Theorem bnj101

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

	Ref	Expression
Hypotheses	bnj101.1	|- E. x ph
	bnj101.2	|- ( ph -> ps )
Assertion	bnj101	|- E. x ps

Proof

Step	Hyp	Ref	Expression
1		bnj101.1	|- E. x ph
2		bnj101.2	|- ( ph -> ps )
3	1 2	eximii	|- E. x ps