Theorem 19.41vvvv 1841

Description: Version of 19.41 2070 with four quantifiers and a dv condition requiring fewer axioms. (Contributed by FL, 14-Jul-2007.)

Assertion

Ref	Expression
19.41vvvv	|- ( E. w E. x E. y E. z ( ph /\ ps ) <-> ( E. w E. x E. y E. z ph /\ ps ) )

Distinct variable groups:   ps, w   ps, x   ps, y   ps, z

Allowed substitution hints:   ph( x, y, z, w)

Proof of Theorem 19.41vvvv

Step	Hyp	Ref	Expression
1		19.41vvv 1840	. . 3 |- ( E. x E. y E. z ( ph /\ ps ) <-> ( E. x E. y E. z ph /\ ps ) )
2	1	exbii 1726	. 2 |- ( E. w E. x E. y E. z ( ph /\ ps ) <-> E. w ( E. x E. y E. z ph /\ ps ) )
3		19.41v 1838	. 2 |- ( E. w ( E. x E. y E. z ph /\ ps ) <-> ( E. w E. x E. y E. z ph /\ ps ) )
4	2, 3	bitri 257	1 |- ( E. w E. x E. y E. z ( ph /\ ps ) <-> ( E. w E. x E. y E. z ph /\ ps ) )

Syntax hints:   <-> wb 189   /\ wa 376   E.wex 1671

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1677  ax-4 1690  ax-5 1766  ax-6 1813

This theorem depends on definitions:  df-bi 190  df-an 378  df-ex 1672

This theorem is referenced by:  elfuns  30753