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Published byClaude Lindsey Modified over 8 years ago
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April 2010Semantic Grammar1 A short guide to Blackburn’s Grammar of English
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April 2010Semantic Grammar2 Outline Blackburn’s Grammar Syntactic Rules Lexical Rules Word Lexicon Semantic Lexicon See englishGrammar.pl in BB1 folder
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April 2010Semantic Grammar3 Coordination Coordinated consitutents are those that are combined with a coordinator (e.g. coordinating conjunction such as “and”) Vincent and Mia Issues with coordination include: –Category of coordinated constituents –Agreement of coordinated constituent – in particular number –Left recursion
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April 2010Semantic Grammar4 Coordination The natural way to write a coordination rule is this: X -> X coordinator X e.g. NP -> NP “and” NP This is left recursive because the first LH category is identical to the LHS category of the rule Left recursion causes problems in Prolog
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April 2010Semantic Grammar5 Syntax Rules s([coord:no,sem:Sem])--> np([coord:_,num:Num,gap:[],sem:NP]), vp([coord:_,inf:fin,num:Num,gap:[],sem:VP]), {combine(s:Sem,[np:NP,vp:VP])}. Standard CF skeleton Features of the form attribute:value Semantic operations
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April 2010Semantic Grammar6 Lexical Rules noun([sem:Sem])--> {lexEntry(noun,[symbol:Sym,syntax:Word])}, Word, {semLex(noun,[symbol:Sym,sem:Sem])}. The rule makes reference to two externally defined predicates (in curly brackets). –lexEntry: the predicate for lexical entries –semLex: semantic macro which constructs the semantic representation
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April 2010Semantic Grammar7 Semantic Rules.... rewrite part of rule.... {combine(s:Sem,[np:NP,vp:VP])}. Here, using the rule, combine simply applies the semantic representation NP to the semantic representation VP by –creating the term app(NP,VP) –betaConverting that term
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April 2010Semantic Grammar8 The Lexicon (see englishLexicon.pl ) The general format of every lexical entry is this: lexEntry(Cat,Features) where –Cat is a syntactic category and –Features are a collection of attribute:value pairs Example: lexEntry(noun,[symbol:car,syntax:[car]]). lexEntry(pn,[symbol:mia,syntax:[mia]]).
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April 2010Semantic Grammar9 The Semantic Lexicon 1 semLex(pn,M):- M = [symbol:Sym, sem:lam(P,app(P,Sym))]. semLex(noun,M):- M = [symbol:Sym, sem:lam(X,Formula)], compose(Formula,Sym,[X]).
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April 2010Semantic Grammar10 The Semantic Lexicon 2 semLex(iv,M):- M = [symbol:Sym, sem:lam(X,Formula)], compose(Formula,Sym,[X]). semLex(tv,M):- M = [symbol:Sym, sem:lam(K,lam(Y,app(K,lam(X,Formula))))], compose(Formula,Sym,[Y,X]).
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