of a text are considered to belong to the same lemma if and only if they have in common all the pertinent features which identify a lemma, distinguishing it from all other lemmas. We have constructed an in­ventory of features which may be used in the definition of a lexical unit. Such an inventory is based upon a survey of the features used both in lexicographic practice and in linguistic theories. Each entry of the dmi is associated with the set of all the possible features of the inventory which may be used in its definition. The user is allowed to disactivate those features which he does not wish to utilize: for example, the differences between nominal and verbal use of participles or those between adjectival pronouns and pronouns, etc. Obviously, if some distinctions are neutralized, the number of lexical units which constitute the dmi, as defined by the user, and very often the number of possible homographs, are reduced. In other words, if we consider the dmi a concrete representation of the Italian lexical system, in which the lexical units are defined using all the features proposed by the dif­ferent lexicological and lexicographical traditions, the user can modify the structure of this system and the inventory of its lexical units in accordance with his specific linguistic requirements (Zampolli, 1973a). In this perspective, the dmi is used not only as a tool for text proces­sing but also as an object of studies and research in itself.

While in studies at the level of la parole the object is given immedi­ately for the ldp in the form of corpora of texts, the object in studies on la langue must be specifically constructed. An example which can be given is the first step in a research on the functional load of the phonological oppositions of a phonematic system. This step consists in the inventory of the minimal pairs existing in the lexicon for each opposition and therefore it presupposes the existence of an inventory of all the different forms of the studied language in phonological tran­scription. The burden of creating an inventory of this type and dimension, and the complexity of the operations required in order to discover and count all the minimal pairs are such that all those tasks are im­possible without a computer. Another example could be a study on the " rendement " of the different suffixes, which requires an inventory of all the words in which each suffix appears.

In order to make research work of this type possible, the dmi has been conceived diversely from most of the other dms in existence. These have usually been realized exclusively as components in trans­lation procedures, information retrieval systems, etc. Such dms, almost always, include only a limited number of lexical items.

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The dmi has a structure and dimensions that allow us to consider it as an exhaustive, automatically processable representation of the lexical component of the Italian linguistic system. The dmi is, therefore, intended as an instrument for research studies at the level of la langue where exhaustive inventories, data and observations are necessary.

1.4. Theoretical background.

The research project described below by N. Calzolari and L. Pecchia is an example of how the dmi can be used in this direction.

The actual situation of linguistic theory is that of constant change and development. Not only are the traditional models being con­tinuously modified but some researchers affirm also that the debate is now between theories which belong to different scientific " paradigms ". Examples usually quoted are the number of different generative-trans­formational schools (interpretive semantics, generative semantics, etc.), relational grammar, cognitive semantics. In this situation, some re­searchers present the following alternatives: whether the scope of the research work conducted in ldp must, of necessity, be directed towards a specific linguistic theory, or whether ldp can produce results which can be utilized by different linguistic schools.

For the sake of simplicity we will examine certain examples from the syntax field. A clear example of ldp activity directed at a specific linguistic theory is, in my opinion, offered by the so-called ' grammar testers ', i.e. those computational systems which apply a lexicon and a grammar for automatic sentence generation.

These systems, at least in the intention of their creators, constitute a concrete and precise specification at the computational level of a determined linguistic theory; the grammar is considered as a program used to produce sentences; the algorithms which interpret the rules are considered as a part of the meta-theory; the production of concrete sentences serves to verify the coherence of the rules, the completeness and lack of contradiction of the formal apparatus and to indicate, practically, the extension of the subset of language generated by the grammar.

Evidently, these systems are intentionally strictly connected with the corresponding linguistic theory, constituting, it could be said, the computational " transcription " of it. The rapid evolution of the theories, the models, the formal apparatus require a continual updating of the corresponding computational systems, which does not seem very easy to realize, at least in practice. Furthermore, the generative-transformational schools whose theories are usually incorporated in these systems have so far only described isolated regions of the linguistic structure, aiming at verifying the adequacy of descriptive methods rather than at de­scribing coherently and exhaustively a language. As a consequence of this, anyone wishing to use the results of their researches in a compu­tational system would face a set of isolated observations distributed in different regions of a language, not systematically linked to each other, but divided by so far unexplored regions.

On the other hand, however, the analytical methods produced by the generative-transformational theories have revealed a very efficient heuristic power, and have considerably increased the precision and subtlety of the observations. The number of new phenomena that have been revealed has grown notably in the last 20 years.

