Step |
Hyp |
Ref |
Expression |
1 |
|
1st2nd2 |
⊢ ( 𝐴 ∈ ( 𝐶 × 𝐷 ) → 𝐴 = 〈 ( 1st ‘ 𝐴 ) , ( 2nd ‘ 𝐴 ) 〉 ) |
2 |
|
1st2nd2 |
⊢ ( 𝐵 ∈ ( 𝑅 × 𝑆 ) → 𝐵 = 〈 ( 1st ‘ 𝐵 ) , ( 2nd ‘ 𝐵 ) 〉 ) |
3 |
1 2
|
eqeqan12d |
⊢ ( ( 𝐴 ∈ ( 𝐶 × 𝐷 ) ∧ 𝐵 ∈ ( 𝑅 × 𝑆 ) ) → ( 𝐴 = 𝐵 ↔ 〈 ( 1st ‘ 𝐴 ) , ( 2nd ‘ 𝐴 ) 〉 = 〈 ( 1st ‘ 𝐵 ) , ( 2nd ‘ 𝐵 ) 〉 ) ) |
4 |
|
fvex |
⊢ ( 1st ‘ 𝐴 ) ∈ V |
5 |
|
fvex |
⊢ ( 2nd ‘ 𝐴 ) ∈ V |
6 |
4 5
|
opth |
⊢ ( 〈 ( 1st ‘ 𝐴 ) , ( 2nd ‘ 𝐴 ) 〉 = 〈 ( 1st ‘ 𝐵 ) , ( 2nd ‘ 𝐵 ) 〉 ↔ ( ( 1st ‘ 𝐴 ) = ( 1st ‘ 𝐵 ) ∧ ( 2nd ‘ 𝐴 ) = ( 2nd ‘ 𝐵 ) ) ) |
7 |
3 6
|
bitr2di |
⊢ ( ( 𝐴 ∈ ( 𝐶 × 𝐷 ) ∧ 𝐵 ∈ ( 𝑅 × 𝑆 ) ) → ( ( ( 1st ‘ 𝐴 ) = ( 1st ‘ 𝐵 ) ∧ ( 2nd ‘ 𝐴 ) = ( 2nd ‘ 𝐵 ) ) ↔ 𝐴 = 𝐵 ) ) |