Please use this identifier to cite or link to this item: http://dspace.mediu.edu.my:8181/xmlui/handle/1721.1/5615
Full metadata record
DC FieldValueLanguage
dc.creatorRistad, Eric Sven-
dc.date2004-10-01T20:17:11Z-
dc.date2004-10-01T20:17:11Z-
dc.date1985-03-01-
dc.date.accessioned2013-10-09T02:40:18Z-
dc.date.available2013-10-09T02:40:18Z-
dc.date.issued2013-10-09-
dc.identifierAIM-837-
dc.identifierhttp://hdl.handle.net/1721.1/5615-
dc.identifier.urihttp://koha.mediu.edu.my:8181/xmlui/handle/1721-
dc.descriptionProponents of generalized phrase structure grammar (GPSG) cite its weak context-free generative power as proof of the computational tractability of GPSG-Recognition. Since context-free languages (CFLs) can be parsed in time proportional to the cube of the sentence length, and GPSGs only generate CFLs, it seems plausible the GPSGs can also be parsed in cubic time. This longstanding, widely assumed GPSG "efficient parsability" result in misleading: parsing the sentences of an arbitrary GPSG is likely to be intractable, because a reduction from 3SAT proves that the universal recognition problem for the GPSGs of Gazdar (1981) is NP-hard. Crucially, the time to parse a sentence of a CFL can be the product of sentence length cubed and context-free grammar size squared, and the GPSG grammar can result in an exponentially large set of derived context-free rules. A central object in the 1981 GPSG theory, the metarule, inherently results in an intractable parsing problem, even when severely constrained. The implications for linguistics and natural language parsing are discussed.-
dc.format11 p.-
dc.format3087711 bytes-
dc.format2405273 bytes-
dc.formatapplication/postscript-
dc.formatapplication/pdf-
dc.languageen_US-
dc.relationAIM-837-
dc.subjectGPSG-
dc.subjectparsing-
dc.subjectcomplexity-
dc.subjectnatural language-
dc.subjectlinguistics-
dc.subjectsnatural language parsing-
dc.titleGPSG-Recognition is NP-Hard-
Appears in Collections:MIT Items

Files in This Item:
There are no files associated with this item.


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.