| Step |
Hyp |
Ref |
Expression |
| 1 |
|
iccshftl.1 |
|
| 2 |
|
iccshftl.2 |
|
| 3 |
|
simpl |
|
| 4 |
|
resubcl |
|
| 5 |
3 4
|
2thd |
|
| 6 |
5
|
adantl |
|
| 7 |
|
lesub1 |
|
| 8 |
7
|
3expb |
|
| 9 |
8
|
adantlr |
|
| 10 |
1
|
breq1i |
|
| 11 |
9 10
|
bitrdi |
|
| 12 |
|
lesub1 |
|
| 13 |
12
|
3expb |
|
| 14 |
13
|
an12s |
|
| 15 |
14
|
adantll |
|
| 16 |
2
|
breq2i |
|
| 17 |
15 16
|
bitrdi |
|
| 18 |
6 11 17
|
3anbi123d |
|
| 19 |
|
elicc2 |
|
| 20 |
19
|
adantr |
|
| 21 |
|
resubcl |
|
| 22 |
1 21
|
eqeltrrid |
|
| 23 |
|
resubcl |
|
| 24 |
2 23
|
eqeltrrid |
|
| 25 |
|
elicc2 |
|
| 26 |
22 24 25
|
syl2an |
|
| 27 |
26
|
anandirs |
|
| 28 |
27
|
adantrl |
|
| 29 |
18 20 28
|
3bitr4d |
|