Math 2.0

example

The Klein four-group is abelian but not cyclic

Example

The Klein four-group is V={e,a,b,c}V = \{e, a, b, c\}, where a2=b2=c2=ea^2 = b^2 = c^2 = e and ab=ba=cab = ba = c. The group is abelian. Each element that is not ee has order 22. Thus each element generates a subgroup with at most 22 elements. No element generates all 44 elements, so VV is not cyclic.

Remarks

Thus the converse of the result that cyclic groups are abelian is false. Up to isomorphism, VV and Z/4Z\mathbb{Z}/4\mathbb{Z} are the only groups of order 44.

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  1. Binary operation definition
  2. Group concept
  3. Commutativity definition
  4. Direct product of groups definition
  5. Laws of exponents in a group statement
  6. Abelian group definition
  7. Order of an element definition
  8. Klein four-group object
  9. The Klein four-group is abelian but not cyclic example

Sources

  1. Web https://en.wikipedia.org/wiki/Klein_four-group, lead section