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<div class="ChapSects"><a href="chap21.html#X81A2A3C97C09685E">21 <span class="Heading"> <span class="SimpleMath">FpG</span>-modules</span></a>
<div class="ContSect"><span class="tocline"><span class="nocss"> </span><a href="chap21.html#X7CFDEEC07F15CF82">21.1 <span class="Heading"> </span></a>
</span>
<div class="ContSSBlock">
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X78A33AD27F99EF01">21.1-1 CompositionSeriesOfFpGModules</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X7BECAE4182051B42">21.1-2 DirectSumOfFpGModules</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X7BADE250862DDD5F">21.1-3 FpGModule</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X834924DF873A86B3">21.1-4 FpGModuleDualBasis</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X851DB60D862610A5">21.1-5 FpGModuleHomomorphism</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X8380187081CE1237">21.1-6 DesuspensionFpGModule</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X87A9EA448236280E">21.1-7 RadicalOfFpGModule</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X87B150217D5AB909">21.1-8 RadicalSeriesOfFpGModule</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X7CEC4AFB8181D098">21.1-9 GeneratorsOfFpGModule</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X7AC4426279F2C004">21.1-10 ImageOfFpGModuleHomomorphism</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X85758F95832207D2">21.1-11 GroupAlgebraAsFpGModule</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X83D91CE68582A650">21.1-12 IntersectionOfFpGModules</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X7F1A1FA280D8C5D0">21.1-13 IsFpGModuleHomomorphismData</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X78F8BC20784828A7">21.1-14 MaximalSubmoduleOfFpGModule</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X85C8FD707F10C22F">21.1-15 MaximalSubmodulesOfFpGModule</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X7C94F977801C1B97">21.1-16 MultipleOfFpGModule</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X804F7A1B79BEC521">21.1-17 ProjectedFpGModule</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X822272997C4A8352">21.1-18 RandomHomomorphismOfFpGModules</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X827146F37E2AA841">21.1-19 Rank</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X7A6C598E82D5A7F8">21.1-20 SumOfFpGModules</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X86CAE52783D8E343">21.1-21 SumOp</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap21.html#X8290448D87105F0B">21.1-22 VectorsToFpGModuleWords</a></span>
</div></div>
</div>
<h3>21 <span class="Heading"> <span class="SimpleMath">FpG</span>-modules</span></h3>
<p><a id="X7CFDEEC07F15CF82" name="X7CFDEEC07F15CF82"></a></p>
<h4>21.1 <span class="Heading"> </span></h4>
<p><a id="X78A33AD27F99EF01" name="X78A33AD27F99EF01"></a></p>
<h5>21.1-1 CompositionSeriesOfFpGModules</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ CompositionSeriesOfFpGModules</code></td><td class="tdright">( global variable )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module <span class="SimpleMath">M</span> and returns a list of <span class="SimpleMath">FpG</span>-modules that constitute a composition series for <span class="SimpleMath">M</span>.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X7BECAE4182051B42" name="X7BECAE4182051B42"></a></p>
<h5>21.1-2 DirectSumOfFpGModules</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ DirectSumOfFpGModules</code>( <var class="Arg">M</var>, <var class="Arg">N</var> )</td><td class="tdright">( function )</td></tr></table></div>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ DirectSumOfFpGModules</code>( [<var class="Arg">M</var>[, <var class="Arg">1</var>], <var class="Arg">M</var>[, <var class="Arg">2</var>], <var class="Arg">...</var>, <var class="Arg">M</var>[, <var class="Arg">k</var>]] )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs two <span class="SimpleMath">FpG</span>-modules <span class="SimpleMath">M</span> and <span class="SimpleMath">N</span> with common group and characteristic. It returns the direct sum of <span class="SimpleMath">M</span> and <span class="SimpleMath">N</span> as an <span class="SimpleMath">FpG</span>-Module.</p>
