File Information
File: 05-lr/acl_arc_1_sum/cleansed_text/xml_by_section/metho/96/c96-2207_metho.xml
Size: 19,636 bytes
Last Modified: 2025-10-06 14:14:20
<?xml version="1.0" standalone="yes"?> <Paper uid="C96-2207"> <Title>HOW THE LINGUISTIC NEGATION CAN HAVE AN EFFECT IN OB3ECT-BASED KNOWLEDGE REPRESENTATION MODEL</Title> <Section position="1" start_page="0" end_page="0" type="metho"> <SectionTitle> HOW THE LINGUISTIC NEGATION CAN HAVE AN EFFECT IN OB3ECT-BASED KNOWLEDGE REPRESENTATION MODEL </SectionTitle> <Paragraph position="0"/> </Section> <Section position="2" start_page="0" end_page="0" type="metho"> <SectionTitle> Abstract </SectionTitle> <Paragraph position="0"> I,I this paper, the coh(H;ell(:e is co/,sider('d within the framcw()rlC/ of' kn(/wh:(lgc representati(/n ()\[ texts. Though the in(;o-}lerel|(;(' ()f a text may resu\]t from a lot of \[)heIlOlllella) w(? restri(;t ourselves in this COllll\[tlllliCatio\[l \[,O illcoh(\]l'OllCe stelrllllillg from negations. We l)re.sent I;he mod('l and the etl'ect o\[' ncga.tion on its objects.</Paragraph> </Section> <Section position="3" start_page="0" end_page="0" type="metho"> <SectionTitle> 1 Introduction </SectionTitle> <Paragraph position="0"> 'l'his c.onmmnical, ion aims t() clarify 1;11('. conce.l)t el (:oh(,renc(~ in knowledge rel)res(mtation for natural language discourses and to pose tim first foundations tk)r formal rel)re.sentation and autotrmtic pro.</Paragraph> <Paragraph position="1"> cessiug of coherence.</Paragraph> <Paragraph position="2"> We must emphasiz(: tirst that coherence in natm ral language disc()urses may result from incoherent parts : a t)arL o\['a discern:st may 1)c contradictory with what is said in other parts without questiou-ing the coh(.'rencc of the whoh~. For examI)le, a (li-gression, a sut)p(/sition, an invalid hypothesis may be inehlded as a part of a dis(;om:se and ruled out l)y what folh)ws. So, a &quot;lapse of memory&quot; el)crates often in text coml)rehension arid \[)rotecl,s the text \['rein dee\]) incoherence. This means, of course, that coherence in natural language discourses is quite diffecent from tim consistency in a mat|w,matit:al theory, which has Lo be consistent in each o\[' its sets of i)rol)ositions. So, a cohcr(mce theory for natural language representation systenls must take into account this fact and limit the c()herence vcrilication to parts of texts actually asserted.</Paragraph> <Paragraph position="3"> At a de('q) level at least, we pose the hypothesis that a text is generally coherent. So the llrob\]era we address to is to try to detect incoherence. Though the incoherence of a text may result from a lot of phenomena, we restri(-t ourselves in this communication to incoherence stemming from negal, ions. But surface negations must lie inter.</Paragraph> <Paragraph position="4"> l)r(d;ed in the t\]'amework of linguistics theory : this is the Iirst l)art of our work (not included here duo.</Paragraph> <Paragraph position="5"> to lack of space.). This study shows that negation is very sehlom at the origin of incoherct,:c. The last paN; of the communication is (levot(~d to the taldng into acc.ount of negatioll in a st)celtic cas(: of knowledge in our of lC/tJowl('.(lge represe\[ttation system.</Paragraph> </Section> <Section position="4" start_page="0" end_page="1140" type="metho"> <SectionTitle> 2 The knowledge representation </SectionTitle> <Paragraph position="0"> me del</Paragraph> <Section position="1" start_page="0" end_page="0" type="sub_section"> <SectionTitle> 2.1 Origin of tim mo(lel </SectionTitle> <Paragraph position="0"> Many knowledge rc/iresentation systems exist; (,lie need for a new one came front the type ()1' kuowledge we aim to represent ;rod fl'om the reasonings we try Lo imp\]em('.nt. Tim framework of the rllo(h'.l is linguistic pragmatics : wc want to represent the linguistic marks of 1)ragmaties (and not the pragmatics of ail al)l)lieation ). Thus, the knowledge associated to a discourse is represented at two levels :a knowledge representation of the npplication do-main (which is outside Lira llaturaI languag(! sys tom) and the model we are concerned wit\]l here, and which is the (h'.c:t)('.st level of our natured language analysis (the pragmatic level). These constrainLs cxt)lain wily the existing knowledge rel)re-.</Paragraph> <Paragraph position="1"> Selltal;ioll systeHts al'e tlO\[, COllVel'li,eiII; \['()r ollr put pose : the information is sl)ecific and, at)eve all, the reasonings to l)er\['(/rni are t/rOl)('r (,o natural language discom:ses. 'l'he prototype ()\[ these rea-sonings is the at)du(-tiv(: one, in which, from a property asserted in the text we infer an object, which t)ossesses this property ~m(\[, then, we consider all the characteristics of tile selected object as valid for I;he text.