Cardinality: Injection between subsets of Uncountable set The 2019 Stack Overflow Developer Survey Results Are InProving a set is uncountableA countable and an uncountable setIs this set uncountable or countable?Real Analysis Cardinality ProofUncountable “relatively independent” subset of finite dimensional vector spaces over an uncountable fieldIf R is uncountable, then (0.1) is uncountable.Two well orders on an uncountable setCardinal arithmetic argument for countability of finite subsets of integers.Geometric solution to find a Set of totally ordered Subsets of $ mathbbN $ is uncountableHow many uncountable subsets of power set of integers are there?
Is an up-to-date browser secure on an out-of-date OS?
Dual Citizen. Exited the US on Italian passport recently
What is the steepest angle that a canal can be traversable without locks?
Why do UK politicians seemingly ignore opinion polls on Brexit?
How can I fix this gap between bookcases I made?
Is "plugging out" electronic devices an American expression?
Monty Hall variation
aging parents with no investments
How do you say "canon" as in "official for a story universe"?
Why is Grand Jury testimony secret?
How is radar separation assured between primary and secondary targets?
Why do some words that are not inflected have an umlaut?
Could JWST stay at L2 "forever"?
Is this food a bread or a loaf?
How to manage monthly salary
Limit the amount of RAM Mathematica may access?
Is bread bad for ducks?
How to answer pointed "are you quitting" questioning when I don't want them to suspect
Should I use my personal or workplace e-mail when registering to external websites for work purpose?
Output the Arecibo Message
What tool would a Roman-age civilization have to grind silver and other metals into dust?
CiviEvent: Public link for events of a specific type
Should I write numbers in words or as numerals when there are multiple next to each other?
Time travel alters history but people keep saying nothing's changed
Cardinality: Injection between subsets of Uncountable set
The 2019 Stack Overflow Developer Survey Results Are InProving a set is uncountableA countable and an uncountable setIs this set uncountable or countable?Real Analysis Cardinality ProofUncountable “relatively independent” subset of finite dimensional vector spaces over an uncountable fieldIf R is uncountable, then (0.1) is uncountable.Two well orders on an uncountable setCardinal arithmetic argument for countability of finite subsets of integers.Geometric solution to find a Set of totally ordered Subsets of $ mathbbN $ is uncountableHow many uncountable subsets of power set of integers are there?
$begingroup$
assuming, S is infinite uncountable, I am trying to come up with injective f: (S union N) -> S. Where N is naturals.
So far I created S0 which consists of infinite sequence of elements of S, such that S0 = s1,s2,s3, .... that way I can have injective f1: N -> S0.
But I am having hard time trying to prove there exist injective f2: S -> S/S0.
functions elementary-set-theory cardinals
$endgroup$
add a comment |
$begingroup$
assuming, S is infinite uncountable, I am trying to come up with injective f: (S union N) -> S. Where N is naturals.
So far I created S0 which consists of infinite sequence of elements of S, such that S0 = s1,s2,s3, .... that way I can have injective f1: N -> S0.
But I am having hard time trying to prove there exist injective f2: S -> S/S0.
functions elementary-set-theory cardinals
$endgroup$
add a comment |
$begingroup$
assuming, S is infinite uncountable, I am trying to come up with injective f: (S union N) -> S. Where N is naturals.
So far I created S0 which consists of infinite sequence of elements of S, such that S0 = s1,s2,s3, .... that way I can have injective f1: N -> S0.
But I am having hard time trying to prove there exist injective f2: S -> S/S0.
functions elementary-set-theory cardinals
$endgroup$
assuming, S is infinite uncountable, I am trying to come up with injective f: (S union N) -> S. Where N is naturals.
So far I created S0 which consists of infinite sequence of elements of S, such that S0 = s1,s2,s3, .... that way I can have injective f1: N -> S0.
But I am having hard time trying to prove there exist injective f2: S -> S/S0.
functions elementary-set-theory cardinals
functions elementary-set-theory cardinals
asked Mar 23 at 5:58
ActssassinActssassin
1
1
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Assume N and S are disjoint.
For each s in s1, s2, s3,.. pull from S a sequence
t$_s$1, t$_s$2, t$_s$3,.. with t$_s$1 = s.
Do this in a manner that none of the sequences have a common element.
This can be done because S is uncountable and all those sequences are requiring a mere countable number of elements.
To create a bijection from S - S0 to S, for each s in s1, s2, s3,..
map t$_s$2 to t$_s$1, t$_s$3 to t$_s$2, etc.
and for all of those elements not in any of the sequences, map them to themselves.
The case that S and N are not disjoint is left for the diligent reader.
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function ()
return StackExchange.using("mathjaxEditing", function ()
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
);
);
, "mathjax-editing");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "69"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3159003%2fcardinality-injection-between-subsets-of-uncountable-set%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Assume N and S are disjoint.
For each s in s1, s2, s3,.. pull from S a sequence
t$_s$1, t$_s$2, t$_s$3,.. with t$_s$1 = s.
Do this in a manner that none of the sequences have a common element.
This can be done because S is uncountable and all those sequences are requiring a mere countable number of elements.
To create a bijection from S - S0 to S, for each s in s1, s2, s3,..
map t$_s$2 to t$_s$1, t$_s$3 to t$_s$2, etc.
and for all of those elements not in any of the sequences, map them to themselves.
The case that S and N are not disjoint is left for the diligent reader.
$endgroup$
add a comment |
$begingroup$
Assume N and S are disjoint.
For each s in s1, s2, s3,.. pull from S a sequence
t$_s$1, t$_s$2, t$_s$3,.. with t$_s$1 = s.
Do this in a manner that none of the sequences have a common element.
This can be done because S is uncountable and all those sequences are requiring a mere countable number of elements.
To create a bijection from S - S0 to S, for each s in s1, s2, s3,..
map t$_s$2 to t$_s$1, t$_s$3 to t$_s$2, etc.
and for all of those elements not in any of the sequences, map them to themselves.
The case that S and N are not disjoint is left for the diligent reader.
$endgroup$
add a comment |
$begingroup$
Assume N and S are disjoint.
For each s in s1, s2, s3,.. pull from S a sequence
t$_s$1, t$_s$2, t$_s$3,.. with t$_s$1 = s.
Do this in a manner that none of the sequences have a common element.
This can be done because S is uncountable and all those sequences are requiring a mere countable number of elements.
To create a bijection from S - S0 to S, for each s in s1, s2, s3,..
map t$_s$2 to t$_s$1, t$_s$3 to t$_s$2, etc.
and for all of those elements not in any of the sequences, map them to themselves.
The case that S and N are not disjoint is left for the diligent reader.
$endgroup$
Assume N and S are disjoint.
For each s in s1, s2, s3,.. pull from S a sequence
t$_s$1, t$_s$2, t$_s$3,.. with t$_s$1 = s.
Do this in a manner that none of the sequences have a common element.
This can be done because S is uncountable and all those sequences are requiring a mere countable number of elements.
To create a bijection from S - S0 to S, for each s in s1, s2, s3,..
map t$_s$2 to t$_s$1, t$_s$3 to t$_s$2, etc.
and for all of those elements not in any of the sequences, map them to themselves.
The case that S and N are not disjoint is left for the diligent reader.
answered Mar 23 at 11:17
William ElliotWilliam Elliot
9,1212820
9,1212820
add a comment |
add a comment |
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3159003%2fcardinality-injection-between-subsets-of-uncountable-set%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown