author | wenzelm |
Mon, 13 Apr 2020 22:08:14 +0200 | |
changeset 71751 | abf3e80bd815 |
parent 68606 | 96a49db47c97 |
child 75963 | 884dbbc8e1b3 |
permissions | -rw-r--r-- |
68582 | 1 |
(* Title: HOL/Algebra/Ideal_Product.thy |
2 |
Author: Paulo Emílio de Vilhena |
|
3 |
*) |
|
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
4 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
5 |
theory Ideal_Product |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
6 |
imports Ideal |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
7 |
begin |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
8 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
9 |
section \<open>Product of Ideals\<close> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
10 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
11 |
text \<open>In this section, we study the structure of the set of ideals of a given ring.\<close> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
12 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
13 |
inductive_set |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
14 |
ideal_prod :: "[ ('a, 'b) ring_scheme, 'a set, 'a set ] \<Rightarrow> 'a set" (infixl "\<cdot>\<index>" 80) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
15 |
for R and I and J (* both I and J are supposed ideals *) where |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
16 |
prod: "\<lbrakk> i \<in> I; j \<in> J \<rbrakk> \<Longrightarrow> i \<otimes>\<^bsub>R\<^esub> j \<in> ideal_prod R I J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
17 |
| sum: "\<lbrakk> s1 \<in> ideal_prod R I J; s2 \<in> ideal_prod R I J \<rbrakk> \<Longrightarrow> s1 \<oplus>\<^bsub>R\<^esub> s2 \<in> ideal_prod R I J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
18 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
19 |
definition ideals_set :: "('a, 'b) ring_scheme \<Rightarrow> ('a set) ring" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
20 |
where "ideals_set R = \<lparr> carrier = { I. ideal I R }, |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
21 |
mult = ideal_prod R, |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
22 |
one = carrier R, |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
23 |
zero = { \<zero>\<^bsub>R\<^esub> }, |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
24 |
add = set_add R \<rparr>" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
25 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
26 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
27 |
subsection \<open>Basic Properties\<close> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
28 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
29 |
lemma (in ring) ideal_prod_in_carrier: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
30 |
assumes "ideal I R" "ideal J R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
31 |
shows "I \<cdot> J \<subseteq> carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
32 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
33 |
fix s assume "s \<in> I \<cdot> J" thus "s \<in> carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
34 |
by (induct s rule: ideal_prod.induct) (auto, meson assms ideal.I_l_closed ideal.Icarr) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
35 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
36 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
37 |
lemma (in ring) ideal_prod_inter: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
38 |
assumes "ideal I R" "ideal J R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
39 |
shows "I \<cdot> J \<subseteq> I \<inter> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
40 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
41 |
fix s assume "s \<in> I \<cdot> J" thus "s \<in> I \<inter> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
42 |
apply (induct s rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
43 |
apply (auto, (meson assms ideal.I_r_closed ideal.I_l_closed ideal.Icarr)+) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
44 |
apply (simp_all add: additive_subgroup.a_closed assms ideal.axioms(1)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
45 |
done |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
46 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
47 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
48 |
lemma (in ring) ideal_prod_is_ideal: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
49 |
assumes "ideal I R" "ideal J R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
50 |
shows "ideal (I \<cdot> J) R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
51 |
proof (rule idealI) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
52 |
show "ring R" using is_ring . |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
53 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
54 |
show "subgroup (I \<cdot> J) (add_monoid R)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
55 |
unfolding subgroup_def |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
56 |
proof (auto) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
57 |
show "\<zero> \<in> I \<cdot> J" using ideal_prod.prod[of \<zero> I \<zero> J R] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
58 |
by (simp add: additive_subgroup.zero_closed assms ideal.axioms(1)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
59 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
60 |
fix s1 s2 assume s1: "s1 \<in> I \<cdot> J" and s2: "s2 \<in> I \<cdot> J" |
68605 | 61 |
have IJcarr: "\<And>a. a \<in> I \<cdot> J \<Longrightarrow> a \<in> carrier R" |
62 |
by (meson assms subsetD ideal_prod_in_carrier) |
|
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
63 |
show "s1 \<in> carrier R" using ideal_prod_in_carrier[OF assms] s1 by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
64 |
show "s1 \<oplus> s2 \<in> I \<cdot> J" by (simp add: ideal_prod.sum[OF s1 s2]) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
65 |
show "inv\<^bsub>add_monoid R\<^esub> s1 \<in> I \<cdot> J" using s1 |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
66 |
proof (induct s1 rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
67 |
case (prod i j) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
68 |
hence "inv\<^bsub>add_monoid R\<^esub> (i \<otimes> j) = (inv\<^bsub>add_monoid R\<^esub> i) \<otimes> j" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
69 |
by (metis a_inv_def assms(1) assms(2) ideal.Icarr l_minus) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
70 |
thus ?case using ideal_prod.prod[of "inv\<^bsub>add_monoid R\<^esub> i" I j J R] assms |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
71 |
by (simp add: additive_subgroup.a_subgroup ideal.axioms(1) prod.hyps subgroup.m_inv_closed) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
72 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
73 |
case (sum s1 s2) thus ?case |
68605 | 74 |
by (metis (no_types) IJcarr a_inv_def add.inv_mult_group ideal_prod.sum sum.hyps) |
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
75 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
76 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
77 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
78 |
