Language Processing with Perl and Prolog: Theories, Implementation, and Application

675 Pages·2014·11.581 MB·

by  Pierre M. Nugues (auth.)

Cognitive Technologies
Pierre M. Nugues
Language
Processing with
Perl and Prolog
Theories, Implementation, and
Application
Second Edition
Cognitive Technologies
ManagingEditors: D.M.Gabbay J.Siekmann
Editorial Board: A.Bundy J.G.Carbonell
M.Pinkal H.Uszkoreit M.Veloso W.Wahlster
M.J.Wooldridge
Forfurthervolumes:
http://www.springer.com/series/5216

Pierre M. Nugues
Language Processing
with Perl and Prolog
Theories, Implementation, and Application
Second Edition
123
PierreM.Nugues
DepartmentofComputerScience
LundUniversity
Lund,Sweden
ManagingEditors
DovM.Gabbay JörgSiekmann
AugustusDeMorganProfessorofLogic ForschungsbereichDeduktions-und
DepartmentofComputerScience Multiagentensysteme
King’sCollegeLondon DFKI
London,UK Saarbrücken,Germany
ISSN1611-2482 CognitiveTechnologies ISSN2197-6635(electronic)
ISBN978-3-642-41463-3 ISBN978-3-642-41464-0(eBook)
DOI10.1007/978-3-642-41464-0
SpringerHeidelbergNewYorkDordrechtLondon
LibraryofCongressControlNumber:2014945101
©Springer-VerlagBerlinHeidelberg2014
Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartof
thematerialisconcerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation,
broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionorinformation
storageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodology
nowknownorhereafterdeveloped.Exemptedfromthislegalreservationarebriefexcerptsinconnection
with reviews or scholarly analysis or material supplied specifically for the purpose of being entered
and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of
this publication or parts thereof is permitted only under the provisions of the Copyright Law of the
Publisher’slocation,initscurrentversion,andpermissionforusemustalwaysbeobtainedfromSpringer.
PermissionsforusemaybeobtainedthroughRightsLinkattheCopyrightClearanceCenter.Violations
areliabletoprosecutionundertherespectiveCopyrightLaw.
Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublication
doesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevant
protectivelawsandregulationsandthereforefreeforgeneraluse.
While the advice and information in this book are believed to be true and accurate at the date of
publication,neithertheauthorsnortheeditorsnorthepublishercanacceptanylegalresponsibilityfor
anyerrorsoromissionsthatmaybemade.Thepublishermakesnowarranty,expressorimplied,with
respecttothematerialcontainedherein.
Printedonacid-freepaper
SpringerispartofSpringerScience+BusinessMedia(www.springer.com)
Àmesparents,
ÀMadeleine

Preface to the Second Edition
Eightyears,from2006to2014,isaverylongtimeincomputerscience.Thetrends
I described in the preface of the first edition have not only been confirmed, but
accelerated.Itriedtoreflectthiswithacompleterevisionofthetechniquesexposed
in this book: I redesigned or updated all the chapters, I introduced two new ones,
and, most notably, I considerably expanded the sections using machine-learning
techniques.Tomakeplaceforthem,Iremovedafewalgorithmsoflesserinterest.
This enabled me to keep the size of the book to ca. 700 pages. The programs and
companionslidesareavailablefromthebookwebsiteathttp://ilppp.cs.lth.se/.
ThisbookcorrespondstoacourseinnaturallanguageprocessingofferedatLund
University.Iamgratefultoallthestudentswhotookitandhelpedmewritethisnew
editionthroughtheircommentsandquestions.Curiousreaderscanvisitthecourse
siteathttp://cs.lth.se/EDAN20/andseehowweusethisbookinateachingcontext.
Iwouldliketothankthemanyreadersofthefirsteditionwhogavemefeedback
or reported errors, the anonymous copy editor of the first and second editions,
Richard Johansson and Michael Covington for their suggestions, as well as Peter
Exner,thePhDcandidateIsupervisedduringthisperiod,forhisenthusiasm.Special
thanks go to Ronan Nugent, my editor at Springer, for his thorough review and
copyeditingalongwithhisadviceonstyleandcontent.
This preface would not be complete without aword tothose who passed away,
myaunt,Madeleine,andmyfather,Pierre.ThereisneveradayIdonotthinkofyou.
Lund,Sweden PierreNugues
April2014
vii

Preface
Inthepast20years,naturallanguageprocessingandcomputationallinguisticshave
considerablymatured.Themovehasmainlybeendrivenbythemassiveincreaseof
textualandspokendataandtheneedtoprocessthemautomatically.Thisdramatic
growthofavailabledataspurredthedesignofnewconceptsandmethods,ortheir
improvement,sothattheycouldscaleupfromafewlaboratoryprototypestoproven
applications used by billions of people. Concurrently, the speed and capacity of
machinesbecameanorderofmagnitudelarger,enablingustoprocessgigabytesof
data and billions of words in a reasonable time, to train, test, retrain, and retest
algorithms like never before. Although systems entirely dedicated to language
processingremainscarce,therearenowscoresofapplicationsthat,tosomeextent,
embedlanguageprocessingtechniques.
Theindustrytrend,aswellastheuser’swishes,towardinformationsystemsable
toprocesstextualdatahasmadelanguageprocessinganewrequirementformany
computer science students. This has shifted the focus of textbooks from readers
being mostly researchers or graduate students to a larger public, from readings by
specialists to pragmatism and applied programming. Natural language processing
techniques are not completely stable, however. They consist of a mix that ranges
fromwell-masteredandroutinetorapidlychanging.Thismakestheexistenceofa
newbookanopportunityaswellasachallenge.
This book tries to take on this challenge and find the right balance. It adopts
a hands-on approach. It is a basic observation that many students have difficulties
going from an algorithm exposed using pseudocode to a runnable program. I did
mybesttobridgethegapandprovidethestudentswithprogramsandready-made
solutions. The book contains real code the reader can study, run, modify, and run
again. I chose to write examples in two languages to make the algorithms easy to
understandandencode:PerlandProlog.
One of the major driving forces behind the recent improvements in natural
languageprocessingistheincreaseoftextresourcesandannotateddata.Thehuge
amount of texts made available by the Internet and never-ending digitization led
many practitioners to evolve from theory-oriented, armchair linguists to frantic
empiricists.Thisbooksattemptsaswellasitcantopayattentiontothistrendand
ix