{"id":"https://openalex.org/W2127339411","doi":"https://doi.org/10.1162/coli_a_00079","title":"Splittability of Bilexical Context-Free Grammars is Undecidable","display_name":"Splittability of Bilexical Context-Free Grammars is Undecidable","publication_year":2011,"publication_date":"2011-07-14","ids":{"openalex":"https://openalex.org/W2127339411","doi":"https://doi.org/10.1162/coli_a_00079","mag":"2127339411"},"language":"en","primary_location":{"id":"doi:10.1162/coli_a_00079","is_oa":true,"landing_page_url":"https://doi.org/10.1162/coli_a_00079","pdf_url":"https://direct.mit.edu/coli/article-pdf/37/4/867/1798917/coli_a_00079.pdf","source":{"id":"https://openalex.org/S155526855","display_name":"Computational Linguistics","issn_l":"0891-2017","issn":["0891-2017","1530-9312"],"is_oa":false,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310320244","host_organization_name":"Association for Computational Linguistics","host_organization_lineage":["https://openalex.org/P4310320244"],"host_organization_lineage_names":["Association for Computational Linguistics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Computational Linguistics","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"bronze","oa_url":"https://direct.mit.edu/coli/article-pdf/37/4/867/1798917/coli_a_00079.pdf","any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5088112856","display_name":"Mark-Jan Nederhof","orcid":"https://orcid.org/0000-0002-1845-6829"},"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":"Mark-Jan Nederhof","raw_affiliation_strings":["University of St. Andrews"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"University of St. Andrews","institution_ids":["https://openalex.org/I16835326"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5068504877","display_name":"Giorgio Satta","orcid":"https://orcid.org/0000-0001-7742-6438"},"institutions":[{"id":"https://openalex.org/I138689650","display_name":"University of Padua","ror":"https://ror.org/00240q980","country_code":"IT","type":"education","lineage":["https://openalex.org/I138689650"]}],"countries":["IT"],"is_corresponding":false,"raw_author_name":"Giorgio Satta","raw_affiliation_strings":["University of Padua","University of Padua ,"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"University of Padua","institution_ids":["https://openalex.org/I138689650"]},{"raw_affiliation_string":"University of Padua ,","institution_ids":["https://openalex.org/I138689650"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":2,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":0.0,"has_fulltext":false,"cited_by_count":0,"citation_normalized_percentile":{"value":0.13471478,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":null,"biblio":{"volume":"37","issue":"4","first_page":"867","last_page":"879"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10181","display_name":"Natural Language Processing Techniques","score":0.9997000098228455,"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":0.9997000098228455,"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/T11269","display_name":"Algorithms and Data Compression","score":0.9940000176429749,"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":0.9869999885559082,"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"}}],"keywords":[{"id":"https://openalex.org/keywords/undecidable-problem","display_name":"Undecidable problem","score":0.9688245058059692},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.7699490785598755},{"id":"https://openalex.org/keywords/parsing","display_name":"Parsing","score":0.7523741722106934},{"id":"https://openalex.org/keywords/context-free-grammar","display_name":"Context-free grammar","score":0.6569989919662476},{"id":"https://openalex.org/keywords/string","display_name":"String (physics)","score":0.6411433219909668},{"id":"https://openalex.org/keywords/context","display_name":"Context (archaeology)","score":0.5614764094352722},{"id":"https://openalex.org/keywords/rule-based-machine-translation","display_name":"Rule-based machine translation","score":0.5392286777496338},{"id":"https://openalex.org/keywords/parsing-expression-grammar","display_name":"Parsing expression grammar","score":0.4718579947948456},{"id":"https://openalex.org/keywords/versa","display_name":"Versa","score":0.4712921679019928},{"id":"https://openalex.org/keywords/context-free-language","display_name":"Context-free language","score":0.4679167568683624},{"id":"https://openalex.org/keywords/lr-parser","display_name":"LR parser","score":0.44697368144989014},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.3988223075866699},{"id":"https://openalex.org/keywords/programming-language","display_name":"Programming