Description: The set of bits of an integer is a subset of NN0 . (Contributed by Mario Carneiro, 5-Sep-2016)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | bitsss | |- ( bits ` N ) C_ NN0 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | bitsval | |- ( m e. ( bits ` N ) <-> ( N e. ZZ /\ m e. NN0 /\ -. 2 || ( |_ ` ( N / ( 2 ^ m ) ) ) ) ) |
|
| 2 | 1 | simp2bi | |- ( m e. ( bits ` N ) -> m e. NN0 ) |
| 3 | 2 | ssriv | |- ( bits ` N ) C_ NN0 |