Step |
Hyp |
Ref |
Expression |
1 |
|
cbvsum.1 |
|
2 |
1
|
cbvcsbv |
|
3 |
2
|
a1i |
|
4 |
3
|
ifeq1d |
|
5 |
4
|
mpteq2dv |
|
6 |
5
|
seqeq3d |
|
7 |
6
|
breq1d |
|
8 |
7
|
mptru |
|
9 |
8
|
anbi2i |
|
10 |
9
|
rexbii |
|
11 |
1
|
cbvcsbv |
|
12 |
11
|
mpteq2i |
|
13 |
12
|
a1i |
|
14 |
13
|
seqeq3d |
|
15 |
14
|
mptru |
|
16 |
15
|
fveq1i |
|
17 |
16
|
eqeq2i |
|
18 |
17
|
anbi2i |
|
19 |
18
|
exbii |
|
20 |
19
|
rexbii |
|
21 |
10 20
|
orbi12i |
|
22 |
21
|
iotabii |
|
23 |
|
df-sum |
|
24 |
|
df-sum |
|
25 |
22 23 24
|
3eqtr4i |
|