Step |
Hyp |
Ref |
Expression |
1 |
|
wrdf |
|- ( W e. Word S -> W : ( 0 ..^ ( # ` W ) ) --> S ) |
2 |
|
lencl |
|- ( W e. Word S -> ( # ` W ) e. NN0 ) |
3 |
2
|
nn0zd |
|- ( W e. Word S -> ( # ` W ) e. ZZ ) |
4 |
|
fzoval |
|- ( ( # ` W ) e. ZZ -> ( 0 ..^ ( # ` W ) ) = ( 0 ... ( ( # ` W ) - 1 ) ) ) |
5 |
3 4
|
syl |
|- ( W e. Word S -> ( 0 ..^ ( # ` W ) ) = ( 0 ... ( ( # ` W ) - 1 ) ) ) |
6 |
5
|
feq2d |
|- ( W e. Word S -> ( W : ( 0 ..^ ( # ` W ) ) --> S <-> W : ( 0 ... ( ( # ` W ) - 1 ) ) --> S ) ) |
7 |
1 6
|
mpbid |
|- ( W e. Word S -> W : ( 0 ... ( ( # ` W ) - 1 ) ) --> S ) |