Theorem breq2dd

Description: Equality deduction for a binary relation. (Contributed by Thierry Arnoux, 10-Jan-2026)

	Ref	Expression
Hypotheses	breq2dd.1	|- ( ph -> A = B )
	breq2dd.2	|- ( ph -> C R A )
Assertion	breq2dd	|- ( ph -> C R B )

Proof

Step	Hyp	Ref	Expression
1		breq2dd.1	|- ( ph -> A = B )
2		breq2dd.2	|- ( ph -> C R A )
3	1	breq2d	|- ( ph -> ( C R A <-> C R B ) )
4	2 3	mpbid	|- ( ph -> C R B )