{"id":"https://openalex.org/W2104411855","doi":"https://doi.org/10.2168/lmcs-9(4:15)2013","title":"Approximation systems for functions in topological and in metric spaces","display_name":"Approximation systems for functions in topological and in metric spaces","publication_year":2013,"publication_date":"2013-11-20","ids":{"openalex":"https://openalex.org/W2104411855","doi":"https://doi.org/10.2168/lmcs-9(4:15)2013","mag":"2104411855"},"language":"en","primary_location":{"id":"doi:10.2168/lmcs-9(4:15)2013","is_oa":true,"landing_page_url":"https://doi.org/10.2168/lmcs-9(4:15)2013","pdf_url":"https://lmcs.episciences.org/890/pdf","source":{"id":"https://openalex.org/S114379355","display_name":"Logical Methods in Computer Science","issn_l":"1860-5974","issn":["1860-5974"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310313916","host_organization_name":"Logical Methods in Computer Science e.V.","host_organization_lineage":["https://openalex.org/P4310313916"],"host_organization_lineage_names":["Logical Methods in Computer Science e.V."],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Logical Methods in Computer Science","raw_type":"journal-article"},"type":"article","indexed_in":["arxiv","crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"diamond","oa_url":"https://lmcs.episciences.org/890/pdf","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5077311090","display_name":"Dimiter Skordev","orcid":"https://orcid.org/0000-0002-5718-3640"},"institutions":[{"id":"https://openalex.org/I58918642","display_name":"Sofia University \"St. Kliment Ohridski\"","ror":"https://ror.org/02jv3k292","country_code":"BG","type":"education","lineage":["https://openalex.org/I58918642"]}],"countries":["BG"],"is_corresponding":true,"raw_author_name":"Dimiter Skordev","raw_affiliation_strings":["Sofia University, Faculty of Mathematics and Informatics, Sofia, Bulgaria","Sofia University, Faculty of Mathematics and Informatics, Sofia, Bulgaria#TAB#"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Sofia University, Faculty of Mathematics and Informatics, Sofia, Bulgaria","institution_ids":["https://openalex.org/I58918642"]},{"raw_affiliation_string":"Sofia University, Faculty of Mathematics and Informatics, Sofia, Bulgaria#TAB#","institution_ids":["https://openalex.org/I58918642"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5077311090"],"corresponding_institution_ids":["https://openalex.org/I58918642"],"apc_list":null,"apc_paid":null,"fwci":0.0,"has_fulltext":true,"cited_by_count":2,"citation_normalized_percentile":{"value":0.14020527,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":90,"max":94},"biblio":{"volume":"Volume 9, Issue 4","issue":null,"first_page":null,"last_page":null},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T12002","display_name":"Computability, Logic, AI Algorithms","score":0.9998000264167786,"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/T12002","display_name":"Computability, Logic, AI Algorithms","score":0.9998000264167786,"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/T11567","display_name":"semigroups and automata theory","score":0.9684000015258789,"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/T11151","display_name":"Advanced Topology and Set Theory","score":0.9652000069618225,"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"}}],"keywords":[{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.7418935894966125},{"id":"https://openalex.org/keywords/computability","display_name":"Computability","score":0.6396516561508179},{"id":"https://openalex.org/keywords/metric-space","display_name":"Metric space","score":0.600286066532135},{"id":"https://openalex.org/keywords/recursively-enumerable-language","display_name":"Recursively enumerable language","score":0.5630621910095215},{"id":"https://openalex.org/keywords/discrete-mathematics","display_name":"Discrete mathematics","score":0.5563169717788696},{"id":"https://openalex.org/keywords/computable-function","display_name":"Computable function","score":0.5522067546844482},{"id":"https://openalex.org/keywords/countable-set","display_name":"Countable set","score":0.5502170324325562},{"id":"https://openalex.org/keywords/recursively-enumerable-set","display_name":"Recursively enumerable set","score":0.542700469493866},{"id":"https://openalex.org/keywords/baire-space","display_name":"Baire space","score":0.4886215329170227},{"id":"https://openalex.org/keywords/uncountable-set","display_name":"Uncountable set","score":0.44075509905815125},{"id":"https://openalex.org/keywords/base","display_name":"Base (topology)","score":0.4355371594429016},{"id":"https://openalex.org/keywords/undecidable-problem","display_name":"Undecidable problem","score":0.42603519558906555},{"id":"https://openalex.org/keywords/function","display_name":"Function (biology)","score":0.42478036880493164},{"id":"https://openalex.org/keywords/closed-set","display_name":"Closed set","score":0.41059979796409607},{"id":"https://openalex.org/keywords/mathematical-analysis","display_name":"Mathematical analysis","score":0.09465473890304565}],"concepts":[{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.7418935894966125},{"id":"https://openalex.org/C152062344","wikidata":"https://www.wikidata.org/wiki/Q818888","display_name":"Computability","level":2,"score":0.6396516561508179},{"id":"https://openalex.org/C198043062","wikidata":"https://www.wikidata.org/wiki/Q180953","display_name":"Metric space","level":2,"score":0.600286066532135},{"id":"https://openalex.org/C203702658","wikidata":"https://www.wikidata.org/wiki/Q1073063","display_name":"Recursively enumerable language","level":2,"score":0.5630621910095215},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.5563169717788696},{"id":"https://openalex.org/C54271186","wikidata":"https://www.wikidata.org/wiki/Q1148456","display_name":"Computable function","level":2,"score":0.5522067546844482},{"id":"https://openalex.org/C110729354","wikidata":"https://www.wikidata.org/wiki/Q185478","display_name":"Countable set","level":2,"score":0.5502170324325562},{"id":"https://openalex.org/C52703633","wikidata":"https://www.wikidata.org/wiki/Q676835","display_name":"Recursively enumerable set","level":3,"score":0.542700469493866},{"id":"https://openalex.org/C166359235","wikidata":"https://www.wikidata.org/wiki/Q1150180","display_name":"Baire space","level":2,"score":0.4886215329170227},{"id":"https://openalex.org/C142399903","wikidata":"https://www.wikidata.org/wiki/Q1128796","display_name":"Uncountable set","level":3,"score":0.44075509905815125},{"id":"https://openalex.org/C42058472","wikidata":"https://www.wikidata.org/wiki/Q810214","display_name":"Base (topology)","level":2,"score":0.4355371594429016},{"id":"https://openalex.org/C192034797","wikidata":"https://www.wikidata.org/wiki/Q3502995","display_name":"Undecidable problem","level":3,"score":0.42603519558906555},{"id":"https://openalex.org/C14036430","wikidata":"https://www.wikidata.org/wiki/Q3736076","display_name":"Function (biology)","level":2,"score":0.42478036880493164},{"id":"https://openalex.org/C164953516","wikidata":"https://www.wikidata.org/wiki/Q320357","display_name":"Closed set","level":2,"score":0.41059979796409607},{"id":"https://openalex.org/C134306372","wikidata":"https://www.wikidata.org/wiki/Q7754","display_name":"Mathematical analysis","level":1,"score":0.09465473890304565},{"id":"https://openalex.org/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.0},{"id":"https://openalex.org/C153269930","wikidata":"https://www.wikidata.org/wiki/Q430001","display_name":"Decidability","level":2,"score":0.0},{"id":"https://openalex.org/C78458016","wikidata":"https://www.wikidata.org/wiki/Q840400","display_name":"Evolutionary biology","level":1,"score":0.0}],"mesh":[],"locations_count":4,"locations":[{"id":"doi:10.2168/lmcs-9(4:15)2013","is_oa":true,"landing_page_url":"https://doi.org/10.2168/lmcs-9(4:15)2013","pdf_url":"https://lmcs.episciences.org/890/pdf","source":{"id":"https://openalex.org/S114379355","display_name":"Logical Methods in Computer Science","issn_l":"1860-5974","issn":["1860-5974"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310313916","host_organization_name":"Logical Methods in Computer Science e.V.","host_organization_lineage":["https://openalex.org/P4310313916"],"host_organization_lineage_names":["Logical Methods in Computer Science e.V."],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Logical Methods in Computer Science","raw_type":"journal-article"},{"id":"pmh:oai:arXiv.org:1310.5656","is_oa":true,"landing_page_url":"http://arxiv.org/abs/1310.5656","pdf_url":"https://arxiv.org/pdf/1310.5656","source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"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":"text"},{"id":"pmh:oai:CiteSeerX.psu:10.1.1.741.4833","is_oa":false,"landing_page_url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.741.4833","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"http://arxiv.org/pdf/1310.5656.pdf","raw_type":"text"},{"id":"pmh:oai:doaj.org/article:6f3187915f4f4c84af57f00861a0486b","is_oa":true,"landing_page_url":"https://doaj.org/article/6f3187915f4f4c84af57f00861a0486b","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":"cc-by-sa","license_id":"https://openalex.org/licenses/cc-by-sa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Logical Methods in Computer Science, Vol Volume 9, Issue 4 (2013)","raw_type":"article"}],"best_oa_location":{"id":"doi:10.2168/lmcs-9(4:15)2013","is_oa":true,"landing_page_url":"https://doi.org/10.2168/lmcs-9(4:15)2013","pdf_url":"https://lmcs.episciences.org/890/pdf","source":{"id":"https://openalex.org/S114379355","display_name":"Logical Methods in Computer Science","issn_l":"1860-5974","issn":["1860-5974"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310313916","host_organization_name":"Logical Methods in Computer Science e.V.","host_organization_lineage":["https://openalex.org/P4310313916"],"host_organization_lineage_names":["Logical Methods in Computer Science e.V."],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Logical Methods in Computer Science","raw_type":"journal-article"},"sustainable_development_goals":[],"awards":[],"funders":[{"id":"https://openalex.org/F4320323575","display_name":"Bulgarian Academy of Sciences","ror":"https://ror.org/01x8hew03"},{"id":"https://openalex.org/F4320327336","display_name":"Vlaamse regering","ror":null}],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W2104411855.pdf","grobid_xml":"https://content.openalex.org/works/W2104411855.grobid-xml"},"referenced_works_count":16,"referenced_works":["https://openalex.org/W120057786","https://openalex.org/W191595573","https://openalex.org/W1509579779","https://openalex.org/W1602845793","https://openalex.org/W1641292742","https://openalex.org/W1964191518","https://openalex.org/W1975886595","https://openalex.org/W2032123501","https://openalex.org/W2051039879","https://openalex.org/W2082475018","https://openalex.org/W2117832390","https://openalex.org/W2530006810","https://openalex.org/W2905135108","https://openalex.org/W4292144699","https://openalex.org/W4297926959","https://openalex.org/W4299529642"],"related_works":["https://openalex.org/W2037833610","https://openalex.org/W1972481159","https://openalex.org/W2094468224","https://openalex.org/W2000487993","https://openalex.org/W1973052363","https://openalex.org/W1980641386","https://openalex.org/W2135152748","https://openalex.org/W2066136688","https://openalex.org/W1564994090","https://openalex.org/W2914940747"],"abstract_inverted_index":{"A":[0],"notable":[1],"feature":[2],"of":[3,12,23,32,51,86,99,106,114,122,131,146,149,192,200,206,209,212,215,245,275,285,300,302],"the":[4,10,13,17,30,41,49,84,91,97,102,107,112,126,135,188,193,198,218,223,234,240,248,253,265,271,276,279,283,297,303],"TTE":[5,104,190],"approach":[6],"to":[7,28,158],"computability":[8,105,191,284],"is":[9,46,63,94,109,156,171,195],"representation":[11],"argument":[14,127,241],"values":[15,20],"and":[16,81,129,151,239,256,270],"corresponding":[18,136],"function":[19,62,108,137,170,194,272],"by":[21,111,197,295],"means":[22],"infinitistic":[24,304],"names.":[25,305],"Two":[26],"ways":[27],"eliminate":[29],"using":[31,296],"such":[33,67,175],"names":[34],"in":[35,40,90,96,222,252,278,291],"certain":[36],"cases":[37],"are":[38],"indicated":[39],"paper.":[42],"The":[43,153],"first":[44,92,224,298],"one":[45,66,71,174],"intended":[47],"for":[48,233,264],"case":[50],"topological":[52],"spaces":[53,160],"with":[54,161],"selected":[55,73,162,219,249],"indexed":[56,163],"denumerable":[57,164],"bases.":[58],"Suppose":[59],"a":[60,76,147,168,182,226,230,257,261,292],"partial":[61,169],"given":[64,172],"from":[65,173,217,247],"space":[68,93,176,255],"into":[69,177],"another":[70,178],"whose":[72],"base":[74,87,123,132],"has":[75],"recursively":[77,117,203],"enumerable":[78,118,204],"index":[79,214,244],"set,":[80],"suppose":[82],"that":[83,282],"intersection":[85],"open":[88],"sets":[89,124,133],"computable":[95],"sense":[98],"Weihrauch-Grubba.":[100],"Then":[101],"ordinary":[103,189],"characterized":[110,196,290],"existence":[113,199],"an":[115,144,201,213,243],"appropriate":[116,202],"relation":[119],"between":[120,236,267],"indices":[121,130],"containing":[125,134],"value":[128],"value.This":[138],"result":[139,148],"can":[140,288],"be":[141,289],"regarded":[142],"as":[143],"improvement":[145],"Korovina":[150],"Kudinov.":[152],"second":[154,254],"way":[155,294,299],"applicable":[157],"metric":[159],"dense":[165,220,250],"subsets.":[166],"If":[167],"one,":[179],"then,":[180],"under":[181],"semi-computability":[183],"assumption":[184],"concerning":[185],"these":[186],"spaces,":[187],"set":[205],"quadruples.":[207],"Any":[208],"them":[210],"consists":[211],"element":[216,238,246,269],"subset":[221,251],"space,":[225],"natural":[227,258],"number":[228,259],"encoding":[229,260],"rational":[231,262],"bound":[232,263],"distance":[235,266],"this":[237,268],"value,":[242],"value.":[273],"One":[274],"examples":[277],"paper":[280],"indicates":[281],"real":[286],"functions":[287],"simple":[293],"elimination":[301]},"counts_by_year":[{"year":2022,"cited_by_count":1},{"year":2017,"cited_by_count":1}],"updated_date":"2026-05-21T06:26:12.895304","created_date":"2025-10-10T00:00:00"}