Theorem eqbrtrid

Description: A chained equality inference for a binary relation. (Contributed by NM, 11-Oct-1999)

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

Proof

Step	Hyp	Ref	Expression
1		eqbrtrid.1	|- A = B
2		eqbrtrid.2	|- ( ph -> B R C )
3		eqid	|- C = C
4	2 1 3	3brtr4g	|- ( ph -> A R C )