Step |
Hyp |
Ref |
Expression |
1 |
|
f1oun2prg |
|
2 |
1
|
imp |
|
3 |
2
|
adantr |
|
4 |
|
s4prop |
|
5 |
4
|
adantr |
|
6 |
5
|
eqeq2d |
|
7 |
6
|
biimpa |
|
8 |
7
|
eqcomd |
|
9 |
8
|
f1oeq1d |
|
10 |
3 9
|
mpbid |
|
11 |
|
dff1o5 |
|
12 |
|
dff12 |
|
13 |
12
|
bicomi |
|
14 |
13
|
anbi1i |
|
15 |
11 14
|
sylbb2 |
|
16 |
|
ffdm |
|
17 |
16
|
simpld |
|
18 |
17
|
anim1i |
|
19 |
18
|
anim1i |
|
20 |
15 19
|
syl |
|
21 |
|
dff12 |
|
22 |
21
|
anbi1i |
|
23 |
20 22
|
sylibr |
|
24 |
|
dff1o5 |
|
25 |
23 24
|
sylibr |
|
26 |
10 25
|
syl |
|
27 |
26
|
exp31 |
|