Theorem 19.9d 1661

Description: A deduction version of one direction of 19.9 1644. (Contributed by NM, 5-Aug-1993.) (Revised by Mario Carneiro, 24-Sep-2016.)

Hypothesis

Ref	Expression
19.9d.1	|- ( ps -> F/ x ph )

Assertion

Ref	Expression
19.9d	|- ( ps -> ( E. x ph -> ph ) )

Proof of Theorem 19.9d

Step	Hyp	Ref	Expression
1		19.9d.1	. . 3 |- ( ps -> F/ x ph )
2		19.9t 1642	. . 3 |- ( F/ x ph -> ( E. x ph <-> ph ) )
3	1, 2	syl 14	. 2 |- ( ps -> ( E. x ph <-> ph ) )
4	3	biimpd 144	1 |- ( ps -> ( E. x ph -> ph ) )

Syntax hints:   -> wi 4   <-> wb 105   F/wnf 1460   E.wex 1492

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-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-4 1510

This theorem depends on definitions:  df-bi 117  df-nf 1461

This theorem is referenced by: (None)