| Step |
Hyp |
Ref |
Expression |
| 1 |
|
lautset.b |
|
| 2 |
|
lautset.l |
|
| 3 |
|
lautset.i |
|
| 4 |
|
elex |
|
| 5 |
|
fveq2 |
|
| 6 |
5 1
|
eqtr4di |
|
| 7 |
6
|
f1oeq2d |
|
| 8 |
|
f1oeq3 |
|
| 9 |
6 8
|
syl |
|
| 10 |
7 9
|
bitrd |
|
| 11 |
|
fveq2 |
|
| 12 |
11 2
|
eqtr4di |
|
| 13 |
12
|
breqd |
|
| 14 |
12
|
breqd |
|
| 15 |
13 14
|
bibi12d |
|
| 16 |
6 15
|
raleqbidv |
|
| 17 |
6 16
|
raleqbidv |
|
| 18 |
10 17
|
anbi12d |
|
| 19 |
18
|
abbidv |
|
| 20 |
|
df-laut |
|
| 21 |
1
|
fvexi |
|
| 22 |
21 21
|
mapval |
|
| 23 |
|
ovex |
|
| 24 |
22 23
|
eqeltrri |
|
| 25 |
|
f1of |
|
| 26 |
25
|
ss2abi |
|
| 27 |
24 26
|
ssexi |
|
| 28 |
|
simpl |
|
| 29 |
28
|
ss2abi |
|
| 30 |
27 29
|
ssexi |
|
| 31 |
19 20 30
|
fvmpt |
|
| 32 |
3 31
|
eqtrid |
|
| 33 |
4 32
|
syl |
|