General Linguistics HPSG – Head-Driven Phrase Structure Grammar Alexandr Rosen Ústav teoretické a komputacníˇ lingvistiky Filozofická fakulta Univerzity Karlovy 27 March 2013 Rosen (FF UK) LTGF 27 March 2013 1 / 60 1 Reading 2 Basics 3 Head features 4 Valency 5 Grammar 6 Semantics 7 Unbounded dependencies 8 Pragmatics 9 References Rosen (FF UK) LTGF 27 March 2013 2 / 60 1 Reading 2 Basics 3 Head features 4 Valency 5 Grammar 6 Semantics 7 Unbounded dependencies 8 Pragmatics 9 References Reading HPSG – brief introductions Levine, R. D. and Meurers W. D. (2005). HPSG – Linguistic Approach, Formal Foundations, and Computer Realization. In: Keith Brown (ed.): Encyclopedia of Language and Linguistics, 2nd edition, Elsevier, Oxford. http://www.ling.ohio-state.edu/~dm/papers/ell2-hpsg.pdf Adam Przepiórkowski and Anna Kups´c´ (2006): HPSG for Slavicists. Glossos, 8. http://dach.ipipan.waw.pl/~adamp/Papers/2000-sling2k/ Rosen (FF UK) LTGF 27 March 2013 4 / 60 Reading HPSG – more extensive introductions with a stress on formalism and implementation issues: [Richter(2004)] http://milca.sfs.uni-tuebingen.de/A4/Course/PDF/gramandpars.pdf an HPSG textbook in English [Sag & Wasow(1999)], [Sag et al.(2003)] an HPSG textbook in German [Müller(2007)] http://hpsg.fu-berlin.de/~stefan/Pub/hpsg-lehrbuch.html Rosen (FF UK) LTGF 27 March 2013 5 / 60 Reading HPSG – standard references Pollard & Sag (1987) Information-Based Syntax and Semantics, Volume I, Center for the Study of language and Information, Stanford [Pollard & Sag(1987)] Pollard & Sag (1994) Head-driven Phrase Structure Grammar, Center for the Study of language and Information, Stanford & The University of Chicago Press, Chicago and London [Pollard & Sag(1994)] HPSG sites: http://hpsg.stanford.edu/ http://www.ling.ohio-state.edu/research/hpsg/ Rosen (FF UK) LTGF 27 March 2013 6 / 60 Reading HPSG – implementations An overview of implemented formalisms and grammars for several linguistic theories, including HPSG: http://hpsg.fu-berlin.de/~stefan/PS/implementations.pdf Rosen (FF UK) LTGF 27 March 2013 7 / 60 1 Reading 2 Basics 3 Head features 4 Valency 5 Grammar 6 Semantics 7 Unbounded dependencies 8 Pragmatics 9 References Basics History 1987: first monograph [Pollard & Sag(1987)] 1994: standard reference [Pollard & Sag(1994)] Immediate successor to Generalized Phrase Structure Grammar – GPSG [Gazdar et al.(1985)] – head features, unbounded dependencies, ID/LP format for rules Eclectic – inspired also by: Functional Unification Grammar – FUG [Kay(1983)] – uniform notation for grammar rules, lexicon, representation Lexical-Functional Grammar – LFG [Kaplan & Bresnan(1982)] – lexical rules Categorial Grammar – CG [Ades & Steedman(1982)] – satisfying valency requirements the Government and Binding paradigm – GB [Chomsky(1981)] – analyses of various language phenomena Rosen (FF UK) LTGF 27 March 2013 9 / 60 Basics Why HPSG? Precision of analysis, both