Theorem 19.27v 1899

Description: Theorem 19.27 of [Margaris] p. 90. (Contributed by NM, 3-Jun-2004.)

Assertion

Ref	Expression
19.27v	|- ( A. x ( ph /\ ps ) <-> ( A. x ph /\ ps ) )

Distinct variable group:   ps, x

Allowed substitution hint:   ph( x)

Proof of Theorem 19.27v

Step	Hyp	Ref	Expression
1		ax-17 1526	. 2 |- ( ps -> A. x ps )
2	1	19.27h 1560	1 |- ( A. x ( ph /\ ps ) <-> ( A. x ph /\ ps ) )

Syntax hints:   /\ wa 104   <-> wb 105   A.wal 1351

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 1447  ax-gen 1449  ax-4 1510  ax-17 1526

This theorem depends on definitions:  df-bi 117

This theorem is referenced by: (None)