ApCoCoA-1:Free groups

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Revision as of 08:09, 16 August 2013 by F lorenz (talk | contribs) (New page: === <div id="Free_groups">Free groups</div> === ==== Description ==== F(n) = <a_{1},...,a_{n} | a_{i}a_{i}^{-1} = a_{i}^{-1}a_{i} = 1> (Reference:...)
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Description

 F(n) = <a_{1},...,a_{n} | a_{i}a_{i}^{-1} = a_{i}^{-1}a_{i} = 1>

(Reference: Kharlampovich, Olga; Myasnikov, Alexei (2006). "Elementary theory of free non-abelian groups". J. Algebra 302 (2): 451–552)

Computation

 /*Use the ApCoCoA package ncpoly.*/
 
 // Number of free  group
 
 MEMORY.N:=4;
 
 Use ZZ/(2)[x[1..MEMORY.N],y[1..MEMORY.N]];
 NC.SetOrdering("LLEX");
 Define CreateRelationsFreeAbelian()
   Relations:=[];
   For Index1 := 1 To MEMORY.N Do
     Append(Relations,[[x[Index1],y[Index1]],[1]]);
     Append(Relations,[[y[Index1],x[Index1]],[1]]);
   EndFor;
   Return Relations;
 EndDefine;
 
 Relations:=CreateRelationsFreeAbelian();
 Relations;
 GB:=NC.GB(Relations);
 GB;