General Linguistics HPSG – Head-Driven Phrase Structure Grammar
Alexandr Rosen
Ústav teoretické a komputacníˇ lingvistiky Filozofická fakulta Univerzity Karlovy
27 March 2013
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2 Basics
3 Head features
4 Valency
5 Grammar
7 Unbounded dependencies
9 References
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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/
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An overview of implemented formalisms and grammars for several linguistic theories, including HPSG: http://hpsg.fu-berlin.de/~stefan/PS/implementations.pdf
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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
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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’
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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 word PHON hshei synsem local category " # noun CATEGORY HEAD CASE nom SUBCAT elist pers-pronoun referential PER 3rd SYNSEM 1 LOCAL CONTENT INDEX NUM sing GEND fem RESTRICTION eset context psoa QUANTS elist CONTEXT BACKGROUND " # female NUCL INST 1 Basics A simple sentence as a tree
phrase PHON hMolly,sleepsi Edges just for readability, SYNSEM ... 1 and 2 are just values HD-DTR 1 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 word word by PHON. 2PHON hMollyi 1PHON hsleepsi SYNSEM ... SYNSEM ...
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phrase PHON hMolly,sleepsi SYNSEM ... word HD-DTR PHON hsleepsi SYNSEM ... word NONHD-DTRS hPHON hMollyii SYNSEM ...
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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 phrase PHON htold,himi synsem SYNSEM HEAD 1 ¨¨HH ¨¨ HH ¨ H ¨¨ HH word word PHON htoldi PHON hhimi synsem SYNSEM ... " # SYNSEM verb HEAD 1 VFORM past phrase PHON hLucy,told,him,thati synsem SYNSEM HEAD 1 ¨¨HH ¨¨ HH ¨¨ HH word phrase PHON h i PHON h i Lucy told,him,that SYNSEM ... synsem SYNSEM HEAD 1 ¨H ¨¨ HH ¨¨ HH phrase word PHON h i PHON h i told,him that SYNSEM ... synsem SYNSEM 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
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phrase PHON hJohn,swimsi synsem SYNSEM HEAD 1 VAL hi ¨¨HH ¨¨ HH ¨¨ HH phrase word PHON hswimsi PHON hJohni synsem SYNSEM 2 SYNSEM HEAD 1 verb VAL h 2 i
Rosen (FF UK) LTGF 27 March 2013 22 / 60 Valency Abbreviations
S VP phrase phrase synsem synsem SYNSEM HEAD verb SYNSEM HEAD verb VAL hi VAL hsigni V NP word phrase synsem synsem SYNSEM HEAD verb SYNSEM HEAD noun VAL list VAL hi
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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 phrase PHON hjirkovi,nereklaˇ i synsem SYNSEM HEAD 4 VAL h 1 , 2 i
¨¨HH ¨ H ¨¨ HH ¨ H word word PHON hjirkovii PHON hnereklaˇ i SYNSEM 3 synsem SYNSEM HEAD 4 VAL h 1 , 2 , 3 i phrase PHON hjirkovi,nic,nereklaˇ i synsem SYNSEM HEAD 4 VAL h 1 i ¨H ¨¨ HH ¨ H ¨¨ HH phrase word PHON hjirkovi,nereklaˇ i PHON hnici synsem SYNSEM 2 SYNSEM HEAD 4 VAL h 1 , 2 i phrase PHON hlucka,jirkovi,nic,nereklaˇ i synsem SYNSEM HEAD 4 VAL hi
¨¨HH ¨ H ¨¨ HH ¨ H word phrase PHON hluckai PHON hjirkovi,nic,nereklaˇ i SYNSEM 1 synsem SYNSEM HEAD 4 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. This information is partially implicit in the standard atomic categories of CF grammar: N, N’, NP, V, VP, S. These are often used as abbreviations. Often the attribute CATEGORY or CAT groups these two features, serving as the locus of the item’s syntactic information. CAT is just one of synsem’s attributes. Rather than signs, valency lists include synsems. Why?
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2 Basics
3 Head features
4 Valency
5 Grammar
6 Semantics
7 Unbounded dependencies
8 Pragmatics
9 References Grammar The grammar architecture
Components of a grammar: Signature (defines possible objects) Theory (specifies constraints on the objects) Components of a theory: Lexical entries (word-specific constraints) Lexical rules (expressing lexical generalizations – morphology, alternations) Principles (syntactic regularities) Schemas (relating phonology and syntactic structure) Relational constraints (list operations etc.)
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Abstracting from word order: ID/LP rules (Immediate Dominance vs. Linear Precedence) dominance in DTR, precedence in PHON Abstracting from word classes: V, N, P, A A general schema: H[ VALENCY 1 ] −→ H[ VALENCY 1 ⊕ h 2 i] 2 Possible instantiations: V[ VALENCY 1 ] −→ V[ VALENCY 1 hi ⊕ h 2 NPi] 2 2 John swims. 2 Mary [loves strawberries]. V[ VALENCY 1 ] −→ V[ VALENCY 1 hNPi ⊕ h 2 NPi] 2 loves 2 strawberries N[ VALENCY 1 ] −→ N[ VALENCY 1 hi ⊕ h 2 DETi] 2 2 [my younger sister’s] boyfriend.
