Description: Existence of a class abstraction of existentially restricted sets. See the comment of abrexexg . See also abrexex2 . (Contributed by NM, 16-Oct-2003) (Proof shortened by Mario Carneiro, 31-Aug-2015)
Ref | Expression | ||
---|---|---|---|
Hypothesis | abrexex.1 | |- A e. _V |
|
Assertion | abrexex | |- { y | E. x e. A y = B } e. _V |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | abrexex.1 | |- A e. _V |
|
2 | abrexexg | |- ( A e. _V -> { y | E. x e. A y = B } e. _V ) |
|
3 | 1 2 | ax-mp | |- { y | E. x e. A y = B } e. _V |