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<Paper uid="C96-1081">
  <Title>Sjur NCrstebC/ Moshagen Computing Centre for the Humanities</Title>
  <Section position="4" start_page="478" end_page="480" type="metho">
    <SectionTitle>
2 The Sign Model
</SectionTitle>
    <Paragraph position="0"> In the sign expansion approach, the lexicon is viewed as a dynamic rule system with lexical frames and various kinds of expansion rules.</Paragraph>
    <Paragraph position="1"> The Sign Model (SM) by Hcllan and Dimitrova-Vulchanova (Hellan and Dimitrova-Vnlchanova, 1994) is a semantically based sign expansion theory and is used as the lexical basis of our lexicon. It posits an abstract level of sign representation that is not associated with any word classes and establishes a framework, within which word relationships as well as relationships between different kinds of linguistic properties can be described in a systematic way. At the abstract level of representation, one defines conceptual/phonological fi'ames that underly the actual words found in a language. The fi'ames combine with lexical expansion rules to create dynamic entries of actual words with morphological and syntactic properties, as illustrated by the LFG representations in  assumed, since the theory is intended to fit into any syntactic theory.</Paragraph>
    <Section position="1" start_page="478" end_page="479" type="sub_section">
      <SectionTitle>
2.1 Minimal Signs
</SectionTitle>
      <Paragraph position="0"> The conceptual/phonological frame, which is referred to as a minimal sign, is made up of a semantic (conceptual) part and a realizational part.</Paragraph>
      <Paragraph position="1"> As we do not have very much to say about phonological representations here, we assmne in the following that tim realizational part is a simple graphemic representation. The semantic part is a conceptual structure of the sign, which is to capture all grammar-relevant aspects of its meaning.</Paragraph>
      <Paragraph position="2"> The meaning of a sign is analyzed as a situation involving a number of participants (also called arguments), and these participants as well as the situation as a whole are modeled in terms of aspectual values, semantic roles, criterial factors, and realizational and selectional properties.</Paragraph>
      <Paragraph position="3"> Consider the minimal sign PAINT in Figure 2, which is the lexical entry underlying the related words paintv , paintN , paintingN , paintableA, etc. The realizational part is the string &amp;quot;t)aint&amp;quot;, whereas the semantic part denotes a situation with two arguments, indexed as 1 and 2. The  aspectual value (-punctuaO describes the situation as durative, whereas the selectional restriction DIM states that argument 2 is to serve as some two-dimensional surface. Argument 1, the painter, possesses the semantic roles SOURCE and CONTROLLER. SOURCE means that this argument is the source of energy for the force involved in a painting process, whereas CONTROLLER indicates that the argument is in control of the process. Correspondingly, argument 2 is the entity on which the force is used (LIMIT) and the entity being controlled by argument 1 (GOAL). Argument 2 is also given the MONOTONIC role, which means that it undergoes some monotonic change in the course of painting. The change, of course, is that the surface is gradually covered by some paint. Each semantic role is further characterized by means of a criterial factor that imposes certain role-related observational properties on the argument. Specifying SOURCE and LIMIT as coloring means that the painter's use of force involves some observable actions that identifies him as painting, and that the surface being painted is recognizable from the same force. The gradual covering of the surface with paint, which is modeled by MONOTONIC, is also of the coloring type, since we can verify the covering by looking at the surface. CONTROLLER's and GOAL'S factor noncriterial means that no particular observable behavior is required for an argument to play these  particular roles. In general, the criterial factors affect, the implicitation of arguments in syntactic expressions (e.g. argument 2 in ,Ion painted) and the introduction of new ones (e.g. red in Jon painted the house red).</Paragraph>
      <Paragraph position="4"> As shown by the lexical entry of WALK in Figure 3, naturally intransitive verbs are rooted in minimal signs with only one conceptual argument. The argument of WALK is a SOURCE and a CONTROLLER, and it undergoes a monotonic development with respect to some one-dimensional path. In a sentence like Jon walked to the school, the phrase to the school describes this monotonic development of argument 1. Away in gon walked away is another optional constituent, that can describe argument l's nmvement along a one-dimensional path.</Paragraph>
