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 ) |