Step |
Hyp |
Ref |
Expression |
1 |
|
symgext.s |
|
2 |
|
symgext.e |
|
3 |
|
eqid |
|
4 |
3 1
|
symgfv |
|
5 |
4
|
adantll |
|
6 |
|
eldifsni |
|
7 |
1 2
|
symgextfv |
|
8 |
7
|
imp |
|
9 |
8
|
neeq1d |
|
10 |
6 9
|
syl5ibr |
|
11 |
5 10
|
mpd |
|
12 |
11
|
adantrr |
|
13 |
|
elsni |
|
14 |
1 2
|
symgextfve |
|
15 |
14
|
adantr |
|
16 |
13 15
|
syl5com |
|
17 |
16
|
adantl |
|
18 |
17
|
impcom |
|
19 |
12 18
|
neeqtrrd |
|
20 |
19
|
ex |
|