    </Section>
    <Section position="2" start_page="479" end_page="480" type="sub_section">
      <SectionTitle>
2.2 Lexical Rules
</SectionTitle>
      <Paragraph position="0"> The general format of the expansion rules is as follows:</Paragraph>
      <Paragraph position="2"> X contains the information to be added and Y the requirement for using the rule. S concerns the structure on which the rule is used and specifies which parts of this structure should be considered by the rule. Interpretationally, the rule in (1) can be applied on a structure Z if Y is a substructure of Z and X unifies with the selection of Z specified in S. The result of the operation is exactly this unified structure, and the operation itself is referred to as a derivation. If the whole lexical entry is to be addressed by the rule, the COMPOSITION part is omitted in the rule specification. Similarly, if the IF Y part is not present, it means that there is no requirement for using the rule. The expansion rules fall into five categories, depending on what kind of information they insert into the lexical representations: (1) Morpho-syntactic augmentations, (2) inflections, (3) conceptual expansions, (4) syntactic mappings, and (5) compositions.</Paragraph>
      <Paragraph position="3"> Morpho-syntactic augmentation rules add a word category and an inflectional paradigm to a minimal sign. The morpho-syntactic augmentation rule shown in Figure 4(a), for example, derives the basic entry for the verb paintv from tile minimal sign PAINT.</Paragraph>
      <Paragraph position="4"> Assuming that tile lexical entry has already been given a word class and a paradigm, the inflectional rule expands the graphemic representation into a particular inflected word form. The rule in Figure 4(b) expands the basic entry for paintv into the more specialized entry for the past form paintedv. The inflectional rules m'e grouped together into paradigms that are associated with the appropriate words (e.g. vl is linked to paintv).</Paragraph>
      <Paragraph position="5"> Conceptual e,r, pansion rules are rules that extend the semantic part of the signs without combining them with other sign structures. These rules are semantically conditioned and typically explain how a particular sign can support a variety of subcategorization frames. The rule in Figure 4(c) shows how a resultative construction like Jon painted the wall red is supported by a minimal sign like PAINT. If the conceptual structure contains an argument that undergoes some monotonic development, the conceptual structure can be expanded with a new argument that serves as the medium for this development and has a dimension matching the criterial property of the MONOTONIC role. When an argument is a medium for some other argument, it means that its monotoni(: development is manifested or materialized through this other argument. Hence, as argument 2 of PAINThas a MONOTONIC role, the rule is able to add an argument that describes the resul}ing monotonic change of the surface being painted.</Paragraph>
      <Paragraph position="6"> The realization of this argument as an adjective (like red) comes from the fact that the new argument, is of dimension coloring. For a minimal sign like WALK (see Figure 3), which contains an argument (the walker) that monotonically moves along some one-dimensional path, the rule adds a new argument of dimensionality 1-dim. The medium must then describe a one-dimensional path, as for example to the school in Jon walked to the school.</Paragraph>
      <Paragraph position="7"> Syntactic mapping rules are rules that derive syntactic properties from conceptual structures.</Paragraph>
      <Paragraph position="8"> Since no special syntactic notions are assumed, we must here decide on an existing syntactic theory before the mapping rules can be defined. The rule shown in Figure 4(d) is based on Gulla's rules (Gulla, 1994) for mapping from SM conceptual structures to LFG grammatical functions (Kaplan and Bresnan, 1982). It states that if a verb is used  Inflectional rule. (c) Conceptual expansion. (d) Mapping rule. (e) Compositiolml rule.</Paragraph>
      <Paragraph position="9"> in a completed seIIse 1, MEDIUM arguments of (timensionality coloring or existence can be mapped onto the XCOMP flmction. Used together with rule 4(c) on PA\[N~I; it introduces an XCOMP element that des(:ribes the resulting state of the surface being painted. A similar al)proaeh to the assignmeat of synt;u:tic flmct, ions in LFG can be found in (Alsina, 1993).</Paragraph>
