public Group <T> Centralizer(FiniteSet <T> subset)
{
return(this.Subgroup(new FiniteSet <T>(_set.Where(g => subset.All(s => _product(g, s).Equals(_product(s, g))))), false));
}
/// <summary>
/// Returns the center Z(G) of the group.
/// </summary>
public Group <T> Center()
{
return(this.Subgroup(new FiniteSet <T>(_set.Where(z => _set.All(g => _product(z, g).Equals(_product(g, z))))), false));
}
