Metamath Proof Explorer


Theorem qsdrng

Description: An ideal M is both left and right maximal if and only if the factor ring Q is a division ring. (Contributed by Thierry Arnoux, 13-Mar-2025)

Ref Expression
Hypotheses qsdrng.0 ⊢ O = opp r ⁡ R
qsdrng.q ⊢ Q = R / 𝑠 R ~ QG M
qsdrng.r ⊢ φ → R ∈ NzRing
qsdrng.2 ⊢ φ → M ∈ 2Ideal ⁡ R
Assertion qsdrng ⊢ φ → Q ∈ DivRing ↔ M ∈ MaxIdeal ⁡ R ∧ M ∈ MaxIdeal ⁡ O

Proof

Step Hyp Ref Expression
1 qsdrng.0 ⊢ O = opp r ⁡ R
2 qsdrng.q ⊢ Q = R / 𝑠 R ~ QG M
3 qsdrng.r ⊢ φ → R ∈ NzRing
4 qsdrng.2 ⊢ φ → M ∈ 2Ideal ⁡ R
5 nzrring ⊢ R ∈ NzRing → R ∈ Ring
6 3 5 syl ⊢ φ → R ∈ Ring
7 6 adantr ⊢ φ ∧ Q ∈ DivRing → R ∈ Ring
8 4 2idllidld ⊢ φ → M ∈ LIdeal ⁡ R
9 8 adantr ⊢ φ ∧ Q ∈ DivRing → M ∈ LIdeal ⁡ R
10 drngnzr ⊢ Q ∈ DivRing → Q ∈ NzRing
11 10 ad2antlr ⊢ φ ∧ Q ∈ DivRing ∧ M = Base R → Q ∈ NzRing
12 eqid ⊢ 2Ideal ⁡ R = 2Ideal ⁡ R
13 2 12 qusring ⊢ R ∈ Ring ∧ M ∈ 2Ideal ⁡ R → Q ∈ Ring
14 6 4 13 syl2anc ⊢ φ → Q ∈ Ring
15 14 adantr ⊢ φ ∧ M = Base R → Q ∈ Ring
16 oveq2 ⊢ M = Base R → R ~ QG M = R ~ QG Base R
17 16 oveq2d ⊢ M = Base R → R / 𝑠 R ~ QG M = R / 𝑠 R ~ QG Base R
18 2 17 eqtrid ⊢ M = Base R → Q = R / 𝑠 R ~ QG Base R
19 18 fveq2d ⊢ M = Base R → Base Q = Base R / 𝑠 R ~ QG Base R
20 6 ringgrpd ⊢ φ → R ∈ Grp
21 eqid ⊢ Base R = Base R
22 eqid ⊢ R / 𝑠 R ~ QG Base R = R / 𝑠 R ~ QG Base R
23 21 22 qustriv ⊢ R ∈ Grp → Base R / 𝑠 R ~ QG Base R = Base R
24 20 23 syl ⊢ φ → Base R / 𝑠 R ~ QG Base R = Base R
25 19 24 sylan9eqr ⊢ φ ∧ M = Base R → Base Q = Base R
26 25 fveq2d ⊢ φ ∧ M = Base R → Base Q = Base R
27 fvex ⊢ Base R ∈ V
28 hashsng ⊢ Base R ∈ V → Base R = 1
29 27 28 ax-mp ⊢ Base R = 1
30 26 29 eqtrdi ⊢ φ ∧ M = Base R → Base Q = 1
31 0ringnnzr ⊢ Q ∈ Ring → Base Q = 1 ↔ ¬ Q ∈ NzRing
32 31 biimpa ⊢ Q ∈ Ring ∧ Base Q = 1 → ¬ Q ∈ NzRing
33 15 30 32 syl2anc ⊢ φ ∧ M = Base R → ¬ Q ∈ NzRing
34 33 adantlr ⊢ φ ∧ Q ∈ DivRing ∧ M = Base R → ¬ Q ∈ NzRing
35 11 34 pm2.65da ⊢ φ ∧ Q ∈ DivRing → ¬ M = Base R
36 35 neqned ⊢ φ ∧ Q ∈ DivRing → M ≠ Base R
37 simplr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M → M ⊆ j
38 simpr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M → ¬ j = M
39 38 neqned ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M → j ≠ M
40 39 necomd ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M → M ≠ j
41 pssdifn0 ⊢ M ⊆ j ∧ M ≠ j → j ∖ M ≠ ∅
42 37 40 41 syl2anc ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M → j ∖ M ≠ ∅
43 n0 ⊢ j ∖ M ≠ ∅ ↔ ∃ x x ∈ j ∖ M
44 42 43 sylib ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M → ∃ x x ∈ j ∖ M
45 3 ad5antr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → R ∈ NzRing
46 4 ad5antr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → M ∈ 2Ideal ⁡ R
47 simp-5r ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → Q ∈ DivRing
48 simp-4r ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → j ∈ LIdeal ⁡ R
49 37 adantr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → M ⊆ j
50 simpr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → x ∈ j ∖ M
51 1 2 45 46 21 47 48 49 50 qsdrnglem2 ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → j = Base R
52 44 51 exlimddv ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j ∧ ¬ j = M → j = Base R
53 52 ex ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j → ¬ j = M → j = Base R
54 53 orrd ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R ∧ M ⊆ j → j = M ∨ j = Base R
