Difference between revisions of "ApCoCoA-1:Cyclic groups"

From ApCoCoAWiki
Line 42: Line 42:
 
   <Comment>Cyclic_group_5</Comment>
 
   <Comment>Cyclic_group_5</Comment>
 
   </FREEALGEBRA>
 
   </FREEALGEBRA>
=====Cyclic group 6=====
+
=====cyclic group 6=====
 
   <FREEALGEBRA createdAt="2014-03-02" createdBy="strohmeier">
 
   <FREEALGEBRA createdAt="2014-03-02" createdBy="strohmeier">
  <vars>a</vars>
+
    <vars>a</vars>
  <basis>
+
    <basis>
  <ncpoly>a^6-1</ncpoly>
+
    <ncpoly>a^6-1</ncpoly>
  </basis>
+
    </basis>
  <Comment>Cyclic_group_6</Comment>
+
    <Comment>Cyclic_group_6</Comment>
 
   </FREEALGEBRA>
 
   </FREEALGEBRA>

Revision as of 14:01, 6 March 2014

Description

Every cyclic group is generated by a single element a. If n is finite the group is isomorphic to Z/nZ, otherwise it can be interpreted as Z with the addition of integers as the group operation. For every cyclic group there only exists one subgroup containing a, the group itself.

C(n) = <a | a^{n} = 1>

Reference

Joseph A. Gallian, Contemporary Abstract Algebra (4th ed.), Boston: Houghton Mifflin, Chapter 4, 1998.

Computation

 /*Use the ApCoCoA package ncpoly.*/
 
 // Number of cyclic group
 MEMORY.N:=5;
 
 Use ZZ/(2)[a];
 NC.SetOrdering("LLEX");
 
 Define CreateRelationsCyclic()
   Relations:=[];
   // Add relation a^n = 1
   Append(Relations,[[a^MEMORY.N],[1]]);
   Return Relations;
 EndDefine;
 
 Relations:=CreateRelationsCyclic();
 Relations;
 
 // Compute a Groebner Basis.
 Gb:=NC.GB(Relations);
 Gb;
 // RESULT for MEMORY.N = 5 :: [[[a^5], [1]]]

Examples in Symbolic Data format

Cyclic group 5
 <FREEALGEBRA createdAt="2014-03-02" createdBy="strohmeier">
 	<vars>a</vars>
 	<basis>
 	<ncpoly>a^5-1</ncpoly>
 	</basis>
 	<Comment>Cyclic_group_5</Comment>
 </FREEALGEBRA>
cyclic group 6
 <FREEALGEBRA createdAt="2014-03-02" createdBy="strohmeier">
 	  <vars>a</vars>
 	  <basis>
 	  <ncpoly>a^6-1</ncpoly>
 	  </basis>
 	  <Comment>Cyclic_group_6</Comment>
 </FREEALGEBRA>