Description: The supremum of a set of ordinals exists. (Contributed by RP, 23-Jan-2025)
Ref | Expression | ||
---|---|---|---|
Assertion | onsupex3 | |- ( ( A C_ On /\ A e. V ) -> |^| { x e. On | A. y e. A y C_ x } e. _V ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | onsupcl3 | |- ( ( A C_ On /\ A e. V ) -> |^| { x e. On | A. y e. A y C_ x } e. On ) |
|
2 | 1 | elexd | |- ( ( A C_ On /\ A e. V ) -> |^| { x e. On | A. y e. A y C_ x } e. _V ) |