Difference between revisions of "Ordered pair"

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==Kuratowski definition==
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An ordered pair <math>(a,b)=\{\{a\},\{a,b\}\}</math>, this way <math>(a,b)\ne(b,a)</math>.
 
An ordered pair <math>(a,b)=\{\{a\},\{a,b\}\}</math>, this way <math>(a,b)\ne(b,a)</math>.
  
 
Ordered pairs are vital in the study of [[Relation|relations]] which leads to [[Function|functions]]
 
Ordered pairs are vital in the study of [[Relation|relations]] which leads to [[Function|functions]]
  
==Proof of existence==
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===Proof of existence===
 
It is easy to prove ordered pairs exist<br/>
 
It is easy to prove ordered pairs exist<br/>
 
Suppose we are given <math>a,b</math> (so we can be sure they exist).
 
Suppose we are given <math>a,b</math> (so we can be sure they exist).

Revision as of 00:10, 11 March 2015

Kuratowski definition

An ordered pair [math](a,b)=\{\{a\},\{a,b\}\}[/math], this way [math](a,b)\ne(b,a)[/math].

Ordered pairs are vital in the study of relations which leads to functions

Proof of existence

It is easy to prove ordered pairs exist
Suppose we are given [math]a,b[/math] (so we can be sure they exist).

By the axiom of a pair we may create [math]\{a,b\}[/math] and [math]\{a,a\}=\{a\}[/math], then we simply have a pair of these, thus [math]\{\{a\},\{a,b\}\}[/math] exists.

The axioms may be found here

Set Theory