      <Paragraph position="10"> The compositional rules combine two sign stru(&gt; I;ures attd create a new compound structure that includes parts of l)oth of them. The rule in Figul'c 4(e) uses a suffix to create a noun \[;hat re\[ers to some controlled, durative activity. Except tbr l;hc control and duration requirement, l;he conc:ep~ tua.1 structure must also contain a criterially anchored argument, i.e. mt argument that includes at least one semantic role that is not noneritcrial. The (\]OMI'OSITION part says that there are two structures involved, a main stru(:ture and a s'u,J.l~x strucl,urc, whei'cas the cxpansioll i)art turns l;he whole conceptual structure into an &amp;rgulilent k. ()n the basis ot&amp;quot; the minimal signs PAINT and WALK, l;he rule (:an create I;he notms paintingN and 'walkingN .</Paragraph>
    </Section>
  </Section>
  <Section position="5" start_page="480" end_page="481" type="metho">
    <SectionTitle>
3 The Expanding Lexicon
</SectionTitle>
    <Paragraph position="0"> In a sign extmnsion le, xi(:on system, we must dis~ tinguish between stored lexical entries and generated lexical entries. The stored entries are all minimal signs, and I;hey are usually not very in-I;eresdng to the lexicon user. The generated entries are produ(:ed by combining stored entries with one or more ext)ansion rules, and these cnt;ri(;s at'(; more or less elaborate spe(:ifica~,ions of actual wor(ls. A simple generated entry is the result of combining th(; minimal sign PAINT in Figure 2 with the morpho-syntactic auginen~ation rule in Figure 4(a). This yMds dm basic verb entry paintv, which (loes not contain any information abou|, syntactic realization. More elabo.rat(; entries are then generated by expanding the paiutv entry with the different subcategorization frames that are possible for paintv. For a user requesting information fl'om the lexicon, l;he stored entries m W be completely hidden and only the elaborate generated ones may be made available.</Paragraph>
    <Paragraph position="1"> Consider the rather elaborate entry in Figure 5, which rel)resents the past form painted used in the following resultative constru(:tion: lt, bllowing the ideas of felicity in (Depraetere, 1995), we define a clause to 1)e completed if it reaches a natural or intt;nded endpoint. A non-repetitive resultative (:ons~ruction is always completed, whereas constructions like ,Ion is painting and Jon paints eve.ry day are incompleted.</Paragraph>
    <Paragraph position="2">  (3) Jon painted the house red.</Paragraph>
    <Paragraph position="3">  The entry specifies a particular word form, contains a conceptual structure with three arguments, and lists the syntactic functions realizing these arguments. Indexing SUBJ with 1 means that argument 1 of the conceptual structure is to be realized as the subject. The whole entry is generated by a series of derivations, where each derivation adds a piece of information to the final lexical entry. Starting with the minimal sign PAINT, we use the rules in Figure 4(a) and 4(b) to generate a simple entry for paintedy. Then we expand the conceptual structure into a completed description (+ completed) using a rule called Completed and apply the rule in Figure 4(c) to add a third argument. The syntactic functions are added by the rule in Figure 4(d) plus two rules that we here can call Subjl and Objl. Subjl assigns the SUBJ function to arguments that contain SOURCE or CONTROLLER roles, whereas Objl requires a + completed description and assigns the OBJ fimction to arguments that have a MONOTONIC role. The generation of the lexical entry in Figure 5, thus, can be written as the following derivational sequence:  ated entry for paintingN.</Paragraph>
    <Paragraph position="4"> quence like that, we first have to indicate which morpho-syntactic rule to use. The system then chooses the correct inflectional paradigm, and it can start trying out the different expansion rules to generate complete lexical entries. The search space for this is restricted, since the rules are semantically conditioned and monotonic, and well-formedness conditions decide when to stop expanding the structure.</Paragraph>
    <Paragraph position="5"> In a similar vein, the noun paintingN (referring to a painting process) is derived from the minimal sign PAINT and the suffix ingN. The compositional rule from Figure 4(e) combines these two structures and produces the lexical entry shown in Figure 6. Category and Infection stem from ingN, Realization is a combination of the values in PAINT and ingN, and Semantics is the minimal sign's conceptual structure expanded into a complex argument indexed as 3. Instead of stor= ing two entries for paintv and paintingN -- that partly contain the same information -- we derive the entries dynamically from a single PAINT entry. null</Paragraph>
  </Section>
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