<?xml version="1.0" standalone="yes"?>
<Paper uid="C96-2181">
  <Title>NKRL, a Knowledge Representation Language for Narrative Natural Language Processing</Title>
  <Section position="3" start_page="0" end_page="0" type="metho">
    <SectionTitle>
LRE P61011.
2. The architecture of NKRL
</SectionTitle>
    <Paragraph position="0"> NKRL is a two layer language.</Paragraph>
    <Paragraph position="1"> The lower layer consists of a set of general tools which are structured into several integrated components, four in our case.</Paragraph>
    <Paragraph position="2"> The descriptive component concerns the tools used to produce the formal representations (called predicative templates) of general classes of narrative events, like &amp;quot;moving a generic object&amp;quot;, &amp;quot;formulate a need&amp;quot;, &amp;quot;be present somewhere&amp;quot;. Predicative templates are characterised by a threefold format, where the central piece is a semantic predicate (a primitive, like BEHAVE, EXPERIENCE, MOVE, PRODUCE etc.) whose arguments (role fillers) are introduced by roles as SUBJ(ect), OBJ(ect), SOURCE, DEST(ination), etc. ; the data structures proper to the descriptive component are then similar to the case-grammar structures. Templates are structured into a hierarchy, H TEMP(lates), corresponding, therefore, to a &amp;quot;taxonomy of events&amp;quot;.</Paragraph>
    <Paragraph position="3"> Templates' instances (predicative occurrences), i.e., the NKRL representation of single, specific events like &amp;quot;Tomorrow, I will move the wardrobe&amp;quot;, &amp;quot;Lucy was looking for a taxi&amp;quot;, &amp;quot;Peter lives in Paris&amp;quot;, ,are in the domain of the factual component.</Paragraph>
    <Paragraph position="4"> The definitional component supplies the NKRL representations, called concepts, of all the general notions, like physical_entity, human_being, taxi_, city_, etc., which can play the role of arguments within the data su'uctures of the two components above. The concepts correspond to sets or collections, organised according to a generalisation/specialisation (tangled) hier~chy which, for historical reasons, is called H_CLASS(es). The data structures used for the concepts are, substantially, frame-like structures ; H_CLASS corresponds relatively well, therefore, to the usual ontologies of terms.</Paragraph>
    <Paragraph position="5"> The enumerative component of NKRL concerns the formal representation of the instances (concrete, countable ex,'unples, see lucy_, wardrobe_l, taxi_53) of the concepts of H CLASS ; their formal representations take the name of individuals.</Paragraph>
    <Paragraph position="6"> Throughout this paper, we will use the italic type style to represent a &amp;quot;concept&amp;quot;, the roman style to represent an &amp;quot;individual_&amp;quot;.</Paragraph>
    <Paragraph position="7"> The upper layer of NKRL consists of two parts.</Paragraph>
    <Paragraph position="8"> The first is a &amp;quot;catalogue&amp;quot;, giving a complete description of the formal characteristics and the modalities of use of the well-formed, &amp;quot;basic templates&amp;quot; (like &amp;quot;moving a generic object&amp;quot; mentioned above) associated with the language -- presently, about 150, pertaining mainly to a (very general) socio-economicopolitical context where the m~fin characters are human being~ or social bodies. By means of proper specialisation operations it is then possible to obtain, from the basic templates, the (specific) &amp;quot;derived&amp;quot; templates that could be concretely needed to implement a particular, practical application -- e.g., &amp;quot;move an industrial process&amp;quot; -- and the corresponding occurrences. In NKRL, the set of legal, basic templates can be considered, at least in a first approach, ,as fixed.</Paragraph>
    <Paragraph position="9"> Analogously, the general concepts which pertain to the upper levels of H_CLASS -- such as human_being, physicalentity, modality_, etc. -form a sort of upper-level, ilwariable ontology.</Paragraph>
  </Section>
  <Section position="4" start_page="0" end_page="1033" type="metho">
    <SectionTitle>
3. Some characteristic NKRL features
</SectionTitle>
    <Paragraph position="0"> Fig. 1 supplies a simple exmnple of NKRL code. It translates a small fragment of COBALT news : &amp;quot;Milan, October 15, 1993. qhe financial daily 11 Sole  24 Ore reported Mediobanca had called a special lx),'ud meeting concerning plums for capital increKse&amp;quot;.  In Fig. 1, cl and c2 are symbolic labels of occurrences ; MOVE and PRODUCE are predicates ; SUB J, OBJ, TOPIC (&amp;quot;,:l propos of...&amp;quot;) are roles. With respect now to the arguments, sole 24 ore, milan_, mediobanca_ (an Italian merchant bank), summoning l, etc. ,'u'e individuals ;financialdaily, special_, cardirtality_ and several_ (this last belonging, like some , all_ etc., to the logical_quantifier intensional sub-tree of II_CLASS) are concepts, q\]~e attributive operator, SPECIF(icatiou), with syulax (SPECIF el Pl -.. Pn), is used to represent some of tile properties which can be asserted about the first element el, concept or individual, of a SPECIF list ; several is used within a SPECIF list having cardinality_ as first element as a standard way of representing the plural number mark, sec c2.</Paragraph>