Rosen (FF UK) LTGF 27 March 2013 31 / 60 Grammar More abstractions
H[ VALENCY 4 ] −→ H[ VALENCY 4 ⊕ h 5 i] 5 phrase → PHON f ( 1 , 2 ) HEAD 3 VALENCY 4 PHON 1 HD-DTR HEAD 3 VALENCY 4 ⊕ h 5 i h i NONHD-DTRS h 5 PHON 2 i
The rule schema includes several types of info: dominance concatenation of PHON values valency satisfaction head features sharing
Rosen (FF UK) LTGF 27 March 2013 32 / 60 Grammar Principles
Schema phrase → PHON f ( 1 , 2 ) h i HD-DTR PHON 1 h i NONHD-DTRS 5 PHON 2 Head Feature Principle phrase → HEAD 3 h i HD-DTR HEAD 3 Valency Principle phrase → SYNSEM | VALENCY 4 h i HD-DTR VALENCY 4 ⊕ h 5 i NONHD-DTRS 5
Rosen (FF UK) LTGF 27 March 2013 33 / 60 Grammar The type sign (simplified)
sign PHON list(phonstring) synsem cat SYNSEM CAT HEAD head VAL list(synsem)
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2 Basics
3 Head features
4 Valency
5 Grammar
6 Semantics
7 Unbounded dependencies
8 Pragmatics
9 References Semantics Semantics
sign PHON list(phonstring) synsem SYNSEM CAT cat CONT cont
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cont ¨H ¨¨ HH ¨¨ HH psoa nom-obj index PERS pers INDEX NUMB numb GEND gend RESTR set(psoa)
Rosen (FF UK) LTGF 27 March 2013 37 / 60 Semantics psoa ¨H ¨¨ HH ¨ H ¨¨ HH ¨ H ¨¨ HH ¨¨ HH " # ... give swim GIVER index SWIMMER index GIVEN index RECIPIENT index psoa PP @ PP @ PP PP @ PP @ PP " #" #" # ... book black quickly INST index INST index INST psoa
Rosen (FF UK) LTGF 27 March 2013 38 / 60 Lexical entry for dala:
sign synsem cat " # verb HEAD CAT VFORM past VAL hNP[nom] i, NP[dat] , NP[acc] i SS 1 [3rd,sg,fem] 2 3 give GIVER 1 CONT GIVEN 3 RECIPIENT 2 Semantics
NP [nom] i [3rd,sg,fem] : synsem cat " # noun CAT HEAD CASE nom VAL hi nom-obj index CONT PERS 3rd INDEX i NUMB sg GEND fem
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A reminder: Lexicon is formally a huge disjunction of constraints on the type word: word → entry1 ∨ entry2 ∨ entry3 ∨ ...
Lexical entry for kniha ‘book’, the value of CONT: nom-obj index PERS 3rd INDEX 1 NUMB sg GEND fem " # book RESTR INST 1
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NP tlustá kniha ‘a thick book’, the value of CONT: nom-obj index PERS 3rd INDEX 1 NUMB sg GEND fem " # " # book thick RESTR , INST 1 INST 1
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2 Basics
3 Head features
4 Valency
5 Grammar
6 Semantics
7 Unbounded dependencies
8 Pragmatics
9 References Unbounded dependencies Unbounded dependencies: LOCAL/NONLOCAL, filler/gap
S ¨¨HH ¨¨ HH NP1 S/NP1 ¨H dumplings ¨¨ HH NP VP/NP1 we ¨¨HH V NP1 adore
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S ¨¨HH ¨¨ HH NP1 S/NP1 ¨H what ¨¨HH ¨ H NP VP/NP1 Mary ¨¨HH V NP1 adores
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S ¨H ¨¨ HH ¨ H NP1 S/NP1 who ¨¨HH ¨¨ HH NP VP/NP1 ¨H Mary ¨¨ HH V VP/NP1 can’t ¨¨HH V NP1 stand
Rosen (FF UK) LTGF 27 March 2013 46 / 60 Unbounded dependencies
S ¨¨HH ¨¨ HH NP1 S/NP1 who ¨¨HH ¨¨ HH NP VP/NP1 Lucy ¨¨HH ¨¨ HH V S’/NP1 said ¨¨HH ¨¨ HH M S/NP1 ¨H that ¨¨ HH ¨ H NP VP/NP1 ¨H Mary ¨¨ HH V VP/NP1 can’t ¨¨HH V NP1 stand
Rosen (FF UK) LTGF 27 March 2013 47 / 60 phrase PHON list(phonstring) synsem local cat LOCAL CAT HEAD head SS VAL list(synsem) " # nonlocal NONLOCAL SLASH set(local) HD-DTR sign NONHD-DTRS list(sign) Unbounded dependencies
phrase ¨H ¨¨ HH val-phrase fill-phrase
