fracas meets transformational grammar - 筑波大学...

FraCaS meets transformational grammar

Yusuke Kubota

Institute for Comparative Research

University of Tsukuba

slides and code available at:

http://www.u.tsukuba.ac.jp/∼kubota.yusuke.fn/papers/unshared-slides.pdf

http://www.u.tsukuba.ac.jp/∼kubota.yusuke.fn/papers/unshared.prolog

Yusuke Kubota FraCaS meets transformational grammar 1 / 20

http://www.u.tsukuba.ac.jp/~kubota.yusuke.fn/papers/unshared-slides.pdf

http://www.u.tsukuba.ac.jp/~kubota.yusuke.fn/papers/unshared.prolog

Overview

Larger goal

I revive the ‘fragment’ approach of Motague grammar intheoretical research in syntax and semantics (which is also oneof the goals of Mineshima et al. (2015, 2016))

More specific goals

I do some modest meta-analysis of Mineshima et al.’s (2015,2016) results

I suggest some possibilities for further facilitatingcommunication between theoretical linguistics andcomputational linguistics


Roadmap

1. Remarks on Mineshima et al. (2015, 2016)

2. Overview the FraCaS ellipsis data

3. Brief introduction to Hybrid TLCG

4. Analysis of ellipsis in Hybrid TLCG

5. Demo


Some aspects of ccg2lambda, New tool in natural language semantics research

I Showed us that inference in higer-order logic is feasible, andyields better results than statistical methods for a certain typeof data.

, Very important first step.

I Already nearly 100% accuracy in some of the sections.

I The system is relatively easy to install, and one can replicatetheir results on one’s own PC.

/ Some potential obstacles:

I (Mainstream) linguists are not familiar with CCG.

I The analysis formulated in ccg2lambda often look differentfrom textbook CCG analyses.

/ Not enough information is provided in an easily accessibleform to encourage related/follow-up work (at least as of11/13/2016).


Some aspects of ccg2lambda, New tool in natural language semantics research

I Showed us that inference in higer-order logic is feasible, andyields better results than statistical methods for a certain typeof data. , Very important first step.

I Already nearly 100% accuracy in some of the sections.

I The system is relatively easy to install, and one can replicatetheir results on one’s own PC.

/ Some potential obstacles:

I (Mainstream) linguists are not familiar with CCG.

I The analysis formulated in ccg2lambda often look differentfrom textbook CCG analyses.

/ Not enough information is provided in an easily accessibleform to encourage related/follow-up work (at least as of11/13/2016).


Textbook CCG analysis vs. ccg2lambda

[Steedman, 2000]

[Martınez-Gomez et al., 2016]


Not enough information given (in print)

From the FraCaS comparative section (not included in the datasetused for evaluation by [Mineshima et al., 2015]):

fracas-230 answer: yes

P1 ITEL won more orders than APCOM did.C ITEL won some orders.

ccg2lambda’s answer: yes



ITEL won more orders than APCOM did.


FraCaS ellipsis section (Search for “fracas xml” on Google)


P1 John spoke to Mary.P2 So did Bill.C Bill spoke to Mary.


P1 John spoke to Mary at four o’clock.P2 And Bill did at five o’clock.C Bill spoke to Mary at five o’clock.


P1 John has spoken to Mary.P2 Bill is going to.C Bill will speak to Mary.


VP ellipsis in CCG?


VP ellipsis in CCG?[Szabolcsi, 1992, 261]

With these observations in mind we may now proceedand see how the phenomenon can be handled in CCG. Itis to be emphasized that in this paper I will not develop adetailed account of VP-ellipsis but concentrate only onthe points relevant for the argument as sketched above.The first task is to accommodate the simplest case ofVP-ellipsis, with which we start:

(40) John [left before Mary did].


