What does $S^1 setminus pt$ mean?

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In this paper, expression $S^1 setminus pt$ is used on page 6. The $pt$ is not definied there. What does it mean and is it a standard notation?

real-analysis notation terminology

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edited Jul 29 at 8:52

Ninja hatori

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asked Jul 29 at 8:01

Andrzej Golonka

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  It's what you get from removing a point from $S^1$. "pt" being short for "point".
  – Lord Shark the Unknown
  Jul 29 at 8:04
  

  
  
  
  

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up vote
0
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favorite

In this paper, expression $S^1 setminus pt$ is used on page 6. The $pt$ is not definied there. What does it mean and is it a standard notation?

real-analysis notation terminology

share|cite|improve this question

edited Jul 29 at 8:52

Ninja hatori

105113

asked Jul 29 at 8:01

Andrzej Golonka

367

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  It's what you get from removing a point from $S^1$. "pt" being short for "point".
  – Lord Shark the Unknown
  Jul 29 at 8:04
  

  
  
  
  

add a comment | 

up vote
0
down vote

favorite

up vote
0
down vote

favorite

In this paper, expression $S^1 setminus pt$ is used on page 6. The $pt$ is not definied there. What does it mean and is it a standard notation?

real-analysis notation terminology

share|cite|improve this question

edited Jul 29 at 8:52

Ninja hatori

105113

asked Jul 29 at 8:01

Andrzej Golonka

367

In this paper, expression $S^1 setminus pt$ is used on page 6. The $pt$ is not definied there. What does it mean and is it a standard notation?

real-analysis notation terminology

share|cite|improve this question

edited Jul 29 at 8:52

Ninja hatori

105113

asked Jul 29 at 8:01

Andrzej Golonka

367

share|cite|improve this question

share|cite|improve this question

edited Jul 29 at 8:52

Ninja hatori

105113

edited Jul 29 at 8:52

Ninja hatori

105113

edited Jul 29 at 8:52

Ninja hatori

105113

105113

asked Jul 29 at 8:01

Andrzej Golonka

367

asked Jul 29 at 8:01

Andrzej Golonka

367

asked Jul 29 at 8:01

Andrzej Golonka

367

367

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  It's what you get from removing a point from $S^1$. "pt" being short for "point".
  – Lord Shark the Unknown
  Jul 29 at 8:04
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  It's what you get from removing a point from $S^1$. "pt" being short for "point".
  – Lord Shark the Unknown
  Jul 29 at 8:04
  

  
  
  
  

2

2

It's what you get from removing a point from $S^1$. "pt" being short for "point".
– Lord Shark the Unknown
Jul 29 at 8:04

It's what you get from removing a point from $S^1$. "pt" being short for "point".
– Lord Shark the Unknown
Jul 29 at 8:04

add a comment | 

3 Answers
3

active

oldest

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up vote
3
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accepted

It just means the circle minus any point. They choose the notation $ pt $ because the specific point is irrelevant, so the author chose not to specify one.

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answered Jul 29 at 8:04

user571438

9367

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2
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Its $S^1$ with a point removed. $S^1$ is symmetric so the point can be chosen arbitrarily.

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answered Jul 29 at 8:05

Elad

53429

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up vote
1
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It is called as cut point for circle i.e removing one point from circle.

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answered Jul 29 at 8:06

Ninja hatori

105113

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3 Answers
3

active

oldest

votes

3 Answers
3

active

oldest

votes

active

oldest

votes

active

oldest

votes

up vote
3
down vote



accepted

It just means the circle minus any point. They choose the notation $ pt $ because the specific point is irrelevant, so the author chose not to specify one.

share|cite|improve this answer

answered Jul 29 at 8:04

user571438

9367

add a comment | 

up vote
3
down vote



accepted

It just means the circle minus any point. They choose the notation $ pt $ because the specific point is irrelevant, so the author chose not to specify one.

share|cite|improve this answer

answered Jul 29 at 8:04

user571438

9367

add a comment | 

up vote
3
down vote



accepted

up vote
3
down vote



accepted

It just means the circle minus any point. They choose the notation $ pt $ because the specific point is irrelevant, so the author chose not to specify one.

share|cite|improve this answer

answered Jul 29 at 8:04

user571438

9367

It just means the circle minus any point. They choose the notation $ pt $ because the specific point is irrelevant, so the author chose not to specify one.

share|cite|improve this answer

answered Jul 29 at 8:04

user571438

9367

share|cite|improve this answer

share|cite|improve this answer

answered Jul 29 at 8:04

user571438

9367

answered Jul 29 at 8:04

user571438

9367

answered Jul 29 at 8:04

user571438

9367

9367

add a comment | 

add a comment | 

up vote
2
down vote

Its $S^1$ with a point removed. $S^1$ is symmetric so the point can be chosen arbitrarily.

share|cite|improve this answer

answered Jul 29 at 8:05

Elad

53429

add a comment | 

up vote
2
down vote

Its $S^1$ with a point removed. $S^1$ is symmetric so the point can be chosen arbitrarily.

share|cite|improve this answer

answered Jul 29 at 8:05

Elad

53429

add a comment | 

up vote
2
down vote

up vote
2
down vote

Its $S^1$ with a point removed. $S^1$ is symmetric so the point can be chosen arbitrarily.

share|cite|improve this answer

answered Jul 29 at 8:05

Elad

53429

Its $S^1$ with a point removed. $S^1$ is symmetric so the point can be chosen arbitrarily.

share|cite|improve this answer

answered Jul 29 at 8:05

Elad

53429

share|cite|improve this answer

share|cite|improve this answer

answered Jul 29 at 8:05

Elad

53429

answered Jul 29 at 8:05

Elad

53429

answered Jul 29 at 8:05

Elad

53429

53429

add a comment | 

add a comment | 

up vote
1
down vote

It is called as cut point for circle i.e removing one point from circle.

share|cite|improve this answer

answered Jul 29 at 8:06

Ninja hatori

105113

add a comment | 

up vote
1
down vote

It is called as cut point for circle i.e removing one point from circle.

share|cite|improve this answer

answered Jul 29 at 8:06

Ninja hatori

105113

add a comment | 

up vote
1
down vote

up vote
1
down vote

It is called as cut point for circle i.e removing one point from circle.

share|cite|improve this answer

answered Jul 29 at 8:06

Ninja hatori

105113

It is called as cut point for circle i.e removing one point from circle.

share|cite|improve this answer

answered Jul 29 at 8:06

Ninja hatori

105113

share|cite|improve this answer

share|cite|improve this answer

answered Jul 29 at 8:06

Ninja hatori

105113

answered Jul 29 at 8:06

Ninja hatori

105113

answered Jul 29 at 8:06

Ninja hatori

105113

105113

add a comment | 

add a comment | 

 

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