Description: Subtraction closure for a member of a finite set of sequential integers. (Contributed by NM, 16-Sep-2005) (Revised by Mario Carneiro, 28-Apr-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | fznn0sub | |- ( K e. ( M ... N ) -> ( N - K ) e. NN0 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elfzuz3 | |- ( K e. ( M ... N ) -> N e. ( ZZ>= ` K ) ) |
|
| 2 | uznn0sub | |- ( N e. ( ZZ>= ` K ) -> ( N - K ) e. NN0 ) |
|
| 3 | 1 2 | syl | |- ( K e. ( M ... N ) -> ( N - K ) e. NN0 ) |