Hybrid TLCG [Kubota, 2010, Kubota and Levine, 2015]

I is a version of Type-Logical Categorial Grammar

I can be thought of as a formalization of transformationalgrammar (or the Heim/Kratzer-style syntax-semanticsinterface)


Movement

(1) S

S

S

VP

PP

yesterday

VP

NP

y

V

saw

NP

John

λy

everyone


‘Vertical Slash’ for movement [Oehrle, 1994]

(2) John saw everyone yesterday.

(3)

john;j; NP

saw;see;(NP\S)/NP

" ϕ;x;NP

#1

/Esaw •ϕ;see(x); NP\S

yesterday;yest;(NP\S)\(NP\S)

saw •ϕ • yesterday; yest(see(x)); NP\S\E

john • saw •ϕ • yesterday; yest(see(x))(j); S




(3)

john;j; NP

saw;see;(NP\S)/NP

" ϕ;x;NP

#1




john • saw •ϕ • yesterday; yest(see(x))(j); S�I1

λϕ.john • saw •ϕ • yesterday; λx.yest(see(x))(j); S�NP




(3)

λσ.σ(everyone);

A

person; S�(S�NP)

john;j; NP

saw;see;(NP\S)/NP

" ϕ;x;NP

#1




john • saw •ϕ • yesterday; yest(see(x))(j); S�I1

λϕ.john • saw •ϕ • yesterday; λx.yest(see(x))(j); S�NP�E

john • saw • everyone • yesterday;

A

person(λx.yest(see(x))(j)); S

where

A

person =def λP [∀x.person(x) → P (x)]


Rules in Hybrid TLCGConnective Introduction Elimination

/

......

......

[ϕ; x; A]n

......

......

......

b • ϕ; F ; B/In

b ; λx.F ; B/A

a ; F ; A/B b ; G; B/E

a • b ; F (G); A

\

......

......

[ϕ; x; A]n

......

......

......

ϕ • b ; F ; B \Inb ; λx.F ; A\B

b ; G; B a ; F ; B\A\E

b • a ; F (G); A

�

......

......

[ϕ; x; A]n

......

......

......

b ; F ; B�In

λϕ.b ; λx.F ; B�A

a ; F ; A�B b ; G; B�E

a(b) ; F (G); A


Ellipsis as binding

Pronominal binding‘Quantificational’ analysis of pronominal binding[Bach and Partee, 1980, Morrill et al., 2011, Barker, 2013]:

(4) λσ.σ(he); λRλx.R(x)(x); (NP\S)�((NP\S)�NP)

(5) Every studenti thinks that hei is clever.

(6) λϕ.thinks • that • ϕ • is • clever;λx.λy.think(clever(x))(y); (NP\S)�NP

(7) thinks • that • he • is • clever;λx.think(clever(x))(x); NP\S


Ellipsis as binding

Pronoun:

(4) λσ.σ(he); λRλx.R(x)(x); (NP\S)�((NP\S)�NP)

‘Binding’ analysis of VP ellipsis[Morrill and Merenciano, 1996, Morrill et al., 2011, Barker, 2013]

(8) λσλϕ.σ(did)(ϕ); λRλP.R(P )(P ); (S�VP)�((S�VP)�VP)

(9) John saw Mary and Bill did, too.


Ellipsis as binding

VP ellipsis derivation

(10) John saw Mary and Bill did, too.

(11)

saw • mary;see(m);VP

λσλϕ.σ(did)(ϕ);λRλP.R(P )(P );(S�VP)�(S�VP�VP)

λϕ2λϕ1.john •ϕ1 • and • bill •ϕ2;λQλP.P (j) ∧Q(b);S�VP�VP

λϕ.john •ϕ • and • bill • did;λP.P (j) ∧ P (b); S�VP

john • saw • mary • and • bill • did;see(m)(j) ∧ see(m)(b); S


Some comparisonccg2lambda

I the grammar is available off the shelf, but need to writesemantic templates by hand

I disambiguation is done by grammar

Hybrid TLCG + LinerOne parser

I need to write a grammar (lexicon), but the amont of work isprobably about the same as (or less than) writing semantictemplates for ‘robust’ parsers

I disambiguation isn’t easy (but should we care?)

