Description: A word over an alphabet is a function from an open range of nonnegative integers (of length equal to the length of the word) into the alphabet. (Contributed by Alexander van der Vekens, 30-Jul-2018)
Ref | Expression | ||
---|---|---|---|
Assertion | iswrdb | |- ( W e. Word S <-> W : ( 0 ..^ ( # ` W ) ) --> S ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | wrdf | |- ( W e. Word S -> W : ( 0 ..^ ( # ` W ) ) --> S ) |
|
2 | iswrdi | |- ( W : ( 0 ..^ ( # ` W ) ) --> S -> W e. Word S ) |
|
3 | 1 2 | impbii | |- ( W e. Word S <-> W : ( 0 ..^ ( # ` W ) ) --> S ) |