</Paragraph> </Section> <Section position="2" start_page="0" end_page="1139" type="sub_section"> <SectionTitle> 2.2 Outline of the rei)resentation mo(h~l </SectionTitle> <Paragraph position="0"> The knowledge rcpres(;ntation rno(h'.\] is an object ()\[IC, expross(.~d ill a particular logic forntalisrn.</Paragraph> <Paragraph position="1"> The underlying logic is that of M'\]SNII';WSKI's logical systems \[Lesniowski, \] 989\], \[Midvi Ih;, 1984\], \[ILouault, \[991\]. In those systems, the primitivt's of an oh jet.l, model correspond to the &quot;is-a&quot; of l;\]w (3aleulus of Names and t;he ingredient \['unctor o1&quot; the. Mereology \[Achou/)a and Rouault, 198!)\]. We have th us a h)gic;d basis for the primitives of most object models and a framework for the. inductive part of the system.</Paragraph> <Paragraph position="2"> 'l'he individuals of the knowledge base are objects. This base is divided into worlds. A world is a structured set of objects which is coherent : the exceptions, change of meanings are taken into account by a change of world. A world is divided into two universes : its intension and its extension. The intension contains those objects whose representation is supposed valid for speakers and situations related to discourse enunciation aitd to the application dolnain : there exists a consensus between the speakers of the discom:se about these objects, which reflects &quot;general&quot; background knowledge (77~e dog is a stupid and spiteJ)U animal), The intensional objects are then kinds of &quot;logical&quot; concepts in their world. The extension of a world contains objects which are particular to a specific situation, a specific time, ... (Peter's dog barked all night long). There is inheritance from intension to extension of the same world, but the extensions of two different worlds do not communicate. In case of change of world, a complex inheritance procedure must transmit only knowledge which insures the coherence of the new world from the. old intension to the new one (This, also stresses tit(; necessity to be able to detect incoherence in a discourse).</Paragraph> <Paragraph position="3"> There are three kinds of objects in the model (and hence in any world and universe) : the individual objects, the action schemata \[Gallo and Rouault, 1992\] and the state schemata.</Paragraph> </Section> <Section position="3" start_page="1139" end_page="1139" type="sub_section"> <SectionTitle> 2.3 The individual objects </SectionTitle> <Paragraph position="0"> In our model, art individual object has the following structure:\[Rouault, 1992\] This part imticate the conditions of validity of an object. It be composed of several objects: World A discourse cart generate worlds. For each object, the system must specify in what world it must be introduced, where it is valid and where we can make inferences that bring it into play. We therefore pose:</Paragraph> <Paragraph position="2"> I is tit(', name of the described object. &quot;world&quot; is the formative functor of name, the variable M is the value of the world that the discourse created.</Paragraph> <Paragraph position="3"> When the knowledge coming from the discourse is incoherent with the knowledge base, there is world change. This change can come equally from a difference of view points between spe.akers expressed in the discourse \[Fredj, :1992\].</Paragraph> <Paragraph position="4"> Universes An universe denotes to a couple (I,I{) formed of an intension (I) and an extension (1{,).</Paragraph> <Paragraph position="5"> The object is defined in the world by a formative %nctor of name, from I \[Berrendonner and Renault, 1991\].</Paragraph> <Paragraph position="6"> U 5 Universe (l) U takes the vahie Inl or Ea:t.</Paragraph> <Paragraph position="7"> Individual and ('lass An object can be an individual or a class. This distinction is based on the singular \[ plural opposition. The individuality is defined by a forlnative fimctor of name, from l: In C/ ind~v (I) in takes the value Ind or CI Here, we discovered two kind of sub-objects: those which are part of the described object and those which relate the object descl:ibed a.nd others objects of the world. The name of an ob.iect represents the sub-object of the denomination.</Paragraph> <Paragraph position="8"> N c de'aomin, al, ion (\[) We also call associate to a name of an object other synonyms. These sub-objects arc defined by the formative flmetor of nalne whose the argument is the name of object.</Paragraph> <Paragraph position="9"> Ni g other-names (I) Structural sub-objects represent the part o\[' ingredience, &quot;part-all&quot;, in the sens of&quot; the mereelegy. It means tltat it describe.s the. relation between an object and its constitive parts. They are of the form: I e in~ir (,U Object Iis a part of objecl, J. i.e. The 'wheel is a parl of the bike.