Let D be a division ring with center F and the multiplicative group D∗
. The
subgroup structure of D∗
is one of subjects which attract the attention of many
authors around the world 1, 2, 48, 13, 14, 16, 19, 22, 23, 26, 28 ...
Some wellknown classical results show that subnormal subgroups of D∗ beha[r]