Theorem spimeh 1849

Description: Existential introduction, using implicit substitution. Compare Lemma 14 of [Tarski] p. 70. (Contributed by NM, 7-Aug-1994.) (Proof shortened by Wolf Lammen, 10-Dec-2017.)

Hypotheses

Ref	Expression
spimeh.1	|- ( ph -> A. x ph )
spimeh.2	|- ( x = y -> ( ph -> ps ) )

Assertion

Ref	Expression
spimeh	|- ( ph -> E. x ps )

Distinct variable group:   x, y

Allowed substitution hints:   ph( x, y)   ps( x, y)

Proof of Theorem spimeh

Step	Hyp	Ref	Expression
1		spimeh.1	. 2 |- ( ph -> A. x ph )
2		ax6ev 1815	. . . 4 |- E. x x = y
3		spimeh.2	. . . 4 |- ( x = y -> ( ph -> ps ) )
4	2, 3	eximii 1717	. . 3 |- E. x ( ph -> ps )
5	4	19.35i 1749	. 2 |- ( A. x ph -> E. x ps )
6	1, 5	syl 17	1 |- ( ph -> E. x ps )

Syntax hints:   -> wi 4   A.wal 1450   E.wex 1671

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1677  ax-4 1690  ax-6 1813

This theorem depends on definitions:  df-bi 190  df-ex 1672

This theorem is referenced by:  bj-spimevw  31333  bj-cbvexiw  31335