Transpositions generate the finitary symmetric group: Difference between revisions

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(New page: ==Statement== ===For a finite set=== The symmetric group on a finite set is generated by the transpositions in it. A transposition is a permutation that interchanges two elements...)
 
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The [[finitary symmetric group]] on any set is generated by the [[transposition]]s in it. A transposition is a permutation that interchanges two elements and leaves all the others fixed; in other words, it is a cycle of length two.
The [[finitary symmetric group]] on any set is generated by the [[transposition]]s in it. A transposition is a permutation that interchanges two elements and leaves all the others fixed; in other words, it is a cycle of length two.
==Related facts==
* [[3-cycles generate the finitary alternating group]]
* [[Symmetric group on a finite set is 2-generated]]
===In terms of IAPS theory===
In terms of IAPS theory, this translates to saying that the transposition on a two-element set forms a one-element permutatively generating set for the [[permutation IAPS]].


==Proof for a finite set==
==Proof for a finite set==

Revision as of 21:08, 18 August 2008

Statement

For a finite set

The symmetric group on a finite set is generated by the transpositions in it. A transposition is a permutation that interchanges two elements and leaves all the others fixed; in other words, it is a cycle of length two.

For an infinite set

The finitary symmetric group on any set is generated by the transpositions in it. A transposition is a permutation that interchanges two elements and leaves all the others fixed; in other words, it is a cycle of length two.

Related facts

In terms of IAPS theory

In terms of IAPS theory, this translates to saying that the transposition on a two-element set forms a one-element permutatively generating set for the permutation IAPS.

Proof for a finite set

Proof using the cycle decomposition

Proof using sorting algorithms