Description: 10 is a nonnegative integer. (Contributed by Mario Carneiro, 19-Apr-2015) (Revised by AV, 6-Sep-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 10nn0 | |- ; 1 0 e. NN0 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 1nn0 | |- 1 e. NN0 |
|
| 2 | 0nn0 | |- 0 e. NN0 |
|
| 3 | 1 2 | deccl | |- ; 1 0 e. NN0 |