Metamath Proof Explorer


Theorem breqdi

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

Ref Expression
Hypotheses breq1d.1 φ A = B
breqdi.1 φ C A D
Assertion breqdi φ C B D

Proof

Step Hyp Ref Expression
1 breq1d.1 φ A = B
2 breqdi.1 φ C A D
3 1 breqd φ C A D C B D
4 2 3 mpbid φ C B D