Theorem reximddv 2464

Description: Deduction from Theorem 19.22 of [Margaris] p. 90. (Contributed by Thierry Arnoux, 7-Dec-2016.)

Hypotheses

Ref	Expression
reximddva.1	|- ( ( ph /\ ( x e. A /\ ps ) ) -> ch )
reximddva.2	|- ( ph -> E. x e. A ps )

Assertion

Ref	Expression
reximddv	|- ( ph -> E. x e. A ch )

Distinct variable group:   ph, x

Allowed substitution hints:   ps( x)   ch( x)   A( x)

Proof of Theorem reximddv

Step	Hyp	Ref	Expression
1		reximddva.2	. 2 |- ( ph -> E. x e. A ps )
2		reximddva.1	. . . 4 |- ( ( ph /\ ( x e. A /\ ps ) ) -> ch )
3	2	expr 367	. . 3 |- ( ( ph /\ x e. A ) -> ( ps -> ch ) )
4	3	reximdva 2463	. 2 |- ( ph -> ( E. x e. A ps -> E. x e. A ch ) )
5	1, 4	mpd 13	1 |- ( ph -> E. x e. A ch )

Syntax hints:   -> wi 4   /\ wa 102   e. wcel 1433   E.wrex 2349

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1376  ax-gen 1378  ax-ie1 1422  ax-ie2 1423  ax-4 1440  ax-17 1459  ax-ial 1467

This theorem depends on definitions:  df-bi 115  df-nf 1390  df-ral 2353  df-rex 2354

This theorem is referenced by:  reximddv2  2465