Description: Lemma 4 for 2wlkd . (Contributed by AV, 14-Feb-2021)
Ref | Expression | ||
---|---|---|---|
Hypotheses | 2wlkd.p | |
|
2wlkd.f | |
||
2wlkd.s | |
||
Assertion | 2wlkdlem4 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 2wlkd.p | |
|
2 | 2wlkd.f | |
|
3 | 2wlkd.s | |
|
4 | 1 2 3 | 2wlkdlem3 | |
5 | simp1 | |
|
6 | 5 | eleq1d | |
7 | simp2 | |
|
8 | 7 | eleq1d | |
9 | simp3 | |
|
10 | 9 | eleq1d | |
11 | 6 8 10 | 3anbi123d | |
12 | 11 | bicomd | |
13 | 4 12 | syl | |
14 | 3 13 | mpbid | |
15 | 2 | fveq2i | |
16 | s2len | |
|
17 | 15 16 | eqtri | |
18 | 17 | oveq2i | |
19 | fz0tp | |
|
20 | 18 19 | eqtri | |
21 | 20 | raleqi | |
22 | c0ex | |
|
23 | 1ex | |
|
24 | 2ex | |
|
25 | fveq2 | |
|
26 | 25 | eleq1d | |
27 | fveq2 | |
|
28 | 27 | eleq1d | |
29 | fveq2 | |
|
30 | 29 | eleq1d | |
31 | 22 23 24 26 28 30 | raltp | |
32 | 21 31 | bitri | |
33 | 14 32 | sylibr | |