{"id":"https://openalex.org/W2965381168","doi":"https://doi.org/10.1007/978-3-030-24886-4_22","title":"Context-free word problem semigroups","display_name":"Context-free word problem semigroups","publication_year":2019,"publication_date":"2019-01-01","ids":{"openalex":"https://openalex.org/W2965381168","doi":"https://doi.org/10.1007/978-3-030-24886-4_22","mag":"2965381168"},"language":"en","primary_location":{"id":"pmh:oai:run.unl.pt:10362/97735","is_oa":true,"landing_page_url":"http://hdl.handle.net/10362/97735","pdf_url":"https://run.unl.pt/bitstreams/cf214908-c99a-467f-bb86-9b57d0688ee7/download","source":{"id":"https://openalex.org/S4306401014","display_name":"New University of Lisbon's Repository (New University of Lisbon)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"conference object"},"type":"article","indexed_in":[],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"https://run.unl.pt/bitstreams/cf214908-c99a-467f-bb86-9b57d0688ee7/download","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5027083615","display_name":"Tara Brough","orcid":"https://orcid.org/0000-0002-3576-0670"},"institutions":[{"id":"https://openalex.org/I83558840","display_name":"Universidade Nova de Lisboa","ror":"https://ror.org/02xankh89","country_code":"PT","type":"education","lineage":["https://openalex.org/I83558840"]}],"countries":["PT"],"is_corresponding":false,"raw_author_name":"Brough, Tara","raw_affiliation_strings":["Centro de Matem\u00e1tica e Aplica\u00e7\u00f5es , Faculdade de Ci\u00eancias e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal","Centro de Matem\u00e1tica e Aplica\u00e7\u00f5es, Faculdade de Ci\u00eancias e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Centro de Matem\u00e1tica e Aplica\u00e7\u00f5es , Faculdade de Ci\u00eancias e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal","institution_ids":["https://openalex.org/I83558840"]},{"raw_affiliation_string":"Centro de Matem\u00e1tica e Aplica\u00e7\u00f5es, Faculdade de Ci\u00eancias e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal","institution_ids":["https://openalex.org/I83558840"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5055005423","display_name":"Alan J. Cain","orcid":"https://orcid.org/0000-0002-0706-1354"},"institutions":[{"id":"https://openalex.org/I83558840","display_name":"Universidade Nova de Lisboa","ror":"https://ror.org/02xankh89","country_code":"PT","type":"education","lineage":["https://openalex.org/I83558840"]}],"countries":["PT"],"is_corresponding":false,"raw_author_name":"Cain, Alan J.","raw_affiliation_strings":["Centro de Matem\u00e1tica e Aplica\u00e7\u00f5es , Faculdade de Ci\u00eancias e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal","Centro de Matem\u00e1tica e Aplica\u00e7\u00f5es, Faculdade de Ci\u00eancias e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Centro de Matem\u00e1tica e Aplica\u00e7\u00f5es , Faculdade de Ci\u00eancias e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal","institution_ids":["https://openalex.org/I83558840"]},{"raw_affiliation_string":"Centro de Matem\u00e1tica e Aplica\u00e7\u00f5es, Faculdade de Ci\u00eancias e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal","institution_ids":["https://openalex.org/I83558840"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5084522629","display_name":"Markus Pfeiffer","orcid":"https://orcid.org/0000-0002-9881-4429"},"institutions":[{"id":"https://openalex.org/I16835326","display_name":"University of St Andrews","ror":"https://ror.org/02wn5qz54","country_code":"GB","type":"education","lineage":["https://openalex.org/I16835326"]}],"countries":["GB"],"is_corresponding":false,"raw_author_name":"Pfeiffer, Markus","raw_affiliation_strings":["School of Computer Science , University of St Andrews , North Haugh , St Andrews , Fife KY16 9SS , United Kingdom","School of Computer Science, University of St\u00a0Andrews, North Haugh, St\u00a0Andrews, Fife, KY16 9SS, UK"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"School of Computer Science , University of St Andrews , North Haugh , St Andrews , Fife KY16 9SS , United Kingdom","institution_ids":["https://openalex.org/I16835326"]},{"raw_affiliation_string":"School of Computer Science, University of St\u00a0Andrews, North Haugh, St\u00a0Andrews, Fife, KY16 9SS, UK","institution_ids":["https://openalex.org/I16835326"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":2,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":0.1777,"has_fulltext":true,"cited_by_count":3,"citation_normalized_percentile":{"value":0.53118628,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":89,"max":95},"biblio":{"volume":null,"issue":null,"first_page":null,"last_page":null},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11567","display_name":"semigroups