in grammar and data Integration of diverse sources of knowledge Declarative grammar Constraint satisfaction system Scaleable, implementable grammars Psychological plausability Rosen (FF UK) LTGF 27 March 2013 10 / 60 Basics Main features 1/2 HPSG grammar is a set of axioms – ‘constraints’ The model: typed feature structures, defined in a hierarchy with multiple inheritance, for morphemes, words, phrases, sentences, ... Lexical entries and grammar rules as constraints on these expressions Constraints are combined and applied by unification Most info is stored in lexical entries, HPSG is very much lexicalized – ‘head-driven’ Rosen (FF UK) LTGF 27 March 2013 11 / 60 Basics Main features 2/2 The concept of sign [de Saussure(1916)] one description to model all properties of words and phrases: phonology/graphemics morphology syntax semantics pragmatics combinatory (syntagmatic) properties Rosen (FF UK) LTGF 27 March 2013 12 / 60 2word 3 6PHON hshei 7 6 7 6 2 37 6 synsem 7 6 7 6 6 77 6 6 2local 377 6 6 77 6 6 6 2 3 777 6 6 6 category 777 6 6 6 777 6 6 6 6 " #7 777 6 6 6 6 noun 7 777 6 6 6CATEGORY 6HEAD 7 777 6 6 6 6 CASE nom 7 777 6 6 6 4 5 777 6 6 6 777 6 6 6 SUBCAT elist 777 6 6 6 777 6 6 6 2 3 777 6 6 6 pers-pronoun 777 6 6 6 777 6 6 6 6 2 37 777 6 6 6 6 referential 7 777 6 6 6 6 7 777 6 6 6 6 6PER 3rd 77 777 6SYNSEM 6 6 6 1 6 77 777 6 6LOCAL 6CONTENT 6INDEX 6 77 777 6 6 6 6 4NUM sing57 777 6 6 6 6 7 777 6 6 6 6 GEND fem 7 777 6 6 6 4 5 777 6 6 6 777 6 6 6 RESTRICTION eset 777 6 6 6 777 6 6 6 2 3777 6 6 6 context 777 6 6 6 777 6 6 6 6 82 397777 6 6 6 6 > psoa >7777 6 6 6 6 > >7777 6 6 6 6 >6QUANTS elist 7>7777 6 6 6CONTEXT 6 <6 7=7777 6 6 6 6BACKGROUND 6 " #7 7777 6 6 6 6 6 female 7 7777 6 6 6 6 >4 5>7777 6 6 4 4 > NUCL >5577 4 4 :> INST 1 ;> 55 Basics A simple sentence as a tree 2 3 phrase 6 7 6PHON hMolly,sleepsi7 6 7 Edges just for readability, 6SYNSEM ... 7 6 7 1 and 2 are just values 6HD-DTR 1 7 4 5 of the attributes NONHD-DTRS h 2 i HD-DTR and NONHD-DTR. ¨H ¨ H HD-DTR and NONHD-DTR ¨¨ HH ¨ H do not represent word order. Word order is determined 2word 3 2word 3 by PHON. 6 7 6 7 24PHON hMollyi5 14PHON hsleepsi5 SYNSEM ... SYNSEM ... Rosen (FF UK) LTGF 27 March 2013 14 / 60 Basics The same sentence only as a feature structure 2phrase 3 6 7 6PHON hMolly,sleepsi 7 6 7 6SYNSEM ... 7 6 7 6 2 3 7 6 word 7 6 7 6HD-DTR 6PHON hsleepsi7 7 6 4 5 7 6 7 6 SYNSEM ... 7 6 7 6 2 3 7 6 word 7 6 7 6NONHD-DTRS h6PHON hMollyi7i7 4 4 5 5 SYNSEM ... Rosen (FF UK) LTGF 27 March 2013 15 / 60 1 Reading 2 Basics 3 Head features 4 Valency 5 Grammar 6 Semantics 7 Unbounded dependencies 8 Pragmatics 9 References Head features Another sentence, with head features told V ;past ¨¨HH ¨ H ¨¨ HH ¨ H Molly him that N;fem;nom;sg N;m;acc;sg N;n;acc;sg Rosen (FF UK) LTGF 27 March 2013 17 / 60 2 3 phrase 6 7 6PHON htold,himi 7 6 2 37 6 7 6 synsem 7 4SYNSEM 4 55 HEAD 1 ¨¨HH ¨¨ HH ¨ H ¨¨ HH 2word 3 2word 3 6PHON htoldi 7 6PHON hhimi7 6 7 4 5 6 2 37 6 synsem 7 SYNSEM ... 