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 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cdmqss | |
|
1 | vx | |
|
2 | vy | |
|
3 | 1 | cv | |
4 | 3 | cdm | |
5 | 4 3 | cqs | |
6 | 2 | cv | |
7 | 5 6 | wceq | |
8 | 7 1 2 | copab | |
9 | 0 8 | wceq | |