Description: Image under the empty relation. (Contributed by FL, 11-Jan-2007)
Ref | Expression | ||
---|---|---|---|
Assertion | 0ima | |- ( (/) " A ) = (/) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | imassrn | |- ( (/) " A ) C_ ran (/) |
|
2 | rn0 | |- ran (/) = (/) |
|
3 | 1 2 | sseqtri | |- ( (/) " A ) C_ (/) |
4 | 0ss | |- (/) C_ ( (/) " A ) |
|
5 | 3 4 | eqssi | |- ( (/) " A ) = (/) |