Theorem bothfbothsame

Description: Given both a, b are equivalent to F. , there exists a proof for a is the same as b. (Contributed by Jarvin Udandy, 31-Aug-2016)

	Ref	Expression
Hypotheses	bothfbothsame.1	$$⊢\phi \leftrightarrow \perp$$
	bothfbothsame.2	$$⊢\psi \leftrightarrow \perp$$
Assertion	bothfbothsame	$$⊢\phi \leftrightarrow \psi$$

Proof

Step	Hyp	Ref	Expression
1		bothfbothsame.1	$$⊢\phi \leftrightarrow \perp$$
2		bothfbothsame.2	$$⊢\psi \leftrightarrow \perp$$
3	1 2	bitr4i	$$⊢\phi \leftrightarrow \psi$$