Description: An integer greater than or equal to 4 is a positive integer. (Contributed by AV, 30-May-2023)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | eluz4nn | |- ( X e. ( ZZ>= ` 4 ) -> X e. NN ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eluz4eluz2 | |- ( X e. ( ZZ>= ` 4 ) -> X e. ( ZZ>= ` 2 ) ) |
|
| 2 | eluz2nn | |- ( X e. ( ZZ>= ` 2 ) -> X e. NN ) |
|
| 3 | 1 2 | syl | |- ( X e. ( ZZ>= ` 4 ) -> X e. NN ) |