Metamath Proof Explorer


Theorem opprrngb

Description: A class is a non-unital ring if and only if its opposite is a non-unital ring. Bidirectional form of opprrng . (Contributed by AV, 15-Feb-2025)

Ref Expression
Hypothesis opprbas.1 𝑂 = ( oppr𝑅 )
Assertion opprrngb ( 𝑅 ∈ Rng ↔ 𝑂 ∈ Rng )

Proof

Step Hyp Ref Expression
1 opprbas.1 𝑂 = ( oppr𝑅 )
2 1 opprrng ( 𝑅 ∈ Rng → 𝑂 ∈ Rng )
3 eqid ( oppr𝑂 ) = ( oppr𝑂 )
4 3 opprrng ( 𝑂 ∈ Rng → ( oppr𝑂 ) ∈ Rng )
5 eqidd ( ⊤ → ( Base ‘ 𝑅 ) = ( Base ‘ 𝑅 ) )
6 eqid ( Base ‘ 𝑅 ) = ( Base ‘ 𝑅 )
7 1 6 opprbas ( Base ‘ 𝑅 ) = ( Base ‘ 𝑂 )
8 3 7 opprbas ( Base ‘ 𝑅 ) = ( Base ‘ ( oppr𝑂 ) )
9 8 a1i ( ⊤ → ( Base ‘ 𝑅 ) = ( Base ‘ ( oppr𝑂 ) ) )
10 eqid ( +g𝑅 ) = ( +g𝑅 )
11 1 10 oppradd ( +g𝑅 ) = ( +g𝑂 )
12 3 11 oppradd ( +g𝑅 ) = ( +g ‘ ( oppr𝑂 ) )
13 12 oveqi ( 𝑥 ( +g𝑅 ) 𝑦 ) = ( 𝑥 ( +g ‘ ( oppr𝑂 ) ) 𝑦 )
14 13 a1i ( ( ⊤ ∧ ( 𝑥 ∈ ( Base ‘ 𝑅 ) ∧ 𝑦 ∈ ( Base ‘ 𝑅 ) ) ) → ( 𝑥 ( +g𝑅 ) 𝑦 ) = ( 𝑥 ( +g ‘ ( oppr𝑂 ) ) 𝑦 ) )
15 eqid ( .r𝑂 ) = ( .r𝑂 )
16 eqid ( .r ‘ ( oppr𝑂 ) ) = ( .r ‘ ( oppr𝑂 ) )
17 7 15 3 16 opprmul ( 𝑥 ( .r ‘ ( oppr𝑂 ) ) 𝑦 ) = ( 𝑦 ( .r𝑂 ) 𝑥 )
18 eqid ( .r𝑅 ) = ( .r𝑅 )
19 6 18 1 15 opprmul ( 𝑦 ( .r𝑂 ) 𝑥 ) = ( 𝑥 ( .r𝑅 ) 𝑦 )
20 17 19 eqtr2i ( 𝑥 ( .r𝑅 ) 𝑦 ) = ( 𝑥 ( .r ‘ ( oppr𝑂 ) ) 𝑦 )
21 20 a1i ( ( ⊤ ∧ ( 𝑥 ∈ ( Base ‘ 𝑅 ) ∧ 𝑦 ∈ ( Base ‘ 𝑅 ) ) ) → ( 𝑥 ( .r𝑅 ) 𝑦 ) = ( 𝑥 ( .r ‘ ( oppr𝑂 ) ) 𝑦 ) )
22 5 9 14 21 rngpropd ( ⊤ → ( 𝑅 ∈ Rng ↔ ( oppr𝑂 ) ∈ Rng ) )
23 22 mptru ( 𝑅 ∈ Rng ↔ ( oppr𝑂 ) ∈ Rng )
24 4 23 sylibr ( 𝑂 ∈ Rng → 𝑅 ∈ Rng )
25 2 24 impbii ( 𝑅 ∈ Rng ↔ 𝑂 ∈ Rng )