Metamath Proof Explorer


Theorem breqdi

Description: Equality deduction for a binary relation. (Contributed by Thierry Arnoux, 5-Oct-2020)

Ref Expression
Hypotheses breq1d.1 φA=B
breqdi.1 φCAD
Assertion breqdi φCBD

Proof

Step Hyp Ref Expression
1 breq1d.1 φA=B
2 breqdi.1 φCAD
3 1 breqd φCADCBD
4 2 3 mpbid φCBD