Step |
Hyp |
Ref |
Expression |
1 |
|
sltsubsubbd.1 |
|
2 |
|
sltsubsubbd.2 |
|
3 |
|
sltsubsubbd.3 |
|
4 |
|
sltsubsubbd.4 |
|
5 |
2 1 4 3
|
sltsubsub3bd |
|
6 |
5
|
notbid |
|
7 |
1 3
|
subscld |
|
8 |
2 4
|
subscld |
|
9 |
|
slenlt |
|
10 |
7 8 9
|
syl2anc |
|
11 |
1 2
|
subscld |
|
12 |
3 4
|
subscld |
|
13 |
|
slenlt |
|
14 |
11 12 13
|
syl2anc |
|
15 |
6 10 14
|
3bitr4d |
|