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 ⊢ RefRel ≀ R

Proof

Step Hyp Ref Expression
1 refrelcoss2 ⊢ I ∩ dom ⁡ ≀ R × ran ⁡ ≀ R ⊆ ≀ R ∧ Rel ⁡ ≀ R
2 dfrefrel2 ⊢ RefRel ≀ R ↔ I ∩ dom ⁡ ≀ R × ran ⁡ ≀ R ⊆ ≀ R ∧ Rel ⁡ ≀ R
3 1 2 mpbir ⊢ RefRel ≀ R