Namespaces
Variants
Actions

Difference between revisions of "G-delta"

From Encyclopedia of Mathematics
Jump to: navigation, search
m (moved Set of type F sigma(G delta) to G-delta: Easier to find.)
Line 1: Line 1:
−
''<img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/s/s084/s084740/s0847404.png" />-set (<img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/s/s084/s084740/s0847406.png" />-set)''
+
{{MSC|28A33}}
  
−
A union (intersection) of a countable number of closed (open) sets. See [[Borel set|Borel set]].
+
[[Category:Classical measure theory]]
 +
 
 +
{{TEX|done}}
 +
 
 +
In a topological space $X$ a subset which is the countable intersection of open sets and which is not itself
 +
open. See [[Borel set]].

Revision as of 08:30, 16 August 2012

2020 Mathematics Subject Classification: Primary: 28A33 [MSN][ZBL]

In a topological space $X$ a subset which is the countable intersection of open sets and which is not itself open. See Borel set.

How to Cite This Entry:
G-delta. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=G-delta&oldid=27594
Retrieved from "https://encyclopediaofmath.org/index.php?title=G-delta&oldid=27594"