On the structure of subgroups of a nilpotent nonperiodic group

The structural characteristic of the normal divisor in a locally nilpotent torsion-free group is given. Moreover, a property of structural isomorphisms of locally nilpotent groups containing no less than two independent elements of infinite order is proved: if H is the subgroup of the mentioned group G, N(H) is its normalizer in G, and is a structural isomorphism of the group G, then N(H) = N(H ).Translated from Matematicheskie Zametki, Vol. 11, No. 4, pp. 389–396, April, 1972.