| Step |
Hyp |
Ref |
Expression |
| 1 |
|
peano2z |
|- ( N e. ZZ -> ( N + 1 ) e. ZZ ) |
| 2 |
|
fzoval |
|- ( ( N + 1 ) e. ZZ -> ( M ..^ ( N + 1 ) ) = ( M ... ( ( N + 1 ) - 1 ) ) ) |
| 3 |
1 2
|
syl |
|- ( N e. ZZ -> ( M ..^ ( N + 1 ) ) = ( M ... ( ( N + 1 ) - 1 ) ) ) |
| 4 |
|
zcn |
|- ( N e. ZZ -> N e. CC ) |
| 5 |
|
ax-1cn |
|- 1 e. CC |
| 6 |
|
pncan |
|- ( ( N e. CC /\ 1 e. CC ) -> ( ( N + 1 ) - 1 ) = N ) |
| 7 |
4 5 6
|
sylancl |
|- ( N e. ZZ -> ( ( N + 1 ) - 1 ) = N ) |
| 8 |
7
|
oveq2d |
|- ( N e. ZZ -> ( M ... ( ( N + 1 ) - 1 ) ) = ( M ... N ) ) |
| 9 |
3 8
|
eqtr2d |
|- ( N e. ZZ -> ( M ... N ) = ( M ..^ ( N + 1 ) ) ) |