Undecidability of the word problem for Yamamura’s HNN-extension under nice conditions

dc.contributor.author	Abu Ayyash, Mohammed
dc.contributor.author	Rodaro, Emanuele
dc.date.accessioned	2018-09-14T09:33:13Z
dc.date.available	2018-09-14T09:33:13Z
dc.date.issued	2016-04
dc.identifier.issn	0037-1912
dc.identifier.uri	http://dspace.bethlehem.edu:8080/xmlui/handle/123456789/65
dc.description.abstract	The solvability of the word problem for Yamamura’s HNN-extensions [S; A1, A2; ϕ] has been proved in some particular cases. However, we show that, contrary to the group case, the word problem for [S; A1A2; ϕ] is undecidable even if we consider S to have finite R-classes, A1 and A2 to be free inverse subsemigroups of finite rank and with zero, and ϕ , ϕ−1 to be computable.	en_US
dc.description.sponsorship	Italian Ministry of Foreign Affairs and Bethlehem University through the Italian project E-PLUS, and also acknowledges the PRIN project 2011 “Automi e Linguaggi Formali: Aspetti Matematici e Applicativi”	en_US
dc.language.iso	en	en_US
dc.publisher	Semigroup Forum	en_US
dc.relation.ispartofseries	DOI 10.1007/s00233-015-9750-0;
dc.subject	HNN-extension · Inverse Semigroups · Word Problem · Undecidability · Amalgams of Inverse Semigroups	en_US
dc.title	Undecidability of the word problem for Yamamura’s HNN-extension under nice conditions	en_US
dc.type	Article	en_US