Metamath Proof Explorer


Theorem brxp

Description: Binary relation on a Cartesian product. (Contributed by NM, 22-Apr-2004)

Ref Expression
Assertion brxp AC×DBACBD

Proof

Step Hyp Ref Expression
1 df-br AC×DBABC×D
2 opelxp ABC×DACBD
3 1 2 bitri AC×DBACBD