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<Paper uid="C94-2202">
  <Title>LEXICAL FUNCTIONS AND MACHINE TRANSLATION</Title>
  <Section position="4" start_page="1241" end_page="1241" type="metho">
    <SectionTitle>
COLLOCATION -~e
</SectionTitle>
    <Paragraph position="0"/>
    <Paragraph position="2"/>
  </Section>
  <Section position="5" start_page="1241" end_page="1242" type="metho">
    <SectionTitle>
3 Issues in Translation
</SectionTitle>
    <Paragraph position="0"> The project has tried to investigate the use of lexical functions as an interlingual device, i.e., one which is shared by the semantic representations of collocations in the language pairs ~.</Paragraph>
    <Paragraph position="1"> The typing of a collocation with such aflmction opens up the way to a treatment of collocations inside a given language module and hence to a substantial reduction in the number of collocations explicitly handled in the multilingual transfer dictionary. The existence of a collocation function is established during analysis. This infi)rmation is used to generate the correct translation in the target hmguage. To illustrate, the English analysis modnle might analyse (1) as (2). The transfer module maps (2) onto (3) which is then synthesised by  the French module to (4).</Paragraph>
    <Paragraph position="2"> (l) heavy smoker-)~ (2) Magn(smoker) -r (3) Magn(fumeur) -4 (4) grand fumeur  The exmnple points out that the translation strategy is a mixture of transfer and interlingua. The bases arc transferred but the representation of the collocate is shared between the source and the target representation. This treatment of collocations rests, among others, on the assmnptions that there are only a limited number of lexical functions, that lexical functions can be assigned consistently, that all (or a signilicant nmnber ot) collocations realise a lexical function, that lexical functions are not restricted to particular languages~ etc. In the following paragraph we present an outline of the translation process. Next, we discuss some of the problems which follow flom our approach and we propose some ways to solve them.</Paragraph>
    <Paragraph position="3"> 4&amp;quot;lb illustrate tile case of huad-conlplenlent structures olle coukl lake some support verb construction (also called ligh! verb consh'uction).</Paragraph>
    <Paragraph position="4"> t;For another application of LFs in a muhilingual NLP context see (Held and l/aab, 1989). For other Imatlnents of collocations in language generation see (Nirenburg et al., 1988) and (Smadja and McKeown, 1990).</Paragraph>
    <Section position="1" start_page="1242" end_page="1242" type="sub_section">
      <SectionTitle>
3deg1 Lexical Functions as Interlingua
</SectionTitle>
      <Paragraph position="0"> it was assumed that the starting point for transfer is the semantic representation of the phrase. Using a semantic representation as input to transfer implies that we relate semantic values of wm'ds and phrases. For our purposes this is very satisfying since we will now be using the semantics of collocates instead of their orthography, in other words: we use lcxical flmctions and abstract away fl'om the particular realisation of a collocate in a particular language.</Paragraph>
      <Paragraph position="1"> We now state the relation between the semantic representations of the source language and target language. The semantic relation between the phrase heavy smoker and its French counterpart can be made explicit in the tbllowing bilingual sign:</Paragraph>
      <Paragraph position="3"> Typically, the lexicon will contain a bilingual sign for each possible value of RELN. Thus, for translating heavy smoker into grandfumeur we will need the obvious entry tot smoker-fumeur plus the entry below:</Paragraph>
    </Section>
  </Section>
  <Section position="6" start_page="1242" end_page="1242" type="metho">
    <SectionTitle>
ENISEM-IND \[ VAR \[~ \]
REST {M'lgn(~)}
</SectionTitle>
    <Paragraph position="0"> The interlingual status of the lexical function is selfevident. Any occurrence of Magn will be left intact during transfer and it will be the generation component that ultimately assigns a monolingual lexical entry to the LF. 6</Paragraph>
    <Section position="1" start_page="1242" end_page="1242" type="sub_section">
      <SectionTitle>
3.2 Problems
</SectionTitle>
      <Paragraph position="0"> l,exical Functions abstract away from certain nuances in meaning and from different syntactic realizations.</Paragraph>
      <Paragraph position="1"> We discuss some of the problems raised by this abstractkm in this section.</Paragraph>
      <Paragraph position="2"> Overgenerality An important problem stems fiom the interpretation of LFs implied by their use as an interlingua- namcly that the meaning of the collocate in some ways reduces to the meaning implied by the lexical./unction. This interpretation is trouble-free if we assume that LFs always deliver unique values; tmlb,'tunately cases to the contrary can be readily observed. An example attested fiom our corpus was the range of adverbial constructions possible with the verbal head oppose: adamantly, bitterl3; consistently, steadjastly, strongly, vehementl); vigorously, deeply, resolutely, etc. The ftmction Magn is an appropriate descriptor in all cases since each adverb functions as a typical intensitier in this context. However each adverb also denotes 6p'or more details we refer the reader to (Hcylen, 1993). There we also discuss our implementation in Alep, the C.E.C.'s unification. based glTHillllilr writing environment.</Paragraph>
