“…Given a group G, two subgroups H and K of G are said to permute if HK ¼ KH, that is, if HK is a subgroup of G. A subgroup H of G is said to be quasinormal in G if it permutes with every subgroup of G. A subgroup H of G is said to be S-quasinormal in G if it permutes with every Sylow subgroup of G. This concept was introduced by Kegel in 1962 and it has been investigated by many authors; see, for example, [1], [3]- [9], [13], [18]- [23], [25]. Recently, in [5], [8], Ballester-Bolinches and Pedraza-Aguilera extended these concepts to quasinormally and S-quasinormally embedded subgroups. A subgroup H of G is quasinormally (resp.…”