Description: The naive version of the definition of reflexive relation ( A. x e. dom R x R x /\ Rel R ) is redundant with respect to reflexive relation (see dfrefrel3 ) in equivalence relation. (Contributed by Peter Mazsa, 25-Oct-2022)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | refrelredund3 | |- redund ( ( A. x e. dom R x R x /\ Rel R ) , RefRel R , EqvRel R ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | refrelredund2 | |- redund ( ( ( _I |` dom R ) C_ R /\ Rel R ) , RefRel R , EqvRel R ) |
|
| 2 | idrefALT | |- ( ( _I |` dom R ) C_ R <-> A. x e. dom R x R x ) |
|
| 3 | 2 | anbi1i | |- ( ( ( _I |` dom R ) C_ R /\ Rel R ) <-> ( A. x e. dom R x R x /\ Rel R ) ) |
| 4 | 3 | redundpbi1 | |- ( redund ( ( ( _I |` dom R ) C_ R /\ Rel R ) , RefRel R , EqvRel R ) <-> redund ( ( A. x e. dom R x R x /\ Rel R ) , RefRel R , EqvRel R ) ) |
| 5 | 1 4 | mpbi | |- redund ( ( A. x e. dom R x R x /\ Rel R ) , RefRel R , EqvRel R ) |