Description: A set is an element of its power set. (Contributed by Stefan O'Rear, 1-Feb-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | pwidg | |- ( A e. V -> A e. ~P A ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ssid | |- A C_ A |
|
| 2 | elpwg | |- ( A e. V -> ( A e. ~P A <-> A C_ A ) ) |
|
| 3 | 1 2 | mpbiri | |- ( A e. V -> A e. ~P A ) |