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The embeddability of ring and semigroup amalgams is undecidable

Published online by Cambridge University Press:  09 April 2009

Marcel Jackson
Affiliation:
Discipline of Mathematics University of TasmaniaGPO Box 252-37 Hobart 7001Australia email: marcel_j@hilbert.maths.utas.edu.au Department of Mathematics La Trobe UniversityBundoora VIC 3083Australia e-mail: m.g.jackson@latrobe.edu.au
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Abstract

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We prove that there is no algorithm to determine when an amalgam of finite rings (or semigroups) can be embedded in the class of rings or in the class of finite rings (respectively, in the class of semigroups or in the class of finite semigroups). These results are in marked contrast with the corresponding problems for groups where every amalgam of finite groups can be embedded in a finite group.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 2000

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