permutable subgroup
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permutable subgroups
Let be a group.A subgroup of is said to be permutableif it permutes with all subgroups of ,that is, for all .We sometimes write to indicate that is a permutable subgroup of .
Permutable subgroups were introduced by Øystein Ore (http://planetmath.org/OysteinOre),who called them quasinormal subgroups.
Normal subgroups are clearly permutable.
Permutable subgroups are ascendant.This is a result of Stonehewer[1],who also showed that in a finitely generated group,all permutable subgroups are subnormal.
References
- 1 Stewart E. Stonehewer,Permutable subgroups of infinite groups,Math. Z. 125 (1972), 1–16. (This paper is http://gdz.sub.uni-goettingen.de/dms/resolveppn/?GDZPPN002410435available from GDZ.)