Implementation of an Arabic morphological analyzer within constraint logic programming framework

This paper presents an Arabic Morphological Analyzer and its implementation in clp(FD), a constraint logic programming language. The Morphological Analyzer (MA) represents a component of an architecture which can process unrestricted text from a source such as Internet. The morphological analyzer uses a constraint-based model to represent the morphological rules for verbs and nouns, a matching algorithm to isolate the affixes and the root of a given word-form, and a linguistic knowledge base consisting in lists of markers. The morphological rules fall into two categories: the regular morphological rules of the Arabic grammar and the exception rules that represent the language exceptions. clp(FD) is particularly suitable for the implementation of our system thanks to its double reasoning: symbolic reasoning expresses the logic properties of the problem and facilitates the implementation of a the linguistic knowledge base, and heuristics, while constraint satisfaction reasoning on finite domains uses constraint propagation to keep the search space manageable.