Metamath Proof Explorer


Theorem exlimi

Description: Inference associated with 19.23 . See exlimiv for a version with a disjoint variable condition requiring fewer axioms. (Contributed by NM, 10-Jan-1993) (Revised by Mario Carneiro, 24-Sep-2016)

Ref Expression
Hypotheses exlimi.1
|- F/ x ps
exlimi.2
|- ( ph -> ps )
Assertion exlimi
|- ( E. x ph -> ps )

Proof

Step Hyp Ref Expression
1 exlimi.1
 |-  F/ x ps
2 exlimi.2
 |-  ( ph -> ps )
3 1 19.23
 |-  ( A. x ( ph -> ps ) <-> ( E. x ph -> ps ) )
4 3 2 mpgbi
 |-  ( E. x ph -> ps )