language","score":0.3520534038543701},{"id":"https://openalex.org/keywords/natural-language-processing","display_name":"Natural language processing","score":0.32841646671295166},{"id":"https://openalex.org/keywords/theoretical-computer-science","display_name":"Theoretical computer science","score":0.2703767418861389},{"id":"https://openalex.org/keywords/l-attributed-grammar","display_name":"L-attributed grammar","score":0.2625466585159302},{"id":"https://openalex.org/keywords/parser-combinator","display_name":"Parser combinator","score":0.1768110692501068},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.17115437984466553},{"id":"https://openalex.org/keywords/decidability","display_name":"Decidability","score":0.10417371988296509}],"concepts":[{"id":"https://openalex.org/C192034797","wikidata":"https://www.wikidata.org/wiki/Q3502995","display_name":"Undecidable problem","level":3,"score":0.9688245058059692},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.7699490785598755},{"id":"https://openalex.org/C186644900","wikidata":"https://www.wikidata.org/wiki/Q194152","display_name":"Parsing","level":2,"score":0.7523741722106934},{"id":"https://openalex.org/C97212296","wikidata":"https://www.wikidata.org/wiki/Q338047","display_name":"Context-free grammar","level":3,"score":0.6569989919662476},{"id":"https://openalex.org/C157486923","wikidata":"https://www.wikidata.org/wiki/Q1376436","display_name":"String (physics)","level":2,"score":0.6411433219909668},{"id":"https://openalex.org/C2779343474","wikidata":"https://www.wikidata.org/wiki/Q3109175","display_name":"Context (archaeology)","level":2,"score":0.5614764094352722},{"id":"https://openalex.org/C53893814","wikidata":"https://www.wikidata.org/wiki/Q7378909","display_name":"Rule-based machine translation","level":2,"score":0.5392286777496338},{"id":"https://openalex.org/C146810361","wikidata":"https://www.wikidata.org/wiki/Q32271","display_name":"Parsing expression grammar","level":5,"score":0.4718579947948456},{"id":"https://openalex.org/C2777655698","wikidata":"https://www.wikidata.org/wiki/Q1209358","display_name":"Versa","level":2,"score":0.4712921679019928},{"id":"https://openalex.org/C198838072","wikidata":"https://www.wikidata.org/wiki/Q729271","display_name":"Context-free language","level":3,"score":0.4679167568683624},{"id":"https://openalex.org/C35164859","wikidata":"https://www.wikidata.org/wiki/Q1756442","display_name":"LR parser","level":4,"score":0.44697368144989014},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.3988223075866699},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.3520534038543701},{"id":"https://openalex.org/C204321447","wikidata":"https://www.wikidata.org/wiki/Q30642","display_name":"Natural language processing","level":1,"score":0.32841646671295166},{"id":"https://openalex.org/C80444323","wikidata":"https://www.wikidata.org/wiki/Q2878974","display_name":"Theoretical computer science","level":1,"score":0.2703767418861389},{"id":"https://openalex.org/C67621940","wikidata":"https://www.wikidata.org/wiki/Q3113340","display_name":"L-attributed grammar","level":4,"score":0.2625466585159302},{"id":"https://openalex.org/C118364021","wikidata":"https://www.wikidata.org/wiki/Q7139956","display_name":"Parser combinator","level":3,"score":0.1768110692501068},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.17115437984466553},{"id":"https://openalex.org/C153269930","wikidata":"https://www.wikidata.org/wiki/Q430001","display_name":"Decidability","level":2,"score":0.10417371988296509},{"id":"https://openalex.org/C77088390","wikidata":"https://www.wikidata.org/wiki/Q8513","display_name":"Database","level":1,"score":0.0},{"id":"https://openalex.org/C37914503","wikidata":"https://www.wikidata.org/wiki/Q156495","display_name":"Mathematical physics","level":1,"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/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.0}],"mesh":[],"locations_count":5,"locations":[{"id":"doi:10.1162/coli_a_00079","is_oa":true,"landing_page_url":"https://doi.org/10.1162/coli_a_00079","pdf_url":"https://direct.mit.edu/coli/article-pdf/37/4/867/1798917/coli_a_00079.pdf","source":{"id":"https://openalex.org/S155526855","display_name":"Computational Linguistics","issn_l":"0891-2017","issn":["0891-2017","1530-9312"],"is_oa":false,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310320244","host_organization_name":"Association for Computational Linguistics","host_organization_lineage":["https://openalex.org/P4310320244"],"host_organization_lineage_names":["Association for Computational Linguistics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Computational