Step |
Hyp |
Ref |
Expression |
1 |
|
incom |
|
2 |
|
disjdif |
|
3 |
1 2
|
eqtr3i |
|
4 |
|
ineq1 |
|
5 |
3 4
|
syl5reqr |
|
6 |
|
undif1 |
|
7 |
|
uneq1 |
|
8 |
6 7
|
syl5reqr |
|
9 |
5 8
|
jca |
|
10 |
|
simpl |
|
11 |
|
disj3 |
|
12 |
|
eqcom |
|
13 |
11 12
|
bitri |
|
14 |
10 13
|
sylib |
|
15 |
|
difeq1 |
|
16 |
|
difun2 |
|
17 |
|
difun2 |
|
18 |
15 16 17
|
3eqtr3g |
|
19 |
18
|
eqeq1d |
|
20 |
19
|
adantl |
|
21 |
14 20
|
mpbid |
|
22 |
9 21
|
impbii |
|