Metamath Proof Explorer

Theorem exlimivv

Description: Inference form of Theorem 19.23 of Margaris p. 90, see 19.23 . (Contributed by NM, 1-Aug-1995)

Ref Expression
Hypothesis exlimivv.1 
|- ( ph -> ps )
Assertion exlimivv 
|- ( E. x E. y ph -> ps )

Proof

Step Hyp Ref Expression
1 exlimivv.1 
 |-  ( ph -> ps )
2 1 exlimiv 
 |-  ( E. y ph -> ps )
3 2 exlimiv 
 |-  ( E. x E. y ph -> ps )