Theorem aiffbbtat

Description: Given a is equivalent to b, b is equivalent to T. there exists a proof for a is equivalent to T. (Contributed by Jarvin Udandy, 29-Aug-2016)

	Ref	Expression
Hypotheses	aiffbbtat.1	|- ( ph <-> ps )
	aiffbbtat.2	|- ( ps <-> T. )
Assertion	aiffbbtat	|- ( ph <-> T. )

Proof

Step	Hyp	Ref	Expression
1		aiffbbtat.1	|- ( ph <-> ps )
2		aiffbbtat.2	|- ( ps <-> T. )
3	1 2	bitri	|- ( ph <-> T. )