Conclusion

I At least for linguistically complex types of data for which nostraightforward CCG analysis is available, Hybrid TLCG seemsto offer a promising alternative.


Bach, E. and Partee, B. (1980).Anaphora and semantic structure.In Kreiman, K. and Ojeda, A.,editors, Papers From theParasession on Pronouns andAnaphora, pages 1–28, ChicagoUniversity, Chicago, Illinois. ChicagoLinguistic Society.

Barker, C. (2013).Scopability and sluicing.Linguistics and Philosophy,36(3):187–223.

Kubota, Y. (2010).(In)flexibility of Constituency inJapanese in Multi-Modal CategorialGrammar with StructuredPhonology.PhD thesis, Ohio State University.

Kubota, Y. and Levine, R. (2015).Against ellipsis: Arguments for thedirect licensing of ‘non-canonical’coordinations.Linguistics and Philosophy,38(6):521–576.

Martınez-Gomez, P., Mineshima, K.,Miyao, Y., and Bekki, D. (2016).ccg2lambda: A compositionalsemantics system.In Proceedings of ACL 2016 SystemDemonstrations, pages 85–90,Berlin, Germany. Association forComputational Linguistics.

Mineshima, K., Martınez-Gomez, P.,Miyao, Y., and Bekki, D. (2015).Higher-order logical inference withcompositional semantics.In Proceedings of the 2015Conference on Empirical Methods inNatural Language Processing, pages2055–2061, Lisbon, Portugal.Association for ComputationalLinguistics.

Mineshima, K., Tanaka, R.,Martınez-Gomez, P., Miyao, Y., andBekki, D. (2016).Building compositional semanticsand higher-order inference systemfor a wide-coverage Japanese CCGparser.


In Proceedings of the 2016Conference on Empirical Methods inNatural Language Processing, pages00–00, Austin, Texas. Associationfor Computational Linguistics.

Moot, R. (2014).Hybrid type-logical grammars,first-order linear logic and thedescriptive inadequacy of Lambdagrammars.ms., Laboratoire Bordelais deRecherche en Informatique.

Moot, R. (2015).Comparing and evaluating extendedLambek calculi.In Kubota, Y. and Levine, R.,editors, Proceedings for ESSLLI2015 Workshop ‘Empirical Advancesin Categorial Grammar’, pages108–131. University of Tsukuba andOhio State University.

Morrill, G. and Merenciano, J.-M.(1996).Generalizing discontinuity.

Traitement Automatique desLangues, 27(2):119–143.

Morrill, G., Valentın, O., and Fadda,M. (2011).The displacement calculus.Journal of Logic, Language andInformation, 20(1):1–48.

Oehrle, R. T. (1994).Term-labeled categorial typesystems.Linguistics and Philosophy,17(6):633–678.

Steedman, M. (2000).The Syntactic Process.MIT Press, Cambridge, Mass.

Szabolcsi, A. (1992).Combinatory grammar andprojection from the lexicon.In Sag, I. A. and Szabolcsi, A.,editors, Lexical Matters, number 24in CSLI Lecture Notes, pages241–268. CSLI Publications,Stanford.


Parser for Hybrid TLCG: LinearOneLinearOne parser [Moot, 2014, Moot, 2015]

I Theorem prover for First-order Linear Logic (linear logic withfirst-order quantifiers)

I Implemented in SWP Prolog

I Available open source(https://github.com/RichardMoot/LinearOne)

Hybrid TLCG parser on LinearOne

I Translate /, \, � to ( (implication in linear logic).

I Keep track of word-order information by indexing stringpositions

I Translate all Hybrid TLCG lexical entries and inference rulesto axioms and inference rules in first-order linear logic

I One-to-one correspondence between proofs in first-order linearlogic and derivations in Hybrid TLCG


https://github.com/RichardMoot/LinearOne

fracas meets transformational grammar - 筑波大学...

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