Semantic Grammar A short guide to Blackburns Grammar
Semantic Grammar A short guide to Blackburn’s Grammar of English April 2010 Semantic Grammar 1
Outline • Blackburn’s Grammar • Syntactic Rules • Lexical Rules • Word Lexicon • Semantic Lexicon See english. Grammar. pl in BB 1 folder April 2010 Semantic Grammar 2
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 April 2010 Semantic Grammar 3
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 April 2010 Semantic Grammar 4
![Syntax Rules s([coord: no, sem: Sem])--> np([coord: _, num: Num, gap: [], sem: NP]),](http://slidetodoc.com/presentation_image_h/31a036a62ba7e665795984db21ab2f9d/image-5.jpg "Syntax Rules s([coord: no, sem: Sem])--> np([coord: _, num: Num, gap: [], sem: NP]),")
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 April 2010 Semantic Grammar 5
![Lexical Rules noun([sem: Sem])--> {lex. Entry(noun, [symbol: Sym, syntax: Word])}, Word, {sem. Lex(noun, [symbol:](http://slidetodoc.com/presentation_image_h/31a036a62ba7e665795984db21ab2f9d/image-6.jpg "Lexical Rules noun([sem: Sem])--> {lex. Entry(noun, [symbol: Sym, syntax: Word])}, Word, {sem. Lex(noun, [symbol:")
Lexical Rules noun([sem: Sem])--> {lex. Entry(noun, [symbol: Sym, syntax: Word])}, Word, {sem. Lex(noun, [symbol: Sym, sem: Sem])}. • The rule makes reference to two externally defined predicates (in curly brackets). – lex. Entry: the predicate for lexical entries – sem. Lex: semantic macro which constructs the semantic representation April 2010 Semantic Grammar 6
![Semantic Rules. . rewrite part of rule. . {combine(s: Sem, [np: NP, vp: VP])}.](http://slidetodoc.com/presentation_image_h/31a036a62ba7e665795984db21ab2f9d/image-7.jpg "Semantic Rules. . rewrite part of rule. . {combine(s: Sem, [np: NP, vp: VP])}.")
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) – beta. Converting that term April 2010 Semantic Grammar 7
The Lexicon (see english. Lexicon. pl) • The general format of every lexical entry is this: • lex. Entry(Cat, Features) where – Cat is a syntactic category and – Features are a collection of attribute: value pairs • Example: lex. Entry(noun, [symbol: car, syntax: [car]]). lex. Entry(pn, [symbol: mia, syntax: [mia]]). April 2010 Semantic Grammar 8
The Semantic Lexicon 1 sem. Lex(pn, M): M = [symbol: Sym, sem: lam(P, app(P, Sym))]. sem. Lex(noun, M): M = [symbol: Sym, sem: lam(X, Formula)], compose(Formula, Sym, [X]). April 2010 Semantic Grammar 9
![The Semantic Lexicon 2 sem. Lex(iv, M): M = [symbol: Sym, sem: lam(X, Formula)],](http://slidetodoc.com/presentation_image_h/31a036a62ba7e665795984db21ab2f9d/image-10.jpg "The Semantic Lexicon 2 sem. Lex(iv, M): M = [symbol: Sym, sem: lam(X, Formula)],")
The Semantic Lexicon 2 sem. Lex(iv, M): M = [symbol: Sym, sem: lam(X, Formula)], compose(Formula, Sym, [X]). sem. Lex(tv, M): M = [symbol: Sym, sem: lam(K, lam(Y, app(K, lam(X, Formula))))], compose(Formula, Sym, [Y, X]). April 2010 Semantic Grammar 10
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