General Linguistics HPSG Head-Driven Phrase Structure Grammar - - PowerPoint PPT Presentation

General Linguistics HPSG – Head-Driven Phrase Structure Grammar

Alexandr Rosen

Ústav teoretické a komputaˇ cní lingvistiky Filozofická fakulta Univerzity Karlovy

27 March 2013

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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 Kup´ s´ c (2006): HPSG for Slavicists. Glossos, 8.

http://dach.ipipan.waw.pl/~adamp/Papers/2000-sling2k/

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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

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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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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

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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

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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

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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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Basics

Main features 2/2

The concept of sign [de Saussure(1916)]

• ne description to model all properties of words and phrases:

phonology/graphemics morphology syntax semantics pragmatics combinatory (syntagmatic) properties

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                                                 word

PHON

she

SYNSEM

                                            synsem

LOCAL

                                        local

CATEGORY

      category

HEAD

• noun

CASE

nom

• SUBCAT

elist      

CONTENT

           pers-pronoun

INDEX 1

     referential

PER

3rd

NUM

sing

GEND

fem     

RESTRICTION

eset           

CONTEXT

          context

BACKGROUND

                   psoa

QUANTS

elist

NUCL

• female

INST 1

• 

                                                                                                                                                                

Basics

A simple sentence as a tree

        phrase

PHON Molly,sleeps SYNSEM ... HD-DTR 1 NONHD-DTRS 2

       

✟✟✟✟✟ ✟ ❍ ❍ ❍ ❍ ❍ ❍

2

   word

PHON Molly SYNSEM ...

  

1

   word

PHON sleeps SYNSEM ...

   Edges just for readability,

1 and 2 are just values

• f the attributes

HD-DTR and NONHD-DTR. HD-DTR and NONHD-DTR

do not represent word order. Word order is determined by PHON.

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Basics

The same sentence only as a feature structure

                   phrase

PHON Molly,sleeps SYNSEM ... HD-DTR

   word

PHON sleeps SYNSEM ...

  

NONHD-DTRS

   word

PHON Molly SYNSEM ...

  

• 

                 

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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

✟✟✟✟✟✟ ❍ ❍ ❍ ❍ ❍ ❍

Molly

N,fem,nom,sg

him

N,m,acc,sg

that

N,n,acc,sg

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       phrase

PHON told,him SYNSEM

 synsem

HEAD 1

        

✟✟✟✟✟✟ ✟ ❍ ❍ ❍ ❍ ❍ ❍ ❍

          word

PHON told SYNSEM

     synsem

HEAD 1

• verb

VFORM past

• 

                 word

PHON him SYNSEM ...

  

       phrase

PHON Lucy,told,him,that SYNSEM

 synsem

HEAD 1

        

✟✟✟✟✟ ✟ ❍ ❍ ❍ ❍ ❍ ❍

   word

PHON Lucy SYNSEM ...

          phrase

PHON told,him,that SYNSEM

 synsem

HEAD 1

        

✟✟✟✟✟ ❍ ❍ ❍ ❍ ❍

       phrase

PHON told,him SYNSEM

 synsem

HEAD 1

            word

PHON that SYNSEM ...

  

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 NP[nom] rain NP[it] hate NP[nom], NP[acc] look NP[nom], PP[at] give NP[nom], NP[acc], NP[acc] give NP[nom], NP[acc], PP[to] try NP[nom], VP[inf] persuade NP[nom], NP[acc], VP[inf] say NP[nom], S[that]

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Valency

         phrase

PHON John,swims SYNSEM

    synsem

HEAD 1 VAL

            

✟✟✟✟✟ ✟ ❍ ❍ ❍ ❍ ❍ ❍

         phrase

PHON swims SYNSEM

    synsem

HEAD 1 verb VAL 2

                 word

PHON John SYNSEM

2

   

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Valency

Abbreviations

S       phrase

SYNSEM

   synsem

HEAD verb VAL

         VP       phrase

SYNSEM

   synsem

HEAD verb VAL sign

         V       word

SYNSEM

   synsem

HEAD verb VAL list

         NP       phrase

SYNSEM

   synsem

HEAD noun VAL

        

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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 neˇ rekla ‘Lucy didn’t say anything to Jirka.’