In front of this situation, the behaviour of ldp researchers may range between two alternatives.

The first position is usually characterized as the rise of a linguistic " computational paradigm ", which is distinct from, if not directly in con­trast with, the generative-transformational paradigm, and tends to assume the computational aspect among the principal characteristics of a lin­guistic theory. The conviction is expressed that the primary " focus " of linguistic research must be shifted from the description of the com­petence as formal abstract mechanisms towards the simulation-like studies of the processes which underlie the production and the com­prehension of the utterances. The " natural language understanding " computational system could constitute a powerful experimental and heuristic tool for the study of the complexity and the constraints of these processes, making it easier to emphasize the mechanisms of interac­tion between the components which are involved in these processes.

The scantiness of the results obtained so far (some of the devotees of this approach have likened the situation to that of medieval alchemy as opposed to modern chemistry) makes it impossible to formulate even a summary judgement. Nevertheless, it is quite clear that this type of research is limited, and will be probably limited, at least for some time in the future, to the consideration of extremely limited language subsets.

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The second position seems to prefer, in the actual situation of linguistic theory, a systematic examination of the data to an im­mediate construction of a formal global model. Obviously, the use of abstractions or notions (e.g. those of transformation or of com-ponential analysis) whose theoretical state may vary depending on the global evolution of the theory itself, but which have been seen to be experimental devices of extraordinary efficiency in the analysis, is not rejected. The complex formal mechanisms proposed by the generative-transformational school is not implemented into a computational system as a representation of a language theory " but some of their characteristics (form of the rules, relationship between the rules, etc.) are utilized to store, handle and organize the data accumulated in the inductive moment of the research.

ldp essentially offers two complementary contributions to this ap­proach. Firstly, it supplies techniques which permit the automatic handling of the data. Secondly, ldp studies algorithms which permit the data to be structured conveniently, organizing them so that their regularity, diversity, correlations, etc., can be evidenced without it being necessary to make this organisation dependent on the " a priori " choice of a general global theoretical model.

The inventories of linguistic units recorded in " machine readable form " must be considered within this framework and, in particular, those lexical inventories in which each lexical unit is supplied with an explicit, suitably coded, representation of its linguistic behaviour should be considered.

In addition, the use of a lexical inventory would facilitate the defini­tion of the degree of exhaustivity of the descriptions and the evaluation of the extension of the phenomena studied. (The term ' extension ' must be here understood obviously not as frequency of appearance in texts but as frequency of appearance in the system).

At the same time, it seems that the time has come to systematize and put at the public disposal the linguistic data accumulated in machine readable form (texts, dictionaries, descriptions, rules, etc.) and the computational tools (software packages, integrated systems, mid level and high level languages for ldp, etc.) produced in different institutes of different countries in different ways, but on the basis of similar method­ological assumptions and of a general common sum of knowledge.

It is within this framework, and not only for applied and oper­ational purposes, that since 1968 (Zampolli, 1968), I have promoted the construction of the dmi as one of the principle projects of the newly constituted dl.

The project described in the following pages by N. Calzolari and L. Pecchia is an original development in the field of semantics along these general planning lines.

2. towards a formalization of lexical definitions 2.1. Preliminary steps.

This part of the article describes an attempt to formalize all the noun-definitions in the Italian Machine Dictionary (dmi). The defi­nitions recorded in the dmi were taken from the Zingarelli Dictionary (1970) after having undergone a first process of normalization and shortening. Part of the normalization process was to classify the Zin-garelli definitions into 9 different types and to mark each of these with a particular code.

The main types of definitions are:

1) the relational (coded as 1), which is composed of a) a fixed part representing a function, and b) a variable part, the basis;

2) the synonymous (coded as 2), which is made up of one or more single words which are referred to for an explanation of the meaning considered;

3) the one per ' genus et differentia ' (coded as 3), which is made up of a) a fixed word considered as a classifier (the ' generic part ' of the definition), and b) a descriptive or predicative phrase of the clas­sifier (the ' specific part ' of the definition).

