Metamath Proof Explorer


Theorem dmcoss2

Description: The domain of cosets is the range. (Contributed by Peter Mazsa, 27-Dec-2018)

Ref Expression
Assertion dmcoss2 domR=ranR

Proof

Step Hyp Ref Expression
1 dmcoss3 domR=domR-1
2 df-rn ranR=domR-1
3 1 2 eqtr4i domR=ranR