Theorem 2ax17 1866

Description: Quantification of two variables over a formula in which they do not occur. (Contributed by Alan Sare, 12-Apr-2011.)

Assertion

Ref	Expression
2ax17	|- ( ph -> A. x A. y ph )

Distinct variable groups:   ph, x   ph, y

Proof of Theorem 2ax17

Step	Hyp	Ref	Expression
1		id 19	. 2 |- ( ph -> ph )
2	1	alrimivv 1863	1 |- ( ph -> A. x A. y ph )

Syntax hints:   -> wi 4   A.wal 1341

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-5 1435  ax-gen 1437  ax-17 1514

This theorem is referenced by: (None)