Metamath Proof Explorer


Theorem opeq12

Description: Equality theorem for ordered pairs. (Contributed by NM, 28-May-1995)

Ref Expression
Assertion opeq12 A = C B = D A B = C D

Proof

Step Hyp Ref Expression
1 opeq1 A = C A B = C B
2 opeq2 B = D C B = C D
3 1 2 sylan9eq A = C B = D A B = C D