Metamath Proof Explorer


Theorem symrelcoss

Description: The class of cosets by R is symmetric. (Contributed by Peter Mazsa, 20-Dec-2021)

Ref Expression
Assertion symrelcoss SymRelR

Proof

Step Hyp Ref Expression
1 symrelcoss2 R-1RRelR
2 dfsymrel2 SymRelRR-1RRelR
3 1 2 mpbir SymRelR