Description: The empty set is in any power set, and it's finite. (Contributed by Glauco Siliprandi, 17-Aug-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0pwfi | |- (/) e. ( ~P A i^i Fin ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0elpw | |- (/) e. ~P A |
|
| 2 | 0fi | |- (/) e. Fin |
|
| 3 | 1 2 | elini | |- (/) e. ( ~P A i^i Fin ) |