    <Paragraph position="1"> The arguments, and file templates/occurrences as a whole, may be characterised by the presence of pro'titular codes, the determiners. For example, the location determiners, represented as lists, are associated with the m'guments (role fillers) by using the colon, &amp;quot;:&amp;quot;, operator, see cl. For the determiners date-1 and date-2, see (Zarri, 1992a).</Paragraph>
    <Paragraph position="2"> A MOVE consUuctiou like that of occurrence el (completive construction) is necessarily used to translate any event concerning the transmission of an information (&amp;quot;... I1 Sole 24 Ore reported ...&amp;quot;). Accordingly, the filler of the OBJ(ect) slot in the occurrences (here, cl) which instantiates the MOVE transmission template is ~dways a symbolic label (c2) which refers to anolher predicative cx:curreuce, i.e., that bearing the informational content to be spread out (&amp;quot;... Mediobanca had called a meeting ...&amp;quot;). We can note that the enunciative situation can be both explicit or implicit. For example, the eompletive construction can be used to deal with a problem originally raised by Naz,'u'enko (1992) in a conceptual graphs context, namely, that of the correct rendering of causal situations where the general framework of the m~tecedent consists of an (implicit) speech situation. Let us examine briefly one of the Nazarenko's exmnples (1992 : 881) : &amp;quot;Peter has a lever since he is flushed&amp;quot;. As Naz~enko remarks, &amp;quot;being flushed&amp;quot; is not the &amp;quot;cause&amp;quot; of &amp;quot;having a fever&amp;quot;, but that of an implicit enunciative situation where we claim (affirm, assert etc.) that someone has a fever. Using the completive construction, this example is easily translated in NKRL using the I'onr occmTences of Fig. 2.</Paragraph>
    <Paragraph position="3">  We cau remark that, in Fig. 2, c6 is a binding occun'ence. Binding structures -- i.e., lists where the elements are conceptual labels, c3 and c5 in Fig. 2 -~ne second-order structures used to represeut the logico-semantic links which can exist between predicative templates or teem'fences. The binding occun'ence c6 -meaning that c3, the main event, has been caused by c5 -- is labelled using one (CAUSE) of the four operators which define together the taxonomy of causality of NKRL, see (Zarri, 1992b). The presence in c5 of a specific determiner -- a temporal modulator, &amp;quot;obs(ervc)&amp;quot;, see again (Zarri, 1992a) -- leads to an iuterprelalion of this occurrence as the description of a situatiou that, that very moment, is observed to exist. We give now, Fig. 3, a (slightly simplified) NKRL represeutation of the narrative sentence : &amp;quot;We have to make orange juice&amp;quot; which, according to  ii i i i Fig. 3 illustrates the standard NKRL way of representing the &amp;quot;wishes, desires, intention&amp;quot; domain. To translate the idea of &amp;quot;acting in order to obtain a given result&amp;quot;, we use : i) An occurrence (here c7), instance of a basic template pertaining to the BEIIAVE branch of the H TEMP hierarchy, and corresponding to the general meaniug of focusing on a result. This occurrence is used to express the &amp;quot;acting&amp;quot;  component -- i.e., it identifies the SUBJ(ect) of the action, the temporal co-ordinates, etc.</Paragraph>
    <Paragraph position="4"> ii) A second predicative occurrence, here c8, all instance of a template structured around a different predicate (e.g., PRODUCE in Fig. 3) and which is used to express the &amp;quot;intended result&amp;quot; component. iii) A binding occmTence, c9, which links together the previous predicative occurrences and which is labelled by means of GOAL, another operator included in tile taxonomy of causality of NKRL.</Paragraph>
    <Paragraph position="5"> Please note that &amp;quot;oblig&amp;quot; and &amp;quot;ment&amp;quot; in Fig. 3 are, like &amp;quot;obs&amp;quot; in Fig. 2, &amp;quot;modulators&amp;quot;, see (Zan-i, 1992b), i.e., particular determiners used to refine or modify the primary interpretation of a template or occurrence as given by the basic &amp;quot;predicate -- roles -- argument&amp;quot; association. &amp;quot;ment(al)&amp;quot; pertains to the modality modulators. &amp;quot;oblig(atory)&amp;quot; suggests that &amp;quot;someone is obliged to do or to endure something, e.g., by authority&amp;quot;, and pertains to the deontic modulators series. Other modulators are the temporal modulators, &amp;quot;begin&amp;quot;, &amp;quot;end&amp;quot;, &amp;quot;obs(erve)&amp;quot;, see also Fig. 2. Modulators work as global operators which take as their argument tile whole (predicative) template or occurrence. When a list of modulators is present, as in the occurrence c7 of Fig. 3, they apply successively to the template/occurrence in a polish notation style to avoid any possibility of scope ambiguity. In the standard constructions for expressing wishes, desires and intentions, tile absence of the &amp;quot;ment(al)&amp;quot; modulator in the BEHAVE occurrence meaus that tile SUBJ(ect) of BEHAVE takes some concrete initiative (acts explicitly) in order to fulfil the result ; if &amp;quot;merit&amp;quot; is present, as in Fig. 3, no concrete action is undertaken, and the &amp;quot;result&amp;quot; reflects only the wishes and desires of the SUBJ(ec0.</Paragraph>
  </Section>
class="xml-element"></Paper>