" 50) -where - "intrel (x, y) (u, v) = (x + v = u + y)" - -quotient_type int = "nat \ nat" / intrel - unfolding equivp_def - by (auto simp add: mem_def expand_fun_eq) - -instantiation int :: "{zero, one, plus, uminus, minus, times, ord, abs, sgn}" +imports "Quotient_Int" begin -ML {* @{term "0 \ int"} *} - -quotient_definition - "0 \ int" is "(0\nat, 0\nat)" - -quotient_definition - "1 \ int" is "(1\nat, 0\nat)" - -fun - plus_raw :: "(nat \ nat) \ (nat \ nat) \ (nat \ nat)" -where - "plus_raw (x, y) (u, v) = (x + u, y + v)" - -quotient_definition - "(op +) \ (int \ int \ int)" is "plus_raw" - -fun - uminus_raw :: "(nat \ nat) \ (nat \ nat)" -where - "uminus_raw (x, y) = (y, x)" - -quotient_definition - "(uminus \ (int \ int))" is "uminus_raw" - -definition - minus_int_def [code del]: "z - w = z + (-w\int)" - -fun - mult_raw :: "(nat \ nat) \ (nat \ nat) \ (nat \ nat)" -where - "mult_raw (x, y) (u, v) = (x*u + y*v, x*v + y*u)" - -quotient_definition - mult_int_def: "(op *) :: (int \ int \ int)" is "mult_raw" - -fun - le_raw :: "(nat \ nat) \ (nat \ nat) \ bool" -where - "le_raw (x, y) (u, v) = (x+v \ u+y)" - -quotient_definition - le_int_def: "(op \) :: int \ int \ bool" is "le_raw" - -definition - less_int_def [code del]: "(z\int) < w = (z \ w \ z \ w)" - -definition - zabs_def: "\i\int\ = (if i < 0 then - i else i)" - -definition - zsgn_def: "sgn (i\int) = (if i = 0 then 0 else if 0 < i then 1 else - 1)" - -instance .. - -end - -lemma plus_raw_rsp[quot_respect]: - shows "(op \ ===> op \ ===> op \) plus_raw plus_raw" - by auto - -lemma uminus_raw_rsp[quot_respect]: - shows "(op \ ===> op \) uminus_raw uminus_raw" - by auto - -lemma mult_raw_fst: - assumes a: "x \ z" - shows "mult_raw x y \ mult_raw z y" - using a - apply(cases x, cases y, cases z) - apply(auto simp add: mult_raw.simps intrel.simps) - apply(rename_tac u v w x y z) - apply(subgoal_tac "u*w + z*w = y*w + v*w & u*x + z*x = y*x + v*x") - apply(simp add: mult_ac) - apply(simp add: add_mult_distrib [symmetric]) - done - -lemma mult_raw_snd: - assumes a: "x \ z" - shows "mult_raw y x \ mult_raw y z" - using a - apply(cases x, cases y, cases z) - apply(auto simp add: mult_raw.simps intrel.simps) - apply(rename_tac u v w x y z) - apply(subgoal_tac "u*w + z*w = y*w + v*w & u*x + z*x = y*x + v*x") - apply(simp add: mult_ac) - apply(simp add: add_mult_distrib [symmetric]) - done - -lemma mult_raw_rsp[quot_respect]: - shows "(op \ ===> op \ ===> op \) mult_raw mult_raw" - apply(simp only: fun_rel_def) - apply(rule allI | rule impI)+ - apply(rule equivp_transp[OF int_equivp]) - apply(rule mult_raw_fst) - apply(assumption) - apply(rule mult_raw_snd) - apply(assumption) - done - -lemma le_raw_rsp[quot_respect]: - shows "(op \ ===> op \ ===> op =) le_raw le_raw" - by auto - -lemma plus_assoc_raw: - shows "plus_raw (plus_raw i j) k \ plus_raw i (plus_raw j k)" - by (cases i, cases j, cases k) (simp) - -lemma plus_sym_raw: - shows "plus_raw i j \ plus_raw j i" - by (cases i, cases j) (simp) - -lemma plus_zero_raw: - shows "plus_raw (0, 0) i \ i" - by (cases i) (simp) - -lemma plus_minus_zero_raw: - shows "plus_raw (uminus_raw i) i \ (0, 0)" - by (cases i) (simp) - -lemma times_assoc_raw: - shows "mult_raw (mult_raw i j) k \ mult_raw i (mult_raw j k)" - by (cases i, cases j, cases k) - (simp add: algebra_simps) - -lemma times_sym_raw: - shows "mult_raw i j \ mult_raw j i" - by (cases i, cases j) (simp add: algebra_simps) - -lemma times_one_raw: - shows "mult_raw (1, 0) i \ i" - by (cases i) (simp) - -lemma times_plus_comm_raw: - shows "mult_raw (plus_raw i j) k \ plus_raw (mult_raw i k) (mult_raw j k)" -by (cases i, cases j, cases k) - (simp add: algebra_simps) - -lemma one_zero_distinct: - shows "\ (0, 0) \ ((1::nat), (0::nat))" - by simp - -text{* The integers form a @{text comm_ring_1}*} - -instance int :: comm_ring_1 -proof - fix i j k :: int - show "(i + j) + k = i + (j + k)" - by (lifting plus_assoc_raw) - show "i + j = j + i" - by (lifting plus_sym_raw) - show "0 + i = (i::int)" - by (lifting plus_zero_raw) - show "- i + i = 0" - by (lifting plus_minus_zero_raw) - show "i - j = i + - j" - by (simp add: minus_int_def) - show "(i * j) * k = i * (j * k)" - by (lifting