SlideShare uma empresa Scribd logo
1 de 1
Baixar para ler offline
Prove that any bounded open subset of R is the union of disjoint open intervals. Please be
thorough in your explantion. Thanks!
Solution
let O be an open subset of a locally connected space X. Let C be a component of O (as a
(sub)space in its own right). Let x?C. Then let Ux be a connected neighbourhood of x in X such
that Ux?O, which can be done as O is open and the connected neighbourhoods form a local base.
Then Ux,C?O are both connected and intersect (in x) so their union Ux?C?O is a connected
subset of O containing x, so by maximality of components Ux?C?C. But then Ux witnesses that
x is an interior point of C, and this shows all points of Care interior points, hence C is open (in
either X or O, that's equivalent).
Now R is locally connected (open intervals form a local base of connected sets) and so every
open set if a disjoint union of its components, which are open connected subsets of R, hence are
open intervals (potentially of infinite "length", i.e. segments). That there are countably many of
them at most, follows from the already given "rational in every interval" argument.

Mais conteúdo relacionado

Semelhante a Prove that any bounded open subset of R is the union of disjoint ope.pdf

MA500-2 Topological Structures 2016Aisling McCluskey, Dar.docx
MA500-2 Topological Structures 2016Aisling McCluskey, Dar.docxMA500-2 Topological Structures 2016Aisling McCluskey, Dar.docx
MA500-2 Topological Structures 2016Aisling McCluskey, Dar.docx
smile790243
 
applied mathematics methods.pdf
applied mathematics methods.pdfapplied mathematics methods.pdf
applied mathematics methods.pdf
CyprianObota
 
Topological_Vector_Spaces_FINAL_DRAFT
Topological_Vector_Spaces_FINAL_DRAFTTopological_Vector_Spaces_FINAL_DRAFT
Topological_Vector_Spaces_FINAL_DRAFT
Oliver Taylor
 
Sets_Venn-Diagrams_operation.pptx
Sets_Venn-Diagrams_operation.pptxSets_Venn-Diagrams_operation.pptx
Sets_Venn-Diagrams_operation.pptx
hello656557
 

Semelhante a Prove that any bounded open subset of R is the union of disjoint ope.pdf (20)

Connection form
Connection formConnection form
Connection form
 
MA500-2 Topological Structures 2016Aisling McCluskey, Dar.docx
MA500-2 Topological Structures 2016Aisling McCluskey, Dar.docxMA500-2 Topological Structures 2016Aisling McCluskey, Dar.docx
MA500-2 Topological Structures 2016Aisling McCluskey, Dar.docx
 
01_AJMS_211_19_REV.pdf
01_AJMS_211_19_REV.pdf01_AJMS_211_19_REV.pdf
01_AJMS_211_19_REV.pdf
 
01_AJMS_211_19_REV.pdf
01_AJMS_211_19_REV.pdf01_AJMS_211_19_REV.pdf
01_AJMS_211_19_REV.pdf
 
16 Machine Learning Universal Approximation Multilayer Perceptron
16 Machine Learning Universal Approximation Multilayer Perceptron16 Machine Learning Universal Approximation Multilayer Perceptron
16 Machine Learning Universal Approximation Multilayer Perceptron
 
On Review of the Cluster Point of a Set in a Topological Space
On Review of the Cluster Point of a Set in a Topological SpaceOn Review of the Cluster Point of a Set in a Topological Space
On Review of the Cluster Point of a Set in a Topological Space
 
International Journal of Mathematics and Statistics Invention (IJMSI)
International Journal of Mathematics and Statistics Invention (IJMSI)International Journal of Mathematics and Statistics Invention (IJMSI)
International Journal of Mathematics and Statistics Invention (IJMSI)
 
Vector spaces
Vector spaces Vector spaces
Vector spaces
 
Topology
TopologyTopology
Topology
 
Uniform spaces -_riyas
Uniform spaces -_riyasUniform spaces -_riyas
Uniform spaces -_riyas
 
The Khalimsky Line Topology- Countability and Connectedness
The Khalimsky Line Topology- Countability and ConnectednessThe Khalimsky Line Topology- Countability and Connectedness
The Khalimsky Line Topology- Countability and Connectedness
 
