Theorem bnj1131

Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

	Ref	Expression
Hypotheses	bnj1131.1	|- ( ph -> A. x ph )
	bnj1131.2	|- E. x ph
Assertion	bnj1131	|- ph

Proof

Step	Hyp	Ref	Expression
1		bnj1131.1	|- ( ph -> A. x ph )
2		bnj1131.2	|- E. x ph
3	1	19.9h	|- ( E. x ph <-> ph )
4	2 3	mpbi	|- ph