Description: If A is a set then the class of cosets by the converse of A is a set. (Contributed by Peter Mazsa, 18-Oct-2019)
Ref | Expression | ||
---|---|---|---|
Assertion | cosscnvex | |- ( A e. V -> ,~ `' A e. _V ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cnvexg | |- ( A e. V -> `' A e. _V ) |
|
2 | cossex | |- ( `' A e. _V -> ,~ `' A e. _V ) |
|
3 | 1 2 | syl | |- ( A e. V -> ,~ `' A e. _V ) |