Step |
Hyp |
Ref |
Expression |
1 |
|
isfth.b |
|
2 |
|
fthfunc |
|
3 |
2
|
ssbri |
|
4 |
|
df-br |
|
5 |
|
funcrcl |
|
6 |
4 5
|
sylbi |
|
7 |
|
oveq12 |
|
8 |
7
|
breqd |
|
9 |
|
simpl |
|
10 |
9
|
fveq2d |
|
11 |
10 1
|
eqtr4di |
|
12 |
11
|
raleqdv |
|
13 |
11 12
|
raleqbidv |
|
14 |
8 13
|
anbi12d |
|
15 |
14
|
opabbidv |
|
16 |
|
df-fth |
|
17 |
|
ovex |
|
18 |
|
simpl |
|
19 |
18
|
ssopab2i |
|
20 |
|
opabss |
|
21 |
19 20
|
sstri |
|
22 |
17 21
|
ssexi |
|
23 |
15 16 22
|
ovmpoa |
|
24 |
6 23
|
syl |
|
25 |
24
|
breqd |
|
26 |
|
relfunc |
|
27 |
26
|
brrelex12i |
|
28 |
|
breq12 |
|
29 |
|
simpr |
|
30 |
29
|
oveqd |
|
31 |
30
|
cnveqd |
|
32 |
31
|
funeqd |
|
33 |
32
|
2ralbidv |
|
34 |
28 33
|
anbi12d |
|
35 |
|
eqid |
|
36 |
34 35
|
brabga |
|
37 |
27 36
|
syl |
|
38 |
25 37
|
bitrd |
|
39 |
38
|
bianabs |
|
40 |
3 39
|
biadanii |
|