Theorem 19.32r 1678

Description: One direction of Theorem 19.32 of [Margaris] p. 90. The converse holds if ph is decidable, as seen at 19.32dc 1677. (Contributed by Jim Kingdon, 28-Jul-2018.)

Hypothesis

Ref	Expression
19.32r.1	|- F/ x ph

Assertion

Ref	Expression
19.32r	|- ( ( ph \/ A. x ps ) -> A. x ( ph \/ ps ) )

Proof of Theorem 19.32r

Step	Hyp	Ref	Expression
1		19.32r.1	. . 3 |- F/ x ph
2		orc 712	. . 3 |- ( ph -> ( ph \/ ps ) )
3	1, 2	alrimi 1520	. 2 |- ( ph -> A. x ( ph \/ ps ) )
4		olc 711	. . 3 |- ( ps -> ( ph \/ ps ) )
5	4	alimi 1453	. 2 |- ( A. x ps -> A. x ( ph \/ ps ) )
6	3, 5	jaoi 716	1 |- ( ( ph \/ A. x ps ) -> A. x ( ph \/ ps ) )

Syntax hints:   -> wi 4   \/ wo 708   A.wal 1351   F/wnf 1458

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-io 709  ax-5 1445  ax-gen 1447  ax-4 1508

This theorem depends on definitions:  df-bi 117  df-nf 1459

This theorem is referenced by:  19.31r  1679