Metamath Proof Explorer


Theorem opprmxidlabs

Description: The maximal ideal of the opposite ring's opposite ring. (Contributed by Thierry Arnoux, 9-Mar-2025)

Ref Expression
Hypotheses oppreqg.o 𝑂 = ( oppr𝑅 )
oppr2idl.2 ( 𝜑𝑅 ∈ Ring )
opprmxidl.3 ( 𝜑𝑀 ∈ ( MaxIdeal ‘ 𝑅 ) )
Assertion opprmxidlabs ( 𝜑𝑀 ∈ ( MaxIdeal ‘ ( oppr𝑂 ) ) )

Proof

Step Hyp Ref Expression
1 oppreqg.o 𝑂 = ( oppr𝑅 )
2 oppr2idl.2 ( 𝜑𝑅 ∈ Ring )
3 opprmxidl.3 ( 𝜑𝑀 ∈ ( MaxIdeal ‘ 𝑅 ) )
4 1 opprring ( 𝑅 ∈ Ring → 𝑂 ∈ Ring )
5 eqid ( oppr𝑂 ) = ( oppr𝑂 )
6 5 opprring ( 𝑂 ∈ Ring → ( oppr𝑂 ) ∈ Ring )
7 2 4 6 3syl ( 𝜑 → ( oppr𝑂 ) ∈ Ring )
8 eqid ( Base ‘ 𝑅 ) = ( Base ‘ 𝑅 )
9 8 mxidlidl ( ( 𝑅 ∈ Ring ∧ 𝑀 ∈ ( MaxIdeal ‘ 𝑅 ) ) → 𝑀 ∈ ( LIdeal ‘ 𝑅 ) )
10 2 3 9 syl2anc ( 𝜑𝑀 ∈ ( LIdeal ‘ 𝑅 ) )
11 1 2 opprlidlabs ( 𝜑 → ( LIdeal ‘ 𝑅 ) = ( LIdeal ‘ ( oppr𝑂 ) ) )
12 10 11 eleqtrd ( 𝜑𝑀 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) )
13 8 mxidlnr ( ( 𝑅 ∈ Ring ∧ 𝑀 ∈ ( MaxIdeal ‘ 𝑅 ) ) → 𝑀 ≠ ( Base ‘ 𝑅 ) )
14 2 3 13 syl2anc ( 𝜑𝑀 ≠ ( Base ‘ 𝑅 ) )
15 2 ad2antrr ( ( ( 𝜑𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ) ∧ 𝑀𝑗 ) → 𝑅 ∈ Ring )
16 3 ad2antrr ( ( ( 𝜑𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ) ∧ 𝑀𝑗 ) → 𝑀 ∈ ( MaxIdeal ‘ 𝑅 ) )
17 simplr ( ( ( 𝜑𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ) ∧ 𝑀𝑗 ) → 𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) )
18 11 ad2antrr ( ( ( 𝜑𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ) ∧ 𝑀𝑗 ) → ( LIdeal ‘ 𝑅 ) = ( LIdeal ‘ ( oppr𝑂 ) ) )
19 17 18 eleqtrrd ( ( ( 𝜑𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ) ∧ 𝑀𝑗 ) → 𝑗 ∈ ( LIdeal ‘ 𝑅 ) )
20 simpr ( ( ( 𝜑𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ) ∧ 𝑀𝑗 ) → 𝑀𝑗 )
21 8 mxidlmax ( ( ( 𝑅 ∈ Ring ∧ 𝑀 ∈ ( MaxIdeal ‘ 𝑅 ) ) ∧ ( 𝑗 ∈ ( LIdeal ‘ 𝑅 ) ∧ 𝑀𝑗 ) ) → ( 𝑗 = 𝑀𝑗 = ( Base ‘ 𝑅 ) ) )
22 15 16 19 20 21 syl22anc ( ( ( 𝜑𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ) ∧ 𝑀𝑗 ) → ( 𝑗 = 𝑀𝑗 = ( Base ‘ 𝑅 ) ) )
23 22 ex ( ( 𝜑𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ) → ( 𝑀𝑗 → ( 𝑗 = 𝑀𝑗 = ( Base ‘ 𝑅 ) ) ) )
24 23 ralrimiva ( 𝜑 → ∀ 𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ( 𝑀𝑗 → ( 𝑗 = 𝑀𝑗 = ( Base ‘ 𝑅 ) ) ) )
25 1 8 opprbas ( Base ‘ 𝑅 ) = ( Base ‘ 𝑂 )
26 5 25 opprbas ( Base ‘ 𝑅 ) = ( Base ‘ ( oppr𝑂 ) )
27 26 ismxidl ( ( oppr𝑂 ) ∈ Ring → ( 𝑀 ∈ ( MaxIdeal ‘ ( oppr𝑂 ) ) ↔ ( 𝑀 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ∧ 𝑀 ≠ ( Base ‘ 𝑅 ) ∧ ∀ 𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ( 𝑀𝑗 → ( 𝑗 = 𝑀𝑗 = ( Base ‘ 𝑅 ) ) ) ) ) )
28 27 biimpar ( ( ( oppr𝑂 ) ∈ Ring ∧ ( 𝑀 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ∧ 𝑀 ≠ ( Base ‘ 𝑅 ) ∧ ∀ 𝑗 ∈ ( LIdeal ‘ ( oppr𝑂 ) ) ( 𝑀𝑗 → ( 𝑗 = 𝑀𝑗 = ( Base ‘ 𝑅 ) ) ) ) ) → 𝑀 ∈ ( MaxIdeal ‘ ( oppr𝑂 ) ) )
29 7 12 14 24 28 syl13anc ( 𝜑𝑀 ∈ ( MaxIdeal ‘ ( oppr𝑂 ) ) )