This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: The empty set is not a positive real. (Contributed by NM, 15-Nov-1995) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0npr |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqid | ||
| 2 | prn0 | ||
| 3 | 2 | necon2bi | |
| 4 | 1 3 | ax-mp |