{"id":"https://openalex.org/W2100850484","doi":"https://doi.org/10.1016/0020-0190(79)90135-2","title":"Finding a homomorphism between two words in NP-complete","display_name":"Finding a homomorphism between two words in NP-complete","publication_year":1979,"publication_date":"1979-08-01","ids":{"openalex":"https://openalex.org/W2100850484","doi":"https://doi.org/10.1016/0020-0190(79)90135-2","mag":"2100850484"},"language":"en","primary_location":{"id":"doi:10.1016/0020-0190(79)90135-2","is_oa":false,"landing_page_url":"https://doi.org/10.1016/0020-0190(79)90135-2","pdf_url":null,"source":{"id":"https://openalex.org/S147953040","display_name":"Information Processing Letters","issn_l":"0020-0190","issn":["0020-0190","1872-6119"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320990","host_organization_name":"Elsevier BV","host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Information Processing Letters","raw_type":"journal-article"},"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5085330298","display_name":"Andrzej Ehrenfreucht","orcid":null},"institutions":[{"id":"https://openalex.org/I188538660","display_name":"University of Colorado Boulder","ror":"https://ror.org/02ttsq026","country_code":"US","type":"education","lineage":["https://openalex.org/I188538660"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Andrzej Ehrenfreucht","raw_affiliation_strings":["Department of Computer Science, University of Colorado, Boulder, CO, U.S.A","[Dept. of Computer Science, University of Colorado Boulder, CO, U.S.A.]"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Computer Science, University of Colorado, Boulder, CO, U.S.A","institution_ids":["https://openalex.org/I188538660"]},{"raw_affiliation_string":"[Dept. of Computer Science, University of Colorado Boulder, CO, U.S.A.]","institution_ids":["https://openalex.org/I188538660"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5110486000","display_name":"Grzegorz Rozenberg","orcid":null},"institutions":[{"id":"https://openalex.org/I210716285","display_name":"University of Applied Sciences Leiden","ror":"https://ror.org/0093src13","country_code":"NL","type":"education","lineage":["https://openalex.org/I210716285"]}],"countries":["NL"],"is_corresponding":false,"raw_author_name":"Grzegorz Rozenberg","raw_affiliation_strings":["Institute of Applied Mathematics and Computer Science, University of Leiden, Leiden, The The Netherlands"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Institute of Applied Mathematics and Computer Science, University of Leiden, Leiden, The The Netherlands","institution_ids":["https://openalex.org/I210716285"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":2,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":{"value":2040,"currency":"USD","value_usd":2040},"apc_paid":null,"fwci":0.0,"has_fulltext":false,"cited_by_count":34,"citation_normalized_percentile":{"value":0.12160162,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":89,"max":98},"biblio":{"volume":"9","issue":"2","first_page":"86","last_page":"88"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10181","display_name":"Natural Language Processing Techniques","score":0.9979000091552734,"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"}},"topics":[{"id":"https://openalex.org/T10181","display_name":"Natural Language Processing Techniques","score":0.9979000091552734,"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"}},{"id":"https://openalex.org/T11567","display_name":"semigroups and automata theory","score":0.9975000023841858,"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/T10601","display_name":"Handwritten Text Recognition Techniques","score":0.970300018787384,"subfield":{"id":"https://openalex.org/subfields/1707","display_name":"Computer Vision and Pattern Recognition"},"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/concatenation","display_name":"Concatenation (mathematics)","score":0.834812343120575},{"id":"https://openalex.org/keywords/morphism","display_name":"Morphism","score":0.826959490776062},{"id":"https://openalex.org/keywords/repetition","display_name":"Repetition (rhetorical device)","score":0.7215767502784729},{"id":"https://openalex.org/keywords/word","display_name":"Word (group theory)","score":0.6884563565254211},{"id":"https://openalex.org/keywords/generalization","display_name":"Generalization","score":0.6412417888641357},{"id":"https://openalex.org/keywords/homomorphism","display_name":"Homomorphism","score":0.6181960105895996},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.524408221244812},{"id":"https://openalex.org/keywords/word-problem","display_name":"Word problem (mathematics