Step |
Hyp |
Ref |
Expression |
1 |
|
iscnrm3rlem4.1 |
|
2 |
|
iscnrm3rlem4.2 |
|
3 |
|
iscnrm3rlem4.3 |
|
4 |
|
iscnrm3rlem4.4 |
|
5 |
|
indifdi |
|
6 |
5
|
a1i |
|
7 |
3
|
difeq2d |
|
8 |
|
dif0 |
|
9 |
7 8
|
eqtrdi |
|
10 |
|
eqid |
|
11 |
10
|
sscls |
|
12 |
1 2 11
|
syl2anc |
|
13 |
|
df-ss |
|
14 |
12 13
|
sylib |
|
15 |
6 9 14
|
3eqtrd |
|
16 |
|
df-ss |
|
17 |
15 16
|
sylibr |
|
18 |
17 4
|
sstrd |
|