Theorem e2bi

Description: Biconditional form of e2 . syl6ib is e2bi without virtual deductions. (Contributed by Alan Sare, 10-Jun-2011) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Hypotheses	e2bi.1	⊢ (    𝜑    ,    𝜓    ▶    𝜒    )
	e2bi.2	⊢ ( 𝜒 ↔ 𝜃 )
Assertion	e2bi	⊢ (    𝜑    ,    𝜓    ▶    𝜃    )

Proof

Step	Hyp	Ref	Expression
1		e2bi.1	⊢ (    𝜑    ,    𝜓    ▶    𝜒    )
2		e2bi.2	⊢ ( 𝜒 ↔ 𝜃 )
3	2	biimpi	⊢ ( 𝜒 → 𝜃 )
4	1 3	e2	⊢ (    𝜑    ,    𝜓    ▶    𝜃    )