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<Paper uid="E87-1048">
  <Title>SOME RE~h~RXS ON CASE RELATIONS</Title>
  <Section position="1" start_page="0" end_page="302" type="abstr">
    <SectionTitle>
ABSTRACT
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    <Paragraph position="0"> The topic of the paper is the problem how to define case relations by semantic predicates. A general principle is outlined, which renders it possible to &amp;quot;calculate&amp;quot; case relations for a given representation of a (verb-)sememe by means of expressions. This principle is based on an assignment of case relations to primitive predicates and modification rules for nested expressions. Contrary to the traditional case grammar it turns out ~ha~ one needs mixed case relations, especially for two reasons: Arguments occur at &amp;quot;too different&amp;quot; places in an expression or arguments ~iave combined case relations. The consequence is that case relations don't form a set of isolated elements but a structured system.</Paragraph>
    <Paragraph position="1"> I. Introduction The paper is not intended for defending case relations in general. I want to s~e~ch only some problems connected with the definition of case relations ~ud will demonstrate consequences, which seem partly a oit &amp;quot;unconventional&amp;quot;.</Paragraph>
    <Paragraph position="2"> I will not enter into the terminological discussion on deep cases, case relations etc. and subsume all these variants under the label &amp;quot;case relation&amp;quot;. This is justified by the obvious fact that there are more proposals and systems than authors. So one will not overcome this chaos by neat terminological distinctions. It is rather typical for publications on deep cases that proposals are presented without sufficient motivation or justification (e. g. Nilsen 1973).</Paragraph>
    <Paragraph position="3"> It has turned out tha~ in the matter of case relations as a field of linguistic and fundamental research intuition and language competence cannot show the right way how to solve the problems of defining them. This is my first conclusion from the general scene. Without doubt it is inevitable to work out some principles on the basis of which case relations may be defined. This would  enable us - to discuss a rather &amp;quot;clear&amp;quot; object (some principles instead of tens (or hundreds) of proposals), - to evaluate and compare existing proposals, null - to connect case relations with other  essential notions.</Paragraph>
    <Paragraph position="4"> Quite another question is &amp;quot;What are case relations good for?&amp;quot;. One cannot ignore the fact that a lot of serious objections against case relations have been advanced, covering a whole range from &amp;quot;they are redundant&amp;quot; till &amp;quot;the swamp of lacking plausible (or even formal) definitions&amp;quot; resulting in the conclusion that case relations are useless especially for computational linguistics (Mellema 1974, Luckhardt 1985). On the other hand many authors are advocates pro case relations, even in MT (e. g. Nagao 1986, Somers 1986). Here the character of case relations as a link (or pivot) is stressed between surface and deep level or between nguages. For sucA situations one can cept the use of case relations without exact definitions having an experimental system as a touchstone.</Paragraph>
    <Paragraph position="5"> Case rela~ion~ are considered here as names or labels of arguments in semantic ~ redicates used for the description of verb-)sememes. This is only one side of the coin! The second important aspect are the means by which deep cases are expressed at the surface (grammatical cases, prepositions, linear order, ...). They have to be taken into account as well, and only both aspects together will yield an adequate picture.</Paragraph>
    <Paragraph position="6"> 2. Case relations and semantic predicates One possibility to grasp the whole problem seems to be the definition of case relations on the basis of semantic predicates. Sememes (of vero-lexemes) are represented by expressions containing primitive semantic predicates. The following expression may be assigned to a verb like &amp;quot;to convey&amp;quot;: (a conveys b from</Paragraph>
    <Paragraph position="8"> (cf. Allen 1984). I will not discuss the question whether ACAUSE (= &amp;quot;agent causation&amp;quot;) and CH~GE-POSITTON are indeed  primitive predicates. I consider them here as that. Furthermore one may discuss whether (5) sufficiently describes the meaning of &amp;quot;to convey&amp;quot;.</Paragraph>
    <Paragraph position="9"> The idea of extracting case relations from representations lige (1) can be bases on the following principles: (A) For each primitlve predicate P there is an assignment of exactly one case relation to every argument place~:</Paragraph>
    <Paragraph position="11"> (B) There are modification rules for case relations which render it possible to &amp;quot;calculate&amp;quot; the case relations for  nested expressions.</Paragraph>
    <Paragraph position="12"> (A) means e. g. that for a primitive predicate like CHANGE-POSITION w know the case relations of the argument places b, c and d: (2) zi(C~JdIGE-POSITION ) = r i for 1 ~ i ~ 3 In this sense one can state without doubt (3) Zl(ACAUSE) = agent (~) z3(CHANGE-POSTTION) = goal (B) may be interpreted in the following way: If we know - MOVE-ACtION has the form given in (1), - the value of z2(ACAUSE), - second place of ACAUSE is filled in by CHA2~E-POSITION, - the value of Zl(CHANGE-POSITION), then we know - the value of z2(EOVE-ACTION ), i. e. the case relation of b in the whole expression (1).</Paragraph>
    <Paragraph position="13"> Formally this may be expressed by a four-place &amp;quot;modification mapping&amp;quot; m: (5) zg(MOVE-ACTION) =</Paragraph>
    <Paragraph position="15"> One may speculate whether all four arguments are indeed necessary, they are surely no~. A similar idea is presented in Thiel 1982 (p. 84 ff.), where the mechanism of modification is applied, tOO.</Paragraph>
    <Paragraph position="16"> A general scheme for (B) is the following: Assume one has</Paragraph>
    <Paragraph position="18"> where x is the j-th argument in Q, S(...) the k-th argument in R and x the 1-th argument in S. Then zg(Q) is a function of R, Zk(R), S an~ Zl(S ). Thiel's proposal, namely zj(Q) = m(R, Zl(S)), would cause some dlfficulties, if R is a many place predicate and there are in R arguments S' and S&amp;quot; with z I, (S')=Zl,, (S&amp;quot;) (cf. the FEED-example below). Thiel himself excludes this case explicitely.</Paragraph>
    <Paragraph position="19"> The principles (A) and (B) form a recursive scheme: (A) provides the results for certain predicates, (B) renders it ~ ossible to determine the results for verb-)sememes in general.</Paragraph>
    <Paragraph position="20"> At arj rage one would get a nice formalism for calculating case frames if (A) and (B) are fulfilled. Unfortunately, there are some additional problems I will deal with below. But at first T take an  example : (7) SET(a, b, c) = ACAUSE( a, BECOI~\[E ( SIT( b, c) ) ) (8) z2(SIT)= locative By a simplification of the general scheme (four-place function m as in (5)) to the special variant one would obtain for (7-8): (9) z~(S~.T) = ~m(A CAUSE, m( BECO},~, 1 o cati re) ) = m(ACAUSE,dlrective) = directive  There are arguments for the assumotion that BECOI~ (and not ACAUSE) modifies locative to dieective (or goal): The description of &amp;quot;to get to a place&amp;quot; contains the expression (10) BEC01~(BE(b,c)) (as in (7)) Here one has the s~ae modification of locative to directive. This is in accordance with Thiel 1982.</Paragraph>
    <Paragraph position="21"> Instead of (7) one coulc take another expression, e. g. by using the predicate ECAUSE (event causation) with the interpretation that &amp;quot;an activity of a causes</Paragraph>
    <Paragraph position="23"> Here the application of (A) and (B) is not quite the same, one has here instead</Paragraph>
    <Paragraph position="25"> These simple examples illustrate some connections between the formal definition of case relatior.s and semantic predicates.</Paragraph>
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