Metamath Proof Explorer


Theorem breqd

Description: Equality deduction for a binary relation. (Contributed by NM, 29-Oct-2011)

Ref Expression
Hypothesis breq1d.1 φA=B
Assertion breqd φCADCBD

Proof

Step Hyp Ref Expression
1 breq1d.1 φA=B
2 breq A=BCADCBD
3 1 2 syl φCADCBD