6 7 6 6 " # 77 6SYNSEM 6 verb 77 6 6 HEAD 1 77 4 4 VFORM past 55 2 3 phrase 6 7 6PHON hLucy,told,him,thati7 6 2 3 7 6 7 6 synsem 7 4SYNSEM 4 5 5 HEAD 1 ¨¨HH ¨¨ HH ¨¨ HH 2 3 2word 3 phrase 6PHON h i7 6PHON h i7 4 Lucy 5 6 told,him,that 7 6 2 37 SYNSEM ... 6 7 6 synsem 7 4SYNSEM 4 55 HEAD 1 ¨H ¨¨ HH ¨¨ HH 2 3 phrase 2word 3 6PHON h i 7 6PHON h i7 6 told,him 7 4 that 5 6 2 37 6 7 SYNSEM ... 6 synsem 7 4SYNSEM 4 55 HEAD 1 1 Reading 2 Basics 3 Head features 4 Valency 5 Grammar 6 Semantics 7 Unbounded dependencies 8 Pragmatics 9 References Valency Arguments represented as complex categories in the lexical entry of the head (similar to categorial grammar) verb VALENCY swim hNP[nom]i rain hNP[it]i hate hNP[nom], NP[acc]i look hNP[nom], PP[at]i give hNP[nom], NP[acc], NP[acc]i give hNP[nom], NP[acc], PP[to]i try hNP[nom], VP[inf ]i persuade hNP[nom], NP[acc], VP[inf ]i say hNP[nom], S[that]i Rosen (FF UK) LTGF 27 March 2013 21 / 60 Valency 2phrase 3 6 7 6PHON hJohn,swimsi7 6 2 3 7 6 synsem 7 6 7 6 6 7 7 6SYNSEM 6HEAD 1 7 7 4 4 5 5 VAL hi ¨¨HH ¨¨ HH ¨¨ HH 2 3 2 3 phrase word 6 7 6 7 6PHON hswimsi 7 6PHON hJohni7 6 2 37 4 5 6 synsem 7 SYNSEM 2 6 7 6 6 77 6SYNSEM 6HEAD 1 verb77 4 4 55 VAL h 2 i Rosen (FF UK) LTGF 27 March 2013 22 / 60 Valency Abbreviations S VP 2phrase 3 2phrase 3 6 2 37 6 2 37 6 synsem 7 6 synsem 7 6 7 6 7 6SYNSEM 6HEAD verb77 6SYNSEM 6HEAD verb77 4 4 55 4 4 55 VAL hi VAL hsigni V NP 2word 3 2phrase 3 6 2 37 6 2 37 6 synsem 7 6 synsem 7 6 7 6 7 6SYNSEM 6HEAD verb77 6SYNSEM 6HEAD noun77 4 4 55 4 4 55 VAL list VAL hi Rosen (FF UK) LTGF 27 March 2013 23 / 60 Valency Valency Unlike head features, valency can change with the level of projection. Thus, the list of valency requirements cannot be included in the value of the attribute HEAD. Lucka Jirkovi nic nereklaˇ ‘Lucy didn’t say anything to Jirka.’ Rosen (FF UK) LTGF 27 March 2013 24 / 60 2phrase 3 6 7 6PHON hjirkovi,nereklaˇ i 7 6 2 37 6 synsem 7 6 7 6 6 77 6SYNSEM 6HEAD 4 77 4 4 55 VAL h 1 , 2 i ¨¨HH ¨ H ¨¨ HH ¨ H 2 3 2 3 word word 6 7 6 7 6PHON hjirkovii7 6PHON hnereklaˇ i 7 4 5 6 2 37 SYNSEM 3 6 synsem 7 6 7 6 6 77 6SYNSEM 6HEAD 4 77 4 4 55 VAL h 1 , 2 , 3 i 2phrase 3 6 7 6PHON hjirkovi,nic,nereklaˇ i7 6 2 3 7 6 synsem 7 6 7 6 6 7 7 6SYNSEM 6HEAD 4 7 7 4 4 5 5 VAL h 1 i ¨H ¨¨ HH ¨ H ¨¨ HH 2 3 2 3 phrase word 6 7 6 7 6PHON hjirkovi,nereklaˇ i 7 6PHON hnici 7 6 2 37 4 5 6 synsem 7 SYNSEM 2 6 7 6 6 77 6SYNSEM 6HEAD 4 77 4 4 55 VAL h 1 , 2 i 2phrase 3 6 7 6PHON hlucka,jirkovi,nic,nereklaˇ i7 6 2 3 7 6 synsem 7 6 7 6 6 7 7 6SYNSEM 6HEAD 4 7 7 4 4 5 5 VAL hi ¨¨HH ¨ H ¨¨ HH ¨ H 2word 3 2phrase 3 6 7 6 7 4PHON hluckai5 6PHON hjirkovi,nic,nereklaˇ i7 6 2 3 7 SYNSEM 1 6 synsem 7 6 7 6 6 7 7 6SYNSEM 6HEAD 4 7 7 4 4 5 5 VAL h 1 i Valency Valency (summary) The features HEAD and VAL provide information about the word’s syntactic word class and the degree its valency requirements are satisfied.