Metamath Proof Explorer


Theorem opeq12

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

Ref Expression
Assertion opeq12 A=CB=DAB=CD

Proof

Step Hyp Ref Expression
1 opeq1 A=CAB=CB
2 opeq2 B=DCB=CD
3 1 2 sylan9eq A=CB=DAB=CD