Theorem hbe1a 2052

Description: Dual statement of hbe1 1519. (Contributed by Wolf Lammen, 15-Sep-2021.)

Assertion

Ref	Expression
hbe1a	|- ( E. x A. x ph -> A. x ph )

Proof of Theorem hbe1a

Step	Hyp	Ref	Expression
1		nfa1 1565	. . 3 |- F/ x A. x ph
2		nf3 1693	. . 3 |- ( F/ x A. x ph <-> A. x ( E. x A. x ph -> A. x ph ) )
3	1, 2	mpbi 145	. 2 |- A. x ( E. x A. x ph -> A. x ph )
4	3	spi 1560	1 |- ( E. x A. x ph -> A. x ph )

Syntax hints:   -> wi 4   A.wal 1371   F/wnf 1484   E.wex 1516

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 1471  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-4 1534  ax-ial 1558  ax-i5r 1559

This theorem depends on definitions:  df-bi 117  df-nf 1485

This theorem is referenced by:  nf5-1  2053