{"id":"https://openalex.org/W2913019368","doi":null,"title":"Regular expression","display_name":"Regular expression","publication_year":2003,"publication_date":"2003-01-01","ids":{"openalex":"https://openalex.org/W2913019368","mag":"2913019368"},"language":"en","primary_location":{"id":"mag:2913019368","doi":null,"is_oa":false,"landing_page_url":"http://dl.acm.org/citation.cfm?id=1074100.1074765","pdf_url":null,"source":{"id":"https://openalex.org/S4306509340","display_name":"Encyclopedia of Computer Science","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"journal"},"license":null,"license_id":null,"version":null,"is_accepted":false,"is_published":false,"raw_source_name":"Encyclopedia of Computer Science","raw_type":null},"parent_works":[],"lineage":["https://openalex.org/W2913019368"],"child_works_count":0,"type":"reference-entry","is_traditional":false,"indexed_in":[],"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/A5113495698","display_name":"Arto K. Salomaa","orcid":null,"observed_orcids":[]},"institutions":[],"countries":[],"is_corresponding":true,"raw_author_name":"Arto Salomaa","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]}],"institutions":[],"countries_distinct_count":0,"institutions_distinct_count":0,"corresponding_author_ids":["https://openalex.org/A5113495698"],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":null,"has_fulltext":false,"cited_by_count":0,"citation_normalized_percentile":null,"cited_by_percentile_year":null,"biblio":{"volume":null,"issue":null,"first_page":"1518","last_page":"1519"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11567","display_name":"semigroups and automata theory","score":1.0,"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":1.0,"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/T11269","display_name":"Algorithms and Data Compression","score":0.0,"subfield":{"id":"https://openalex.org/subfields/2614","display_name":"Theoretical Computer Science"},"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/T10126","display_name":"Logic, programming, and type systems","score":0.0,"subfield":{"id":"https://openalex.org/subfields/1712","display_name":"Software"},"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/regular-expressions","display_name":"regular expressions","score":0.9990000128746033},{"id":"https://openalex.org/keywords/regular-languages","display_name":"regular languages","score":0.753000020980835},{"id":"https://openalex.org/keywords/finite-state-machines","display_name":"finite automata","score":0.9729999899864197},{"id":"https://openalex.org/keywords/union","display_name":"unions","score":0.5600000023841858},{"id":"https://openalex.org/keywords/catenation","display_name":"catenation","score":0.9120000004768372},{"id":"https://openalex.org/keywords/kleene-star","display_name":"Kleene star","score":0.8069999814033508},{"id":"https://openalex.org/keywords/formal-languages","display_name":"formal languages","score":0.5889999866485596},{"id":"https://openalex.org/keywords/pattern-matching","display_name":"pattern matching","score":0.6669999957084656},{"id":"https://openalex.org/keywords/dna-computing","display_name":"DNA computing","score":0.9700000286102295}],"concepts":[{"id":"https://openalex.org/C76787000","wikidata":"https://www.wikidata.org/wiki/Q334951","display_name":"Catenation","level":3,"score":0.9839211702346802},{"id":"https://openalex.org/C52370388","wikidata":"https://www.wikidata.org/wiki/Q752532","display_name":"Regular language","level":3,"score":0.7384607791900635},{"id":"https://openalex.org/C90805587","wikidata":"https://www.wikidata.org/wiki/Q10944557","display_name":"Word (group theory)","level":2,"score":0.6617324352264404},{"id":"https://openalex.org/C121329065","wikidata":"https://www.wikidata.org/wiki/Q185612","display_name":"Regular expression","level":2,"score":0.6375565528869629},{"id":"https://openalex.org/C146834321","wikidata":"https://www.wikidata.org/wiki/Q2979672","display_name":"Closure (psychology)","level":2,"score":0.6316646337509155},{"id":"https://openalex.org/C87619178","wikidata":"https://www.wikidata.org/wiki/Q126002","display_name":"Concatenation (mathematics)","level":2,"score":0.6214810013771057},{"id":"https://openalex.org/C112876837","wikidata":"https://www.wikidata.org/wiki/Q837518","display_name":"Alphabet","level":2,"score":0.5829596519470215},{"id":"https://openalex.org/C117354338","wikidata":"https://www.wikidata.org/wiki/Q1165112","display_name":"Singleton","level":3,"score":0.48391395807266235},{"id":"https://openalex.org/C146072743","wikidata":"https://www.wikidata.org/wiki/Q192161","display_name":"Formal language","level":2,"score":0.4733032286167145},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.463895320892334},{"id":"https://openalex.org/C90559484","wikidata":"https://www.wikidata.org/wiki/Q778379","display_name":"Expression (computer