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On one-relator groups having elements of finite order

Authors: J. Fischer, A. Karrass and D. Solitar
Journal: Proc. Amer. Math. Soc. 33 (1972), 297-301
MSC: Primary 20F05
MathSciNet review: 0311780
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Abstract: Let G be a one-relator group having torsion. It is easy to show that there exists a normal subgroup N which is of finite index and torsion-free. We prove that N is free iff G is the free product of a free group and a finite cyclic group; N is a proper free product iff G is a proper free product of a free group and a one-relator group. In the proof, use is made of the following result: the elements of finite order in G generate a group which is the free product of conjugates of a finite cyclic group.

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Keywords: One-relator groups, free products
Article copyright: © Copyright 1972 American Mathematical Society

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