Theorem 19.9v 1751

Description: Special case of Theorem 19.9 of [Margaris] p. 89. (Contributed by NM, 28-May-1995.) (Revised by NM, 21-May-2007.)

Assertion

Ref	Expression
19.9v	|- ( E. x ph <-> ph )

Distinct variable group:   ph, x

Proof of Theorem 19.9v

Step	Hyp	Ref	Expression
1		ax-17 1419	. 2 |- ( ph -> A. x ph )
2	1	19.9h 1534	1 |- ( E. x ph <-> ph )

Syntax hints:   <-> wb 98   E.wex 1381

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-4 1400  ax-17 1419

This theorem depends on definitions:  df-bi 110

This theorem is referenced by:  spc2gv  2643  spc3gv  2645  mo2icl  2720  brtpos2  5866