Theorem 2alimdv

Description: Deduction form of Theorem 19.20 of Margaris p. 90 with two quantifiers, see alim . (Contributed by NM, 27-Apr-2004)

	Ref	Expression
Hypothesis	2alimdv.1	|- ( ph -> ( ps -> ch ) )
Assertion	2alimdv	|- ( ph -> ( A. x A. y ps -> A. x A. y ch ) )

Proof

Step	Hyp	Ref	Expression
1		2alimdv.1	|- ( ph -> ( ps -> ch ) )
2	1	alimdv	|- ( ph -> ( A. y ps -> A. y ch ) )
3	2	alimdv	|- ( ph -> ( A. x A. y ps -> A. x A. y ch ) )