Description: An element of a class exists. Version of elisset with a disjoint variable condition on V , x , avoiding df-clab . Prefer its use over elisset when sufficient (for instance in usages where x is a dummy variable). (Contributed by BJ, 14-Sep-2019)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | elissetv | |- ( A e. V -> E. x x = A ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | dfclel | |- ( A e. V <-> E. x ( x = A /\ x e. V ) ) |
|
| 2 | exsimpl | |- ( E. x ( x = A /\ x e. V ) -> E. x x = A ) |
|
| 3 | 1 2 | sylbi | |- ( A e. V -> E. x x = A ) |