<?xml version="1.0" standalone="yes"?>
<Paper uid="E83-1021">
  <Title>i AN APPROACH TO NATURAL LANGUAGE IN THE SI-NETS PARADIGtl</Title>
  <Section position="4" start_page="123" end_page="123" type="metho">
    <SectionTitle>
IV WHY A NEW LANGUAGE?
</SectionTitle>
    <Paragraph position="0"> The question now arises whether it is possible to reduce these types of operations to a set of functions of a formal language each of which covers a well defined process which corresponds to a well defined set of operations on SI-Nets - to a set of KL-Magma functions.</Paragraph>
    <Paragraph position="1"> The choice of a new language has many motivations: a) from the conceptual viewpoint, this means reducing operations to functions that are well defined from a semantic viet~polnt which lend clearness to tile process to be represented.</Paragraph>
    <Paragraph position="2"> a) from the epistemological viewpoint, it is reasonable to think that a language, such as KL-Magma, may be extended by another language thus achieving a higher degree of abstraction.</Paragraph>
    <Paragraph position="3"> c) a language is a uniform mechanism for the integration of interpreters of several symbolic processes. This integration is likely to bring out more clearly relevant phenomena of the process represented.</Paragraph>
  </Section>
  <Section position="5" start_page="123" end_page="124" type="metho">
    <SectionTitle>
V KL-CONC
</SectionTitle>
    <Paragraph position="0"> On the basis of the linguistic assumptions previously outlincd and using KL-Hagma as a language which handles SI-Nets, we are now designing and implementing an experimental, language, KL-ConL, whose functions try to simulate the conceptual operations previously described.</Paragraph>
    <Paragraph position="1"> A. KL-Conc: Internal Organization Before describing KL-Conc functions in detail, it is worth while discussing its internal organization.</Paragraph>
    <Paragraph position="2">  In the framework of KL-oNE, a relevant distinction has been drawn between the Terminological Box (T-Box) and the Assertional Box (A-Box) (Brachman, 1981). The T-~ox maintains the detailed description of the objects while the A-Box contains the set of the assertions on the objects. The former corresponds to the ability of describing by the use of NPs, and the latter to that of constructing complex sentences.</Paragraph>
    <Paragraph position="3"> A discussion has arisen whether it Is possible to handle the two boxes, which correspond to two different areas of memory, using the same language.</Paragraph>
    <Paragraph position="4"> In KL-O~E, new functions have been added in order to glve it an assert~onal power (nexus, context) (Woods 1979).</Paragraph>
    <Paragraph position="5"> A recent extellsion of KL-O~IE (Brachmsn et al., 1983) has adopted the solution of cresting two distinct languages: one for the T-Box and the other for the A-Box. The fon~er Is a sort of KL-ONE viewed in a functional way while the latter Is a language based on First Order Predicate Logic.</Paragraph>
    <Paragraph position="6"> KL-~IACHA is only able to handle the T-Box and it has no assertional power. Instead, by KL-Cone we are trying to design a language which covers both terminological and assertional aspects, even if it is more biased towards assertlonallty. It is our intention to handle the T-Box mainly in an assertlonal way.</Paragraph>
    <Paragraph position="7"> In order to achieve thls goal we have introduced the distinction between Long Term Hemory (L~I) and ~orklng |~emory (~,I) which in part covers the traditional one between T-Box and A-Box.</Paragraph>
    <Paragraph position="8"> The LT~' is represented in EL-Magma data structures; this contains descriptional knowledge about generic and individual objects.</Paragraph>
    <Paragraph position="9"> The W~! contains the history of the objects organized in a structured way. This is the central component of our current hypothesis. The |;H contains the traces of contextual relationships between objects, as well as operations triggered on and by objects; it can also contain other symbolic systems. The task of the ~JM is mainly to hold hypotheses to be mapped onto the LT~! which requires the cooperation of several interpreters. The Introduction of a larger number of memory spaces increases the power of the language. For instance, a structured WU is likely to improve the number of s~nbolic systems interacting with one another. This makes It possible to insert into the language functions based on different processes. Taking for instance the history of the objects as a reference point, the objects themselves can be accessed according as they appear in the time flow. The function: &lt;LAST arbitrary_name&gt; returns the last object, created or manipulated, belonging to the class named by arbitrary n~ze. In other words, this allows the user to refer to objects using anaphorical references, that is to say using a s~nbolic system which is organized and represented in a different way from epistemology. By the WM we are trying to create the basic mechanism to handle these types of processes.</Paragraph>