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         phrase

PHON jirkovi,neˇ

rekla

SYNSEM

    synsem

HEAD 4 VAL 1 , 2

            

✟✟✟✟✟✟ ❍ ❍ ❍ ❍ ❍ ❍

    word

PHON jirkovi SYNSEM

3

             word

PHON neˇ

rekla

SYNSEM

    synsem

HEAD 4 VAL 1 , 2 , 3

            

         phrase

PHON jirkovi,nic,neˇ

rekla

SYNSEM

    synsem

HEAD 4 VAL 1

            

✟✟✟✟✟ ✟ ❍ ❍ ❍ ❍ ❍ ❍

         phrase

PHON jirkovi,neˇ

rekla

SYNSEM

    synsem

HEAD 4 VAL 1 , 2

                 word

PHON nic SYNSEM

2

   

         phrase

PHON lucka,jirkovi,nic,neˇ

rekla

SYNSEM

    synsem

HEAD 4 VAL

            

✟✟✟✟✟✟ ❍ ❍ ❍ ❍ ❍ ❍

   word

PHON lucka SYNSEM 1

            phrase

PHON jirkovi,nic,neˇ

rekla

SYNSEM

    synsem

HEAD 4 VAL 1

            

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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1

Reading

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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Grammar

Rules

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 ⊕ 2 ] 2

Possible instantiations:

V [ VALENCY 1 ] − → V [ VALENCY 1 ⊕ 2 NP] 2 2 John swims. 2 Mary [loves strawberries]. V [ VALENCY 1 ] − → V [ VALENCY 1 NP ⊕ 2 NP] 2 loves 2 strawberries N [ VALENCY 1 ] − → N [ VALENCY 1 ⊕ 2 DET] 2 2 [my younger sister’s] boyfriend.

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Grammar

More abstractions

H [ VALENCY 4 ] − → H [ VALENCY 4 ⊕ 5 ]

5

phrase →               

PHON f ( 1 , 2 ) HEAD 3 VALENCY 4 HD-DTR

  

PHON 1 HEAD 3 VALENCY 4 ⊕ 5

  

NONHD-DTRS 5

• PHON 2
• 

              The rule schema includes several types of info:

dominance concatenation of PHON values valency satisfaction head features sharing

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Grammar

Principles

Schema phrase →     

PHON f ( 1 , 2 ) HD-DTR

• PHON 1
• NONHD-DTRS 5
• PHON 2
• 

    Head Feature Principle phrase →  

HEAD 3 HD-DTR

• HEAD 3
• 

 Valency Principle phrase →     

SYNSEM | VALENCY 4 HD-DTR

• VALENCY 4 ⊕ 5
• NONHD-DTRS 5

    

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Grammar

The type sign (simplified)

             sign

PHON list(phonstring) SYNSEM

       synsem

CAT

    cat

HEAD head VAL list(synsem)

                       

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1

Reading

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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Semantics

cont

✟✟✟✟ ✟ ❍ ❍ ❍ ❍ ❍

psoa            nom-obj

INDEX

      index

PERS pers NUMB numb GEND gend

     

RESTR set(psoa)

          

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Semantics

psoa

✟✟✟✟✟✟✟✟✟✟ ✟ ❍ ❍ ❍ ❍ ❍ ❍ ❍ ❍ ❍ ❍ ❍

      give

GIVER index GIVEN index RECIPIENT index

     

• swim

SWIMMER index

• ...

psoa

✏✏✏✏✏✏✏✏✏✏✏ ✏

• ❅

❅ ❅ ❅ P P P P P P P P P P P P

• book

INST index

• black

INST index

• quickly

INST psoa

• ...

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Lexical entry for dala:

                         sign

SS

                      synsem

CAT

       cat

HEAD

• verb

VFORM past

• VAL NP[nom] 1 [3rd,sg,fem], NP[dat] 2 , NP[acc] 3

      

CONT

      give

GIVER 1 GIVEN 3 RECIPIENT 2

                                                    

Semantics

NP[nom] i [3rd,sg,fem] :

                         synsem

CAT

       cat

HEAD

• noun

CASE nom

• VAL

      

CONT

         nom-obj

INDEX i

      index

PERS 3rd NUMB sg GEND fem

                                       

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Semantics

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 1

      index

PERS 3rd NUMB sg GEND fem

     

RESTR

  

• book

INST 1

• 

                

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Semantics

NP tlustá kniha ‘a thick book’, the value of CONT:                nom-obj

INDEX 1

      index

PERS 3rd NUMB sg GEND fem

     

RESTR

  

• book

INST 1

• ,
• thick

INST 1

• 

                

