{"id":"https://openalex.org/W2093306186","doi":"https://doi.org/10.1016/0020-0190(92)90082-7","title":"The pre-NTS property is undecidable for context-free grammars","display_name":"The pre-NTS property is undecidable for context-free grammars","publication_year":1992,"publication_date":"1992-12-01","ids":{"openalex":"https://openalex.org/W2093306186","doi":"https://doi.org/10.1016/0020-0190(92)90082-7","mag":"2093306186"},"language":"en","primary_location":{"id":"doi:10.1016/0020-0190(92)90082-7","is_oa":false,"landing_page_url":"https://doi.org/10.1016/0020-0190(92)90082-7","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/A5012300835","display_name":"Louxin Zhang","orcid":"https://orcid.org/0000-0003-0260-824X"},"institutions":[{"id":"https://openalex.org/I151746483","display_name":"University of Waterloo","ror":"https://ror.org/01aff2v68","country_code":"CA","type":"education","lineage":["https://openalex.org/I151746483"]}],"countries":["CA"],"is_corresponding":true,"raw_author_name":"Louxin Zhang","raw_affiliation_strings":["Department of Computer Science, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1","Dept, of Computer Science, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Computer Science, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1","institution_ids":["https://openalex.org/I151746483"]},{"raw_affiliation_string":"Dept, of Computer Science, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1","institution_ids":["https://openalex.org/I151746483"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5012300835"],"corresponding_institution_ids":["https://openalex.org/I151746483"],"apc_list":{"value":2040,"currency":"USD","value_usd":2040},"apc_paid":null,"fwci":0.4598,"has_fulltext":false,"cited_by_count":2,"citation_normalized_percentile":{"value":0.65852342,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":null,"biblio":{"volume":"44","issue":"4","first_page":"181","last_page":"184"},"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/T12029","display_name":"DNA and Biological Computing","score":0.998199999332428,"subfield":{"id":"https://openalex.org/subfields/1312","display_name":"Molecular Biology"},"field":{"id":"https://openalex.org/fields/13","display_name":"Biochemistry, Genetics and Molecular Biology"},"domain":{"id":"https://openalex.org/domains/1","display_name":"Life Sciences"}},{"id":"https://openalex.org/T10126","display_name":"Logic, programming, and type systems","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"}}],"keywords":[{"id":"https://openalex.org/keywords/undecidable-problem","display_name":"Undecidable problem","score":0.9536781311035156},{"id":"https://openalex.org/keywords/property","display_name":"Property (philosophy)","score":0.6771504878997803},{"id":"https://openalex.org/keywords/context-free-grammar","display_name":"Context-free grammar","score":0.645005464553833},{"id":"https://openalex.org/keywords/rule-based-machine-translation","display_name":"Rule-based machine translation","score":0.6161496043205261},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.6093879342079163},{"id":"https://openalex.org/keywords/embedded-pushdown-automaton","display_name":"Embedded pushdown automaton","score":0.5783520936965942},{"id":"https://openalex.org/keywords/context","display_name":"Context (archaeology)","score":0.5150744318962097},{"id":"https://openalex.org/keywords/deterministic-context-free-grammar","display_name":"Deterministic context-free grammar","score":0.4467311203479767},{"id":"https://openalex.org/keywords/programming-language","display_name":"Programming language","score":0.42834314703941345},{"id":"https://openalex.org/keywords/theoretical-computer-science","display_name":"Theoretical computer science","score":0.37988758087158203},{"id":"https://openalex.org/keywords/tree-adjoining-grammar","display_name":"Tree-adjoining grammar","score":0.3441472053527832},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.3338696360588074},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.275642991065979},{"id":"https://openalex.org/keywords/decidability","display_name":"Decidability","score":0.2707390785217285}],"concepts":[{"id":"https://openalex.org/C192034797","wikidata":"https://www.wikidata.org/wiki/Q3502995","display_name":"Undecidable problem","level":3,"score":0.9536781311035156},{"id":"https://openalex.org/C189950617","wikidata":"https://www.wikidata.org/wiki/Q937228","display_name":"Property (philosophy)","level":2,"score":0.6771504878997803},{"id":"https://openalex.org/C97212296","wikidata":"https://www.wikidata.org/wiki/Q338047","display_name":"Context-free grammar","level":3,"score":0.645005464553833},{"id":"https://openalex.org/C53893814","wikidata":"https://www.wikidata.org/wiki/Q7378909","display_name":"Rule-based machine translation","level":2,"score":0.6161496043205261},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.6093879342079163},{"id":"https://openalex.org/C27034413","wikidata":"https://www.wikidata.org/wiki/Q5370010","display_name":"Embedded pushdown automaton","level":5,"score":0.5783520936965942},{"id":"https://openalex.org/C2779343474","wikidata":"https://www.wikidata.org/wiki/Q3109175","display_name":"Context (archaeology)","level":2,"score":0.5150744318962097},{"id":"https://openalex.org/C177638518","wikidata":"https://www.wikidata.org/wiki/Q3435975","display_name":"Deterministic context-free grammar","level":5,"score":0.4467311203479767},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.42834314703941345},{"id":"https://openalex.org/C80444323","wikidata":"https://www.wikidata.org/wiki/Q2878974","display_name":"Theoretical computer science","level":1,"score":0.37988758087158203},{"id":"https://openalex.org/C134083981","wikidata":"https://www.wikidata.org/wiki/Q1754022","display_name":"Tree-adjoining grammar","level":4,"score":0.3441472053527832},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.3338696360588074},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.275642991065979},{"id":"https://openalex.org/C153269930","wikidata":"https://www.wikidata.org/wiki/Q430001","display_name":"Decidability","level":2,"score":0.2707390785217285},{"id":"https://openalex.org/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.0},{"id":"https://openalex.org/C138885662","wikidata":"https://www.wikidata.org/wiki/Q5891","display_name":"Philosophy","level":0,"score":0.0},{"id":"https://openalex.org/C151730666","wikidata":"https://www.wikidata.org/wiki/Q7205","display_name":"Paleontology","level":1,"score":0.0},{"id":"https://openalex.org/C111472728","wikidata":"https://www.wikidata.org/wiki/Q9471","display_name":"Epistemology","level":1,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1016/0020-0190(92)90082-7","is_oa":false,"landing_page_url":"https://doi.org/10.1016/0020-0190(92)90082-7","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":[{"score":0.7099999785423279,"display_name":"Quality Education","id":"https://metadata.un.org/sdg/4"}],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":9,"referenced_works":["https://openalex.org/W1963712259","https://openalex.org/W1997305350","https://openalex.org/W2002089154","https://openalex.org/W2033706603","https://openalex.org/W2057232839","https://openalex.org/W2058267787","https://openalex.org/W2135953325","https://openalex.org/W2797656628","https://openalex.org/W4302339081"],"related_works":["https://openalex.org/W191660820","https://openalex.org/W2019032507","https://openalex.org/W1609763579","https://openalex.org/W2067980891","https://openalex.org/W4294576161","https://openalex.org/W207821149","https://openalex.org/W2084935533","https://openalex.org/W24640121","https://openalex.org/W2403874525","https://openalex.org/W2364393301"],"abstract_inverted_index":null,"counts_by_year":[],"updated_date":"2026-07-23T08:03:31.855105","created_date":"2025-10-10T00:00:00"}