science)","level":2,"score":0.452629953622818},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.43473267555236816},{"id":"https://openalex.org/C114614502","wikidata":"https://www.wikidata.org/wiki/Q76592","display_name":"Combinatorics","level":1,"score":0.39363494515419006},{"id":"https://openalex.org/C94375191","wikidata":"https://www.wikidata.org/wiki/Q11205","display_name":"Arithmetic","level":1,"score":0.36829811334609985},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.3625044822692871},{"id":"https://openalex.org/C112505250","wikidata":"https://www.wikidata.org/wiki/Q787116","display_name":"Automaton","level":2,"score":0.29926735162734985},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.25583723187446594},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.208207368850708},{"id":"https://openalex.org/C80444323","wikidata":"https://www.wikidata.org/wiki/Q2878974","display_name":"Theoretical computer science","level":1,"score":0.20048555731773376},{"id":"https://openalex.org/C41895202","wikidata":"https://www.wikidata.org/wiki/Q8162","display_name":"Linguistics","level":1,"score":0.13767492771148682},{"id":"https://openalex.org/C2524010","wikidata":"https://www.wikidata.org/wiki/Q8087","display_name":"Geometry","level":1,"score":0.07749330997467041},{"id":"https://openalex.org/C162324750","wikidata":"https://www.wikidata.org/wiki/Q8134","display_name":"Economics","level":0,"score":0.0},{"id":"https://openalex.org/C54355233","wikidata":"https://www.wikidata.org/wiki/Q7162","display_name":"Genetics","level":1,"score":0.0},{"id":"https://openalex.org/C34447519","wikidata":"https://www.wikidata.org/wiki/Q179522","display_name":"Market economy","level":1,"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/C552990157","wikidata":"https://www.wikidata.org/wiki/Q7430","display_name":"DNA","level":2,"score":0.0},{"id":"https://openalex.org/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.0},{"id":"https://openalex.org/C2779234561","wikidata":"https://www.wikidata.org/wiki/Q11995","display_name":"Pregnancy","level":2,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"mag:2913019368","doi":null,"is_oa":false,"landing_page_url":"http://dl.acm.org/citation.cfm?id=1074100.1074765","pdf_url":null,"source":{"id":"https://openalex.org/S4306509340","display_name":"Encyclopedia of Computer Science","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"journal"},"license":null,"license_id":null,"version":null,"is_accepted":false,"is_published":false,"raw_source_name":"Encyclopedia of Computer Science","raw_type":null}],"best_oa_location":null,"sustainable_development_goals":[],"study_designs":[],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":3,"referenced_works":["https://openalex.org/W1967181601","https://openalex.org/W2134845608","https://openalex.org/W4242889986"],"related_works":["https://openalex.org/W252108735","https://openalex.org/W2483561013","https://openalex.org/W4254878942","https://openalex.org/W4403324891","https://openalex.org/W6926534023","https://openalex.org/W2016189575","https://openalex.org/W4230275554","https://openalex.org/W2911338205","https://openalex.org/W1549690229","https://openalex.org/W1540583425"],"abstract_inverted_index":{"The":[0,40,63],"formal":[1],"description":[2],"of":[3,15,58,85,92,109,114,119,122,161,166,198,201,206],"a":[4,8,16,23,29,54,56,110,141],"language":[5,30,46,111,146],"acceptable":[6],"by":[7,149],"finite":[9],"automaton":[10],"or":[11],"for":[12,144],"the":[13,44,49,74,79,105,115,123,145,162,170],"behavior":[14],"sequential":[17],"switching":[18],"circuit":[19],"is":[20,31,55,73,140],"known":[21],"as":[22],"regular":[24,38,64,142],"expression.":[25],"It":[26],"tells":[27],"how":[28],"built":[32],"up":[33],"from":[34,195],"atomic":[35,41],"languages,":[36],"using":[37],"operations.":[39],"languages":[42,87],"are":[43,66],"empty":[45,116,163],"\u03c6":[47],"and":[48,69,89,100,104,118,130,152,165,177,209],"singleton":[50],"sets":[51],"{a},":[52],"where":[53,126],"letter":[57],"some":[59],"previously":[60],"specified":[61],"alphabet.":[62],"operations":[65],"union,":[67],"catenation,":[68],"catenation":[70,80,106],"closure.":[71],"Union":[72],"ordinary":[75],"set":[76],"theoretical":[77],"union;":[78],"(sometimes":[81],"called":[82],"concatenation)":[83],"XY":[84],"two":[86],"X":[88,99,112,159],"Y":[90],"consists":[91,113,160],"all":[93,120,167],"words":[94,121,168,202],"xy":[95],"with":[96,175],"x":[97],"\u2208":[98,102,133],"y":[101],"Y;":[103],"closure":[107],"X*":[108],"word":[117,164],"form":[124],"x1...xn,":[125],"n":[127],"\u2265":[128],"1":[129],"each":[131],"xi":[132],"X.":[134],"For":[135],"example,":[136],"(ab":[137],"\u222a":[138],"b)*":[139],"expression":[143],"X,":[147],"obtained":[148],"catenating":[150],"ab":[151],"b":[153,176],"in":[154,191,212],"an":[155],"arbitrary":[156],"fashion;":[157],"i.e.":[158],"over":[169],"alphabet":[171],"{a,":[172],"b}":[173],"ending":[174],"having":[178],"no":[179],"subwords":[180],"aa.":[181],"Regular":[182],"expressions":[183],"have":[184],"turned":[185],"out":[186],"to":[187,203],"be":[188],"very":[189],"useful":[190],"diverse":[192],"areas,":[193],"ranging":[194],"simple":[196],"tasks":[197],"describing":[199],"patterns":[200],"challenging":[204],"problems":[205],"characterizing":[207],"input":[208],"output":[210],"formalisms":[211],"DNA":[213],"computing":[214],"(see":[215],"MOLECULAR":[216],"COMPUTING).":[217]},"counts_by_year":[],"updated_date":"2026-11-14T11:04:58.165337","created_date":"2019-02-21T00:00:00"}