Step |
Hyp |
Ref |
Expression |
1 |
|
tosso.b |
|
2 |
|
tosso.l |
|
3 |
|
tosso.s |
|
4 |
1 2 3
|
pleval2 |
|
5 |
4
|
3expb |
|
6 |
1 2 3
|
pleval2 |
|
7 |
|
equcom |
|
8 |
7
|
orbi2i |
|
9 |
6 8
|
bitrdi |
|
10 |
9
|
3com23 |
|
11 |
10
|
3expb |
|
12 |
5 11
|
orbi12d |
|
13 |
|
df-3or |
|
14 |
|
or32 |
|
15 |
|
orordir |
|
16 |
14 15
|
bitri |
|
17 |
13 16
|
bitri |
|
18 |
12 17
|
bitr4di |
|
19 |
18
|
2ralbidva |
|
20 |
19
|
pm5.32i |
|
21 |
1 2 3
|
pospo |
|
22 |
21
|
anbi1d |
|
23 |
20 22
|
syl5bb |
|
24 |
1 2
|
istos |
|
25 |
|
df-so |
|
26 |
25
|
anbi1i |
|
27 |
|
an32 |
|
28 |
26 27
|
bitri |
|
29 |
23 24 28
|
3bitr4g |
|