Metamath Proof Explorer


Theorem eqopi

Description: Equality with an ordered pair. (Contributed by NM, 15-Dec-2008) (Revised by Mario Carneiro, 23-Feb-2014)

Ref Expression
Assertion eqopi ⊢ A ∈ V × W ∧ 1 st ⁡ A = B ∧ 2 nd ⁡ A = C → A = B C

Proof

Step Hyp Ref Expression
1 xpss ⊢ V × W ⊆ V × V
2 1 sseli ⊢ A ∈ V × W → A ∈ V × V
3 elxp6 ⊢ A ∈ V × V ↔ A = 1 st ⁡ A 2 nd ⁡ A ∧ 1 st ⁡ A ∈ V ∧ 2 nd ⁡ A ∈ V
4 3 simplbi ⊢ A ∈ V × V → A = 1 st ⁡ A 2 nd ⁡ A
5 opeq12 ⊢ 1 st ⁡ A = B ∧ 2 nd ⁡ A = C → 1 st ⁡ A 2 nd ⁡ A = B C
6 4 5 sylan9eq ⊢ A ∈ V × V ∧ 1 st ⁡ A = B ∧ 2 nd ⁡ A = C → A = B C
7 2 6 sylan ⊢ A ∈ V × W ∧ 1 st ⁡ A = B ∧ 2 nd ⁡ A = C → A = B C