Description: The null class is an equivalence relation. (Contributed by Peter Mazsa, 31-Dec-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | eqvrel0 | |- EqvRel (/) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | disjALTV0 | |- Disj (/) |
|
| 2 | 1 | disjimi | |- EqvRel ,~ (/) |
| 3 | coss0 | |- ,~ (/) = (/) |
|
| 4 | 3 | eqvreleqi | |- ( EqvRel ,~ (/) <-> EqvRel (/) ) |
| 5 | 2 4 | mpbi | |- EqvRel (/) |