AbstractsMathematics

The problem of normal extensions in groups (see Kurosh [1] Chapter XII) has been studied in considerable detail and has reached the point of a reasonable solution. The corresponding problem of general extensions in groups, although studied quite extensively, has not yet reached that point. The aim of the present thesis is to generalise some of the results obtained in the case of normal extensions to the general case. It was proved by Baer [1] that the cosets of a group H modulo an arbitrary subgroup G can be given a structure called a mixed group.