发信人: sunnyrose(知其所以然), 信区: math
标 题: Find a Gδσ that is neither Fσ nor Gδ.
发信站: 饮水思源 (2013年04月02日00:59:51 星期二)
How can we find a Gδσ that is neither Fσ nor Gδ ?
A subset of R^n is
•G δ if it is the intersection of countably many open sets
•F σ if it is the union of countably many closed sets
•G δσ if it is the union of countably many G δ 's
--
二手卖家
※ 来源:·饮水思源 bbs.sjtu.edu.cn·[FROM: 128.100.68.246]
标 题: Find a Gδσ that is neither Fσ nor Gδ.
发信站: 饮水思源 (2013年04月02日00:59:51 星期二)
How can we find a Gδσ that is neither Fσ nor Gδ ?
A subset of R^n is
•G δ if it is the intersection of countably many open sets
•F σ if it is the union of countably many closed sets
•G δσ if it is the union of countably many G δ 's
--
二手卖家
※ 来源:·饮水思源 bbs.sjtu.edu.cn·[FROM: 128.100.68.246]
No comments:
Post a Comment