Description: Symmetric relation implies that the domain and the range are equal. (Contributed by Peter Mazsa, 29-Dec-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | symrelim |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | rncnv | ||
2 | dfsymrel4 | ||
3 | 2 | simplbi | |
4 | 3 | rneqd | |
5 | 1 4 | syl5eqr |