    <Paragraph position="10"> B. KL-Conc: External Organization KL-Conc functions handle real world objects, so the user only needs to know a set of functions to be applied to objects. In this way, the structure of the Sl-?let which internally organizes the data, is hidden; the only t~ta which are transparent are objects, which may be individual or generic, together with syntactic rules for combining functions. These last are very flexible. Objects can be accessed using arbitrary names or by means of syntactic combinations which conceptually correspond to complex tests on the nature of objects, the configuration of objects etc.. Objects can be accessed according as they appear in the time flow.</Paragraph>
    <Paragraph position="11"> The user can use the same name both for generic and individual objects. This is made possible by means of an internal generator of names which, starting from the name of a generic object, provides any individual of that class with a different name. This feature covers the part of the naming system of NL which uses the same name for individuals and prototypes. This does not cover the use of proper names which has been taken in JARGON (Woods, 1979) as the only means for naming individuals, thus oversimplifying the real system used by NL (Mark, 1981).</Paragraph>
    <Paragraph position="12"> Objects can be accessed without the use of names, but by means of functions or combinations of functions in order to perfo~ complex tests on the nature of objects. This means referring to objects by testing properties or configurations. C. KL-Conc Functions KL-Conc has functions for creating, testing and retrieving objects. This is the list of tile functions so far designed:</Paragraph>
  </Section>
  <Section position="6" start_page="124" end_page="125" type="metho">
    <SectionTitle>
ADD--CONFIGURATION OF PROPERTIES
TEST PROPERTY
TEST CONFICURATION OF PROPERTIES
</SectionTitle>
    <Paragraph position="0"> The semantics of some KL-Cone functions may now be described in order to clarify how they  realize our linguistic assumptions. The semantics is given in terms of operations on SI-Nets. As far as generic knowledge is concerned, the function: &lt;GEL\] arbltrary_na~;,e&gt; returns the generic concept named by arbitraryname. If the concept does not exist in the LTM a new generic concept is created. The new concept is then returned. This function works both as a predicate and as a creating function. It is worth noticing that in KL-Hogma there are two distinct functions, one for the predicate (&lt;Generic__Concept._P anything&gt;), and the other for creating (&lt;Create Concept name type of concept&gt;). The function &lt;PEWI~:D arbitrary_name&gt; creates a new individual concept and establishes it as an individuator of the generic concept named by arbitrary name; if the generic concept does not exist in t~e LT~I it is created. An internal generator provides tile newly created individual concept wlth o nnme. This function corresponds to the follo~llng set of KL-\[!agn.la functions:</Paragraph>
    <Paragraph position="2"> (Establish as Individuator X1 X) This is one of the most &amp;quot;declarative&amp;quot; functions since it creates a new individual concept without searching in the LTN. In other words, tile user must be conscious that the new object is added to the L lqq and it is different from all the other objects. A more psychological oriented behavlour would require to test in advance the nature of the new object in order to decide whether the object is similar to or coincides with an individual object already inserted into tile LTH. The salute problem has been overcome in KRYPTO.~: by means of tile swltcb TELL/ASK (Brachman et al., 19P3).</Paragraph>
    <Paragraph position="3"> The function &lt;JUSTOr!E arbitrary name&gt; verifies whether there exists a unique individual either named by arbltrary, name or defined by tests or combinations of tests according to KL-Conc syntax. In other words, this means verifying if the object is unique as to its name, or as to one of its properties etc. The KL-Conc expressions for the two meanings are, respectively:</Paragraph>
