Theorem exdistr2 1926

Description: Distribution of existential quantifiers. (Contributed by NM, 17-Mar-1995.)

Assertion

Ref	Expression
exdistr2	|- ( E. x E. y E. z ( ph /\ ps ) <-> E. x ( ph /\ E. y E. z ps ) )

Distinct variable groups:   ph, y   ph, z

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

Proof of Theorem exdistr2

Step	Hyp	Ref	Expression
1		19.42vv 1923	. 2 |- ( E. y E. z ( ph /\ ps ) <-> ( ph /\ E. y E. z ps ) )
2	1	exbii 1616	1 |- ( E. x E. y E. z ( ph /\ ps ) <-> E. x ( ph /\ E. y E. z ps ) )

Syntax hints:   /\ wa 104   <-> wb 105   E.wex 1503

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1458  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-4 1521  ax-17 1537  ax-ial 1545

This theorem depends on definitions:  df-bi 117

This theorem is referenced by: (None)