Step |
Hyp |
Ref |
Expression |
1 |
|
inxpssres |
|
2 |
|
sstr2 |
|
3 |
1 2
|
ax-mp |
|
4 |
3
|
ssrabi |
|
5 |
|
dfrefrels2 |
|
6 |
4 5
|
sseqtrri |
|
7 |
|
in32 |
|
8 |
|
inrab |
|
9 |
|
dfsymrels2 |
|
10 |
9
|
ineq2i |
|
11 |
|
refsymrels2 |
|
12 |
8 10 11
|
3eqtr4i |
|
13 |
12
|
ineq1i |
|
14 |
|
inass |
|
15 |
7 13 14
|
3eqtr3ri |
|
16 |
|
in32 |
|
17 |
|
inass |
|
18 |
15 16 17
|
3eqtri |
|
19 |
|
df-redund |
|
20 |
6 18 19
|
mpbir2an |
|