Metamath Proof Explorer


Theorem goeleq12bg

Description: Two "Godel-set of membership" codes for two variables are equal iff the two corresponding variables are equal. (Contributed by AV, 8-Oct-2023)

Ref Expression
Assertion goeleq12bg ( ( ( 𝑀 ∈ ω ∧ 𝑁 ∈ ω ) ∧ ( 𝐼 ∈ ω ∧ 𝐽 ∈ ω ) ) → ( ( 𝐼𝑔 𝐽 ) = ( 𝑀𝑔 𝑁 ) ↔ ( 𝐼 = 𝑀𝐽 = 𝑁 ) ) )

Proof

Step Hyp Ref Expression
1 goel ( ( 𝐼 ∈ ω ∧ 𝐽 ∈ ω ) → ( 𝐼𝑔 𝐽 ) = ⟨ ∅ , ⟨ 𝐼 , 𝐽 ⟩ ⟩ )
2 goel ( ( 𝑀 ∈ ω ∧ 𝑁 ∈ ω ) → ( 𝑀𝑔 𝑁 ) = ⟨ ∅ , ⟨ 𝑀 , 𝑁 ⟩ ⟩ )
3 1 2 eqeqan12rd ( ( ( 𝑀 ∈ ω ∧ 𝑁 ∈ ω ) ∧ ( 𝐼 ∈ ω ∧ 𝐽 ∈ ω ) ) → ( ( 𝐼𝑔 𝐽 ) = ( 𝑀𝑔 𝑁 ) ↔ ⟨ ∅ , ⟨ 𝐼 , 𝐽 ⟩ ⟩ = ⟨ ∅ , ⟨ 𝑀 , 𝑁 ⟩ ⟩ ) )
4 0ex ∅ ∈ V
5 opex 𝐼 , 𝐽 ⟩ ∈ V
6 4 5 opth ( ⟨ ∅ , ⟨ 𝐼 , 𝐽 ⟩ ⟩ = ⟨ ∅ , ⟨ 𝑀 , 𝑁 ⟩ ⟩ ↔ ( ∅ = ∅ ∧ ⟨ 𝐼 , 𝐽 ⟩ = ⟨ 𝑀 , 𝑁 ⟩ ) )
7 eqid ∅ = ∅
8 7 biantrur ( ⟨ 𝐼 , 𝐽 ⟩ = ⟨ 𝑀 , 𝑁 ⟩ ↔ ( ∅ = ∅ ∧ ⟨ 𝐼 , 𝐽 ⟩ = ⟨ 𝑀 , 𝑁 ⟩ ) )
9 opthg ( ( 𝐼 ∈ ω ∧ 𝐽 ∈ ω ) → ( ⟨ 𝐼 , 𝐽 ⟩ = ⟨ 𝑀 , 𝑁 ⟩ ↔ ( 𝐼 = 𝑀𝐽 = 𝑁 ) ) )
10 9 adantl ( ( ( 𝑀 ∈ ω ∧ 𝑁 ∈ ω ) ∧ ( 𝐼 ∈ ω ∧ 𝐽 ∈ ω ) ) → ( ⟨ 𝐼 , 𝐽 ⟩ = ⟨ 𝑀 , 𝑁 ⟩ ↔ ( 𝐼 = 𝑀𝐽 = 𝑁 ) ) )
11 8 10 bitr3id ( ( ( 𝑀 ∈ ω ∧ 𝑁 ∈ ω ) ∧ ( 𝐼 ∈ ω ∧ 𝐽 ∈ ω ) ) → ( ( ∅ = ∅ ∧ ⟨ 𝐼 , 𝐽 ⟩ = ⟨ 𝑀 , 𝑁 ⟩ ) ↔ ( 𝐼 = 𝑀𝐽 = 𝑁 ) ) )
12 6 11 syl5bb ( ( ( 𝑀 ∈ ω ∧ 𝑁 ∈ ω ) ∧ ( 𝐼 ∈ ω ∧ 𝐽 ∈ ω ) ) → ( ⟨ ∅ , ⟨ 𝐼 , 𝐽 ⟩ ⟩ = ⟨ ∅ , ⟨ 𝑀 , 𝑁 ⟩ ⟩ ↔ ( 𝐼 = 𝑀𝐽 = 𝑁 ) ) )
13 3 12 bitrd ( ( ( 𝑀 ∈ ω ∧ 𝑁 ∈ ω ) ∧ ( 𝐼 ∈ ω ∧ 𝐽 ∈ ω ) ) → ( ( 𝐼𝑔 𝐽 ) = ( 𝑀𝑔 𝑁 ) ↔ ( 𝐼 = 𝑀𝐽 = 𝑁 ) ) )