20D15 20D10 5 20D20 3 20D30 2 \(\sigma\)-nilpotent group 2 finite group 2 20D99 1 Finite group; cover-avoidance property; \(p\)-supersoluble groups; saturated formation 1 Hall \(S\)-permutably embedded subgroup 1 Schmidt subgroup 1 Sylow subgroup 1 \(K\)-lattice saturated formation 1 \(P\sigma T\)-group 1 \(S\)-permutable closure 1 \(S\)-permutable subgroup 1 \(\cal F\) -critical group,\(\cal F\) -maximal subgroup 1 \(\cal F\)-hypercentre 1 \(\sigma\)-permutable subgroup 1 \(\sigma\)-soluble group 1 \(p\)-groups 1 boundary condition 1 coclass 1 finite groups 1 hereditary formation 1 maximal subgroup 1 nilpotent group 1 saturated formation 1 soluble group 1 supersoluble group 1 supersolublegroup 1