Step |
Hyp |
Ref |
Expression |
1 |
|
isirred2.1 |
|
2 |
|
isirred2.2 |
|
3 |
|
isirred2.3 |
|
4 |
|
isirred2.4 |
|
5 |
|
eldif |
|
6 |
|
eldif |
|
7 |
|
eldif |
|
8 |
6 7
|
anbi12i |
|
9 |
|
an4 |
|
10 |
8 9
|
bitri |
|
11 |
10
|
imbi1i |
|
12 |
|
impexp |
|
13 |
|
pm4.56 |
|
14 |
|
df-ne |
|
15 |
13 14
|
imbi12i |
|
16 |
|
con34b |
|
17 |
15 16
|
bitr4i |
|
18 |
17
|
imbi2i |
|
19 |
12 18
|
bitri |
|
20 |
11 19
|
bitri |
|
21 |
20
|
2albii |
|
22 |
|
r2al |
|
23 |
|
r2al |
|
24 |
21 22 23
|
3bitr4i |
|
25 |
5 24
|
anbi12i |
|
26 |
|
eqid |
|
27 |
1 2 3 26 4
|
isirred |
|
28 |
|
df-3an |
|
29 |
25 27 28
|
3bitr4i |
|