fix s x assume s: "s \<in> I \<cdot> J" and x: "x \<in> carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
79 |
show "x \<otimes> s \<in> I \<cdot> J" using s |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
80 |
proof (induct s rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
81 |
case (prod i j) thus ?case using ideal_prod.prod[of "x \<otimes> i" I j J R] assms |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
82 |
by (simp add: x ideal.I_l_closed ideal.Icarr m_assoc) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
83 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
84 |
case (sum s1 s2) thus ?case |
68605 | 85 |
proof - |
86 |
have IJ: "I \<cdot> J \<subseteq> carrier R" |
|
87 |
by (metis (no_types) assms(1) assms(2) ideal.axioms(2) ring.ideal_prod_in_carrier) |
|
88 |
then have "s2 \<in> carrier R" |
|
89 |
using sum.hyps(3) by blast |
|
90 |
moreover have "s1 \<in> carrier R" |
|
91 |
using IJ sum.hyps(1) by blast |
|
92 |
ultimately show ?thesis |
|
93 |
by (simp add: ideal_prod.sum r_distr sum.hyps x) |
|
94 |
qed |
|
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
95 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
96 |
show "s \<otimes> x \<in> I \<cdot> J" using s |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
97 |
proof (induct s rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
98 |
case (prod i j) thus ?case using ideal_prod.prod[of i I "j \<otimes> x" J R] assms x |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
99 |
by (simp add: x ideal.I_r_closed ideal.Icarr m_assoc) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
100 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
101 |
case (sum s1 s2) thus ?case |
68605 | 102 |
proof - |
103 |
have "s1 \<in> carrier R" "s2 \<in> carrier R" |
|
104 |
by (meson assms subsetD ideal_prod_in_carrier sum.hyps)+ |
|
105 |
then show ?thesis |
|
106 |
by (metis ideal_prod.sum l_distr sum.hyps(2) sum.hyps(4) x) |
|
107 |
qed |
|
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
108 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
109 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
110 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
111 |
lemma (in ring) ideal_prod_eq_genideal: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
112 |
assumes "ideal I R" "ideal J R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
113 |
shows "I \<cdot> J = Idl (I <#> J)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
114 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
115 |
have "I <#> J \<subseteq> I \<cdot> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
116 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
117 |
fix s assume "s \<in> I <#> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
118 |
then obtain i j where "i \<in> I" "j \<in> J" "s = i \<otimes> j" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
119 |
unfolding set_mult_def by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
120 |
thus "s \<in> I \<cdot> J" using ideal_prod.prod by simp |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
121 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
122 |
thus "Idl (I <#> J) \<subseteq> I \<cdot> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
123 |
unfolding genideal_def using ideal_prod_is_ideal[OF assms] by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
124 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
125 |
show "I \<cdot> J \<subseteq> Idl (I <#> J)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
126 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
127 |
fix s assume "s \<in> I \<cdot> J" thus "s \<in> Idl (I <#> J)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
128 |
proof (induct s rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
129 |
case (prod i j) hence "i \<otimes> j \<in> I <#> J" unfolding set_mult_def by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
130 |
thus ?case unfolding genideal_def by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
131 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
132 |
case (sum s1 s2) thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
133 |
by (simp add: additive_subgroup.a_closed additive_subgroup.a_subset |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
134 |
assms genideal_ideal ideal.axioms(1) set_mult_closed) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
135 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
136 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
137 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
138 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
139 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
140 |
lemma (in ring) ideal_prod_simp: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
141 |
assumes "ideal I R" "ideal J R" (* the second assumption could be suppressed *) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
142 |
shows "I = I <+> (I \<cdot> J)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
143 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
144 |
show "I \<subseteq> I <+> I \<cdot> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
145 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
146 |
fix i assume "i \<in> I" hence "i \<oplus> \<zero> \<in> I <+> I \<cdot> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
147 |
using set_add_def'[of R I "I \<cdot> J"] ideal_prod_is_ideal[OF assms] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
148 |
additive_subgroup.zero_closed[OF ideal.axioms(1), of "I \<cdot> J" R] by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
149 |
thus "i \<in> I <+> I \<cdot> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
150 |
using \<open>i \<in> I\<close> assms(1) ideal.Icarr by fastforce |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
151 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
152 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
153 |
show "I <+> I \<cdot> J \<subseteq> I" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
154 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
155 |
fix s assume "s \<in> I <+> I \<cdot> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
156 |
then obtain i ij where "i \<in> I" "ij \<in> I \<cdot> J" "s = i \<oplus> ij" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
157 |
using set_add_def'[of R I "I \<cdot> J"] by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
158 |
thus "s \<in> I" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
159 |
using ideal_prod_inter[OF assms] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
160 |
by (meson additive_subgroup.a_closed assms(1) ideal.axioms(1) inf_sup_ord(1) subsetCE) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
161 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
162 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
163 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
164 |
lemma (in ring) ideal_prod_one: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
165 |
assumes "ideal I R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
166 |
shows "I \<cdot> (carrier R) = I" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
167 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
168 |
show "I \<cdot> (carrier R) \<subseteq> I" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