Lectures on Analytic Geometry
Lectures on Analytic GeometryLectures on Analytic Geometry
Lectures on Analytic Geometry
 
Math for Intelligent Systems - 01 Linear Algebra 01 Vector Spaces
Math for Intelligent Systems - 01 Linear Algebra 01  Vector SpacesMath for Intelligent Systems - 01 Linear Algebra 01  Vector Spaces
Math for Intelligent Systems - 01 Linear Algebra 01 Vector Spaces
 
H03702061062
H03702061062H03702061062
H03702061062
 
applied mathematics methods.pdf
applied mathematics methods.pdfapplied mathematics methods.pdf
applied mathematics methods.pdf
 
Gnt lecture notes (1)
Gnt lecture notes (1)Gnt lecture notes (1)
Gnt lecture notes (1)
 
MarkDrachMeinelThesisFinal
MarkDrachMeinelThesisFinalMarkDrachMeinelThesisFinal
MarkDrachMeinelThesisFinal
 
Connectedness
ConnectednessConnectedness
Connectedness
 
Topological_Vector_Spaces_FINAL_DRAFT
Topological_Vector_Spaces_FINAL_DRAFTTopological_Vector_Spaces_FINAL_DRAFT
Topological_Vector_Spaces_FINAL_DRAFT
 
Sets_Venn-Diagrams_operation.pptx
Sets_Venn-Diagrams_operation.pptxSets_Venn-Diagrams_operation.pptx
Sets_Venn-Diagrams_operation.pptx
 

Mais de reshmaashok3

Prove that Dirichlets discontinuous function is not Reimann integr.pdf
Prove that Dirichlets discontinuous function is not Reimann integr.pdfProve that Dirichlets discontinuous function is not Reimann integr.pdf
Prove that Dirichlets discontinuous function is not Reimann integr.pdf
reshmaashok3
 

Mais de reshmaashok3 (11)

Prove that if a is odd, then a + 2 is odd.SolutionLet a be odd.pdf
Prove that if a is odd, then a + 2 is odd.SolutionLet a be odd.pdfProve that if a is odd, then a + 2 is odd.SolutionLet a be odd.pdf
Prove that if a is odd, then a + 2 is odd.SolutionLet a be odd.pdf
 
Prove that f is onto.I will rate lifesaver for any help..pdf
Prove that f is onto.I will rate lifesaver for any help..pdfProve that f is onto.I will rate lifesaver for any help..pdf
Prove that f is onto.I will rate lifesaver for any help..pdf
 
Prove that every monotone bounded sequence converges. (if the sequen.pdf
Prove that every monotone bounded sequence converges. (if the sequen.pdfProve that every monotone bounded sequence converges. (if the sequen.pdf
Prove that every monotone bounded sequence converges. (if the sequen.pdf
 
Prove that C = R2 as vector spaces over R and use this to show that.pdf
Prove that C = R2 as vector spaces over R and use this to show that.pdfProve that C = R2 as vector spaces over R and use this to show that.pdf
Prove that C = R2 as vector spaces over R and use this to show that.pdf
 
Prove that Dirichlets discontinuous function is not Reimann integr.pdf
Prove that Dirichlets discontinuous function is not Reimann integr.pdfProve that Dirichlets discontinuous function is not Reimann integr.pdf
Prove that Dirichlets discontinuous function is not Reimann integr.pdf
 
Prove that every ideal of Zn is principal. Is Zn principalSolut.pdf
Prove that every ideal of Zn is principal. Is Zn principalSolut.pdfProve that every ideal of Zn is principal. Is Zn principalSolut.pdf
Prove that every ideal of Zn is principal. Is Zn principalSolut.pdf
 
Prove that both and Ø are independent of every other event A includ.pdf
Prove that both  and Ø are independent of every other event A includ.pdfProve that both  and Ø are independent of every other event A includ.pdf
Prove that both and Ø are independent of every other event A includ.pdf
 
prove that ZZ is not a vector space over the field RSolutionS.pdf
prove that ZZ is not a vector space over the field RSolutionS.pdfprove that ZZ is not a vector space over the field RSolutionS.pdf
prove that ZZ is not a vector space over the field RSolutionS.pdf
 
