{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T14:37:52Z","timestamp":1777646272763,"version":"3.51.4"},"reference-count":0,"publisher":"SAGE Publications","issue":"3","license":[{"start":{"date-parts":[[1999,8,1]],"date-time":"1999-08-01T00:00:00Z","timestamp":933465600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Fundamenta Informaticae"],"published-print":{"date-parts":[[1999,8]]},"abstract":"<jats:p>\n                    In this paper we investigate computational complexity of the PERF-consistency and PERF-entailment problems for ground normal logic programs. In [3] it is proved that these problems belong to \u03a3\n                    <jats:sub>2<\/jats:sub>\n                    <jats:sup>P<\/jats:sup>\n                    and II\n                    <jats:sub>2<\/jats:sub>\n                    <jats:sup>P<\/jats:sup>\n                    correspondingly. The question of obtaining more accurate results was left as open. We prove that both problems belong to \u0394\n                    <jats:sub>2<\/jats:sub>\n                    <jats:sup>P<\/jats:sup>\n                    . Lower bounds on the complexity of these problems are also established in terms of a new complexity class D\n                    <jats:sub>2<\/jats:sub>\n                    which is a subset of \u0394\n                    <jats:sub>2<\/jats:sub>\n                    <jats:sup>P<\/jats:sup>\n                    . It is shown that PERF-consistency is a D\n                    <jats:sub>2<\/jats:sub>\n                    -complete problem and PERF-entailment is co-D\n                    <jats:sub>2<\/jats:sub>\n                    -complete.\n                  <\/jats:p>","DOI":"10.3233\/fi-1999-39302","type":"journal-article","created":{"date-parts":[[2019,12,2]],"date-time":"2019-12-02T21:55:23Z","timestamp":1575323723000},"page":"249-258","source":"Crossref","is-referenced-by-count":1,"title":["On the Complexity of Perfect Models of Logic Programs"],"prefix":"10.1177","volume":"39","author":[{"given":"Sergey M.","family":"Dudakov","sequence":"first","affiliation":[{"name":"Dept. of CS, Tver State Univ., 33 Zhelyabova str., Tver, 170013, Russia. p000104@tversu.ru"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[1999,8,1]]},"container-title":["Fundamenta Informaticae"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.3233\/FI-1999-39302","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.3233\/FI-1999-39302","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T06:34:47Z","timestamp":1777444487000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.3233\/FI-1999-39302"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1999,8]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1999,8]]}},"alternative-id":["10.3233\/FI-1999-39302"],"URL":"https:\/\/doi.org\/10.3233\/fi-1999-39302","relation":{},"ISSN":["0169-2968","1875-8681"],"issn-type":[{"value":"0169-2968","type":"print"},{"value":"1875-8681","type":"electronic"}],"subject":[],"published":{"date-parts":[[1999,8]]}}}