169 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
170 |
fix s assume "s \<in> I \<cdot> (carrier R)" thus "s \<in> I" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
171 |
by (induct s rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
172 |
(simp_all add: assms ideal.I_r_closed additive_subgroup.a_closed ideal.axioms(1)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
173 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
174 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
175 |
show "I \<subseteq> I \<cdot> (carrier R)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
176 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
177 |
fix i assume "i \<in> I" thus "i \<in> I \<cdot> (carrier R)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
178 |
by (metis assms ideal.Icarr ideal_prod.simps one_closed r_one) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
179 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
180 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
181 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
182 |
lemma (in ring) ideal_prod_zero: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
183 |
assumes "ideal I R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
184 |
shows "I \<cdot> { \<zero> } = { \<zero> }" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
185 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
186 |
show "I \<cdot> { \<zero> } \<subseteq> { \<zero> }" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
187 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
188 |
fix s assume "s \<in> I \<cdot> {\<zero>}" thus "s \<in> { \<zero> }" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
189 |
using assms ideal.Icarr by (induct s rule: ideal_prod.induct) (fastforce, simp) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
190 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
191 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
192 |
show "{ \<zero> } \<subseteq> I \<cdot> { \<zero> }" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
193 |
by (simp add: additive_subgroup.zero_closed assms |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
194 |
ideal.axioms(1) ideal_prod_is_ideal zeroideal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
195 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
196 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
197 |
lemma (in ring) ideal_prod_assoc: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
198 |
assumes "ideal I R" "ideal J R" "ideal K R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
199 |
shows "(I \<cdot> J) \<cdot> K = I \<cdot> (J \<cdot> K)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
200 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
201 |
show "(I \<cdot> J) \<cdot> K \<subseteq> I \<cdot> (J \<cdot> K)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
202 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
203 |
fix s assume "s \<in> (I \<cdot> J) \<cdot> K" thus "s \<in> I \<cdot> (J \<cdot> K)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
204 |
proof (induct s rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
205 |
case (sum s1 s2) thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
206 |
by (simp add: ideal_prod.sum) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
207 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
208 |
case (prod i k) thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
209 |
proof (induct i rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
210 |
case (prod i j) thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
211 |
using ideal_prod.prod[OF prod(1) ideal_prod.prod[OF prod(2-3),of R], of R] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
212 |
by (metis assms ideal.Icarr m_assoc) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
213 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
214 |
case (sum s1 s2) thus ?case |
68605 | 215 |
proof - |
216 |
have "s1 \<in> carrier R" "s2 \<in> carrier R" |
|
217 |
by (meson assms subsetD ideal.axioms(2) ring.ideal_prod_in_carrier sum.hyps)+ |
|
218 |
moreover have "k \<in> carrier R" |
|
219 |
by (meson additive_subgroup.a_Hcarr assms(3) ideal.axioms(1) sum.prems) |
|
220 |
ultimately show ?thesis |
|
221 |
by (metis ideal_prod.sum l_distr sum.hyps(2) sum.hyps(4) sum.prems) |
|
222 |
qed |
|
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
223 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
224 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
225 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
226 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
227 |
show "I \<cdot> (J \<cdot> K) \<subseteq> (I \<cdot> J) \<cdot> K" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
228 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
229 |
fix s assume "s \<in> I \<cdot> (J \<cdot> K)" thus "s \<in> (I \<cdot> J) \<cdot> K" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
230 |
proof (induct s rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
231 |
case (sum s1 s2) thus ?case by (simp add: ideal_prod.sum) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
232 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
233 |
case (prod i j) show ?case using prod(2) prod(1) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
234 |
proof (induct j rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
235 |
case (prod j k) thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
236 |
using ideal_prod.prod[OF ideal_prod.prod[OF prod(3) prod(1), of R] prod (2), of R] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
237 |
by (metis assms ideal.Icarr m_assoc) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
238 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
239 |
case (sum s1 s2) thus ?case |
68605 | 240 |
proof - |
241 |
have "\<And>a A B. \<lbrakk>a \<in> B \<cdot> A; ideal A R; ideal B R\<rbrakk> \<Longrightarrow> a \<in> carrier R" |
|
242 |
by (meson subsetD ideal_prod_in_carrier) |
|
243 |
moreover have "i \<in> carrier R" |
|
244 |
by (meson additive_subgroup.a_Hcarr assms(1) ideal.axioms(1) sum.prems) |
|
245 |
ultimately show ?thesis |
|
246 |
by (metis (no_types) assms(2) assms(3) ideal_prod.sum r_distr sum) |
|
247 |
qed |
|
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
248 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
249 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
250 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
251 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
252 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
253 |
lemma (in ring) ideal_prod_r_distr: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
254 |
assumes "ideal I R" "ideal J R" "ideal K R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
255 |
shows "I \<cdot> (J <+> K) = (I \<cdot> J) <+> (I \<cdot> K)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
256 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
257 |
show "I \<cdot> (J <+> K) \<subseteq> I \<cdot> J <+> I \<cdot> K" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
258 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
259 |
fix s assume "s \<in> I \<cdot> (J <+> K)" thus "s \<in> I \<cdot> J <+> I \<cdot> K" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