Linguistics","raw_type":"journal-article"},{"id":"pmh:oai:CiteSeerX.psu:10.1.1.222.4712","is_oa":false,"landing_page_url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.222.4712","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"http://www.aclweb.org/anthology-new/J/J11/J11-4009.pdf","raw_type":"text"},{"id":"pmh:oai:doaj.org/article:d12743fcf015416f8c10da6b70462425","is_oa":false,"landing_page_url":"https://doaj.org/article/d12743fcf015416f8c10da6b70462425","pdf_url":null,"source":{"id":"https://openalex.org/S4306401280","display_name":"DOAJ (DOAJ: Directory of Open Access Journals)","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":"Computational Linguistics, Vol 37, Iss 4 (2021)","raw_type":"article"},{"id":"pmh:oai:research-repository.st-andrews.ac.uk:10023/2415","is_oa":false,"landing_page_url":"https://hdl.handle.net/10023/2415","pdf_url":null,"source":{"id":"https://openalex.org/S4306400230","display_name":"St Andrews Research Repository (St Andrews Research Repository)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I16835326","host_organization_name":"University of St Andrews","host_organization_lineage":["https://openalex.org/I16835326"],"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":"Journal article"},{"id":"pmh:oai:www.research.unipd.it:11577/2490703","is_oa":false,"landing_page_url":"http://hdl.handle.net/11577/2490703","pdf_url":null,"source":{"id":"https://openalex.org/S4377196283","display_name":"Research Padua  Archive (University of Padua)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I138689650","host_organization_name":"University of Padua","host_organization_lineage":["https://openalex.org/I138689650"],"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":"info:eu-repo/semantics/article"}],"best_oa_location":{"id":"doi:10.1162/coli_a_00079","is_oa":true,"landing_page_url":"https://doi.org/10.1162/coli_a_00079","pdf_url":"https://direct.mit.edu/coli/article-pdf/37/4/867/1798917/coli_a_00079.pdf","source":{"id":"https://openalex.org/S155526855","display_name":"Computational Linguistics","issn_l":"0891-2017","issn":["0891-2017","1530-9312"],"is_oa":false,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310320244","host_organization_name":"Association for Computational Linguistics","host_organization_lineage":["https://openalex.org/P4310320244"],"host_organization_lineage_names":["Association for Computational Linguistics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Computational Linguistics","raw_type":"journal-article"},"sustainable_development_goals":[{"id":"https://metadata.un.org/sdg/4","display_name":"Quality Education","score":0.6800000071525574}],"awards":[],"funders":[],"has_content":{"pdf":true,"grobid_xml":false},"content_urls":{"pdf":"https://content.openalex.org/works/W2127339411.pdf"},"referenced_works_count":10,"referenced_works":["https://openalex.org/W174472240","https://openalex.org/W1595271312","https://openalex.org/W2002089154","https://openalex.org/W2036890855","https://openalex.org/W2052449326","https://openalex.org/W2092654472","https://openalex.org/W2096466920","https://openalex.org/W2139895384","https://openalex.org/W2155693943","https://openalex.org/W2952654140"],"related_works":["https://openalex.org/W2037099835","https://openalex.org/W92795209","https://openalex.org/W2356184147","https://openalex.org/W2021932667","https://openalex.org/W1574669355","https://openalex.org/W3147354785","https://openalex.org/W2085190866","https://openalex.org/W2186329031","https://openalex.org/W1982991377","https://openalex.org/W1762192966"],"abstract_inverted_index":{"Bilexical":[0],"context-free":[1],"grammars":[2],"(2-LCFGs)":[3],"have":[4,26],"proved":[5],"to":[6,20,72,84],"be":[7,69],"accurate":[8],"models":[9,25],"for":[10],"statistical":[11],"natural":[12],"language":[13],"parsing.":[14],"Existing":[15],"dynamic":[16],"programming":[17],"algorithms":[18],"used":[19],"parse":[21],"sentences":[22],"under":[23],"these":[24],"running":[27],"time":[28,67],"of":[29,47,54,81,98],"O(\u2223w\u2223":[30,73],"4":[31],"),":[32],"where":[33],"w":[34],"is":[35,41,64,79,100],"the":[36,44,55,93],"input":[37],"string.":[38],"A":[39],"2-LCFG":[40],"splittable":[42],"if":[43],"left":[45],"arguments":[46],"a":[48,62],"lexical":[49],"head":[50],"are":[51],"always":[52],"independent":[53],"right":[56],"arguments,":[57],"and":[58],"vice":[59],"versa.":[60],"When":[61],"2-LCFGs":[63,99],"splittable,":[65],"parsing":[66,85],"can":[68],"asymptotically":[70],"improved":[71],"3":[74],").":[75],"Testing":[76],"this":[77,88],"property":[78],"therefore":[80],"central":[82],"interest":[83],"efficiency.":[86],"In":[87],"article,":[89],"however,":[90],"we":[91],"show":[92],"negative":[94],"result":[95],"that":[96],"splittability":[97],"undecidable.":[101]},"counts_by_year":[],"updated_date":"2026-05-22T06:13:13.366637","created_date":"2025-10-10T00:00:00"}