<?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 (HAP) - Chapter 16: Meataxe modules</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><a href="../www/index.html"><small>HAP home</small></a> <div class="chlinkprevnexttop"> <a href="chap0.html">Top of Book</a> <a href="chap15.html">Previous Chapter</a> <a href="chap17.html">Next Chapter</a> </div> <p><a id="X85B05BBA78ED7BE2" name="X85B05BBA78ED7BE2"></a></p> <div class="ChapSects"><a href="chap16.html#X85B05BBA78ED7BE2">16. <span class="Heading"> Meataxe modules</span></a> </div> <h3>16. <span class="Heading"> Meataxe modules</span></h3> <div class="pcenter"><table cellspacing="10" class="GAPDocTable"> <tr> <td class="tdleft"><code class="code">DesuspensionMtxModule(M)</code></p> <p>Inputs a meataxe module M over the field of p elements and returns an FpG-module DM. The two modules are related mathematically by the existence of a short exact sequence DM --> FM --> M with FM a free module. Thus the homological properties of DM are equal to those of M with a dimension shift.</p> <p>(If G:=Group(M.generators) is a p-group then FM is a projective cover of M in the sense that the homomorphism FM --> M does not factor as FM --> P --> M for any projective module P.)</td> </tr> <tr> <td class="tdleft"><code class="code">FpG_to_MtxModule(M)</code></p> <p>Inputs an FpG-module M and returns an isomorphic meataxe module.</td> </tr> <tr> <td class="tdleft"><code class="code"> GeneratorsOfMtxModule(M)</code></p> <p>Inputs a meataxe module M acting on, say, the vector space V. The function returns a minimal list of row vectors in V which generate V as a G-module (where G=Group(M.generators) ).</td> </tr> </table><br /><p> </p><br /> </div> <div class="chlinkprevnextbot"> <a href="chap0.html">Top of Book</a> <a href="chap15.html">Previous Chapter</a> <a href="chap17.html">Next Chapter</a> </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="chap8.html">8</a> <a href="chap9.html">9</a> <a href="chap10.html">10</a> <a href="chap11.html">11</a> <a href="chap12.html">12</a> <a href="chap13.html">13</a> <a href="chap14.html">14</a> <a href="chap15.html">15</a> <a href="chap16.html">16</a> <a href="chap17.html">17</a> <a href="chap18.html">18</a> <a href="chap19.html">19</a> <a href="chap20.html">20</a> <a href="chap21.html">21</a> <a href="chap22.html">22</a> <a href="chap23.html">23</a> <a href="chap24.html">24</a> <a href="chap25.html">25</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>