Metamath Proof Explorer


Theorem disjdmqs

Description: If a relation is disjoint, its domain quotient is equal to the domain quotient of the cosets by it. Lemma for partim2 and petlem via disjdmqseq . (Contributed by Peter Mazsa, 16-Sep-2021)

Ref Expression
Assertion disjdmqs ⊢ Disj R → dom ⁡ R / R = dom ⁡ ≀ R / ≀ R

Proof

Step Hyp Ref Expression
1 disjdmqsss ⊢ Disj R → dom ⁡ R / R ⊆ dom ⁡ ≀ R / ≀ R
2 disjdmqscossss ⊢ Disj R → dom ⁡ ≀ R / ≀ R ⊆ dom ⁡ R / R
3 1 2 eqssd ⊢ Disj R → dom ⁡ R / R = dom ⁡ ≀ R / ≀ R