Description: A binary relation does not contain the empty set. (Contributed by AV, 15-Nov-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | 0nelrel | |- ( Rel R -> (/) e/ R ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0nelrel0 | |- ( Rel R -> -. (/) e. R ) |
|
2 | df-nel | |- ( (/) e/ R <-> -. (/) e. R ) |
|
3 | 1 2 | sylibr | |- ( Rel R -> (/) e/ R ) |