Description: A function does not contain the empty set. (Contributed by BJ, 26-Nov-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0nelfun | |- ( Fun R -> (/) e/ R ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | funrel | |- ( Fun R -> Rel R ) |
|
| 2 | 0nelrel | |- ( Rel R -> (/) e/ R ) |
|
| 3 | 1 2 | syl | |- ( Fun R -> (/) e/ R ) |