Description: Membership in a half-open range of nonnegative integers, generalization of elfzo0 requiring the upper bound to be an integer only. (Contributed by Alexander van der Vekens, 23-Sep-2018)
Ref | Expression | ||
---|---|---|---|
Assertion | elfzo0z | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elfzo0 | |
|
2 | nnz | |
|
3 | 2 | 3anim2i | |
4 | simp1 | |
|
5 | elnn0z | |
|
6 | 0red | |
|
7 | zre | |
|
8 | 7 | adantr | |
9 | zre | |
|
10 | 9 | adantl | |
11 | lelttr | |
|
12 | 6 8 10 11 | syl3anc | |
13 | elnnz | |
|
14 | 13 | simplbi2 | |
15 | 14 | adantl | |
16 | 12 15 | syld | |
17 | 16 | expd | |
18 | 17 | impancom | |
19 | 5 18 | sylbi | |
20 | 19 | 3imp | |
21 | simp3 | |
|
22 | 4 20 21 | 3jca | |
23 | 3 22 | impbii | |
24 | 1 23 | bitri | |