<p>Alternatively, the function can input a list of <span class="SimpleMath">FpG</span>-modules with common group <span class="SimpleMath">G</span>. It returns the direct sum of the list.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X7BADE250862DDD5F" name="X7BADE250862DDD5F"></a></p>
<h5>21.1-3 FpGModule</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ FpGModule</code>( <var class="Arg">A</var>, <var class="Arg">P</var> )</td><td class="tdright">( function )</td></tr></table></div>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ FpGModule</code>( <var class="Arg">A</var>, <var class="Arg">G</var>, <var class="Arg">p</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs a <span class="SimpleMath">p</span>-group <span class="SimpleMath">P</span> and a matrix <span class="SimpleMath">A</span> whose rows have length a multiple of the order of <span class="SimpleMath">G</span>. It returns the <q>canonical</q> <span class="SimpleMath">FpG</span>-module generated by the rows of <span class="SimpleMath">A</span>.</p>
<p>A small non-prime-power group <span class="SimpleMath">G</span> can also be input, provided the characteristic <span class="SimpleMath">p</span> is entered as a third input variable.</p>
<p><strong class="button">Examples:</strong> <span class="URL"><a href="../tutorial/chap11.html">1</a></span> , <span class="URL"><a href="../www/SideLinks/About/aboutAbelianCategories.html">2</a></span> , <span class="URL"><a href="../www/SideLinks/About/aboutIntro.html">3</a></span> , <span class="URL"><a href="../www/SideLinks/About/aboutTorAndExt.html">4</a></span> </p>
<p><a id="X834924DF873A86B3" name="X834924DF873A86B3"></a></p>
<h5>21.1-4 FpGModuleDualBasis</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ FpGModuleDualBasis</code>( <var class="Arg">M</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module <span class="SimpleMath">M</span>. It returns a record <span class="SimpleMath">R</span> with two components:</p>
<ul>
<li><p><span class="SimpleMath">R.freeModule</span> is the free module <span class="SimpleMath">FG</span> of rank one.</p>
</li>
<li><p><span class="SimpleMath">R.basis</span> is a list representing an <span class="SimpleMath">F</span>-basis for the module <span class="SimpleMath">Hom_FG(M,FG)</span>. Each term in the list is a matrix <span class="SimpleMath">A</span> whose rows are vectors in <span class="SimpleMath">FG</span> such that <span class="SimpleMath">M!.generators[i] ⟶ A[i]</span> extends to a module homomorphism <span class="SimpleMath">M ⟶ FG</span>.</p>
</li>
</ul>
<p><strong class="button">Examples:</strong></p>
<p><a id="X851DB60D862610A5" name="X851DB60D862610A5"></a></p>
<h5>21.1-5 FpGModuleHomomorphism</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ FpGModuleHomomorphism</code>( <var class="Arg">M</var>, <var class="Arg">N</var>, <var class="Arg">A</var> )</td><td class="tdright">( function )</td></tr></table></div>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ FpGModuleHomomorphismNC</code>( <var class="Arg">M</var>, <var class="Arg">N</var>, <var class="Arg">A</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs <span class="SimpleMath">FpG</span>-modules <span class="SimpleMath">M</span> and <span class="SimpleMath">N</span> over a common <span class="SimpleMath">p</span>-group <span class="SimpleMath">G</span>. Also inputs a list <span class="SimpleMath">A</span> of vectors in the vector space spanned by <span class="SimpleMath">N!.matrix</span>. It tests that the function</p>
<p><span class="SimpleMath">M!.generators[i] ⟶ A[i]</span></p>
<p>extends to a homomorphism of <span class="SimpleMath">FpG</span>-modules and, if the test is passed, returns the corresponding <span class="SimpleMath">FpG</span>-module homomorphism. If the test is failed it returns fail.</p>
<p>The "NC" version of the function assumes that the input defines a homomorphism and simply returns the <span class="SimpleMath">FpG</span>-module homomorphism.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X8380187081CE1237" name="X8380187081CE1237"></a></p>
