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	$$⊢\phi \leftrightarrow \psi$$
	aiffbbtat.2	$$⊢\psi \leftrightarrow \top$$
Assertion	aiffbbtat	$$⊢\phi \leftrightarrow \top$$

Proof

Step	Hyp	Ref	Expression
1		aiffbbtat.1	$$⊢\phi \leftrightarrow \psi$$
2		aiffbbtat.2	$$⊢\psi \leftrightarrow \top$$
3	1 2	bitri	$$⊢\phi \leftrightarrow \top$$