</Paragraph> <Paragraph position="10"> Functive. It indicates a relation between the object considered and another object. This relation is marked on the surface by a verb or normalised verbal form \[Berrendonner and al, 1992\]. A functive has the following form:</Paragraph> <Paragraph position="12"> Where Iis the object described and J is the object with which i is connected by the functivc f</Paragraph> </Section> <Section position="4" start_page="1139" end_page="1140" type="sub_section"> <SectionTitle> 2.4 Predicative obje('.ts </SectionTitle> <Paragraph position="0"> The functives of an individual object act as relations between objects. We have to pose the properties of such relations : depending on if they refer to an action or a state, a relation is defined by an action schema or a state schema. An action schema contains the following sub-objects \[Gallo and Renault, 1992\] :the name(s) of the action, the nature of the arguments, the state(s) evenl;ually entailed by the action (result, pro(|uct, ...) and the scenario associated to the i)rocess, whi('it depends on the discourse <lo,min.</Paragraph> </Section> <Section position="5" start_page="1140" end_page="1140" type="sub_section"> <SectionTitle> 2.5 Structuring of the knowledge base </SectionTitle> <Paragraph position="0"> In the intensional universe of a world, the in(lividuals (also named types) are nodes of a lattice (the lattice o1&quot; types), the hierarchy l)eing represente.d by t;he ingredient( fun(tot. The types are also linked by their stru('tura\] and fun(tire sub=ol<jects. Of course, the extensional objects arc, lmke(\[ also/>y their structural and functives subobje(:ts. And each such object is in accord with its un<lerlying tyl>e.</Paragraph> </Section> </Section> <Section position="5" start_page="1140" end_page="1141" type="metho"> <SectionTitle> 3 Negations in the object-based </SectionTitle> <Paragraph position="0"> knowledge representation model</Paragraph> <Section position="1" start_page="1140" end_page="1140" type="sub_section"> <SectionTitle> 3.1 Negations and objects </SectionTitle> <Paragraph position="0"> '\]'\]m aim of the mo(l(;l is to rot)resent dynamically the knowledge associated with a (list(mrs( at a given point (time) of its progression. Thus, each object may (;hang( during this progress : we must then (listinguish betwe(:n this &quot;punctu&l&quot; repre senCation and the history of objects (which ig is necessary to maintain in the (:as( of a dialogue, for exaniple). We are concerned here only with the updating of a knowledge/)ase containing the knowledge valid for a discourse at a given time of its progression.</Paragraph> <Paragraph position="1"> Un(ier ~his restriction, the knowledge stored in the base is positive : when the discern:s( asserts a negatiw ~, fact (Do(is arc not slupid), this presttpl)OScs that the positive corresponding fiu:t (Doqs arc slupid) has ah:e~dy been asserted (exl)licitly or implicitly) nnd that a eonl, radiction may arise. In a mono-sl)eaker discourse (text), the general situation seems to be : tim assertion of a negative fact simply (:rases the positive one (of course, this erasing is virtual when the positive fact is only l>resul)posed). In a multi-speaker discourse (dialogue, for example, a negotiation is sell(able to de tide which of the two possibilities (the positive or the negative fact) is to be incht(h~ in the knowledge base. In all these cases, we have to be able to infer properties about objects from negative assertions; which in tttrtt, need to re.present the formal properties o\[&quot; different kinds of negations operating on sub-objects of an object.</Paragraph> </Section> <Section position="2" start_page="1140" end_page="1141" type="sub_section"> <SectionTitle> 3.2 Negation on types </SectionTitle> <Paragraph position="0"> As indicate(l l)reviously, only the intensional objects (the types) haw.' a &quot; h)gical&quot; behaviour : they represent generM knowledge valid in the discourse.</Paragraph> <Paragraph position="1"> The infer('.n(:0~ rules about negations are valid only it, the intensional universe. We then have to define what are the types of negations involved in the type rel)resentation.</Paragraph> <Paragraph position="2"> 3.2.1. Negation about the worht The type is negated in the present worhl but mq> posed valid elsewhere.</Paragraph> <Paragraph position="3"> For the linguists, the negation is not a simple problem For tit(: mathematical logiciau, a negation is a simple problem Starting from a worhl where the negation is a, simple problem (which, \[or example, is matheTnatieal logician), thc previous assertion entails tim opening of a new world, in which the new fact is asserted (7'he ncgation is uot a simple problem). When a discourse is expressed by mono-speaker, the assertion <)f a positive fact (the ncgation is not a simple fact) provoke a contradiction in the same world. This contradi<:tion can 1)e based at least on the dill'create betwec.n sub-objects of type: 'is ~, 'is not'. The solution seemingly substitutes a positive fact by a negative fa.ct one.