260 |
proof(induct s rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
261 |
case (prod i jk) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
262 |
then obtain j k where j: "j \<in> J" and k: "k \<in> K" and jk: "jk = j \<oplus> k" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
263 |
using set_add_def'[of R J K] by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
264 |
hence "i \<otimes> j \<oplus> i \<otimes> k \<in> I \<cdot> J <+> I \<cdot> K" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
265 |
using ideal_prod.prod[OF prod(1) j,of R] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
266 |
ideal_prod.prod[OF prod(1) k,of R] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
267 |
set_add_def'[of R "I \<cdot> J" "I \<cdot> K"] by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
268 |
thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
269 |
using assms ideal.Icarr r_distr jk j k prod(1) by metis |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
270 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
271 |
case (sum s1 s2) thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
272 |
by (simp add: add_ideals additive_subgroup.a_closed assms ideal.axioms(1) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
273 |
local.ring_axioms ring.ideal_prod_is_ideal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
274 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
275 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
276 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
277 |
{ fix s J K assume A: "ideal J R" "ideal K R" "s \<in> I \<cdot> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
278 |
have "s \<in> I \<cdot> (J <+> K) \<and> s \<in> I \<cdot> (K <+> J)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
279 |
proof - |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
280 |
from \<open>s \<in> I \<cdot> J\<close> have "s \<in> I \<cdot> (J <+> K)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
281 |
proof (induct s rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
282 |
case (prod i j) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
283 |
hence "(j \<oplus> \<zero>) \<in> J <+> K" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
284 |
using set_add_def'[of R J K] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
285 |
additive_subgroup.zero_closed[OF ideal.axioms(1), of K R] A(2) by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
286 |
thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
287 |
by (metis A(1) additive_subgroup.a_Hcarr ideal.axioms(1) ideal_prod.prod prod r_zero) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
288 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
289 |
case (sum s1 s2) thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
290 |
by (simp add: ideal_prod.sum) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
291 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
292 |
thus ?thesis |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
293 |
by (metis A(1) A(2) ideal_def ring.union_genideal sup_commute) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
294 |
qed } note aux_lemma = this |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
295 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
296 |
show "I \<cdot> J <+> I \<cdot> K \<subseteq> I \<cdot> (J <+> K)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
297 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
298 |
fix s assume "s \<in> I \<cdot> J <+> I \<cdot> K" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
299 |
then obtain s1 s2 where s1: "s1 \<in> I \<cdot> J" and s2: "s2 \<in> I \<cdot> K" and s: "s = s1 \<oplus> s2" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
300 |
using set_add_def'[of R "I \<cdot> J" "I \<cdot> K"] by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
301 |
thus "s \<in> I \<cdot> (J <+> K)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
302 |
using aux_lemma[OF assms(2) assms(3) s1] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
303 |
aux_lemma[OF assms(3) assms(2) s2] by (simp add: ideal_prod.sum) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
304 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
305 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
306 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
307 |
lemma (in cring) ideal_prod_commute: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
308 |
assumes "ideal I R" "ideal J R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
309 |
shows "I \<cdot> J = J \<cdot> I" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
310 |
proof - |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
311 |
{ fix I J assume A: "ideal I R" "ideal J R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
312 |
have "I \<cdot> J \<subseteq> J \<cdot> I" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
313 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
314 |
fix s assume "s \<in> I \<cdot> J" thus "s \<in> J \<cdot> I" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
315 |
proof (induct s rule: ideal_prod.induct) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
316 |
case (prod i j) thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
317 |
using m_comm[OF ideal.Icarr[OF A(1) prod(1)] ideal.Icarr[OF A(2) prod(2)]] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
318 |
by (simp add: ideal_prod.prod) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
319 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
320 |
case (sum s1 s2) thus ?case by (simp add: ideal_prod.sum) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
321 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
322 |
qed } |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
323 |
thus ?thesis using assms by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
324 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
325 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
326 |
text \<open>The following result would also be true for locale ring\<close> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
327 |
lemma (in cring) ideal_prod_distr: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
328 |
assumes "ideal I R" "ideal J R" "ideal K R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
329 |
shows "I \<cdot> (J <+> K) = (I \<cdot> J) <+> (I \<cdot> K)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
330 |
and "(J <+> K) \<cdot> I = (J \<cdot> I) <+> (K \<cdot> I)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
331 |
by (simp_all add: assms ideal_prod_commute local.ring_axioms |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
332 |
ring.add_ideals ring.ideal_prod_r_distr) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
333 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
334 |
lemma (in cring) ideal_prod_eq_inter: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
335 |
assumes "ideal I R" "ideal J R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
336 |
and "I <+> J = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
337 |
shows "I \<cdot> J = I \<inter> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
338 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
339 |