education)","score":0.4795346260070801},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.45611047744750977},{"id":"https://openalex.org/keywords/encoding","display_name":"Encoding (memory)","score":0.415659099817276},{"id":"https://openalex.org/keywords/combinatorics","display_name":"Combinatorics","score":0.3920244872570038},{"id":"https://openalex.org/keywords/arithmetic","display_name":"Arithmetic","score":0.34133654832839966},{"id":"https://openalex.org/keywords/discrete-mathematics","display_name":"Discrete mathematics","score":0.33466482162475586},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.23757025599479675},{"id":"https://openalex.org/keywords/linguistics","display_name":"Linguistics","score":0.13752669095993042}],"concepts":[{"id":"https://openalex.org/C87619178","wikidata":"https://www.wikidata.org/wiki/Q126002","display_name":"Concatenation (mathematics)","level":2,"score":0.834812343120575},{"id":"https://openalex.org/C137212723","wikidata":"https://www.wikidata.org/wiki/Q1948412","display_name":"Morphism","level":2,"score":0.826959490776062},{"id":"https://openalex.org/C2776141515","wikidata":"https://www.wikidata.org/wiki/Q1274479","display_name":"Repetition (rhetorical device)","level":2,"score":0.7215767502784729},{"id":"https://openalex.org/C90805587","wikidata":"https://www.wikidata.org/wiki/Q10944557","display_name":"Word (group theory)","level":2,"score":0.6884563565254211},{"id":"https://openalex.org/C177148314","wikidata":"https://www.wikidata.org/wiki/Q170084","display_name":"Generalization","level":2,"score":0.6412417888641357},{"id":"https://openalex.org/C4042151","wikidata":"https://www.wikidata.org/wiki/Q215111","display_name":"Homomorphism","level":2,"score":0.6181960105895996},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.524408221244812},{"id":"https://openalex.org/C90988201","wikidata":"https://www.wikidata.org/wiki/Q255912","display_name":"Word problem (mathematics education)","level":2,"score":0.4795346260070801},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.45611047744750977},{"id":"https://openalex.org/C125411270","wikidata":"https://www.wikidata.org/wiki/Q18653","display_name":"Encoding (memory)","level":2,"score":0.415659099817276},{"id":"https://openalex.org/C114614502","wikidata":"https://www.wikidata.org/wiki/Q76592","display_name":"Combinatorics","level":1,"score":0.3920244872570038},{"id":"https://openalex.org/C94375191","wikidata":"https://www.wikidata.org/wiki/Q11205","display_name":"Arithmetic","level":1,"score":0.34133654832839966},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.33466482162475586},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.23757025599479675},{"id":"https://openalex.org/C41895202","wikidata":"https://www.wikidata.org/wiki/Q8162","display_name":"Linguistics","level":1,"score":0.13752669095993042},{"id":"https://openalex.org/C138885662","wikidata":"https://www.wikidata.org/wiki/Q5891","display_name":"Philosophy","level":0,"score":0.0},{"id":"https://openalex.org/C134306372","wikidata":"https://www.wikidata.org/wiki/Q7754","display_name":"Mathematical analysis","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}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1016/0020-0190(79)90135-2","is_oa":false,"landing_page_url":"https://doi.org/10.1016/0020-0190(79)90135-2","pdf_url":null,"source":{"id":"https://openalex.org/S147953040","display_name":"Information Processing Letters","issn_l":"0020-0190","issn":["0020-0190","1872-6119"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320990","host_organization_name":"Elsevier BV","host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Information Processing Letters","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[],"awards":[],"funders":[{"id":"https://openalex.org/F4320332538","display_name":"University of Colorado Boulder","ror":"https://ror.org/02ttsq026"}],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":1,"referenced_works":["https://openalex.org/W1655990431"],"related_works":["https://openalex.org/W2373577936","https://openalex.org/W4221148444","https://openalex.org/W4387678054","https://openalex.org/W2389596151","https://openalex.org/W3095575180","https://openalex.org/W4306784355","https://openalex.org/W1999245519","https://openalex.org/W3157704859","https://openalex.org/W1558831501","https://openalex.org/W4318559625"],"abstract_inverted_index":null,"counts_by_year":[{"year":2024,"cited_by_count":2},{"year":2021,"cited_by_count":1},{"year":2019,"cited_by_count":1},{"year":2018,"cited_by_count":1},{"year":2017,"cited_by_count":1},{"year":2016,"cited_by_count":2},{"year":2015,"cited_by_count":4},{"year":2014,"cited_by_count":1},{"year":2013,"cited_by_count":4},{"year":2012,"cited_by_count":3}],"updated_date":"2026-07-23T08:03:31.855105","created_date":"2025-10-10T00:00:00"}
