Connectedness is connected union-closed: Difference between revisions

From Topospaces
No edit summary
 
Line 1: Line 1:
{{topospace metaproperty satisfaction|
property = connected space|
metaproperty = connected union-closed property of topological spaces}}
==Statement==
==Statement==


Line 7: Line 11:
# <math>A</math> is a [[connected space]] in the [[subspace topology]].
# <math>A</math> is a [[connected space]] in the [[subspace topology]].
# For each <math>i \in I</math>, <math>B_i</math> is a [[connected space]] in the [[subspace topology]].
# For each <math>i \in I</math>, <math>B_i</math> is a [[connected space]] in the [[subspace topology]].
# <math>A \cap B_i</math> is non-empty for each <math>i \in I</math>>
# <math>A \cap B_i</math> is non-empty for each <math>i \in I</math>.


Then, the space:
Then, the space:

Latest revision as of 18:09, 26 January 2012

This article gives the statement, and possibly proof, of a topological space property (i.e., connected space) satisfying a topological space metaproperty (i.e., connected union-closed property of topological spaces)
View all topological space metaproperty satisfactions | View all topological space metaproperty dissatisfactions
Get more facts about connected space |Get facts that use property satisfaction of connected space | Get facts that use property satisfaction of connected space|Get more facts about connected union-closed property of topological spaces

Statement

Version using a pivoting set

Suppose X is a topological space. Suppose A is a subset of X and Bi,i∈I is a collection of subsets of X. Suppose that:

  1. A is a connected space in the subspace topology.
  2. For each i∈I, Bi is a connected space in the subspace topology.
  3. A∩Bi is non-empty for each i∈I.

Then, the space:

A∪⋃i∈IBi

is a connected space in the subspace topology from X.

Version using finite hopping

Fill this in later