The framework of our research is typical of componential analysis, according to which even that which appears to be " a list of basic irregularities " (Bloomfield, 1933, p. 162), i.e. the lexicon, could become a well-structured and therefore formalizable set, in other words, - laura pecchia - antonio zampolli a system. We were first given the idea for the analysis by the theory of componential analysis, but we have attempted to expand its field of application which, up to now, has been dedicated only to well struc­tured sets, as shown in the work of componential anthropologists, (the domains of words of kinship), or to lemmas isolated from the rest of the lexicon (the well known example of Katz: 'bachelor'). Our intention has been that of extending the application of this theory to all nouns of the Italian lexicon. We are helped in this by the great quantity of material at our disposal in the dmi. As we are well aware of the li­mitations of componential analysis, we have used it only as a tool, not as an end, in achieving our purpose.

From the entire corpus of lemmas and definitions in the dmi we have excluded those lemmas and definitions which are marked as archaic or rare. We have analyzed, up to now, all those definitions classed under codes 3 and 5, i.e. those with one generic and one specific part. These are the most numerous groups of definitions. After this selection had been made, the total number of lexical items on which we are actually working is 28,873, among which 20,453 are monosemic and 8,420 polysémie; the total amount of their definitions is 44,051. We have worked on this corpus of lemmas and definitions using programs and checks of different kinds, working in two main directions which will be discussed later in more detail. Firstly, we have extracted a considerable number of markers which would be assigned to the highest possible number of lemmas. Secondly, we have started an analysis of prepositions, of prepositional groups and of other syntagms which can be considered as grammatical in a very generic sense. These syn­tagms have been chosen because they satisfy, simultaneously, the fol­lowing two criteria:

a) that of occurring with a high frequency in the definitions;

h) that of showing well defined semantic relations existing be­tween noun and noun, or between verb and noun, or between noun and proposition.

2.2. Markers.

In the first phase of our work, the aim was to extract a certain number of ' markers ', starting mainly from the definitions; in other words, working in an inductive way. We obtained the first basic work­ing elements from a control of the frequency-list of the forms found in the corpus of noun-definitions. This list helped us to make a first purely provisional inventory of lemmas which might be used as ' markers '.

Then, by looking up the concordances of these definitions, we were able to test the validity of these basic elements. In fact we have ascertained that the most frequent lemmas in the set of noun-definitions, (i.e., the lexical entries which will be most probably used as ' semantic markers ') almost always appear in the context in a generic sense and in the first position, only occasionally assuming a specific sense in dif­ferent positions. The fact that, as expected, with the exclusion of syn­tactic words such as prepositions, conjunctions, articles, etc., the highest frequency-indexes pertain to the grammatical category of nouns has also been relevant.

We shall use the name ' markers ' to refer to these most frequent lemmas : but there is a difference between our ' markers ' and the markers referred to in componential analysis; although our markers function as markers usually do, i.e., they describe a meaning or part of it, they remain essentially lemmas. It is thus not necessary to use a metalanguage different from the language which is being described; the elements of the lexicon can be given a metalinguistic function.

These markers have been grouped into lists on the basis of different semantic criteria such as synonymy, antonymy, etc. We have also made a distinction between markers behaving as one-place predicates and markers behaving as two- or «-place predicates.

A first group of 450 semantic markers was extracted and matched by a program with the generic part of all the definitions. We have verified that 22,146 definitions out of 47,291 were covered, in their generic part, by these markers. This first part of the work is described in more detail in Calzolari, Moretti (1976).

In the prosecution of the work, through further additions or sub­stitutions of semantic markers which were either provided by literature on this subject, or resulted from our intuition, or by other successive analyses on the corpus, we have covered 40,135 definitions with 407 markers.

We have ascertained that, in almost every case, the generic part of the definitions of the dmi (and therefore of the Zingarelli) gives the word whose level is immediately higher with respect to that of the defined lemma (considering a hierarchical classification moving from the more specific to the more general, i.e. from a greater to a smaller intension). This homogeneity in the definitions justifies the validity - laura pecchia - antonio zampolli of the method we have adopted to refer all the lemmas back to the markers.

In practice, for the lemmas not covered by markers after the first procedure of matching, i.e. for those lemmas which are defined, in their generic part, by words which are too specific to be used as markers, we have established some chains which refer back to more and more generic words until at least one marker is reached. In order to construct these chains we used a procedure to convert all the lemmas into numbers : this seemed to be the simplest way to keep in main storage the great quantity of data we had to work with. Using a program which works on these numbers, we have simulated a path for each lemma. This path starts from the lemma itself, and the program examines the generic part of the definition of the lemma. The program checks if this generic part is included in the list of markers, and in any case examines this generic part itself as a lemma to be defined and looks for its definition; the procedure continues in this way until the generic part of a definition is found to be a marker without any other more generic marker above it. By this procedure, 91% of the definitions have been reconducted to the markers, i.e. 40,135 out of 44,051.