      <Paragraph position="3"> some other nleaning aspect(s). 'file inlprecisio|l of I,l;s will nlean that we have no means of distinguishing between the vmious intensifiers possible it |tile context of a given keyword, and hence will not have sufticient in forination to choose the most appropriate translation where, correspondingly, nntltiple possibilities exist in tile target language. All important question here is how dramatic this loss of translation quality really is.</Paragraph>
      <Paragraph position="4"> It is essentially ill addressing the issue of ovelgenerality that Mel'~:uk introduces sub- and superscripts to lexical functions, enhancing their precision and making them sensitive to meaning aspects of tile lcxical items over which they operate. Superscripts are illtended to make the nleaning of tile I,F nlore precise and he|me |nero likely to imply unary inappings between argu|nents and vahlcs, subscripts a|e used to reference a particular semautic COlllpOUellt of a keyword.</Paragraph>
      <Paragraph position="5"> The introduclion of such devices into tile account of l,Fs demtmstrates hoth the need tk)r precision and the fact lbat it does seeul necessary to address semantic aspects of lexemes stand |ng it |co-occurrence relatio|ls.</Paragraph>
      <Paragraph position="6"> Ill fact it has been asserted by sonm (e.g., (Anick and Pustciovsky, 1990), (lteid and Raab, 1989)) that collocational systems are systematically predictable from the lexical Selllantics Of nt)tUlS, it) till atteln\]Jt to explore this notion furthel; we have investigated the appr(lach to nolninal semantics known as Qualia structure (Pustejovsky, 1991) and conside|ed how this lnay ct)tnpleu|ent the LF notion to inlprove its descriptive powe |r. alnoDg tile prolnising avenues that occur to tlS are, firstly, tile postulation of I,F subscripts based on the four Qualia roles (assuming thal these are tim lexically hies) relevant aspects of noun selnantics) and, secondly, the application of l,Fs to senlaulic (Qualia) structures rather titan monolithic lexenles; cg: tile I ,l; Ibm is used in delivering evahlative qualitiers which are standard expressions of praise or approval. One could ilnagine application of the ftmctio ||over the Coustitttlivc and Agentive tolcs of file noun lecture, to deliver: Flon(Const : lecture) =intormative Ben(Agent-. : lecture) = clear In both cases tile idea is that tile precision of tile lexical function is essentially enhanced by appealing to tile semantic facets of ils argunlcnt.</Paragraph>
      <Paragraph position="7"> Syntaetic Divergences Allother issue that has lo be raised conccl'lls tile trat|slation el'collocations into noncolh)cational constructions. It' we are to ulaintain a co||sistent interlingual approach to tile hanslation of these cases, we illUSt cXlelld our l,F-bascd approach accordingly. We consider o|/e case brielly.</Paragraph>
      <Paragraph position="8"> Cross-lingtlistic analysis reveals many cases where nonlinal-based collocational ctmstructs are real|sod as conlpot|nds in Gernmnic hulguages, e.g., hunch of keys sleutelbos. A possible account of such phenomena nlay be developed fronl the coucept (11: merged I,Fs (Mel'Suk and 7,olkovsky, \]970), Mcrged i,Fs are ill.</Paragraph>
      <Paragraph position="9"> tended It) be used ill cases where a value lexeme exists )'For i/ COlllllat'i,'-;on belwC/c/1 aspects of Ou.'l\[ia slrtlCllll'CS alld lcx ical ftmclions see (I lcylcn, to appear).</Paragraph>
      <Paragraph position="10"> which appears to effectively reduce (&amp;quot;|ncrge&amp;quot;) an LF meani|lg and its specitied a|gu|nent to a single lcxi-.</Paragraph>
      <Paragraph position="11"> calised for|n, rather than projecting a syntagmatic unit.</Paragraph>
      <Paragraph position="12"> We could argue that ill cases of compound lbrtnation, exactly tile same process is to lie accounted tbr, siuce the Ctl|nl)ound embodies both the concept mediated by tile LF and its argument lexetne. We coukl therefore allow compounds to be delivered as values of merged I,F's, eg: //Mult(sleutel)= steutelbos.</Paragraph>
      <Paragraph position="13"> These observations are uscful in the MT COl|text if we assmne that we cau effect a |nappiug betweeu merged and unmerged lhSs and thcrefore capture tile correspondence between distinct structural realisations of tile same concept. One way to ennflate such a Inappi|~g |night be through the use of Mel'~:uk's lexical paraphrasing rules. For instance, one could conceive ol' a lexical paraphtasiug rule as follows~: W-}- Mult(W) e, &gt;//Mull(W).</Paragraph>
      <Paragraph position="14"> If we assurne that ill our |uouolingual English lexicou, we assign tile collocate bunch as tile Mult value of keyword kt?.,, and that accordingly in tile Dutch iexical entry Ior sleutel we instant|ate sleutelbos as the vahle of tile nlerged 1,1;//Mult, then we can use the paraphraslug rule to effect a nlaplfing between tile two 13;'s and hence arrive at an iuterlingual approach to tile trauslation of tile example, despite structural |nisu\]atches, i.e., key + bunch\[ Mult(key)\] sleutel bos\[ llMuit( sleutel ) l l;u~lher examples exist where productive nlorphological processes (e.g., affixation 'q) lead to tile lexicali sat|tin in one language of concepts that exist as syntagnla|ic constructs ill another. Again, we suggest tile usc ot'|nerged l,Fs and corresptmding nlappings via lexical paraphrasing rule,; as a possible Iranshttion strategy in these cases,</Paragraph>
    </Section>
  </Section>
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