<h5>21.1-6 DesuspensionFpGModule</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ DesuspensionFpGModule</code>( <var class="Arg">M</var>, <var class="Arg">n</var> )</td><td class="tdright">( function )</td></tr></table></div>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ DesuspensionFpGModule</code>( <var class="Arg">R</var>, <var class="Arg">n</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs a positive integer <span class="SimpleMath">n</span> and and FpG-module <span class="SimpleMath">M</span>. It returns an FpG-module <span class="SimpleMath">D^nM</span> which is mathematically related to <span class="SimpleMath">M</span> via an exact sequence <span class="SimpleMath">0 ⟶ D^nM ⟶ R_n ⟶ ... ⟶ R_0 ⟶ M ⟶ 0</span> where <span class="SimpleMath">R_∗</span> is a free resolution. (If <span class="SimpleMath">G=Group(M)</span> is of prime-power order then the resolution is minimal.)</p>
<p>Alternatively, the function can input a positive integer <span class="SimpleMath">n</span> and at least <span class="SimpleMath">n</span> terms of a free resolution <span class="SimpleMath">R</span> of <span class="SimpleMath">M</span>.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X87A9EA448236280E" name="X87A9EA448236280E"></a></p>
<h5>21.1-7 RadicalOfFpGModule</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ RadicalOfFpGModule</code>( <var class="Arg">M</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module <span class="SimpleMath">M</span> with <span class="SimpleMath">G</span> a <span class="SimpleMath">p</span>-group, and returns the Radical of <span class="SimpleMath">M</span> as an <span class="SimpleMath">FpG</span>-module. (Ig <span class="SimpleMath">G</span> is not a <span class="SimpleMath">p</span>-group then a submodule of the radical is returned.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X87B150217D5AB909" name="X87B150217D5AB909"></a></p>
<h5>21.1-8 RadicalSeriesOfFpGModule</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ RadicalSeriesOfFpGModule</code>( <var class="Arg">M</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module <span class="SimpleMath">M</span> and returns a list of <span class="SimpleMath">FpG</span>-modules that constitute the radical series for <span class="SimpleMath">M</span>.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X7CEC4AFB8181D098" name="X7CEC4AFB8181D098"></a></p>
<h5>21.1-9 GeneratorsOfFpGModule</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ GeneratorsOfFpGModule</code>( <var class="Arg">M</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module <span class="SimpleMath">M</span> and returns a matrix whose rows correspond to a minimal generating set for <span class="SimpleMath">M</span>.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X7AC4426279F2C004" name="X7AC4426279F2C004"></a></p>
<h5>21.1-10 ImageOfFpGModuleHomomorphism</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ ImageOfFpGModuleHomomorphism</code>( <var class="Arg">f</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module homomorphism <span class="SimpleMath">f:M ⟶ N</span> and returns its image <span class="SimpleMath">f(M)</span> as an <span class="SimpleMath">FpG</span>-module.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X85758F95832207D2" name="X85758F95832207D2"></a></p>
<h5>21.1-11 GroupAlgebraAsFpGModule</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ GroupAlgebraAsFpGModule</code>( <var class="Arg">G</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs a <span class="SimpleMath">p</span>-group <span class="SimpleMath">G</span> and returns its mod <span class="SimpleMath">p</span> group algebra as an <span class="SimpleMath">FpG</span>-module.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X83D91CE68582A650" name="X83D91CE68582A650"></a></p>