show "I \<cdot> J \<subseteq> I \<inter> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
340 |
using assms ideal_prod_inter by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
341 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
342 |
show "I \<inter> J \<subseteq> I \<cdot> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
343 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
344 |
have "\<one> \<in> I <+> J" using assms(3) one_closed by simp |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
345 |
then obtain i j where ij: "i \<in> I" "j \<in> J" "\<one> = i \<oplus> j" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
346 |
using set_add_def'[of R I J] by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
347 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
348 |
fix s assume s: "s \<in> I \<inter> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
349 |
hence "(i \<otimes> s \<in> I \<cdot> J) \<and> (s \<otimes> j \<in> I \<cdot> J)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
350 |
using ij(1-2) by (simp add: ideal_prod.prod) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
351 |
moreover have "s = (i \<otimes> s) \<oplus> (s \<otimes> j)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
352 |
using ideal.Icarr[OF assms(1) ij(1)] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
353 |
ideal.Icarr[OF assms(2) ij(2)] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
354 |
ideal.Icarr[OF assms(1), of s] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
355 |
by (metis ij(3) s m_comm[of s i] Int_iff r_distr r_one) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
356 |
ultimately show "s \<in> I \<cdot> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
357 |
using ideal_prod.sum by fastforce |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
358 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
359 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
360 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
361 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
362 |
subsection \<open>Structure of the Set of Ideals\<close> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
363 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
364 |
text \<open>We focus on commutative rings for convenience.\<close> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
365 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
366 |
lemma (in cring) ideals_set_is_semiring: "semiring (ideals_set R)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
367 |
proof - |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
368 |
have "abelian_monoid (ideals_set R)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
369 |
apply (rule abelian_monoidI) unfolding ideals_set_def |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
370 |
apply (simp_all add: add_ideals zeroideal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
371 |
apply (simp add: add.set_mult_assoc additive_subgroup.a_subset ideal.axioms(1) set_add_defs(1)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
372 |
apply (metis Un_absorb1 additive_subgroup.a_subset additive_subgroup.zero_closed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
373 |
cgenideal_minimal cgenideal_self empty_iff genideal_minimal ideal.axioms(1) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
374 |
local.ring_axioms order_refl ring.genideal_self subset_antisym subset_singletonD |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
375 |
union_genideal zero_closed zeroideal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
376 |
by (metis sup_commute union_genideal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
377 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
378 |
moreover have "monoid (ideals_set R)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
379 |
apply (rule monoidI) unfolding ideals_set_def |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
380 |
apply (simp_all add: ideal_prod_is_ideal oneideal |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
381 |
ideal_prod_commute ideal_prod_one) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
382 |
by (metis ideal_prod_assoc ideal_prod_commute) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
383 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
384 |
ultimately show ?thesis |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
385 |
unfolding semiring_def semiring_axioms_def ideals_set_def |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
386 |
by (simp_all add: ideal_prod_distr ideal_prod_commute ideal_prod_zero zeroideal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
387 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
388 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
389 |
lemma (in cring) ideals_set_is_comm_monoid: "comm_monoid (ideals_set R)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
390 |
proof - |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
391 |
have "monoid (ideals_set R)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
392 |
apply (rule monoidI) unfolding ideals_set_def |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
393 |
apply (simp_all add: ideal_prod_is_ideal oneideal |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
394 |
ideal_prod_commute ideal_prod_one) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
395 |
by (metis ideal_prod_assoc ideal_prod_commute) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
396 |
thus ?thesis |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
397 |
unfolding comm_monoid_def comm_monoid_axioms_def |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
398 |
by (simp add: ideal_prod_commute ideals_set_def) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
399 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
400 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
401 |
lemma (in cring) ideal_prod_eq_Inter_aux: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
402 |
assumes "I: {..(Suc n)} \<rightarrow> { J. ideal J R }" |
68606
96a49db47c97
removal of smt and certain refinements
paulson <lp15@cam.ac.uk>
parents:
68605
diff
changeset
|
403 |
and "\<And>i j. \<lbrakk> i \<le> Suc n; j \<le> Suc n \<rbrakk> \<Longrightarrow> |
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
404 |
i \<noteq> j \<Longrightarrow> (I i) <+> (I j) = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
405 |
shows "(\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..n}. I k) <+> (I (Suc n)) = carrier R" using assms |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
406 |
proof (induct n arbitrary: I) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
407 |
case 0 |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
408 |
hence "(\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..0}. I k) <+> I (Suc 0) = (I 0) <+> (I (Suc 0))" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
409 |
using comm_monoid.finprod_0[OF ideals_set_is_comm_monoid, of I] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
410 |
by (simp add: atMost_Suc ideals_set_def) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
411 |
also have " ... = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
412 |
using 0(2)[of 0 "Suc 0"] by simp |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
