we observe that the transform, with respect to any operator of 6r, of the commutators formed with t and the operators of G is the product of two such commutators. All of these commutators must, therefore, form a group which is transformed into itself by G. When t transforms G into itself the given commutators generate the smallest self-conjugate subgroup of G which has the property that all of ...

We show that the normal closure of any periodic element mapping class group a nonorientable surface whose order is greater than 2 contains commutator subgroup, which for g≥7 equal to twist and provide necessary sufficient conditions closures involutions contain subgroup. Finally, we criterion normally generate M(Ng) give examples.

In this paper, we present a characterization of groups [Formula: see text] order text], prime, in which not all elements the commutator subgroup are commutators text]. way, obtain several structural results on