|location||Borel sigma algebra|
|visits||member for||1 year, 1 month|
|seen||Aug 30 '14 at 6:04|
A countable union of closed sets is called $F_\sigma$ set. The letter $F$ stands for fermé, or closed and $\sigma$ for somme, or sum.
|bio||website||none||visits||member for||1 year, 1 month|
|location||Borel sigma algebra||seen||Aug 30 '14 at 6:04|
0 Votes Cast
This user has not cast any votes