413 |
finally show ?case . |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
414 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
415 |
interpret ISet: comm_monoid "ideals_set R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
416 |
by (simp add: ideals_set_is_comm_monoid) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
417 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
418 |
case (Suc n) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
419 |
let ?I' = "\<lambda>i. I (Suc i)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
420 |
have "?I': {..(Suc n)} \<rightarrow> { J. ideal J R }" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
421 |
using Suc.prems(1) by auto |
68606
96a49db47c97
removal of smt and certain refinements
paulson <lp15@cam.ac.uk>
parents:
68605
diff
changeset
|
422 |
moreover have "\<And>i j. \<lbrakk> i \<le> Suc n; j \<le> Suc n \<rbrakk> \<Longrightarrow> |
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
423 |
i \<noteq> j \<Longrightarrow> (?I' i) <+> (?I' j) = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
424 |
by (simp add: Suc.prems(2)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
425 |
ultimately have "(\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..n}. ?I' k) <+> (?I' (Suc n)) = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
426 |
using Suc.hyps by metis |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
427 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
428 |
moreover have I_carr: "I: {..Suc (Suc n)} \<rightarrow> carrier (ideals_set R)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
429 |
unfolding ideals_set_def using Suc by simp |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
430 |
hence I'_carr: "I \<in> Suc ` {..n} \<rightarrow> carrier (ideals_set R)" by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
431 |
ultimately have "(\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {(Suc 0)..Suc n}. I k) <+> (I (Suc (Suc n))) = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
432 |
using ISet.finprod_reindex[of I "\<lambda>i. Suc i" "{..n}"] by (simp add: atMost_atLeast0) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
433 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
434 |
hence "(carrier R) \<cdot> (I 0) = ((\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {Suc 0..Suc n}. I k) <+> I (Suc (Suc n))) \<cdot> (I 0)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
435 |
by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
436 |
moreover have fprod_cl1: "ideal (\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {Suc 0..Suc n}. I k) R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
437 |
by (metis I'_carr ISet.finprod_closed One_nat_def ideals_set_def image_Suc_atMost |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
438 |
mem_Collect_eq partial_object.select_convs(1)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
439 |
ultimately |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
440 |
have "I 0 = (\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {Suc 0..Suc n}. I k) \<cdot> (I 0) <+> I (Suc (Suc n)) \<cdot> (I 0)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
441 |
by (metis PiE Suc.prems(1) atLeast0_atMost_Suc atLeast0_atMost_Suc_eq_insert_0 |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
442 |
atMost_atLeast0 ideal_prod_commute ideal_prod_distr(2) ideal_prod_one insertI1 |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
443 |
mem_Collect_eq oneideal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
444 |
also have " ... = (I 0) \<cdot> (\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {Suc 0..Suc n}. I k) <+> I (Suc (Suc n)) \<cdot> (I 0)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
445 |
using fprod_cl1 ideal_prod_commute Suc.prems(1) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
446 |
by (simp add: atLeast0_atMost_Suc_eq_insert_0 atMost_atLeast0) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
447 |
also have " ... = (I 0) \<otimes>\<^bsub>(ideals_set R)\<^esub> (\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {Suc 0..Suc n}. I k) <+> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
448 |
I (Suc (Suc n)) \<cdot> (I 0)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
449 |
by (simp add: ideals_set_def) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
450 |
finally have I0: "I 0 = (\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..Suc n}. I k) <+> I (Suc (Suc n)) \<cdot> (I 0)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
451 |
using ISet.finprod_insert[of "{Suc 0..Suc n}" 0 I] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
452 |
I_carr I'_carr atMost_atLeast0 ISet.finprod_0' atMost_Suc by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
453 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
454 |
have I_SucSuc_I0: "ideal (I (Suc (Suc n))) R \<and> ideal (I 0) R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
455 |
using Suc.prems(1) by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
456 |
have fprod_cl2: "ideal (\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..Suc n}. I k) R" |
68605 | 457 |
by (metis (no_types) ISet.finprod_closed I_carr Pi_split_insert_domain atMost_Suc ideals_set_def mem_Collect_eq partial_object.select_convs(1)) |
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
458 |
have "carrier R = I (Suc (Suc n)) <+> I 0" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
459 |
by (simp add: Suc.prems(2)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
460 |
also have " ... = I (Suc (Suc n)) <+> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
461 |
((\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..Suc n}. I k) <+> I (Suc (Suc n)) \<cdot> (I 0))" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
462 |
using I0 by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
463 |
also have " ... = I (Suc (Suc n)) <+> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
464 |
(I (Suc (Suc n)) \<cdot> (I 0) <+> (\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..Suc n}. I k))" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
465 |
using fprod_cl2 I_SucSuc_I0 by (metis Un_commute ideal_prod_is_ideal union_genideal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
466 |
also have " ... = (I (Suc (Suc n)) <+> I (Suc (Suc n)) \<cdot> (I 0)) <+> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
467 |
(\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..Suc n}. I k)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
468 |
using fprod_cl2 I_SucSuc_I0 by (metis add.set_mult_assoc ideal_def ideal_prod_in_carrier |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
469 |
oneideal ring.ideal_prod_one set_add_defs(1)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
470 |
also have " ... = I (Suc (Suc n)) <+> (\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..Suc n}. I k)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
471 |
using ideal_prod_simp[of "I (Suc (Suc n))" "I 0"] I_SucSuc_I0 by simp |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
472 |
also have " ... = (\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..Suc n}. I k) <+> I (Suc (Suc n))" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
473 |
