Sophie

Sophie

distrib > Mandriva > 2010.0 > i586 > media > contrib-release > by-pkgid > 91213ddcfbe7f54821d42c2d9e091326 > files > 2943

gap-system-packages-4.4.12-5mdv2010.0.i586.rpm

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>GAP (Wedderga) - Chapter 3: Strong Shoda pairs</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
<meta name="generator" content="GAPDoc2HTML" />
<link rel="stylesheet" type="text/css" href="manual.css" />
</head>
<body>


<div class="chlinktop"><span class="chlink1">Goto Chapter: </span><a href="chap0.html">Top</a>  <a href="chap1.html">1</a>  <a href="chap2.html">2</a>  <a href="chap3.html">3</a>  <a href="chap4.html">4</a>  <a href="chap5.html">5</a>  <a href="chap6.html">6</a>  <a href="chap7.html">7</a>  <a href="chapBib.html">Bib</a>  <a href="chapInd.html">Ind</a>  </div>

<div class="chlinkprevnexttop">&nbsp;<a href="chap0.html">Top of Book</a>&nbsp;  &nbsp;<a href="chap2.html">Previous Chapter</a>&nbsp;  &nbsp;<a href="chap4.html">Next Chapter</a>&nbsp;  </div>

<p><a id="X81DAF5267D30C83A" name="X81DAF5267D30C83A"></a></p>
<div class="ChapSects"><a href="chap3.html#X81DAF5267D30C83A">3 <span class="Heading">Strong Shoda pairs</span></a>
<div class="ContSect"><span class="nocss">&nbsp;</span><a href="chap3.html#X807C74B07C4B99AF">3.1 <span class="Heading">Computing strong Shoda pairs</span></a>
<span class="ContSS"><br /><span class="nocss">&nbsp;&nbsp;</span><a href="chap3.html#X820A398687A79B9D">3.1-1 StrongShodaPairs</a></span>
</div>
<div class="ContSect"><span class="nocss">&nbsp;</span><a href="chap3.html#X7B49C1BC834E57E3">3.2 <span class="Heading">Properties related with Shoda pairs</span></a>
<span class="ContSS"><br /><span class="nocss">&nbsp;&nbsp;</span><a href="chap3.html#X7C17476F854F1E34">3.2-1 IsStrongShodaPair</a></span>
<span class="ContSS"><br /><span class="nocss">&nbsp;&nbsp;</span><a href="chap3.html#X823B8DEC7ECC3326">3.2-2 IsShodaPair</a></span>
<span class="ContSS"><br /><span class="nocss">&nbsp;&nbsp;</span><a href="chap3.html#X80C4ED17809FC547">3.2-3 IsStronglyMonomial</a></span>
</div>
</div>

<h3>3 <span class="Heading">Strong Shoda pairs</span></h3>

<p><a id="X807C74B07C4B99AF" name="X807C74B07C4B99AF"></a></p>

<h4>3.1 <span class="Heading">Computing strong Shoda pairs</span></h4>

<p><a id="X820A398687A79B9D" name="X820A398687A79B9D"></a></p>

<h5>3.1-1 StrongShodaPairs</h5>

<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">&gt; StrongShodaPairs</code>( <var class="Arg">G</var> )</td><td class="tdright">( attribute )</td></tr></table></div>
<p><b>Returns: </b>A list of pairs of subgroups of the input group.</p>

<p>The input should be a finite group <var class="Arg">G</var>.</p>

<p>Computes a list of representatives of the equivalence classes of <em>strong Shoda pairs</em> (<a href="chap7.html#X81DAF5267D30C83A"><b>7.15</b></a>) of a finite group <var class="Arg">G</var>.</p>


<table class="example">
<tr><td><pre>

gap&gt; StrongShodaPairs( SymmetricGroup(4) );
[ [ Sym( [ 1 .. 4 ] ), Group([ (1,3)(2,4), (1,4)(2,3), (2,4,3), (1,2) ]) ],
  [ Sym( [ 1 .. 4 ] ), Group([ (1,3)(2,4), (1,4)(2,3), (2,4,3) ]) ],
  [ Group([ (1,2)(3,4), (1,3,2,4), (3,4) ]), Group([ (1,2)(3,4), (1,3,2,4) ])
     ],
  [ Group([ (1,2)(3,4), (3,4), (1,3,2,4) ]), Group([ (1,2)(3,4), (3,4) ]) ],
  [ Group([ (1,4)(2,3), (1,3)(2,4), (2,4,3) ]),
      Group([ (1,4)(2,3), (1,3)(2,4) ]) ] ]
gap&gt; StrongShodaPairs( DihedralGroup(64) );
[ [ &lt;pc group of size 64 with 6 generators&gt;,
      Group([ f6, f5, f4, f3, f1, f2 ]) ],
  [ &lt;pc group of size 64 with 6 generators&gt;, Group([ f6, f5, f4, f3, f1*f2 ])
     ],
  [ &lt;pc group of size 64 with 6 generators&gt;, Group([ f6, f5, f4, f3, f2 ]) ],
  [ &lt;pc group of size 64 with 6 generators&gt;, Group([ f6, f5, f4, f3, f1 ]) ],
  [ Group([ f1*f2, f4*f5*f6, f5*f6, f6, f3, f3 ]),
      Group([ f6, f5, f4, f1*f2 ]) ],
  [ Group([ f6, f5, f2, f3, f4 ]), Group([ f6, f5 ]) ],
  [ Group([ f6, f2, f3, f4, f5 ]), Group([ f6 ]) ],
  [ Group([ f2, f3, f4, f5, f6 ]), Group([  ]) ] ]

