{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,10,23]],"date-time":"2023-10-23T04:58:28Z","timestamp":1698037108078},"reference-count":14,"publisher":"Wiley","issue":"4","license":[{"start":{"date-parts":[[2007,3,22]],"date-time":"2007-03-22T00:00:00Z","timestamp":1174521600000},"content-version":"vor","delay-in-days":5924,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Systems &amp; Computers in Japan"],"published-print":{"date-parts":[[1991,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Multiple context\u2010free grammars (mcfg's) and head grammars (hg's) are subclasses of generalized context\u2010free grammars introduced by Pollard to describe the syntax of natural languages. In this paper, the following properties of mcfg's and hg's are shown: (1) the class <jats:italic>HL<\/jats:italic> of languages generated by hg's is the same as that generated by the tree adjoining grammars introduced by Joshi et al.; (2) <jats:italic>HL<\/jats:italic> is the same as that generated by left\u2010wrapping hg's (or right\u2010wrapping hg's) which is a proper subclass of hg's; (3) <jats:italic>HL<\/jats:italic> is properly included in the one generated by 2\u2010mcfg's, which is a proper subclass of mcfg's. As a corollary of (1), it is also shown that <jats:italic>HL<\/jats:italic> is a substitution closed full AFL.<\/jats:p>","DOI":"10.1002\/scj.4690220405","type":"journal-article","created":{"date-parts":[[2007,7,7]],"date-time":"2007-07-07T20:53:14Z","timestamp":1183841594000},"page":"41-56","source":"Crossref","is-referenced-by-count":1,"title":["The generative power of multiple context\u2010free grammars and head grammars"],"prefix":"10.1002","volume":"22","author":[{"given":"Takashi","family":"Matsumura","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hiroyuki","family":"Seki","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mamoru","family":"Fujii","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tadao","family":"Kasami","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2007,3,22]]},"reference":[{"key":"e_1_2_1_2_2","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3975(79)90041-0"},{"key":"e_1_2_1_3_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-0000(75)80019-5"},{"key":"e_1_2_1_4_2","unstructured":"T.Kasami H.Seki andM.Fujii.Generalized context\u2010free grammars multiple context\u2010free grammars and head grammars. Technical Report Osaka University (1987);"},{"key":"e_1_2_1_4_3","unstructured":"also in: Preprint of WG on Natural Language of IPSJ 87\u2010NL\u201063\u20101 (1987)."},{"issue":"5","key":"e_1_2_1_5_2","first-page":"758","article-title":"Generalized context\u2010free grammars and multiple context\u2010free grammars","volume":"71","author":"Kasami T.","year":"1988","journal-title":"Trans. I.E.I.C.E."},{"issue":"6","key":"e_1_2_1_6_2","first-page":"935","article-title":"On the membership problem for head grammars and multiple context\u2010free grammars","volume":"71","author":"Kasami T.","year":"1988","journal-title":"Trans. I.E.I.C.E."},{"key":"e_1_2_1_7_2","first-page":"276","volume-title":"Formal Language Theory","author":"Kasami T.","year":"1988"},{"key":"e_1_2_1_8_2","unstructured":"T.Matsumura H.Seki M.Fujii andT.Kasami.Some results on multiple context\u2010free grammars. In: Paper of Technical Group COMP88\u201078 I.E.I.C.E. (1989)."},{"key":"e_1_2_1_9_2","unstructured":"C. J.Pollard.Generalized Phrase Structure Grammars Head Grammars and Natural Language. Ph.D. dissertation. Stanford University (1984)."},{"key":"e_1_2_1_10_2","volume-title":"Mathematics of Language","author":"Roach K.","year":"1987"},{"key":"e_1_2_1_11_2","unstructured":"K.Vijay\u2010Shanker.A Study of Tree Adjoining Grammars. Ph.D. dissertation University of Pennsylvania (1987)."},{"key":"e_1_2_1_12_2","doi-asserted-by":"crossref","unstructured":"K.Vijay\u2010Shanker D. J.Weir andA. K.Joshi.Tree adjoining and head wrapping. In: Proc. 11th Intl. Conf. on Comput. Ling. pp.202\u2013207(1986).","DOI":"10.3115\/991365.991425"},{"key":"e_1_2_1_13_2","doi-asserted-by":"crossref","unstructured":"K.Vijay\u2010Shanker D. J.Weir andA. K.Joshi.Characterizing structural descriptions produced by various grammatical formalisms. In: Proc. 25th meeting of Assoc. Comput. Ling. pp.104\u2013111(1987).","DOI":"10.3115\/981175.981190"},{"key":"e_1_2_1_14_2","unstructured":"D. J.Weir.Characterizing Mildly Context\u2010Sensitive Grammar Formalisms. Ph.D. dissertation University of Pennsylvania (1988)."}],"container-title":["Systems and Computers in Japan"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fscj.4690220405","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/scj.4690220405","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,23]],"date-time":"2023-10-23T02:36:34Z","timestamp":1698028594000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/scj.4690220405"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1991,1]]},"references-count":14,"journal-issue":{"issue":"4","published-print":{"date-parts":[[1991,1]]}},"alternative-id":["10.1002\/scj.4690220405"],"URL":"https:\/\/doi.org\/10.1002\/scj.4690220405","archive":["Portico"],"relation":{},"ISSN":["0882-1666","1520-684X"],"issn-type":[{"value":"0882-1666","type":"print"},{"value":"1520-684X","type":"electronic"}],"subject":[],"published":{"date-parts":[[1991,1]]}}}