</Paragraph> <Paragraph position="4"> A fact preserLted as a type is negated as such and related to extensional objects (or the converse) : 7'hc doq is not a stupid animal, but Fctcr's is.</Paragraph> <Paragraph position="5"> it is sitnply a change of v;Jtte elf tile, eardinality value. 3.2.4 Negation about denominations Negation can focus on the &quot;denominations&quot; a.nd &quot;others-names&quot; sub-objects, l)enyi,g a &quot;denomination&quot; or &quot;other- natncs&quot;, means to denying a property of the object. \[n this (:a.se, a new prop(~rty is sld)stit,ed to a s.b-object. \[';xamplc: the pcrsonal computer is uot an 'IBM', but a 'COPAM+ '. Note, belbre, replacing a ne.w property~ the me(hi must verify that the new property is really a, property o |a lypc because there is a case: where a substitution makes no sense: the personal compaler is not an 'IBM', but a 'print(r&quot; Here it is the ingrcdien(:e relation whi(:h is negated i.e. 7'he wall is part of a housc. \[n some (:rises, the he:gallon of \[A isingr It\] suggests the ingredi(mcc of the object A to another type (J, such that there exists a type 1) which is greater than 13 and (7 in the lattice of types : The spoke wheel is not a part of a ear (it Zs part of a bike').</Paragraph> <Paragraph position="6"> 3.2.6 Negation on notional sub-obje(-ts 7'he lcavcs arc green/ The leaves arc not green '\['he infer(nee possibilities from the negative assertion arc: of two kinds : - There is a finite opposition between the notion and its &quot;lexical negation&quot; (Blood is red / 111ood is not rcd= It is (>f another eolour).</Paragraph> <Paragraph position="7"> - There is a contimmm (as in big/small) and we can not infer small from not big.</Paragraph> <Paragraph position="8"> 3.2.7 Ne.gation on fun(tire sub-objects As indicated previously, the uuinber of a.ttested arguments of the predicate may change the interpretation of the negation : \]. 'The cow docs not cat' is the negation of 'The. cow cats' 2. 'The cow does not ('.at meat' is generally not the negation of the property 'The cow eats meat amon~t other kinds of food)' but the assertion of '27tc cow cats something' and (,he negation of the choice of meat as food. Ifere we still refer to another type having with meat the satne generic class (food) in the lattice of types.</Paragraph> <Paragraph position="9"> 3. We have the same situation in: The cow does not eat with a knife The cow does not cat grass with a knifc Thc cow does not eat meat in Paris In these examples, only the choice of the last argument seems to bc concerned by the negation.</Paragraph> </Section> <Section position="3" start_page="1141" end_page="1141" type="sub_section"> <SectionTitle> 3.3 Negation of extensional objects </SectionTitle> <Paragraph position="0"> A type underlies extensional objects : a change in the properties of a type entails the same change in the associated extensional objects. Of course, the reverse is not true : an extensionM object may have properties not possessed by the underlying type. From this it resalts that the only coherence for an extensional object is internal : it can not have contradictory sub-objects.</Paragraph> <Paragraph position="1"> Note that ~n extensional object may be an individual or a (:lass ; of course, all the elements of the class must have the same properties. \]n fact, class and individual always coexist. Therefore, it is legal to infer a class of type T when the discourse introduces art individual of type '\['. This is obvious in 'It is one of the neighbour's dogs' and also in 'lie does not have children, only one'. The last example shows that the negation of a property about a class may have two interpretation: the ordinary one, in which the prop-erty is negated for tit(', individual of the class attd the negation of the (:lass itself (or, conversely, of the individual) to pose the property about an individual (a (:lass).</Paragraph> <Paragraph position="2"> lit the sentence : ' Only Peter came ', we pose a prop-erty Mmttt Peter; then 'only' introduces the class and, of the same time, indicates that the class contains only Peter. This entails that tit(', negation may focus on only (negation that the class contains only one individnM) or on the property (Pcter caste), then asserted about 'only Peter'.</Paragraph> <Paragraph position="3"> Another interesting example is 'All students succeed' : we assert a property about the class student and, then, specify that the class is studious, that is : the property is valid for all individuals of the (:lass. in other words, that the class is the extensional projection of the type student: As in previous example, (,he negation can operate on all (the class is not studious) or on tire property asserted about ,~11 students.</Paragraph> </Section> </Section> class="xml-element"></Paper>