Description: If a nonnegative integer in a finite interval of integers is not the upper bound of the interval, it is contained in the corresponding half-open integer range. (Contributed by Alexander van der Vekens, 15-Jun-2018)
Ref | Expression | ||
---|---|---|---|
Assertion | fzofzim | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elfz2nn0 | |
|
2 | simpl1 | |
|
3 | necom | |
|
4 | nn0re | |
|
5 | nn0re | |
|
6 | ltlen | |
|
7 | 4 5 6 | syl2an | |
8 | 7 | bicomd | |
9 | elnn0z | |
|
10 | 0red | |
|
11 | zre | |
|
12 | 11 | adantr | |
13 | 5 | adantl | |
14 | lelttr | |
|
15 | 10 12 13 14 | syl3anc | |
16 | nn0z | |
|
17 | elnnz | |
|
18 | 17 | simplbi2 | |
19 | 16 18 | syl | |
20 | 19 | adantl | |
21 | 15 20 | syld | |
22 | 21 | expd | |
23 | 22 | impancom | |
24 | 9 23 | sylbi | |
25 | 24 | imp | |
26 | 8 25 | sylbid | |
27 | 26 | expd | |
28 | 3 27 | syl7bi | |
29 | 28 | 3impia | |
30 | 29 | imp | |
31 | 8 | biimpd | |
32 | 31 | exp4b | |
33 | 32 | 3imp | |
34 | 3 33 | biimtrid | |
35 | 34 | imp | |
36 | 2 30 35 | 3jca | |
37 | 36 | ex | |
38 | 1 37 | sylbi | |
39 | 38 | impcom | |
40 | elfzo0 | |
|
41 | 39 40 | sylibr | |