Step |
Hyp |
Ref |
Expression |
1 |
|
dfdif2 |
|
2 |
|
dfnul3 |
|
3 |
2
|
uneq2i |
|
4 |
|
un0 |
|
5 |
|
unrab |
|
6 |
3 4 5
|
3eqtr3i |
|
7 |
|
ianor |
|
8 |
|
eluni |
|
9 |
8
|
anbi1i |
|
10 |
|
df-rex |
|
11 |
|
elin |
|
12 |
11
|
anbi2i |
|
13 |
|
df-an |
|
14 |
12 13
|
bitr3i |
|
15 |
14
|
anbi2i |
|
16 |
|
eldifsn |
|
17 |
|
necom |
|
18 |
17
|
anbi2i |
|
19 |
16 18
|
bitri |
|
20 |
19
|
anbi2i |
|
21 |
|
ancom |
|
22 |
21
|
anbi2ci |
|
23 |
|
anass |
|
24 |
20 22 23
|
3bitri |
|
25 |
|
an32 |
|
26 |
24 25
|
bitr3i |
|
27 |
15 26
|
bitr3i |
|
28 |
27
|
exbii |
|
29 |
|
19.41v |
|
30 |
10 28 29
|
3bitri |
|
31 |
|
rexnal |
|
32 |
9 30 31
|
3bitr2ri |
|
33 |
32
|
con1bii |
|
34 |
7 33
|
bitr3i |
|
35 |
34
|
rabbii |
|
36 |
1 6 35
|
3eqtri |
|
37 |
36
|
neeq1i |
|
38 |
|
rabn0 |
|
39 |
37 38
|
bitri |
|