Prove that the set of all infinite bitstrings is uncountable.Sol.pdf
Prove that the set of all infinite bitstrings is uncountable.Sol.pdfProve that the set of all infinite bitstrings is uncountable.Sol.pdf
Prove that the set of all infinite bitstrings is uncountable.Sol.pdf
 
Prove that the bisection method converges linearly.SolutionFor.pdf
Prove that the bisection method converges linearly.SolutionFor.pdfProve that the bisection method converges linearly.SolutionFor.pdf
Prove that the bisection method converges linearly.SolutionFor.pdf
 
prove that integral sin(mpixL)sin(npixL)dx from -L to L = {0.pdf
prove that integral sin(mpixL)sin(npixL)dx from -L to L = {0.pdfprove that integral sin(mpixL)sin(npixL)dx from -L to L = {0.pdf
prove that integral sin(mpixL)sin(npixL)dx from -L to L = {0.pdf
 

Último

Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
ZurliaSoop
 
Salient Features of India constitution especially power and functions
Salient Features of India constitution especially power and functionsSalient Features of India constitution especially power and functions
Salient Features of India constitution especially power and functions
KarakKing
 

Último (20)

Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
 
Kodo Millet PPT made by Ghanshyam bairwa college of Agriculture kumher bhara...
Kodo Millet  PPT made by Ghanshyam bairwa college of Agriculture kumher bhara...Kodo Millet  PPT made by Ghanshyam bairwa college of Agriculture kumher bhara...
Kodo Millet PPT made by Ghanshyam bairwa college of Agriculture kumher bhara...
 
NO1 Top Black Magic Specialist In Lahore Black magic In Pakistan Kala Ilam Ex...
NO1 Top Black Magic Specialist In Lahore Black magic In Pakistan Kala Ilam Ex...NO1 Top Black Magic Specialist In Lahore Black magic In Pakistan Kala Ilam Ex...
NO1 Top Black Magic Specialist In Lahore Black magic In Pakistan Kala Ilam Ex...
 
Exploring_the_Narrative_Style_of_Amitav_Ghoshs_Gun_Island.pptx
Exploring_the_Narrative_Style_of_Amitav_Ghoshs_Gun_Island.pptxExploring_the_Narrative_Style_of_Amitav_Ghoshs_Gun_Island.pptx
Exploring_the_Narrative_Style_of_Amitav_Ghoshs_Gun_Island.pptx
 
COMMUNICATING NEGATIVE NEWS - APPROACHES .pptx
COMMUNICATING NEGATIVE NEWS - APPROACHES .pptxCOMMUNICATING NEGATIVE NEWS - APPROACHES .pptx
COMMUNICATING NEGATIVE NEWS - APPROACHES .pptx
 
HMCS Max Bernays Pre-Deployment Brief (May 2024).pptx
HMCS Max Bernays Pre-Deployment Brief (May 2024).pptxHMCS Max Bernays Pre-Deployment Brief (May 2024).pptx
HMCS Max Bernays Pre-Deployment Brief (May 2024).pptx
 
HMCS Vancouver Pre-Deployment Brief - May 2024 (Web Version).pptx
HMCS Vancouver Pre-Deployment Brief - May 2024 (Web Version).pptxHMCS Vancouver Pre-Deployment Brief - May 2024 (Web Version).pptx
HMCS Vancouver Pre-Deployment Brief - May 2024 (Web Version).pptx
 
Salient Features of India constitution especially power and functions
Salient Features of India constitution especially power and functionsSalient Features of India constitution especially power and functions
Salient Features of India constitution especially power and functions
 
Graduate Outcomes Presentation Slides - English
Graduate Outcomes Presentation Slides - EnglishGraduate Outcomes Presentation Slides - English
Graduate Outcomes Presentation Slides - English
 
