Description: Membership of an element of a finite set of sequential integers in a finite set of sequential integers with the same upper bound and a lower bound less than the upper bound. (Contributed by AV, 21-Oct-2018)
Ref | Expression | ||
---|---|---|---|
Assertion | elfzelfzlble | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elfz2 | |
|
2 | 3simpc | |
|
3 | 2 | adantr | |
4 | 1 3 | sylbi | |
5 | 4 | anim2i | |
6 | simpl | |
|
7 | 6 | anim2i | |
8 | 7 | ancomd | |
9 | zsubcl | |
|
10 | 8 9 | syl | |
11 | 6 | adantl | |
12 | simprr | |
|
13 | 10 11 12 | 3jca | |
14 | 5 13 | syl | |
15 | 14 | 3adant3 | |
16 | elfzel2 | |
|
17 | 16 | zred | |
18 | 17 | adantl | |
19 | zre | |
|
20 | 19 | adantr | |
21 | elfzelz | |
|
22 | 21 | zred | |
23 | 22 | adantl | |
24 | 18 20 23 | 3jca | |
25 | simp1 | |
|
26 | readdcl | |
|
27 | 26 | 3adant1 | |
28 | ltle | |
|
29 | 25 27 28 | syl2anc | |
30 | lesubadd2 | |
|
31 | 29 30 | sylibrd | |
32 | 24 31 | syl | |
33 | 32 | 3impia | |
34 | elfzle2 | |
|
35 | 34 | 3ad2ant2 | |
36 | 15 33 35 | jca32 | |
37 | elfz2 | |
|
38 | 36 37 | sylibr | |