55 54 ex ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ R → M ⊆ j → j = M ∨ j = Base R
56 55 ralrimiva ⊢ φ ∧ Q ∈ DivRing → ∀ j ∈ LIdeal ⁡ R M ⊆ j → j = M ∨ j = Base R
57 21 ismxidl ⊢ R ∈ Ring → M ∈ MaxIdeal ⁡ R ↔ M ∈ LIdeal ⁡ R ∧ M ≠ Base R ∧ ∀ j ∈ LIdeal ⁡ R M ⊆ j → j = M ∨ j = Base R
58 57 biimpar ⊢ R ∈ Ring ∧ M ∈ LIdeal ⁡ R ∧ M ≠ Base R ∧ ∀ j ∈ LIdeal ⁡ R M ⊆ j → j = M ∨ j = Base R → M ∈ MaxIdeal ⁡ R
59 7 9 36 56 58 syl13anc ⊢ φ ∧ Q ∈ DivRing → M ∈ MaxIdeal ⁡ R
60 1 opprring ⊢ R ∈ Ring → O ∈ Ring
61 6 60 syl ⊢ φ → O ∈ Ring
62 61 adantr ⊢ φ ∧ Q ∈ DivRing → O ∈ Ring
63 4 adantr ⊢ φ ∧ Q ∈ DivRing → M ∈ 2Ideal ⁡ R
64 63 1 2idlridld ⊢ φ ∧ Q ∈ DivRing → M ∈ LIdeal ⁡ O
65 simplr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M → M ⊆ j
66 simpr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M → ¬ j = M
67 66 neqned ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M → j ≠ M
68 67 necomd ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M → M ≠ j
69 65 68 41 syl2anc ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M → j ∖ M ≠ ∅
70 69 43 sylib ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M → ∃ x x ∈ j ∖ M
71 eqid ⊢ opp r ⁡ O = opp r ⁡ O
72 eqid ⊢ O / 𝑠 O ~ QG M = O / 𝑠 O ~ QG M
73 1 opprnzr ⊢ R ∈ NzRing → O ∈ NzRing
74 3 73 syl ⊢ φ → O ∈ NzRing
75 74 ad5antr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → O ∈ NzRing
76 1 6 oppr2idl ⊢ φ → 2Ideal ⁡ R = 2Ideal ⁡ O
77 4 76 eleqtrd ⊢ φ → M ∈ 2Ideal ⁡ O
78 77 ad5antr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → M ∈ 2Ideal ⁡ O
79 1 21 opprbas ⊢ Base R = Base O
80 eqid ⊢ opp r ⁡ Q = opp r ⁡ Q
81 80 opprdrng ⊢ Q ∈ DivRing ↔ opp r ⁡ Q ∈ DivRing
82 21 1 2 6 4 opprqusdrng ⊢ φ → opp r ⁡ Q ∈ DivRing ↔ O / 𝑠 O ~ QG M ∈ DivRing
83 82 biimpa ⊢ φ ∧ opp r ⁡ Q ∈ DivRing → O / 𝑠 O ~ QG M ∈ DivRing
84 81 83 sylan2b ⊢ φ ∧ Q ∈ DivRing → O / 𝑠 O ~ QG M ∈ DivRing
85 84 ad4antr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → O / 𝑠 O ~ QG M ∈ DivRing
86 simp-4r ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → j ∈ LIdeal ⁡ O
87 65 adantr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → M ⊆ j
88 simpr ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → x ∈ j ∖ M
89 71 72 75 78 79 85 86 87 88 qsdrnglem2 ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M ∧ x ∈ j ∖ M → j = Base R
90 70 89 exlimddv ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j ∧ ¬ j = M → j = Base R
91 90 ex ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j → ¬ j = M → j = Base R
92 91 orrd ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O ∧ M ⊆ j → j = M ∨ j = Base R
93 92 ex ⊢ φ ∧ Q ∈ DivRing ∧ j ∈ LIdeal ⁡ O → M ⊆ j → j = M ∨ j = Base R
94 93 ralrimiva ⊢ φ ∧ Q ∈ DivRing → ∀ j ∈ LIdeal ⁡ O M ⊆ j → j = M ∨ j = Base R
95 79 ismxidl ⊢ O ∈ Ring → M ∈ MaxIdeal ⁡ O ↔ M ∈ LIdeal ⁡ O ∧ M ≠ Base R ∧ ∀ j ∈ LIdeal ⁡ O M ⊆ j → j = M ∨ j = Base R
96 95 biimpar ⊢ O ∈ Ring ∧ M ∈ LIdeal ⁡ O ∧ M ≠ Base R ∧ ∀ j ∈ LIdeal ⁡ O M ⊆ j → j = M ∨ j = Base R → M ∈ MaxIdeal ⁡ O
97 62 64 36 94 96 syl13anc ⊢ φ ∧ Q ∈ DivRing → M ∈ MaxIdeal ⁡ O
98 59 97 jca ⊢ φ ∧ Q ∈ DivRing → M ∈ MaxIdeal ⁡ R ∧ M ∈ MaxIdeal ⁡ O
99 3 adantr ⊢ φ ∧ M ∈ MaxIdeal ⁡ R ∧ M ∈ MaxIdeal ⁡ O → R ∈ NzRing
100 simprl ⊢ φ ∧ M ∈ MaxIdeal ⁡ R ∧ M ∈ MaxIdeal ⁡ O → M ∈ MaxIdeal ⁡ R
101 simprr ⊢ φ ∧ M ∈ MaxIdeal ⁡ R ∧ M ∈ MaxIdeal ⁡ O → M ∈ MaxIdeal ⁡ O
102 1 2 99 100 101 qsdrngi ⊢ φ ∧ M ∈ MaxIdeal ⁡ R ∧ M ∈ MaxIdeal ⁡ O → Q ∈ DivRing
103 98 102 impbida ⊢ φ → Q ∈ DivRing ↔ M ∈ MaxIdeal ⁡ R ∧ M ∈ MaxIdeal ⁡ O