Description: One-half is not an integer. (Contributed by NM, 31-Jul-2004)
Ref | Expression | ||
---|---|---|---|
Assertion | halfnz | |- -. ( 1 / 2 ) e. ZZ |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 2re | |- 2 e. RR |
|
2 | 1lt2 | |- 1 < 2 |
|
3 | recnz | |- ( ( 2 e. RR /\ 1 < 2 ) -> -. ( 1 / 2 ) e. ZZ ) |
|
4 | 1 2 3 | mp2an | |- -. ( 1 / 2 ) e. ZZ |