Description: Quantitative version of ssexg : a subset of an element of a class is an element of the powerclass of the union of that class. (Contributed by BJ, 6-Apr-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | bj-sselpwuni | |- ( ( A C_ B /\ B e. V ) -> A e. ~P U. V ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ssexg | |- ( ( A C_ B /\ B e. V ) -> A e. _V ) | |
| 2 | ssuni | |- ( ( A C_ B /\ B e. V ) -> A C_ U. V ) | |
| 3 | 1 2 | elpwd | |- ( ( A C_ B /\ B e. V ) -> A e. ~P U. V ) |