and automata theory","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/1703","display_name":"Computational Theory and Mathematics"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T11567","display_name":"semigroups and automata theory","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/1703","display_name":"Computational Theory and Mathematics"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10304","display_name":"Geometric and Algebraic Topology","score":0.9983000159263611,"subfield":{"id":"https://openalex.org/subfields/2608","display_name":"Geometry and Topology"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10181","display_name":"Natural Language Processing Techniques","score":0.9955999851226807,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/monoid","display_name":"Monoid","score":0.7597478628158569},{"id":"https://openalex.org/keywords/semigroup","display_name":"Semigroup","score":0.7581011056900024},{"id":"https://openalex.org/keywords/context","display_name":"Context (archaeology)","score":0.7070263624191284},{"id":"https://openalex.org/keywords/automaticity","display_name":"Automaticity","score":0.670986533164978},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.6488238573074341},{"id":"https://openalex.org/keywords/word","display_name":"Word (group theory)","score":0.6467546224594116},{"id":"https://openalex.org/keywords/word-problem","display_name":"Word problem (mathematics education)","score":0.5745344161987305},{"id":"https://openalex.org/keywords/connection","display_name":"Connection (principal bundle)","score":0.4942455589771271},{"id":"https://openalex.org/keywords/algebra-over-a-field","display_name":"Algebra over a field","score":0.418315589427948},{"id":"https://openalex.org/keywords/arithmetic","display_name":"Arithmetic","score":0.36188411712646484},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.35021042823791504},{"id":"https://openalex.org/keywords/discrete-mathematics","display_name":"Discrete mathematics","score":0.28149107098579407},{"id":"https://openalex.org/keywords/pure-mathematics","display_name":"Pure mathematics","score":0.21931955218315125},{"id":"https://openalex.org/keywords/history","display_name":"History","score":0.04950401186943054},{"id":"https://openalex.org/keywords/psychology","display_name":"Psychology","score":0.04424479603767395}],"concepts":[{"id":"https://openalex.org/C206901836","wikidata":"https://www.wikidata.org/wiki/Q208237","display_name":"Monoid","level":2,"score":0.7597478628158569},{"id":"https://openalex.org/C207405024","wikidata":"https://www.wikidata.org/wiki/Q207348","display_name":"Semigroup","level":2,"score":0.7581011056900024},{"id":"https://openalex.org/C2779343474","wikidata":"https://www.wikidata.org/wiki/Q3109175","display_name":"Context (archaeology)","level":2,"score":0.7070263624191284},{"id":"https://openalex.org/C33002781","wikidata":"https://www.wikidata.org/wiki/Q4826617","display_name":"Automaticity","level":3,"score":0.670986533164978},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.6488238573074341},{"id":"https://openalex.org/C90805587","wikidata":"https://www.wikidata.org/wiki/Q10944557","display_name":"Word (group theory)","level":2,"score":0.6467546224594116},{"id":"https://openalex.org/C90988201","wikidata":"https://www.wikidata.org/wiki/Q255912","display_name":"Word problem (mathematics education)","level":2,"score":0.5745344161987305},{"id":"https://openalex.org/C13355873","wikidata":"https://www.wikidata.org/wiki/Q2920850","display_name":"Connection (principal bundle)","level":2,"score":0.4942455589771271},{"id":"https://openalex.org/C136119220","wikidata":"https://www.wikidata.org/wiki/Q1000660","display_name":"Algebra over a field","level":2,"score":0.418315589427948},{"id":"https://openalex.org/C94375191","wikidata":"https://www.wikidata.org/wiki/Q11205","display_name":"Arithmetic","level":1,"score":0.36188411712646484},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.35021042823791504},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.28149107098579407},{"id":"https://openalex.org/C202444582","wikidata":"https://www.wikidata.org/wiki/Q837863","display_name":"Pure