Description: The powerclass of the cartesian square of the universal class is the class of all sets which are binary relations. (Contributed by BJ, 21-Dec-2023)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | pwvabrel | |- ~P ( _V X. _V ) = { x | Rel x } | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | pwvrel | |- ( x e. _V -> ( x e. ~P ( _V X. _V ) <-> Rel x ) ) | |
| 2 | 1 | elv | |- ( x e. ~P ( _V X. _V ) <-> Rel x ) | 
| 3 | 2 | eqabi |  |-  ~P ( _V X. _V ) = { x | Rel x } |