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1

Reading

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

✟✟✟ ✟ ❍ ❍ ❍ ❍

NP1 dumplings S/NP1

✟✟ ✟ ❍ ❍ ❍

NP we VP/NP1

✟ ✟ ❍ ❍

V adore NP1 ǫ

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Unbounded dependencies

S

✟✟✟ ✟ ❍ ❍ ❍ ❍

NP1 what S/NP1

✟✟✟ ✟ ❍ ❍ ❍ ❍

NP Mary VP/NP1

✟✟ ❍ ❍

V adores NP1 ǫ

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Unbounded dependencies

S

✟✟✟ ✟ ❍ ❍ ❍ ❍

NP1 who S/NP1

✟✟✟ ✟ ❍ ❍ ❍ ❍

NP Mary VP/NP1

✟✟ ✟ ❍ ❍ ❍

V can’t VP/NP1

✟ ✟ ❍ ❍

V stand NP1 ǫ

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Unbounded dependencies

S

✟✟✟ ✟ ❍ ❍ ❍ ❍

NP1 who S/NP1

✟✟✟ ✟ ❍ ❍ ❍ ❍

NP Lucy VP/NP1

✟✟✟ ✟ ❍ ❍ ❍ ❍

V said S’/NP1

✟✟✟ ✟ ❍ ❍ ❍ ❍

M that S/NP1

✟✟✟ ✟ ❍ ❍ ❍ ❍

NP Mary VP/NP1

✟✟ ✟ ❍ ❍ ❍

V can’t VP/NP1

✟ ✟ ❍ ❍

V stand NP1 ǫ

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                           phrase

PHON list(phonstring) SS

                 synsem

LOCAL

       local

CAT

   cat

HEAD head VAL list(synsem)

         

NONLOCAL

• nonlocal

SLASH set(local)

• 

               

HD-DTR sign NONHD-DTRS list(sign)

                          

Unbounded dependencies

phrase

✟✟✟ ✟ ❍ ❍ ❍ ❍

val-phrase fill-phrase

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Unbounded dependencies

Filler phrase                      fill-phrase

PHON dumplings,we,adore SYNSEM | NONLOCAL | SLASH{} HEAD-DTR

    val-phrase

PHON we,adore SYNSEM | NONLOCAL | SLASH

• 1
• 

  

NONHD-DTRS

          word

PHON dumplings SYNSEM | LOCAL 1

                              

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Unbounded dependencies

Trace         word

PHON SYNSEM

 

LOCAL 1 NONLOCAL | SLASH

• 1
• 

        

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   fill-phrase

P dumplings,we,adore

..SUBJ ..COMPS ..SLASH{}   

✟✟✟✟✟ ❍ ❍ ❍ ❍ ❍

   word

P dumplings

..LOCAL 1        val-phrase

P we,adore

..SUBJ ..COMPS ..SLASH

• 1
• 

  

✟✟✟✟ ✟ ❍ ❍ ❍ ❍ ❍

   word

P we SS 3

       val-phrase

P adore

..SUBJ 3 ..COMPS ..SLASH

• 1
• 

  

✟✟✟✟✟✟ ❍ ❍ ❍ ❍ ❍ ❍

   word

P adore

..SUBJ 3 ..COMPS 2 ..SLASH{}           word

P SS 2

 

LOCAL 1

..SLASH

• 1
• 

       

1

Reading

2

Basics

3

Head features

4

Valency

5

Grammar

6

Semantics

7

Unbounded dependencies

8

Pragmatics

9

References

                                              word

PHON já SS

                                         synsem

CAT

      cat

HEAD

• noun

CASE nom

• VAL

     

CONT

           nom-obj

INDEX 1

     index

PERS 1st NUM sg GEND gend

    

RESTR{}

          

CTX

         ctx

C-INDS

   c-inds

SPEAKER 1 ADDRESSEE index

  

BCKGRND{}

                                                                                               

                                                 word

PHON vy SS

                                           synsem

CAT

       cat

HEAD

• noun

CASE nom

• VAL
• SUBJ , COMPS
• 

     

CONT

      nom-obj

INDEX 1

• index

PERS 2nd, NUM pl, GEND gend

• RESTR{}

     

CTX

               ctx

C-INDS

   c-inds

SPEAKER 2 ADDRESSEE 1

  

BCKGRND

          honor

HONORER 2 HONORED 1

   ,

• non-aggreg

INST 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.

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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].

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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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References

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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