mathematics","level":1,"score":0.21931955218315125},{"id":"https://openalex.org/C95457728","wikidata":"https://www.wikidata.org/wiki/Q309","display_name":"History","level":0,"score":0.04950401186943054},{"id":"https://openalex.org/C15744967","wikidata":"https://www.wikidata.org/wiki/Q9418","display_name":"Psychology","level":0,"score":0.04424479603767395},{"id":"https://openalex.org/C166957645","wikidata":"https://www.wikidata.org/wiki/Q23498","display_name":"Archaeology","level":1,"score":0.0},{"id":"https://openalex.org/C2524010","wikidata":"https://www.wikidata.org/wiki/Q8087","display_name":"Geometry","level":1,"score":0.0},{"id":"https://openalex.org/C169900460","wikidata":"https://www.wikidata.org/wiki/Q2200417","display_name":"Cognition","level":2,"score":0.0},{"id":"https://openalex.org/C169760540","wikidata":"https://www.wikidata.org/wiki/Q207011","display_name":"Neuroscience","level":1,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"pmh:oai:run.unl.pt:10362/97735","is_oa":true,"landing_page_url":"http://hdl.handle.net/10362/97735","pdf_url":"https://run.unl.pt/bitstreams/cf214908-c99a-467f-bb86-9b57d0688ee7/download","source":{"id":"https://openalex.org/S4306401014","display_name":"New University of Lisbon's Repository (New University of Lisbon)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"conference object"}],"best_oa_location":{"id":"pmh:oai:run.unl.pt:10362/97735","is_oa":true,"landing_page_url":"http://hdl.handle.net/10362/97735","pdf_url":"https://run.unl.pt/bitstreams/cf214908-c99a-467f-bb86-9b57d0688ee7/download","source":{"id":"https://openalex.org/S4306401014","display_name":"New University of Lisbon's Repository (New University of Lisbon)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"conference object"},"sustainable_development_goals":[{"display_name":"Reduced inequalities","score":0.49000000953674316,"id":"https://metadata.un.org/sdg/10"}],"awards":[{"id":"https://openalex.org/G5454278309","display_name":null,"funder_award_id":"/2017","funder_id":"https://openalex.org/F4320334779","funder_display_name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia"},{"id":"https://openalex.org/G5986682413","display_name":null,"funder_award_id":"UID/MAT/00297/2019","funder_id":"https://openalex.org/F4320334779","funder_display_name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia"},{"id":"https://openalex.org/G7123698595","display_name":null,"funder_award_id":"CT0001","funder_id":"https://openalex.org/F4320334779","funder_display_name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia"},{"id":"https://openalex.org/G967523963","display_name":"Semigrupos: conjuga\u00e7\u00e3o, computa\u00e7\u00e3o, cristais e combinat\u00f3ria.","funder_award_id":"PTDC/MAT-PUR/31174/2017","funder_id":"https://openalex.org/F4320334779","funder_display_name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia"}],"funders":[{"id":"https://openalex.org/F4320323459","display_name":"Universidade Nova de Lisboa","ror":"https://ror.org/02xankh89"},{"id":"https://openalex.org/F4320334779","display_name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","ror":"https://ror.org/00snfqn58"}],"has_content":{"pdf":true,"grobid_xml":true},"content_urls":{"pdf":"https://content.openalex.org/works/W2965381168.pdf","grobid_xml":"https://content.openalex.org/works/W2965381168.grobid-xml"},"referenced_works_count":25,"referenced_works":["https://openalex.org/W421997344","https://openalex.org/W1496412704","https://openalex.org/W1545078593","https://openalex.org/W1993901943","https://openalex.org/W1997160882","https://openalex.org/W2020570874","https://openalex.org/W2020692304","https://openalex.org/W2028001482","https://openalex.org/W2060229474","https://openalex.org/W2067625801","https://openalex.org/W2080270431","https://openalex.org/W2103276942","https://openalex.org/W2119954155","https://openalex.org/W2129945171","https://openalex.org/W2139334518","https://openalex.org/W2161087482","https://openalex.org/W2167918683","https://openalex.org/W2572054965","https://openalex.org/W2915052804","https://openalex.org/W2962996020","https://openalex.org/W3099396151","https://openalex.org/W3103968237","https://openalex.org/W4235484205","https://openalex.org/W4302339081","https://openalex.org/W4302964898"],"related_works":["https://openalex.org/W2130856794","https://openalex.org/W2150654765","https://openalex.org/W1492906489","https://openalex.org/W4226435716","https://openalex.org/W4302805923","https://openalex.org/W1583233859","https://openalex.org/W2964044258","https://openalex.org/W2035319530","https://openalex.org/W2924422330","https://openalex.org/W4285069402"],"abstract_inverted_index":null,"counts_by_year":[{"year":2025,"cited_by_count":1},{"year":2023,"cited_by_count":1},{"year":2020,"cited_by_count":1}],"updated_date":"2026-08-13T07:04:57.449891","created_date":"2025-10-10T00:00:00"}