</pre></td></tr></table>

<p><a id="X7B49C1BC834E57E3" name="X7B49C1BC834E57E3"></a></p>

<h4>3.2 <span class="Heading">Properties related with Shoda pairs</span></h4>

<p><a id="X7C17476F854F1E34" name="X7C17476F854F1E34"></a></p>

<h5>3.2-1 IsStrongShodaPair</h5>

<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">&gt; IsStrongShodaPair</code>( <var class="Arg">G, K, H</var> )</td><td class="tdright">( operation )</td></tr></table></div>
<p>The first argument should be a finite group <var class="Arg">G</var>, the second one a sugroup <var class="Arg">K</var> of <var class="Arg">G</var> and the third one a subgroup of <var class="Arg">K</var>.</p>

<p>Returns <code class="keyw">true</code> if (<var class="Arg">K</var>,<var class="Arg">H</var>) is a <em>strong Shoda pair</em> (<a href="chap7.html#X81DAF5267D30C83A"><b>7.15</b></a>) of <var class="Arg">G</var>, and <code class="keyw">false</code> otherwise.</p>


<table class="example">
<tr><td><pre>

gap&gt; G:=SymmetricGroup(3);; K:=Group([(1,2,3)]);; H:=Group( () );;
gap&gt; IsStrongShodaPair( G, K, H );
true
gap&gt; IsStrongShodaPair( G, G, H );
false
gap&gt; IsStrongShodaPair( G, K, K );
false
gap&gt; IsStrongShodaPair( G, G, K );
true

</pre></td></tr></table>

<p><a id="X823B8DEC7ECC3326" name="X823B8DEC7ECC3326"></a></p>

<h5>3.2-2 IsShodaPair</h5>

<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">&gt; IsShodaPair</code>( <var class="Arg">G, K, H</var> )</td><td class="tdright">( operation )</td></tr></table></div>
<p>The first argument should be a finite group <var class="Arg">G</var>, the second a subgroup <var class="Arg">K</var> of <var class="Arg">G</var> and the third one a subgroup of <var class="Arg">K</var>.</p>

<p>Returns <code class="keyw">true</code> if (<var class="Arg">K</var>,<var class="Arg">H</var>) is a <em>Shoda pair</em> (<a href="chap7.html#X80C058BE81824B23"><b>7.14</b></a>) of <var class="Arg">G</var>.</p>

<p>Note that every strong Shoda pair is a Shoda pair, but the converse is not true.</p>


<table class="example">
<tr><td><pre>

gap&gt; G:=AlternatingGroup(5);;
gap&gt; K:=AlternatingGroup(4);;
gap&gt; H := Group( (1,2)(3,4), (1,3)(2,4) );;
gap&gt; IsStrongShodaPair( G, K, H );
false
gap&gt; IsShodaPair( G, K, H );
true

</pre></td></tr></table>

<p><a id="X80C4ED17809FC547" name="X80C4ED17809FC547"></a></p>

<h5>3.2-3 IsStronglyMonomial</h5>

<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">&gt; IsStronglyMonomial</code>( <var class="Arg">G</var> )</td><td class="tdright">( operation )</td></tr></table></div>
<p>The input <var class="Arg">G</var> should be a finite group.</p>

<p>Returns <code class="keyw">true</code> if <var class="Arg">G</var> is a <em>strongly monomial</em> (<a href="chap7.html#X84C694978557EFE5"><b>7.16</b></a>) finite group.</p>


<table class="example">
<tr><td><pre>

gap&gt; S4:=SymmetricGroup(4);;
gap&gt; IsStronglyMonomial(S4);
true
gap&gt; G:=SmallGroup(24,3);;
gap&gt; IsStronglyMonomial(G);
false
gap&gt; IsMonomial(G);
false
gap&gt; G:=SmallGroup(1000,86);;
gap&gt; IsMonomial(G);
true
gap&gt; IsStronglyMonomial(G);
false

</pre></td></tr></table>


<div class="chlinkprevnextbot">&nbsp;<a href="chap0.html">Top of Book</a>&nbsp;  &nbsp;<a href="chap2.html">Previous Chapter</a>&nbsp;  &nbsp;<a href="chap4.html">Next Chapter</a>&nbsp;  </div>


<div class="chlinkbot"><span class="chlink1">Goto Chapter: </span><a href="chap0.html">Top</a>  <a href="chap1.html">1</a>  <a href="chap2.html">2</a>  <a href="chap3.html">3</a>  <a href="chap4.html">4</a>  <a href="chap5.html">5</a>  <a href="chap6.html">6</a>  <a href="chap7.html">7</a>  <a href="chapBib.html">Bib</a>  <a href="chapInd.html">Ind</a>  </div>

<hr />
<p class="foot">generated by <a href="http://www.math.rwth-aachen.de/~Frank.Luebeck/GAPDoc">GAPDoc2HTML</a></p>
</body>
</html>