On some invariants of finite groups

A normal subgroup N of a group G is said to be an‎ omissible subgroup of G if it has the following property‎: ‎whenever X\leq G is such that G=XN‎, ‎then G=X‎. ‎In this note we construct various groups G‎, ‎each of which has an omissible subgroup N\neq ۱ such that G/N\cong SL_۲(k) where k is a field of positive characteristic‎.

کلیدواژه ها:

generating set ، independent set ، (p ، q)-group ، lattice of subgroups