Description: An equivalence relation is a relation. (Contributed by Mario Carneiro, 12-Aug-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | errel | |- ( R Er A -> Rel R ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-er | |- ( R Er A <-> ( Rel R /\ dom R = A /\ ( `' R u. ( R o. R ) ) C_ R ) ) |
|
2 | 1 | simp1bi | |- ( R Er A -> Rel R ) |