<html><head><title>[ModIsom] 6 Relatively free Algebras</title></head>
<body text="#000000" bgcolor="#ffffff">
[<a href = "chapters.htm">Up</a>] [<a href ="CHAP005.htm">Previous</a>] [<a href = "theindex.htm">Index</a>]
<h1>6 Relatively free Algebras</h1><p>
<P>
<H3>Sections</H3>
<oL>
<li> <A HREF="CHAP006.htm#SECT001">Computing Kurosh Algebras</a>
<li> <A HREF="CHAP006.htm#SECT002">A Library of Kurosh Algebras</a>
<li> <A HREF="CHAP006.htm#SECT003">Example of accessing the library of Kurosh algebras</a>
</ol><p>
<p>
As described in <a href="biblio.htm#Eic11"><cite>Eic11</cite></a>, the nilpotent quotient algorithm also allows
to determine certain relatively free algebras; that is, algebras that are
free within a variety.
<p>
<p>
<h2><a name="SECT001">6.1 Computing Kurosh Algebras</a></h2>
<p><p>
<a name = "SSEC001.1"></a>
<li><code>KuroshAlgebra( d, n, F ) F</code>
<p>
determines a nilpotent table for the largest associative algebra on
<i>d</i> generators over the field <i>F</i> so that every element <i>a</i> of the
algebra satisfies <i>a</i><sup><i>n</i></sup> = 0.
<p>
<a name = "SSEC001.2"></a>
<li><code>ExpandExponentLaw( T, n )</code>
<p>
suppose that <i>T</i> is the nilpotent table of a Kurosh algebra of exponent
<i>n</i> defined over a prime field. This function determines polynomials
describing the corresponding Kurosh algebras over all fields with the same
characteristic as the prime field.
<p>
<p>
<h2><a name="SECT002">6.2 A Library of Kurosh Algebras</a></h2>
<p><p>
The package contains a library of Kurosh algebras. This can be accessed
as follows.
<p>
<a name = "SSEC002.1"></a>
<li><code>KuroshAlgebraByLib(d, n, F) F</code>
<p>
At current, the library contains the Kurosh algebras for
<i>n</i>=2,
(<i>d</i>,<i>n</i>) = (2,3),
(<i>d</i>,<i>n</i>) = (3,3) and <i>F</i> = <b>Q</b> or |<i>F</i>| ∈ {2,3,4},
(<i>d</i>,<i>n</i>) = (4,3) and <i>F</i> = <b>Q</b> or |<i>F</i>| ∈ {2,3,4},
(<i>d</i>,<i>n</i>) = (2,4) and <i>F</i> = <b>Q</b> or |<i>F</i>| ∈ {2,3,4,9},
(<i>d</i>,<i>n</i>) = (2,5) and <i>F</i> = <b>Q</b> or |<i>F</i>| ∈ {2,3,4,5,8,9}.
<p>
<p>
<h2><a name="SECT003">6.3 Example of accessing the library of Kurosh algebras</a></h2>
<p><p>
<pre>
gap> KuroshAlgebra(2,2,Rationals);
... some printout ..
rec( bas := [ [ 1, 0, 0, 0 ], [ 0, 1, 1, 0 ], [ 0, 0, 0, 1 ], [ 0, 1, 0, 0 ] ]
, com := false, dim := 3, fld := Rationals, rnk := 2,
tab := [ [ [ 0, 0, 0 ], [ 0, 0, -1 ], [ 0, 0, 0 ] ],
[ [ 0, 0, 1 ], [ 0, 0, 0 ], [ 0, 0, 0 ] ] ], wds := [ ,, [ 2, 1 ] ],
wgs := [ 1, 1, 2 ] )
</pre>
<p>
<p>
[<a href = "chapters.htm">Up</a>] [<a href ="CHAP005.htm">Previous</a>] [<a href = "theindex.htm">Index</a>]
<P>
<address>ModIsom manual<br>September 2024
</address></body></html>
¤ Dauer der Verarbeitung: 0.12 Sekunden
(vorverarbeitet)
¤
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung ist noch experimentell.