using fprod_cl2 I_SucSuc_I0 by (metis Un_commute union_genideal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
474 |
finally show ?case by simp |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
475 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
476 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
477 |
theorem (in cring) ideal_prod_eq_Inter: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
478 |
assumes "I: {..n :: nat} \<rightarrow> { J. ideal J R }" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
479 |
and "\<And>i j. \<lbrakk> i \<in> {..n}; j \<in> {..n} \<rbrakk> \<Longrightarrow> i \<noteq> j \<Longrightarrow> (I i) <+> (I j) = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
480 |
shows "(\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..n}. I k) = (\<Inter> k \<in> {..n}. I k)" using assms |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
481 |
proof (induct n) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
482 |
case 0 thus ?case |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
483 |
using comm_monoid.finprod_0[OF ideals_set_is_comm_monoid] by (simp add: ideals_set_def) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
484 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
485 |
interpret ISet: comm_monoid "ideals_set R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
486 |
by (simp add: ideals_set_is_comm_monoid) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
487 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
488 |
case (Suc n) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
489 |
hence IH: "(\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..n}. I k) = (\<Inter> k \<in> {..n}. I k)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
490 |
by (simp add: atMost_Suc) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
491 |
hence "(\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..Suc n}. I k) = I (Suc n) \<otimes>\<^bsub>(ideals_set R)\<^esub> (\<Inter> k \<in> {..n}. I k)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
492 |
using ISet.finprod_insert[of "{Suc 0..Suc n}" 0 I] atMost_Suc_eq_insert_0[of n] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
493 |
by (metis ISet.finprod_Suc Suc.prems(1) ideals_set_def partial_object.select_convs(1)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
494 |
hence "(\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..Suc n}. I k) = I (Suc n) \<cdot> (\<Inter> k \<in> {..n}. I k)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
495 |
by (simp add: ideals_set_def) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
496 |
moreover have "(\<Inter> k \<in> {..n}. I k) <+> I (Suc n) = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
497 |
using ideal_prod_eq_Inter_aux[of I n] by (simp add: Suc.prems IH) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
498 |
moreover have "ideal (\<Inter> k \<in> {..n}. I k) R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
499 |
using ring.i_Intersect[of R "I ` {..n}"] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
500 |
by (metis IH ISet.finprod_closed Pi_split_insert_domain Suc.prems(1) atMost_Suc |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
501 |
ideals_set_def mem_Collect_eq partial_object.select_convs(1)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
502 |
ultimately |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
503 |
have "(\<Otimes>\<^bsub>(ideals_set R)\<^esub> k \<in> {..Suc n}. I k) = (\<Inter> k \<in> {..n}. I k) \<inter> I (Suc n)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
504 |
using ideal_prod_eq_inter[of "\<Inter> k \<in> {..n}. I k" "I (Suc n)"] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
505 |
ideal_prod_commute[of "\<Inter> k \<in> {..n}. I k" "I (Suc n)"] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
506 |
by (metis PiE Suc.prems(1) atMost_iff mem_Collect_eq order_refl) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
507 |
thus ?case by (simp add: Int_commute atMost_Suc) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
508 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
509 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
510 |
corollary (in cring) inter_plus_ideal_eq_carrier: |
68606
96a49db47c97
removal of smt and certain refinements
paulson <lp15@cam.ac.uk>
parents:
68605
diff
changeset
|
511 |
assumes "\<And>i. i \<le> Suc n \<Longrightarrow> ideal (I i) R" |
96a49db47c97
removal of smt and certain refinements
paulson <lp15@cam.ac.uk>
parents:
68605
diff
changeset
|
512 |
and "\<And>i j. \<lbrakk> i \<le> Suc n; j \<le> Suc n; i \<noteq> j \<rbrakk> \<Longrightarrow> I i <+> I j = carrier R" |
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
513 |
shows "(\<Inter> i \<le> n. I i) <+> (I (Suc n)) = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
514 |
using ideal_prod_eq_Inter[of I n] ideal_prod_eq_Inter_aux[of I n] by (auto simp add: assms) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
515 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
516 |
corollary (in cring) inter_plus_ideal_eq_carrier_arbitrary: |
68606
96a49db47c97
removal of smt and certain refinements
paulson <lp15@cam.ac.uk>
parents:
68605
diff
changeset
|
517 |
assumes "\<And>i. i \<le> Suc n \<Longrightarrow> ideal (I i) R" |
96a49db47c97
removal of smt and certain refinements
paulson <lp15@cam.ac.uk>
parents:
68605
diff
changeset
|
518 |
and "\<And>i j. \<lbrakk> i \<le> Suc n; j \<le> Suc n; i \<noteq> j \<rbrakk> \<Longrightarrow> I i <+> I j = carrier R" |
96a49db47c97
removal of smt and certain refinements
paulson <lp15@cam.ac.uk>
parents:
68605
diff
changeset
|
519 |
and "j \<le> Suc n" |
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
520 |
shows "(\<Inter> i \<in> ({..(Suc n)} - { j }). I i) <+> (I j) = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
521 |
proof - |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
522 |
define I' where "I' = (\<lambda>i. if i = Suc n then (I j) else |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
523 |
if i = j then (I (Suc n)) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
524 |
else (I i))" |
68606
96a49db47c97
removal of smt and certain refinements
paulson <lp15@cam.ac.uk>
parents:
68605
diff
changeset
|
525 |
have "\<And>i. i \<le> Suc n \<Longrightarrow> ideal (I' i) R" |
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
526 |
using I'_def assms(1) assms(3) by auto |
68606
96a49db47c97
removal of smt and certain refinements
paulson <lp15@cam.ac.uk>
parents:
68605
diff
changeset
|
527 |
moreover have "\<And>i j. \<lbrakk> i \<le> Suc n; j \<le> Suc n; i \<noteq> j \<rbrakk> \<Longrightarrow> I' i <+> I' j = carrier R" |
68569
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
528 |
using I'_def assms(2-3) by force |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
529 |
ultimately have "(\<Inter> i \<le> n. I' i) <+> (I' (Suc n)) = carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
530 |
using inter_plus_ideal_eq_carrier by simp |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
531 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
532 |
moreover have "I' ` {..n} = I ` ({..(Suc n)} - { j })" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
533 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
534 |
