Second-countable T1 space: Difference between revisions

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{{topospace property}}
{{topospace property}}
{{topospace property conjunction}}
{{topospace property conjunction|second-countable space|T1 space}}
 
==Relation with other properties==
 
===Stronger properties===
 
{| class="sortable" border="1"
! Property !! Meaning !! Proof of implication !! Proof of strictness (reverse implication failure) !! Intermediate notions
|-
| [[Weaker than::Polish space]] || || || ||
|-
| [[Weaker than::separable metrizable space]] || || || ||
|}
 
===Weaker properties===
 
{| class="sortable" border="1"
! Property !! Meaning !! Proof of implication !! Proof of strictness (reverse implication failure) !! Intermediate notions
|-
| [[Stronger than::second-countable space]]|| || || ||
|-
| [[Stronger than::T1 space]] || || || ||
|-
| [[Stronger than::perfect space]] || || [[second-countable and T1 implies perfect]] || ||
|}
 
===Control of cardinality===
 
* [[Second-countable and T1 implies cardinality at most that of the continuum]]

Latest revision as of 20:37, 26 January 2012

Definition

A topological space is termed a second-countable T1 space if it is both a second-countable space and a T1 space.

This article defines a property of topological spaces: a property that can be evaluated to true/false for any topological space|View a complete list of properties of topological spaces

This article describes a property of topological spaces obtained as a conjunction of the following two properties: second-countable space and T1 space

Relation with other properties

Stronger properties

Property Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
Polish space
separable metrizable space

Weaker properties

Property Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
second-countable space
T1 space
perfect space second-countable and T1 implies perfect

Control of cardinality