times_assoc_raw) - show "i * j = j * i" - by (lifting times_sym_raw) - show "1 * i = i" - by (lifting times_one_raw) - show "(i + j) * k = i * k + j * k" - by (lifting times_plus_comm_raw) - show "0 \ (1::int)" - by (lifting one_zero_distinct) -qed - -lemma plus_raw_rsp_aux: - assumes a: "a \ b" "c \ d" - shows "plus_raw a c \ plus_raw b d" - using a - by (cases a, cases b, cases c, cases d) - (simp) - -lemma add: - "(abs_int (x,y)) + (abs_int (u,v)) = - (abs_int (x + u, y + v))" - apply(simp add: plus_int_def id_simps) - apply(fold plus_raw.simps) - apply(rule Quotient_rel_abs[OF Quotient_int]) - apply(rule plus_raw_rsp_aux) - apply(simp_all add: rep_abs_rsp_left[OF Quotient_int]) - done - -definition int_of_nat_raw: - "int_of_nat_raw m = (m :: nat, 0 :: nat)" - -quotient_definition - "int_of_nat :: nat \ int" is "int_of_nat_raw" - -lemma[quot_respect]: - shows "(op = ===> op \) int_of_nat_raw int_of_nat_raw" - by (simp add: equivp_reflp[OF int_equivp]) - -lemma int_of_nat: - shows "of_nat m = int_of_nat m" - by (induct m) - (simp_all add: zero_int_def one_int_def int_of_nat_def int_of_nat_raw add) - -lemma le_antisym_raw: - shows "le_raw i j \ le_raw j i \ i \ j" - by (cases i, cases j) (simp) - -lemma le_refl_raw: - shows "le_raw i i" - by (cases i) (simp) - -lemma le_trans_raw: - shows "le_raw i j \ le_raw j k \ le_raw i k" - by (cases i, cases j, cases k) (simp) - -lemma le_cases_raw: - shows "le_raw i j \ le_raw j i" - by (cases i, cases j) - (simp add: linorder_linear) - -instance int :: linorder -proof - fix i j k :: int - show antisym: "i \ j \ j \ i \ i = j" - by (lifting le_antisym_raw) - show "(i < j) = (i \ j \ \ j \ i)" - by (auto simp add: less_int_def dest: antisym) - show "i \ i" - by (lifting le_refl_raw) - show "i \ j \ j \ k \ i \ k" - by (lifting le_trans_raw) - show "i \ j \ j \ i" - by (lifting le_cases_raw) -qed - -instantiation int :: distrib_lattice -begin - -definition - "(inf \ int \ int \ int) = min" - -definition - "(sup \ int \ int \ int) = max" - -instance - by intro_classes - (auto simp add: inf_int_def sup_int_def min_max.sup_inf_distrib1) - -end - -lemma le_plus_raw: - shows "le_raw i j \ le_raw (plus_raw k i) (plus_raw k j)" - by (cases i, cases j, cases k) (simp) - -instance int :: ordered_cancel_ab_semigroup_add -proof - fix i j k :: int - show "i \ j \ k + i \ k + j" - by (lifting le_plus_raw) -qed - -abbreviation - "less_raw i j \ le_raw i j \ \(i \ j)" - -lemma zmult_zless_mono2_lemma: - fixes i j::int - and k::nat - shows "i < j \ 0 < k \ of_nat k * i < of_nat k * j" - apply(induct "k") - apply(simp) - apply(case_tac "k = 0") - apply(simp_all add: left_distrib add_strict_mono) - done - -lemma zero_le_imp_eq_int_raw: - fixes k::"(nat \ nat)" - shows "less_raw (0, 0) k \ (\n > 0. k \ int_of_nat_raw n)" - apply(cases k) - apply(simp add:int_of_nat_raw) - apply(auto) - apply(rule_tac i="b" and j="a" in less_Suc_induct) - apply(auto) - done - -lemma zero_le_imp_eq_int: - fixes k::int - shows "0 < k \ \n > 0. k = of_nat n" - unfolding less_int_def int_of_nat - by (lifting zero_le_imp_eq_int_raw) - -lemma zmult_zless_mono2: - fixes i j k::int - assumes a: "i < j" "0 < k" - shows "k * i < k * j" - using a - by (drule_tac zero_le_imp_eq_int) (auto simp add: zmult_zless_mono2_lemma) - -text{*The integers form an ordered integral domain*} -instance int :: linordered_idom -proof - fix i j k :: int - show "i < j \ 0 < k \ k * i < k * j" - by (rule zmult_zless_mono2) - show "\i\ = (if i < 0 then -i else i)" - by (simp only: zabs_def) - show "sgn (i\int) = (if i=0 then 0 else if 0i. P i \ P (plus_raw i (1, 0))" - and c: "\i. P i \ P (plus_raw i (uminus_raw (1, 0)))" - shows "P x" -proof (cases x, clarify) - fix a b - show "P (a, b)" - proof (induct a arbitrary: b rule: Nat.induct) - case zero - show "P (0, b)" using assms by (induct b) auto - next - case (Suc n) - then show ?case using assms by auto - qed -qed - -lemma int_induct: - fixes x :: int - assumes a: "P 0" - and b: "\i. P i \ P (i + 1)" - and c: "\i. P i \ P (i - 1)" - shows "P x" - using a b c unfolding minus_int_def - by (lifting int_induct_raw) - subsection {* Embedding of the Integers into any @{text ring_1}: @{text of_int}*} (*