Description: Reverse closure of the closed set operation. (Contributed by Stefan O'Rear, 22-Feb-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | cldrcl | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elfvdm | |
|
2 | fncld | |
|
3 | 2 | fndmi | |
4 | 1 3 | eleqtrdi | |