Step |
Hyp |
Ref |
Expression |
1 |
|
id |
|- ( m = M -> m = M ) |
2 |
|
oveq1 |
|- ( n = N -> ( n - 1 ) = ( N - 1 ) ) |
3 |
1 2
|
oveqan12d |
|- ( ( m = M /\ n = N ) -> ( m ... ( n - 1 ) ) = ( M ... ( N - 1 ) ) ) |
4 |
|
df-fzo |
|- ..^ = ( m e. ZZ , n e. ZZ |-> ( m ... ( n - 1 ) ) ) |
5 |
|
ovex |
|- ( M ... ( N - 1 ) ) e. _V |
6 |
3 4 5
|
ovmpoa |
|- ( ( M e. ZZ /\ N e. ZZ ) -> ( M ..^ N ) = ( M ... ( N - 1 ) ) ) |
7 |
|
simpl |
|- ( ( M e. ZZ /\ N e. ZZ ) -> M e. ZZ ) |
8 |
|
fzof |
|- ..^ : ( ZZ X. ZZ ) --> ~P ZZ |
9 |
8
|
fdmi |
|- dom ..^ = ( ZZ X. ZZ ) |
10 |
9
|
ndmov |
|- ( -. ( M e. ZZ /\ N e. ZZ ) -> ( M ..^ N ) = (/) ) |
11 |
7 10
|
nsyl5 |
|- ( -. M e. ZZ -> ( M ..^ N ) = (/) ) |
12 |
|
simpl |
|- ( ( M e. ZZ /\ ( N - 1 ) e. ZZ ) -> M e. ZZ ) |
13 |
|
fzf |
|- ... : ( ZZ X. ZZ ) --> ~P ZZ |
14 |
13
|
fdmi |
|- dom ... = ( ZZ X. ZZ ) |
15 |
14
|
ndmov |
|- ( -. ( M e. ZZ /\ ( N - 1 ) e. ZZ ) -> ( M ... ( N - 1 ) ) = (/) ) |
16 |
12 15
|
nsyl5 |
|- ( -. M e. ZZ -> ( M ... ( N - 1 ) ) = (/) ) |
17 |
11 16
|
eqtr4d |
|- ( -. M e. ZZ -> ( M ..^ N ) = ( M ... ( N - 1 ) ) ) |
18 |
17
|
adantr |
|- ( ( -. M e. ZZ /\ N e. ZZ ) -> ( M ..^ N ) = ( M ... ( N - 1 ) ) ) |
19 |
6 18
|
pm2.61ian |
|- ( N e. ZZ -> ( M ..^ N ) = ( M ... ( N - 1 ) ) ) |