Metamath Proof Explorer


Theorem euimOLD

Description: Obsolete version of euim as of 1-Oct-2023. (Contributed by NM, 19-Oct-2005) (Proof shortened by Andrew Salmon, 14-Jun-2011) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Assertion euimOLD
|- ( ( E. x ph /\ A. x ( ph -> ps ) ) -> ( E! x ps -> E! x ph ) )

Proof

Step Hyp Ref Expression
1 ax-1
 |-  ( E. x ph -> ( E! x ps -> E. x ph ) )
2 euimmo
 |-  ( A. x ( ph -> ps ) -> ( E! x ps -> E* x ph ) )
3 1 2 anim12ii
 |-  ( ( E. x ph /\ A. x ( ph -> ps ) ) -> ( E! x ps -> ( E. x ph /\ E* x ph ) ) )
4 df-eu
 |-  ( E! x ph <-> ( E. x ph /\ E* x ph ) )
5 3 4 syl6ibr
 |-  ( ( E. x ph /\ A. x ( ph -> ps ) ) -> ( E! x ps -> E! x ph ) )