Metamath Proof Explorer


Theorem refrelcoss

Description: The class of cosets by R is reflexive. (Contributed by Peter Mazsa, 4-Jul-2020)

Ref Expression
Assertion refrelcoss RefRelR

Proof

Step Hyp Ref Expression
1 refrelcoss2 IdomR×ranRRRelR
2 dfrefrel2 RefRelRIdomR×ranRRRelR
3 1 2 mpbir RefRelR