Description: Converse of a singleton of an ordered pair. (Contributed by NM, 23-Jan-2015) (Proof shortened by BJ, 12-Feb-2022)
Ref | Expression | ||
---|---|---|---|
Assertion | cnvsng |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cnvcnvsn | ||
2 | relsnopg | ||
3 | 2 | ancoms | |
4 | dfrel2 | ||
5 | 3 4 | sylib | |
6 | 1 5 | syl5eqr |