<h5>21.1-12 IntersectionOfFpGModules</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ IntersectionOfFpGModules</code>( <var class="Arg">M</var>, <var class="Arg">N</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs two <span class="SimpleMath">FpG</span>-modules <span class="SimpleMath">M, N</span> arising as submodules in a common free module <span class="SimpleMath">(FG)^n</span> where <span class="SimpleMath">G</span> is a finite group and <span class="SimpleMath">F</span> the field of <span class="SimpleMath">p</span>-elements. It returns the <span class="SimpleMath">FpG</span>-module arising as the intersection of <span class="SimpleMath">M</span> and <span class="SimpleMath">N</span>.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X7F1A1FA280D8C5D0" name="X7F1A1FA280D8C5D0"></a></p>
<h5>21.1-13 IsFpGModuleHomomorphismData</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ IsFpGModuleHomomorphismData</code>( <var class="Arg">M</var>, <var class="Arg">N</var>, <var class="Arg">A</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs <span class="SimpleMath">FpG</span>-modules <span class="SimpleMath">M</span> and <span class="SimpleMath">N</span> over a common <span class="SimpleMath">p</span>-group <span class="SimpleMath">G</span>. Also inputs a list <span class="SimpleMath">A</span> of vectors in the vector space spanned by <span class="SimpleMath">N!.matrix</span>. It returns true if the function</p>
<p><span class="SimpleMath">M!.generators[i] ⟶ A[i]</span></p>
<p>extends to a homomorphism of <span class="SimpleMath">FpG</span>-modules. Otherwise it returns false.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X78F8BC20784828A7" name="X78F8BC20784828A7"></a></p>
<h5>21.1-14 MaximalSubmoduleOfFpGModule</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ MaximalSubmoduleOfFpGModule</code>( <var class="Arg">M</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module <span class="SimpleMath">M</span> and returns one maximal <span class="SimpleMath">FpG</span>-submodule of <span class="SimpleMath">M</span>.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X85C8FD707F10C22F" name="X85C8FD707F10C22F"></a></p>
<h5>21.1-15 MaximalSubmodulesOfFpGModule</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ MaximalSubmodulesOfFpGModule</code>( <var class="Arg">M</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module <span class="SimpleMath">M</span> and returns the list of maximal <span class="SimpleMath">FpG</span>-submodules of <span class="SimpleMath">M</span>.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X7C94F977801C1B97" name="X7C94F977801C1B97"></a></p>
<h5>21.1-16 MultipleOfFpGModule</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ MultipleOfFpGModule</code>( <var class="Arg">w</var>, <var class="Arg">M</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module <span class="SimpleMath">M</span> and a list <span class="SimpleMath">w:=[g_1 , ..., g_t]</span> of elements in the group <span class="SimpleMath">G=M!.group</span>. The list <span class="SimpleMath">w</span> can be thought of as representing the element <span class="SimpleMath">w=g_1 + ... + g_t</span> in the group algebra <span class="SimpleMath">FG</span>, and the function returns a semi-echelon matrix <span class="SimpleMath">B</span> which is a basis for the vector subspace <span class="SimpleMath">wM</span> .</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X804F7A1B79BEC521" name="X804F7A1B79BEC521"></a></p>
<h5>21.1-17 ProjectedFpGModule</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ ProjectedFpGModule</code>( <var class="Arg">M</var>, <var class="Arg">k</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module <span class="SimpleMath">M</span> of ambient dimension <span class="SimpleMath">n|G|</span>, and an integer <span class="SimpleMath">k</span> between <span class="SimpleMath">1</span> and <span class="SimpleMath">n</span>. The module <span class="SimpleMath">M</span> is a submodule of the free module <span class="SimpleMath">(FG)^n</span> . Let <span class="SimpleMath">M_k</span> denote the intersection of <span class="SimpleMath">M</span> with the last <span class="SimpleMath">k</span> summands of <span class="SimpleMath">(FG)^n</span> . The function returns the image of the projection of <span class="SimpleMath">M_k</span> onto the <span class="SimpleMath">k</span>-th summand of <span class="SimpleMath">(FG)^n</span> . This image is returned an <span class="SimpleMath">FpG</span>-module with ambient dimension <span class="SimpleMath">|G|</span>.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X822272997C4A8352" name="X822272997C4A8352"></a></p>
