Step |
Hyp |
Ref |
Expression |
1 |
|
df-refld |
|
2 |
1
|
oveq1i |
|
3 |
|
resubdrg |
|
4 |
3
|
simpli |
|
5 |
|
nn0ssre |
|
6 |
|
ressabs |
|
7 |
4 5 6
|
mp2an |
|
8 |
2 7
|
eqtri |
|
9 |
|
retos |
|
10 |
|
rearchi |
|
11 |
9 10
|
pm3.2i |
|
12 |
|
nn0subm |
|
13 |
|
subrgsubg |
|
14 |
|
subgsubm |
|
15 |
4 13 14
|
mp2b |
|
16 |
1
|
subsubm |
|
17 |
15 16
|
ax-mp |
|
18 |
12 5 17
|
mpbir2an |
|
19 |
|
submarchi |
|
20 |
11 18 19
|
mp2an |
|
21 |
8 20
|
eqeltrri |
|