Metamath Proof Explorer


Theorem xpopth

Description: An ordered pair theorem for members of Cartesian products. (Contributed by NM, 20-Jun-2007)

Ref Expression
Assertion xpopth ( ( 𝐴 ∈ ( 𝐶 × 𝐷 ) ∧ 𝐵 ∈ ( 𝑅 × 𝑆 ) ) → ( ( ( 1st ‘ 𝐴 ) = ( 1st ‘ 𝐵 ) ∧ ( 2nd ‘ 𝐴 ) = ( 2nd ‘ 𝐵 ) ) ↔ 𝐴 = 𝐵 ) )

Proof

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 ) )