This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: A power class is never empty. (Contributed by NM, 3-Sep-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | pwne0 | |- ~P A =/= (/) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0elpw | |- (/) e. ~P A |
|
| 2 | 1 | ne0ii | |- ~P A =/= (/) |