Description: 10 is a positive integer. (Contributed by NM, 8-Nov-2012) (Revised by AV, 6-Sep-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | 10nn | |- ; 1 0 e. NN |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 9p1e10 | |- ( 9 + 1 ) = ; 1 0 |
|
2 | 9nn | |- 9 e. NN |
|
3 | peano2nn | |- ( 9 e. NN -> ( 9 + 1 ) e. NN ) |
|
4 | 2 3 | ax-mp | |- ( 9 + 1 ) e. NN |
5 | 1 4 | eqeltrri | |- ; 1 0 e. NN |