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On subgroups of amalgamated free products

Published online by Cambridge University Press:  24 October 2008

Edward T. Ordman
Edward T. Ordman
Affiliation:
University of Kentucky, Lexington, Kentucky, U.S.A.
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Extract

In 1934 Kurosh(9) proved that ‘a subgroup of a free product of groups is again a free product’. Many other proofs of this, and attempts to generalize it to amalgamated free products, have appeared (e.g. (7), (1), (10) and (8)). Recently the theory of groupoids has been applied to this area with increasing success. In 1966 Higgins (6) used groupoids to prove the generalization of Grushko's Theorem (3) due to Wagner (14).

Type
Research Article
Information
Mathematical Proceedings of the Cambridge Philosophical Society , Volume 69 , Issue 1 , January 1971 , pp. 13 - 23
Copyright
Copyright © Cambridge Philosophical Society 1971

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References

REFERENCES

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