Step |
Hyp |
Ref |
Expression |
1 |
|
peano1 |
|
2 |
|
elelsuc |
|
3 |
|
satf0sucom |
|
4 |
1 2 3
|
mp2b |
|
5 |
|
omex |
|
6 |
5 5
|
xpex |
|
7 |
|
xpexg |
|
8 |
|
simpl |
|
9 |
|
goelel3xp |
|
10 |
|
eleq1 |
|
11 |
9 10
|
syl5ibrcom |
|
12 |
11
|
rexlimivv |
|
13 |
12
|
ad2antll |
|
14 |
|
eleq1 |
|
15 |
1 14
|
mpbiri |
|
16 |
15
|
ad2antrl |
|
17 |
7 8 13 16
|
opabex2 |
|
18 |
5 6 17
|
mp2an |
|
19 |
18
|
rdg0 |
|
20 |
4 19
|
eqtri |
|