Description: The zeroth bit of an odd number is zero. (Contributed by Mario Carneiro, 5-Sep-2016) (Revised by AV, 19-Jun-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | bits0oALTV | |- ( N e. Odd -> 0 e. ( bits ` N ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | oddz | |- ( N e. Odd -> N e. ZZ ) | |
| 2 | bits0ALTV | |- ( N e. ZZ -> ( 0 e. ( bits ` N ) <-> N e. Odd ) ) | |
| 3 | 1 2 | syl | |- ( N e. Odd -> ( 0 e. ( bits ` N ) <-> N e. Odd ) ) | 
| 4 | 3 | ibir | |- ( N e. Odd -> 0 e. ( bits ` N ) ) |