Description: The absolute value of an integer is an integer. (Contributed by Stefan O'Rear, 24-Sep-2014)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | zabscl | |- ( A e. ZZ -> ( abs ` A ) e. ZZ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nn0abscl | |- ( A e. ZZ -> ( abs ` A ) e. NN0 ) |
|
| 2 | 1 | nn0zd | |- ( A e. ZZ -> ( abs ` A ) e. ZZ ) |