Organization and Programming of the Multistore Parser

nize and explain structural patterns in natural-language sentences (specifically English) and eventually yield an output in which the relations between the various items of the sentence are hierarchically displayed. The recognition of these structural patterns is made by means of a system of rules which operate on a sequence of words, i.e. a sentence, whose individual characteristics are pre-established. By individual characteristics are meant the possibilities a word has to correlate (i.e. to form a syntactic combination) with another item; these possibilities are represented by 'correlators', that is, by syntactic elements which link two items in a correlation. Each word is characterized by a set of pre-established data: a) the S-code, which distinguishes between the various senses of a homograph. For instance, a word like "READ" These distinctions are essential,'since whenever a homo-graph occurs, one and only one of its meanings can be taken into consideration to make the final pattern, unless , of course, the sentence is ambiguous and more than-2-one final pattern is to be recognized, as in: i) present tense I READ THE BOOK ii) past tense b) the sequence of correlational indices (Ic's), that is, the string of potential links that each word-sense has. Each Ic represents a possible syntactic connection between two items and is identified by: i) the code number of the relation it establishes between two items; 2) the 'type' of correlation. There are six different types of correlation which split into two groups:'explicit' correlators and 'implicit' correlators. By 'explicit' correlator we mean a linking element which is represented by a linguistic item; prepositions and conjunctions are explicit correlators; by 'implicit' correlator we mean a relation between two items, which is not expressed by any linguistic item but is indicated by the relative position of the two items (which we call their correlational function).