Metamath Proof Explorer


Definition df-dmqss

Description: Define the class of domain quotients. Domain quotients are pairs of sets, typically a relation and a set, where the quotient (see df-qs ) of the relation on its domain is equal to the set. See comments of df-ers for the motivation for this definition. (Contributed by Peter Mazsa, 16-Apr-2019)

Ref Expression
Assertion df-dmqss DomainQss=xy|domx/x=y

Detailed syntax breakdown

Step Hyp Ref Expression
0 cdmqss classDomainQss
1 vx setvarx
2 vy setvary
3 1 cv setvarx
4 3 cdm classdomx
5 4 3 cqs classdomx/x
6 2 cv setvary
7 5 6 wceq wffdomx/x=y
8 7 1 2 copab classxy|domx/x=y
9 0 8 wceq wffDomainQss=xy|domx/x=y