Theorem exbi 1773

Description: Theorem 19.18 of [Margaris] p. 90. (Contributed by NM, 12-Mar-1993.)

Assertion

Ref	Expression
exbi	|- ( A. x ( ph <-> ps ) -> ( E. x ph <-> E. x ps ) )

Proof of Theorem exbi

Step	Hyp	Ref	Expression
1		id 22	. 2 |- ( ( ph <-> ps ) -> ( ph <-> ps ) )
2	1	alexbii 1760	1 |- ( A. x ( ph <-> ps ) -> ( E. x ph <-> E. x ps ) )

Syntax hints:   -> wi 4   <-> wb 196   A.wal 1481   E.wex 1704

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737

This theorem depends on definitions:  df-bi 197  df-ex 1705

This theorem is referenced by:  exbii  1774  nfbiit  1777  19.19  2097  bj-2exbi  32599  bj-3exbi  32600  2exbi  38579  rexbidar  38650  onfrALTlem5VD  39121  onfrALTlem1VD  39126  csbxpgVD  39130  csbrngVD  39132  csbunigVD  39134  e2ebindVD  39148  e2ebindALT  39165