  </Section>
  <Section position="7" start_page="125" end_page="125" type="metho">
    <SectionTitle>
(JUSTO~E table)
(JUSTONE (TESI~PROPERTY table red))
</SectionTitle>
    <Paragraph position="0"> This function has a complex behavlour, since, intuitively, it must verify the unlqueness of an object and must return: i) the individual if unique; ll) the llst of individuals if more than one satisfies the conditions .given by assertions; Ill) NIL if no invlvldual exists satisfying the conditions (Carnap, 1947). The three answers have different meanln~s, since they imply different operations to be triggered on the memory spaces or, at any rate, they have different effects on the behavlour of functions where JUSTONE can be nested.</Paragraph>
    <Paragraph position="1"> The function:</Paragraph>
  </Section>
  <Section position="8" start_page="125" end_page="126" type="metho">
    <SectionTitle>
&lt;TEST CONFIGURATION OF PROPERTIES
</SectionTitle>
    <Paragraph position="0"> ~rbltrary_namel arbltrary_name2&gt; verifies whether arbitrary name2 exists in the horizontal chain . of r~les starting from arbitrary_namel (see Figure 4)</Paragraph>
    <Paragraph position="2"> we intend to add roles to concepts so that the user needs not have any specific kno~Jledge about the distinction between generic and instance roles or, seen from a different viewpoint, between properties of prototypes and properties of individuals. Taking NL as the reference point, we think that the above mentioned distinction is peculiar only to certain linguistic elements; in the case of operations on propertles, no distinction is made; it is the conceptual operations governing the operations on properties that control the correct application of the adding or testing properties. Consequently, the function ADD PROPERTY must be designed In order to make it pos~Ible to trigger the correct procedures depending on the type of objects which it is applied to. For this purpose, we intend to use a metarepresentation of KL-Hagma (Cappelli et al., 1983) which, on detecting tile type of object, automatically apply the appropriate procedures.</Paragraph>
    <Paragraph position="3"> This implies a system which creates or tests knowledge structures interpreting its own syntax.</Paragraph>
    <Paragraph position="4"> Let's now briefly describe two possible behavlours of this function.</Paragraph>
    <Paragraph position="5"> Wtlen applied to individual concepts, thls creates a new instance role establishing it as a  satisfler of a higher generic role of the generic concept ancestor of the individual concept. If a possible generic role does not exist it is created without inserting any V/R in the generic role, since it could be a more general concept than the generic concept ancestor of the value of the newly created instance role. The structures created by this function are shown in figure 5 by dotted lines.</Paragraph>
  </Section>
  <Section position="9" start_page="126" end_page="126" type="metho">
    <SectionTitle>
&amp;quot;~0// I
</SectionTitle>
    <Paragraph position="0"> The functions described in this article represent only a subset of the operations which can be embodied in tile language. In this sense, the number of KL-Conc functions is likely to be increased in order to cover new processes.</Paragraph>
    <Paragraph position="1"> So far, we have designed the functions for those operations which exhibit the same behaviour whatever domain they are applied to, since they represent the &amp;quot;deep&amp;quot; behavlour of syntactic elements. It is to be emphasized that we have tried to reduce to the fomn of functions of a language, all the operations of NL which are domaln-lndependent and which represent aspects of the abstract syntactic ability of structuring knowledge facts (Cappelll etal., 1983; Cappelll and Moretti, 1983) Using KL-Conc it is possible to investigate how linguistic elements can be described in temns of conceptual operations. This is a further step towards the linguistic level. On reaching this level, the task will be to discover how the conceptual operations are embodied in linguistic forms.</Paragraph>
    <Paragraph position="2"> The previously mentioned Italian articles may be described as follows: Figure 5 ~en applied to generlc concepts, the function adds a new generic role, trying to link it with a higher generic role. If no generic role is found, a higher generic role is created without providing it with any information other than the one inferred from the structure of the newly created subrole.</Paragraph>
  </Section>
class="xml-element"></Paper>