show "I' ` {..n} \<subseteq> I ` ({..Suc n} - {j})" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
535 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
536 |
fix x assume "x \<in> I' ` {..n}" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
537 |
then obtain i where i: "i \<in> {..n}" "I' i = x" by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
538 |
thus "x \<in> I ` ({..Suc n} - {j})" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
539 |
proof (cases) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
540 |
assume "i = j" thus ?thesis using i I'_def by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
541 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
542 |
assume "i \<noteq> j" thus ?thesis using I'_def i insert_iff by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
543 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
544 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
545 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
546 |
show "I ` ({..Suc n} - {j}) \<subseteq> I' ` {..n}" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
547 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
548 |
fix x assume "x \<in> I ` ({..Suc n} - {j})" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
549 |
then obtain i where i: "i \<in> {..Suc n}" "i \<noteq> j" "I i = x" by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
550 |
thus "x \<in> I' ` {..n}" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
551 |
proof (cases) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
552 |
assume "i = Suc n" thus ?thesis using I'_def assms(3) i(2-3) by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
553 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
554 |
assume "i \<noteq> Suc n" thus ?thesis using I'_def i by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
555 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
556 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
557 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
558 |
ultimately show ?thesis using I'_def by metis |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
559 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
560 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
561 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
562 |
subsection \<open>Another Characterization of Prime Ideals\<close> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
563 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
564 |
text \<open>With product of ideals being defined, we can give another definition of a prime ideal\<close> |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
565 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
566 |
lemma (in ring) primeideal_divides_ideal_prod: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
567 |
assumes "primeideal P R" "ideal I R" "ideal J R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
568 |
and "I \<cdot> J \<subseteq> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
569 |
shows "I \<subseteq> P \<or> J \<subseteq> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
570 |
proof (cases) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
571 |
assume "\<exists> i \<in> I. i \<notin> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
572 |
then obtain i where i: "i \<in> I" "i \<notin> P" by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
573 |
have "J \<subseteq> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
574 |
proof |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
575 |
fix j assume j: "j \<in> J" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
576 |
hence "i \<otimes> j \<in> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
577 |
using ideal_prod.prod[OF i(1) j, of R] assms(4) by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
578 |
thus "j \<in> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
579 |
using primeideal.I_prime[OF assms(1), of i j] i j |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
580 |
by (meson assms(2-3) ideal.Icarr) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
581 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
582 |
thus ?thesis by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
583 |
next |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
584 |
assume "\<not> (\<exists> i \<in> I. i \<notin> P)" thus ?thesis by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
585 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
586 |
|
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
587 |
lemma (in cring) divides_ideal_prod_imp_primeideal: |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
588 |
assumes "ideal P R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
589 |
and "P \<noteq> carrier R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
590 |
and "\<And>I J. \<lbrakk> ideal I R; ideal J R; I \<cdot> J \<subseteq> P \<rbrakk> \<Longrightarrow> I \<subseteq> P \<or> J \<subseteq> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
591 |
shows "primeideal P R" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
592 |
proof - |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
593 |
have "\<And>a b. \<lbrakk> a \<in> carrier R; b \<in> carrier R; a \<otimes> b \<in> P \<rbrakk> \<Longrightarrow> a \<in> P \<or> b \<in> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
594 |
proof - |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
595 |
fix a b assume A: "a \<in> carrier R" "b \<in> carrier R" "a \<otimes> b \<in> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
596 |
have "(PIdl a) \<cdot> (PIdl b) = Idl (PIdl (a \<otimes> b))" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
597 |
using ideal_prod_eq_genideal[of "Idl { a }" "Idl { b }"] |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
598 |
A(1-2) cgenideal_eq_genideal cgenideal_ideal cgenideal_prod by auto |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
599 |
hence "(PIdl a) \<cdot> (PIdl b) = PIdl (a \<otimes> b)" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
600 |
by (simp add: A Idl_subset_ideal cgenideal_ideal cgenideal_minimal |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
601 |
genideal_self oneideal subset_antisym) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
602 |
hence "(PIdl a) \<cdot> (PIdl b) \<subseteq> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
603 |
by (simp add: A(3) assms(1) cgenideal_minimal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
604 |
hence "(PIdl a) \<subseteq> P \<or> (PIdl b) \<subseteq> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
605 |
by (simp add: A assms(3) cgenideal_ideal) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
606 |
thus "a \<in> P \<or> b \<in> P" |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
607 |
using A cgenideal_self by blast |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
608 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
609 |
thus ?thesis |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
610 |
using assms is_cring by (simp add: primeidealI) |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
611 |
qed |
c64319959bab
Lots of new algebra theories by Martin Baillon and Paulo Emílio de Vilhena
paulson <lp15@cam.ac.uk>
parents:
diff
changeset
|
612 |
|
68582 | 613 |
end |