By means of these chains, we have given the noun-dictionary a resemblance to a tree-structure. This tree-structure has been formed using the definitions of the dmi for almost all the lemmas; the hierar­chical structure we have given to the markers has, on the contrary, been partly taken from the definitions, and partly imposed by us ac­cording to the traditional rules of class inclusion.

Fig. 1. Examples of chains from lemmas to markers.

a) the linking of markers: for example, the pertinence relation PARTE (part) makes it possible to link the markers PERSONA (person), UOMO (man), DONNA (woman), with a set of markers such as MANO (hand), CAPELLI (hair), BOCCA (mouth), TESTA (head), CAPO (head), etc.; and/or

b) the joining of the generic to the specific part of the definitions, for example in the definition of ACCHIAPPAMOSCHE = Strumento atto a catturare mosche (Fly-swatter = instrument apt to catch flies) the function SCOPO (aim), in its lexicalization ATTO A (apt to), links the marker STRUMENTO (instrument) to its specification.

For the final structure of the definitions, we think that the markers can either be considered as n-place predicates joined to their arguments by these various types of functions, or as nodes of a semantic network linked to the specific part of the definitions, i.e. the other nodes, by arcs which express these various types of functions.

Such relations can be used as the starting point in the study of the use of prepositions and prepositional syntagms in the Italian language and, particularly, in the language of vocabulary definitions.

Unifying these functions is also of great help in structuralizing the definitions, at a higher level of formalization, assisting greatly in the extraction of all the data linked by the same function.

We have also noticed that some types of sentence-structure occur more frequently in the definitions. Besides considering the functions in isolation, we have been working on a quantitative examination of the various possible matchings of these functions among themselves; this has been done with the aim of also identifying the kinds of sentence-structures more frequently used by lexicographers in the compilation of dictionaries. A practical goal for us is to work further towards the unifying of the definitions, by leading them back, as far as possible, to the more frequent and common structures.

2.4. Perspectives.

Our research had a number of different aims but was principally directed towards the lexicographic aspect. This aspect consists in an attempt to analyze the defining method adopted by Italian lexicographic tradition as shown by the Zingarelli. This analysis has been developed in two different stages:

66nicoietta - laura pecchia - antonio zampollinicoietta - laura pecchia - antonio zampolli

1) An analysis of the terminology used in the definitions, through the enucleation of markers. We have seen that, among the most frequent lemmas in the definitions (i.e. among those words whose extension is greater or, in other words, whose intension is smaller), those words considered as markers by literature on this subject appear.

2) A check of the definitions considered from the point of view of their structure. This emphasized the very high frequency of certain types of functional syntagms as being more suitable in compiling defi­nitions. It will be interesting to have a comparative examination with dictionaries of other languages.

The semantic aspect is very closely related to the lexicographic aspect of this study. Our aim was to give a hierarchical type of organ­ization, even if provisional, to the large set of Italian nouns at our disposal. In doing so, we have taken what in our opinion is the first step towards a decomposition of a meaning into distinctive markers, i.e. the attribution as main semantic marker of the lemma which is at an immediately higher level in a hierarchical scale. Many hierarchical scales can be individualized in the lexicon, or more precisely among the meanings of the lexical items.

We have also begun, through the study of prepositional functions, the second step in the decomposition of a meaning into markers: the linking of markers with other markers, the individualization of the different kinds of relations which exist among markers, and of those relations which exist between primary and secondary markers expressed respectively by the generic and the specific part of the definitions.

There is also an important practical aspect of this work: that of making the definitions of the dmi more uniform from a semantic point of view. This is achieved by indicating the semantic uniformities which are latent under the different lexicalizations of the same markers or of identical relations, and by reducing these diversities of lexical forms to one single symbol reflecting their uniformity. This will make the looking up of the dmi easier.

This work should also be of relevance, at a future date, in connection with an analysis of the verb which takes into consideration the above mentioned analyses of the noun at a level of selectional restrictions at first, and, later, extends these analyses to the level of " knowledge of the world ". Thus, we feel that our work can provide a first step for a future utilization of the dmi in syntactic and semantic analyses of the Italian language.