Theorem exan 1672

Description: Place a conjunct in the scope of an existential quantifier. (Contributed by NM, 18-Aug-1993.) (Proof shortened by Andrew Salmon, 25-May-2011.)

Hypothesis

Ref	Expression
exan.1	|- ( E. x ph /\ ps )

Assertion

Ref	Expression
exan	|- E. x ( ph /\ ps )

Proof of Theorem exan

Step	Hyp	Ref	Expression
1		hbe1 1472	. . . 4 |- ( E. x ph -> A. x E. x ph )
2	1	19.28h 1542	. . 3 |- ( A. x ( E. x ph /\ ps ) <-> ( E. x ph /\ A. x ps ) )
3		exan.1	. . 3 |- ( E. x ph /\ ps )
4	2, 3	mpgbi 1429	. 2 |- ( E. x ph /\ A. x ps )
5		19.29r 1601	. 2 |- ( ( E. x ph /\ A. x ps ) -> E. x ( ph /\ ps ) )
6	4, 5	ax-mp 5	1 |- E. x ( ph /\ ps )

Syntax hints:   /\ wa 103   A.wal 1330   E.wex 1469

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1424  ax-gen 1426  ax-ie1 1470  ax-ie2 1471  ax-4 1488  ax-ial 1515

This theorem depends on definitions:  df-bi 116

This theorem is referenced by:  bm1.3ii  4057  bdbm1.3ii  13260