Theorem 19.28v 1823

Description: Theorem 19.28 of [Margaris] p. 90. (Contributed by NM, 25-Mar-2004.)

Assertion

Ref	Expression
19.28v	|- ( A. x ( ph /\ ps ) <-> ( ph /\ A. x ps ) )

Distinct variable group:   ph, x

Allowed substitution hint:   ps( x)

Proof of Theorem 19.28v

Step	Hyp	Ref	Expression
1		ax-17 1460	. 2 |- ( ph -> A. x ph )
2	1	19.28h 1495	1 |- ( A. x ( ph /\ ps ) <-> ( ph /\ A. x ps ) )

Syntax hints:   /\ wa 102   <-> wb 103   A.wal 1283

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1377  ax-gen 1379  ax-4 1441  ax-17 1460

This theorem depends on definitions:  df-bi 115

This theorem is referenced by:  reu6  2790  dfer2  6194