Description: A word over an alphabet is a word over the universal class. (Contributed by AV, 8-Feb-2021) (Proof shortened by JJ, 18-Nov-2022)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | wrdv | |- ( W e. Word V -> W e. Word _V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ssv | |- V C_ _V |
|
| 2 | sswrd | |- ( V C_ _V -> Word V C_ Word _V ) |
|
| 3 | 1 2 | ax-mp | |- Word V C_ Word _V |
| 4 | 3 | sseli | |- ( W e. Word V -> W e. Word _V ) |