This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: A standard nonnegative integer is an extended nonnegative integer, deduction form. (Contributed by AV, 10-Dec-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | nn0xnn0d.1 | ||
| Assertion | nn0xnn0d |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nn0xnn0d.1 | ||
| 2 | nn0ssxnn0 | ||
| 3 | 2 1 | sselid |