<h5>21.1-18 RandomHomomorphismOfFpGModules</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ RandomHomomorphismOfFpGModules</code>( <var class="Arg">M</var>, <var class="Arg">N</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs two <span class="SimpleMath">FpG</span>-modules <span class="SimpleMath">M</span> and <span class="SimpleMath">N</span> over a common group <span class="SimpleMath">G</span>. It returns a random matrix <span class="SimpleMath">A</span> whose rows are vectors in <span class="SimpleMath">N</span> such that the function</p>
<p><span class="SimpleMath">M!.generators[i] ⟶ A[i]</span></p>
<p>extends to a homomorphism <span class="SimpleMath">M ⟶ N</span> of <span class="SimpleMath">FpG</span>-modules. (There is a problem with this function at present.)</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X827146F37E2AA841" name="X827146F37E2AA841"></a></p>
<h5>21.1-19 Rank</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ Rank</code>( <var class="Arg">f</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module homomorphism <span class="SimpleMath">f:M ⟶ N</span> and returns the dimension of the image of <span class="SimpleMath">f</span> as a vector space over the field <span class="SimpleMath">F</span> of <span class="SimpleMath">p</span> elements.</p>
<p><strong class="button">Examples:</strong> <span class="URL"><a href="../tutorial/chap1.html">1</a></span> , <span class="URL"><a href="../tutorial/chap7.html">2</a></span> , <span class="URL"><a href="../www/SideLinks/About/aboutPeriodic.html">3</a></span> </p>
<p><a id="X7A6C598E82D5A7F8" name="X7A6C598E82D5A7F8"></a></p>
<h5>21.1-20 SumOfFpGModules</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ SumOfFpGModules</code>( <var class="Arg">M</var>, <var class="Arg">N</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs two <span class="SimpleMath">FpG</span>-modules <span class="SimpleMath">M, N</span> arising as submodules in a common free module <span class="SimpleMath">(FG)^n</span> where <span class="SimpleMath">G</span> is a finite group and <span class="SimpleMath">F</span> the field of <span class="SimpleMath">p</span>-elements. It returns the <span class="SimpleMath">FpG</span>-Module arising as the sum of <span class="SimpleMath">M</span> and <span class="SimpleMath">N</span>.</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X86CAE52783D8E343" name="X86CAE52783D8E343"></a></p>
<h5>21.1-21 SumOp</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ SumOp</code>( <var class="Arg">f</var>, <var class="Arg">g</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs two <span class="SimpleMath">FpG</span>-module homomorphisms <span class="SimpleMath">f,g:M ⟶ N</span> with common sorce and common target. It returns the sum <span class="SimpleMath">f+g:M ⟶ N</span> . (This operation is also available using "+".</p>
<p><strong class="button">Examples:</strong></p>
<p><a id="X8290448D87105F0B" name="X8290448D87105F0B"></a></p>
<h5>21.1-22 VectorsToFpGModuleWords</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ VectorsToFpGModuleWords</code>( <var class="Arg">M</var>, <var class="Arg">L</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Inputs an <span class="SimpleMath">FpG</span>-module <span class="SimpleMath">M</span> and a list <span class="SimpleMath">L=[v_1,... ,v_k]</span> of vectors in <span class="SimpleMath">M</span>. It returns a list <span class="SimpleMath">L'= [x_1,...,x_k]</span> . Each <span class="SimpleMath">x_j=[[W_1,G_1],...,[W_t,G_t]]</span> is a list of integer pairs corresponding to an expression of <span class="SimpleMath">v_j</span> as a word</p>
<p><span class="SimpleMath">v_j = g_1*w_1 + g_2*w_1 + ... + g_t*w_t</span></p>
<p>where</p>
<p><span class="SimpleMath">g_i=Elements(M!.group)[G_i]</span></p>
<p><span class="SimpleMath">w_i=GeneratorsOfFpGModule(M)[W_i]</span> .</p>
<p><strong class="button">Examples:</strong></p>
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