Theorem e0bir

Description: Elimination rule identical to mpbir . The non-virtual deduction form is the virtual deduction form, which is mpbir . (Contributed by Alan Sare, 15-Jun-2011) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Hypotheses	e0bir.1	$$⊢\phi$$
	e0bir.2	$$⊢\psi \leftrightarrow \phi$$
Assertion	e0bir	$$⊢\psi$$

Proof

Step	Hyp	Ref	Expression
1		e0bir.1	$$⊢\phi$$
2		e0bir.2	$$⊢\psi \leftrightarrow \phi$$
3	1 2	mpbir	$$⊢\psi$$