| Step |
Hyp |
Ref |
Expression |
| 1 |
|
zre |
|- ( N e. ZZ -> N e. RR ) |
| 2 |
|
chpval |
|- ( N e. RR -> ( psi ` N ) = sum_ n e. ( 1 ... ( |_ ` N ) ) ( Lam ` n ) ) |
| 3 |
1 2
|
syl |
|- ( N e. ZZ -> ( psi ` N ) = sum_ n e. ( 1 ... ( |_ ` N ) ) ( Lam ` n ) ) |
| 4 |
|
flid |
|- ( N e. ZZ -> ( |_ ` N ) = N ) |
| 5 |
4
|
oveq2d |
|- ( N e. ZZ -> ( 1 ... ( |_ ` N ) ) = ( 1 ... N ) ) |
| 6 |
5
|
sumeq1d |
|- ( N e. ZZ -> sum_ n e. ( 1 ... ( |_ ` N ) ) ( Lam ` n ) = sum_ n e. ( 1 ... N ) ( Lam ` n ) ) |
| 7 |
3 6
|
eqtrd |
|- ( N e. ZZ -> ( psi ` N ) = sum_ n e. ( 1 ... N ) ( Lam ` n ) ) |