Theorem bj-19.21bit

Description: Closed form of 19.21bi . (Contributed by BJ, 20-Oct-2019)

	Ref	Expression
Assertion	bj-19.21bit	|- ( ( ph -> A. x ps ) -> ( ph -> ps ) )

Proof

Step	Hyp	Ref	Expression
1		sp	|- ( A. x ps -> ps )
2	1	imim2i	|- ( ( ph -> A. x ps ) -> ( ph -> ps ) )