Metamath Proof Explorer


Theorem refrelcoss3

Description: The class of cosets by R is reflexive, see dfrefrel3 . (Contributed by Peter Mazsa, 30-Jul-2019)

Ref Expression
Assertion refrelcoss3 ⊢ ∀ x ∈ dom ⁡ ≀ R ∀ y ∈ ran ⁡ ≀ R x = y → x ≀ R y ∧ Rel ⁡ ≀ R

Proof

Step Hyp Ref Expression
1 refrelcosslem ⊢ ∀ x ∈ dom ⁡ ≀ R x ≀ R x
2 idinxpssinxp4 ⊢ ∀ x ∈ dom ⁡ ≀ R ∀ y ∈ dom ⁡ ≀ R x = y → x ≀ R y ↔ ∀ x ∈ dom ⁡ ≀ R x ≀ R x
3 1 2 mpbir ⊢ ∀ x ∈ dom ⁡ ≀ R ∀ y ∈ dom ⁡ ≀ R x = y → x ≀ R y
4 rncossdmcoss ⊢ ran ⁡ ≀ R = dom ⁡ ≀ R
5 4 raleqi ⊢ ∀ y ∈ ran ⁡ ≀ R x = y → x ≀ R y ↔ ∀ y ∈ dom ⁡ ≀ R x = y → x ≀ R y
6 5 ralbii ⊢ ∀ x ∈ dom ⁡ ≀ R ∀ y ∈ ran ⁡ ≀ R x = y → x ≀ R y ↔ ∀ x ∈ dom ⁡ ≀ R ∀ y ∈ dom ⁡ ≀ R x = y → x ≀ R y
7 3 6 mpbir ⊢ ∀ x ∈ dom ⁡ ≀ R ∀ y ∈ ran ⁡ ≀ R x = y → x ≀ R y
8 relcoss ⊢ Rel ⁡ ≀ R
9 7 8 pm3.2i ⊢ ∀ x ∈ dom ⁡ ≀ R ∀ y ∈ ran ⁡ ≀ R x = y → x ≀ R y ∧ Rel ⁡ ≀ R