TỔNG ÔN TẬP THI VÀO LỚP 10 MÔN TIẾNG ANH NĂM HỌC 2023 - 2024 CÓ ĐÁP ÁN (NGỮ Â...
TỔNG ÔN TẬP THI VÀO LỚP 10 MÔN TIẾNG ANH NĂM HỌC 2023 - 2024 CÓ ĐÁP ÁN (NGỮ Â...TỔNG ÔN TẬP THI VÀO LỚP 10 MÔN TIẾNG ANH NĂM HỌC 2023 - 2024 CÓ ĐÁP ÁN (NGỮ Â...
TỔNG ÔN TẬP THI VÀO LỚP 10 MÔN TIẾNG ANH NĂM HỌC 2023 - 2024 CÓ ĐÁP ÁN (NGỮ Â...
 
ICT role in 21st century education and it's challenges.
ICT role in 21st century education and it's challenges.ICT role in 21st century education and it's challenges.
ICT role in 21st century education and it's challenges.
 
How to Manage Global Discount in Odoo 17 POS
How to Manage Global Discount in Odoo 17 POSHow to Manage Global Discount in Odoo 17 POS
How to Manage Global Discount in Odoo 17 POS
 
Sociology 101 Demonstration of Learning Exhibit
Sociology 101 Demonstration of Learning ExhibitSociology 101 Demonstration of Learning Exhibit
Sociology 101 Demonstration of Learning Exhibit
 
UGC NET Paper 1 Mathematical Reasoning & Aptitude.pdf
UGC NET Paper 1 Mathematical Reasoning & Aptitude.pdfUGC NET Paper 1 Mathematical Reasoning & Aptitude.pdf
UGC NET Paper 1 Mathematical Reasoning & Aptitude.pdf
 
Wellbeing inclusion and digital dystopias.pptx
Wellbeing inclusion and digital dystopias.pptxWellbeing inclusion and digital dystopias.pptx
Wellbeing inclusion and digital dystopias.pptx
 
Fostering Friendships - Enhancing Social Bonds in the Classroom
Fostering Friendships - Enhancing Social Bonds  in the ClassroomFostering Friendships - Enhancing Social Bonds  in the Classroom
Fostering Friendships - Enhancing Social Bonds in the Classroom
 
On_Translating_a_Tamil_Poem_by_A_K_Ramanujan.pptx
On_Translating_a_Tamil_Poem_by_A_K_Ramanujan.pptxOn_Translating_a_Tamil_Poem_by_A_K_Ramanujan.pptx
On_Translating_a_Tamil_Poem_by_A_K_Ramanujan.pptx
 
How to Give a Domain for a Field in Odoo 17
How to Give a Domain for a Field in Odoo 17How to Give a Domain for a Field in Odoo 17
How to Give a Domain for a Field in Odoo 17
 
Plant propagation: Sexual and Asexual propapagation.pptx
Plant propagation: Sexual and Asexual propapagation.pptxPlant propagation: Sexual and Asexual propapagation.pptx
Plant propagation: Sexual and Asexual propapagation.pptx
 
How to Create and Manage Wizard in Odoo 17
How to Create and Manage Wizard in Odoo 17How to Create and Manage Wizard in Odoo 17
How to Create and Manage Wizard in Odoo 17
 

Prove that any bounded open subset of R is the union of disjoint ope.pdf

  • 1. Prove that any bounded open subset of R is the union of disjoint open intervals. Please be thorough in your explantion. Thanks! Solution let O be an open subset of a locally connected space X. Let C be a component of O (as a (sub)space in its own right). Let x?C. Then let Ux be a connected neighbourhood of x in X such that Ux?O, which can be done as O is open and the connected neighbourhoods form a local base. Then Ux,C?O are both connected and intersect (in x) so their union Ux?C?O is a connected subset of O containing x, so by maximality of components Ux?C?C. But then Ux witnesses that x is an interior point of C, and this shows all points of Care interior points, hence C is open (in either X or O, that's equivalent). Now R is locally connected (open intervals form a local base of connected sets) and so every open set if a disjoint union of its components, which are open connected subsets of R, hence are open intervals (potentially of infinite "length", i.e. segments). That there are countably many of them at most, follows from the already given "rational in every interval" argument.