Description: Lemma for the leftpad theorems. (Contributed by Thierry Arnoux, 7-Aug-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | lpadlem1.1 | |- ( ph -> C e. S ) | |
| Assertion | lpadlem1 | |- ( ph -> ( ( 0 ..^ ( L - ( # ` W ) ) ) X. { C } ) e. Word S ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | lpadlem1.1 | |- ( ph -> C e. S ) | |
| 2 | fconst6g |  |-  ( C e. S -> ( ( 0 ..^ ( L - ( # ` W ) ) ) X. { C } ) : ( 0 ..^ ( L - ( # ` W ) ) ) --> S ) | |
| 3 | iswrdi |  |-  ( ( ( 0 ..^ ( L - ( # ` W ) ) ) X. { C } ) : ( 0 ..^ ( L - ( # ` W ) ) ) --> S -> ( ( 0 ..^ ( L - ( # ` W ) ) ) X. { C } ) e. Word S ) | |
| 4 | 1 2 3 | 3syl |  |-  ( ph -> ( ( 0 ..^ ( L - ( # ` W ) ) ) X. { C } ) e. Word S ) |