Metamath Proof Explorer


Theorem elALT

Description: Alternate proof of el , shorter but requiring ax-sep . (Contributed by NM, 4-Jan-2002) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion elALT y x y

Proof

Step Hyp Ref Expression
1 vex x V
2 selsALT x V y x y
3 1 2 ax-mp y x y