Description: A quotient set exists. (Contributed by FL, 19-May-2007) (Revised by Mario Carneiro, 9-Jul-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | qsexg | |- ( A e. V -> ( A /. R ) e. _V ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-qs | |- ( A /. R ) = { y | E. x e. A y = [ x ] R } |
|
2 | abrexexg | |- ( A e. V -> { y | E. x e. A y = [ x ] R } e. _V ) |
|
3 | 1 2 | eqeltrid | |- ( A e. V -> ( A /. R ) e. _V ) |