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Filler phrase fill-phrase PHON hdumplings,we,adorei SYNSEM | NONLOCAL | SLASH {} val-phrase PHON hwe,adorei HEAD-DTR n o SYNSEM | NONLOCAL | SLASH 1 word NONHD-DTRS PHON hdumplingsi SYNSEM | LOCAL 1
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Trace word PHON hi LOCAL 1 SYNSEM n o NONLOCAL | SLASH 1
Rosen (FF UK) LTGF 27 March 2013 51 / 60 fill-phrase P h i dumplings,we,adore ..SUBJ hi..COMPS hi..SLASH {} ¨H ¨¨ HH ¨¨ HH word val-phrase P hdumplingsi P hwe,adorei n o ..LOCAL 1 ..SUBJ hi..COMPS hi..SLASH 1 ¨¨HH ¨ H ¨¨ HH word val-phrase P hwei P hadorei n o SS 3 ..SUBJ h 3 i..COMPS hi..SLASH 1 ¨¨HH ¨¨ HH ¨¨ HH word word P hadorei P hi ..SUBJ h 3 i..COMPS h 2 i..SLASH {} LOCAL 1 SS 2 n o ..SLASH 1 1 Reading
2 Basics
3 Head features
4 Valency
5 Grammar
6 Semantics
7 Unbounded dependencies
8 Pragmatics
9 References word PHON hjái synsem cat " # noun CAT HEAD CASE nom VAL hi nom-obj index PERS 1st SS CONT INDEX 1 NUM sg GEND gend RESTR {} ctx c-inds CTX C-INDS SPEAKER 1 ADDRESSEE index BCKGRND {} word PHON hvyi synsem cat " # noun CAT HEAD CASE nom h i VAL SUBJ hi, COMPS hi nom-obj " # index CONT INDEX 1 PERS 2nd, NUM pl, GEND gend SS RESTR {} ctx c-inds C-INDS SPEAKER 2 ADDRESSEE 1 CTX honor " # non-aggreg BCKGRND HONORER 2 , INST 1 HONORED 1 1 Reading
2 Basics
3 Head features
4 Valency
5 Grammar
6 Semantics
7 Unbounded dependencies
8 Pragmatics
9 References References
Ades, A. E. & Steedman, M. J. (1982). On the order of words. Linguistics and Philosophy, 4, 517–558. 10.1007/BF00360804. Chomsky, N. (1981). Lectures on Government and Binding. Foris, Dordrecht. Dalrymple, M., Kaplan, R. M., Maxwell, J. T., & Zaenen, A., editors (1995). Formal Issues in Lexical-Functional Grammar. CSLI Publications, Stanford, CA.
Rosen (FF UK) LTGF 27 March 2013 57 / 60 References de Saussure, F. (1916). Cours de linguistique générale. Paris. Publié par Ch. Bally et A. Sechehay avec la collaboration de A Riedlinger. Gazdar, G., Klein, E., Pullum, G., & Sag, I. (1985). Generalized phrase structure grammar. Harvard University Press, Cambridge, MA, USA. Kaplan, R. D. & Bresnan, J. (1982). Lexical-Functional Grammar: A Formal System for Grammatical Representation. In J. Bresnan, editor, The Mental Representation of Grammatical Relations, pages 173–281. The MIT Press, Cambridge, MA. Reprinted in [Dalrymple et al.(1995), 29-130].
Rosen (FF UK) LTGF 27 March 2013 58 / 60 References
Kay, M. (1983). Unification Grammar. Technical report, Xerox Palo Alto Research Center, Palo Alto, California. Müller, S. (2007). Head-Driven Phrase Structure Grammar: Eine Einführung. Number 17 in Stauffenburg Einführungen. Staffenburg Verlag, Tübingen. Pollard, C. & Sag, I. A. (1994). Head-Driven Phrase Structure Grammar. University of Chicago Press. Pollard, C. J. & Sag, I. A. (1987). Information-Based Syntax and Semantics. Number 13 in CSLI Lecture Notes. CSLI, Stanford, California, USA.
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Richter, F. (2004). A Web-based Course in Grammar Formalisms and Parsing. An electronic course book, http://milca.sfs.uni-tuebingen.de/A4/Course/PDF/gramandpars.pdf. Sag, I. A. & Wasow, T. (1999). Syntactic Theory: A Formal Introduction. CSLI Publications, Stanford, CA. Sag, I. A., Wasow, T., & Bender, E. M. (2003). Syntactic Theory: A Formal Introduction. CSLI Publications, Stanford, CA, 2 edition.
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