tailieunhanh - Báo cáo khoa học: "Using Mazurkiewicz Trace Languages for Partition-Based Morphology"

Partition-based morphology is an approach of finite-state morphology where a grammar describes a special kind of regular relations, which split all the strings of a given tuple into the same number of substrings. They are compiled in finite-state machines. In this paper, we address the question of merging grammars using different partitionings into a single finite-state machine. A morphological description may then be obtained by parallel or sequential application of constraints expressed on different partition notions (. morpheme, phoneme, grapheme). . | Using Mazurkiewicz Trace Languages for Partition-Based Morphology Francois Barthelemy CNAM Cedric 292 rue Saint-Martin 75003 Paris France INRIA Atoll domaine de Voluceau 78153 Le Chesnay cedex France barthe@ Abstract Partition-based morphology is an approach of hnite-state morphology where a grammar describes a special kind of regular relations which split all the strings of a given tuple into the same number of substrings. They are compiled in hnite-state machines. In this paper we address the question of merging grammars using different partitionings into a single hnite-state machine. A morphological description may then be obtained by parallel or sequential application of constraints expressed on different partition notions . morpheme phoneme grapheme . The theory of Mazurkiewicz Trace Languages a well known semantics of parallel systems provides a way of representing and compiling such a description. 1 Partition-Based Morphology Finite-State Morphology is based on the idea that regular relations are an appropriate formalism to describe the morphology of a natural language. Such a relation is a set of pairs the hrst component being an actual form called surface form the second component being an abstract description of this form called lexical form. It is usually implemented by a hnite-state transducer. Relations are not oriented so the same transducer may be used both for analysis and generation. They may be non-deterministic when the same form belongs to several pairs. Furthermore hnite state machines have interesting properties they are composable and efhcient. 928 There are two main trends in Finite-State Morphology rewrite-rule systems and two-level rule systems. Rewrite-rule systems describe the morphology of languages using contextual rewrite rules which are easily applied in cascade. Rules are compiled into hnite-state transducers and merged using transducer composition Kaplan and Kay 1994 . The other important trend of Finite-State Mor phology