Metamath Proof Explorer


Theorem dmcoss2

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

Ref Expression
Assertion dmcoss2 ⊢ dom ⁡ ≀ R = ran ⁡ R

Proof

Step Hyp Ref Expression
1 dmcoss3 ⊢ dom ⁡ ≀ R = dom ⁡ R -1
2 df-rn ⊢ ran ⁡ R = dom ⁡ R -1
3 1 2 eqtr4i ⊢ dom ⁡ ≀ R = ran ⁡ R