Description: Reverse closure of the closed set operation. (Contributed by Stefan O'Rear, 22-Feb-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | cldrcl | ⊢ ( 𝐶 ∈ ( Clsd ‘ 𝐽 ) → 𝐽 ∈ Top ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elfvdm | ⊢ ( 𝐶 ∈ ( Clsd ‘ 𝐽 ) → 𝐽 ∈ dom Clsd ) | |
2 | fncld | ⊢ Clsd Fn Top | |
3 | 2 | fndmi | ⊢ dom Clsd = Top |
4 | 1 3 | eleqtrdi | ⊢ ( 𝐶 ∈ ( Clsd ‘ 𝐽 ) → 𝐽 ∈ Top ) |