This I)aper presents an implemented multi-tape twolevel model capable, of describing Semitic non-linear morphology. The eomputational fi'amcwork behind the eraTent work is motivated by [Kay 1987]; the formal isdn presented here is an extension to the formalism pro'ted by [Puhnan and Hepple 1993]. The objettires of the current work arc: to stay as (',lose as possible, in spirit, to standard two-level morphology, to st,w close to the linguistic description of Semitic stems, and to present a model which can be used with ease by the Semitist. The paper illustrates that if finite-state transducers (FSTs) in a standard two-level mori)hology modal are replaced with multi-tape anxiliary versions (AFSTs), one can account for Semitic root-andq)attern morphology using high level notation.

This paper describes an algorithm for the compilation of a two (or more) level or- thographic or phonelogical rule notation into finite state transducers. The no- tation is an alternative to the standard one deriving from Koskenniemi's work: it is believed to have some practical descriptive advantages, and is quite widely used, but has a different interpretation. Efficient interpreters exist for the notation, but until now it has not been clear how to compile to equivalent automata in a transparent way. The present paper shows how to do this, using some of the conceptual tools provided by Kaplan and Kay's regular relations calculus.

We present MAGEAD, a morphological analyzer and generator for the Arabic language family. Our work is novel in that it explicitly addresses the need for processing the morphology of the dialects. MAGEAD performs an on-line analysis to or generation from a root+pattern+features representation, it has separate phonological and orthographic representations, and it allows for combining morphemes from different dialects. We present a detailed evaluation of MAGEAD.

This paper presents a generalised twolevel implementation which can handle linear and non-linear morphological operations.

This paper presents an overview of research on computational Arabic morphology which is done in the West, as well as a new multi-tape model which consits of three components: A lexical component which mapps the autosegmental morphemes of Arabic (e.g., pattern, root and vocalism in stems) to a surface form. A rewrite-rules component takes care of conditional changes. A morphotactic component provides for morphotactic parsing. 1 Introduction Research in Arabic morphology has been a popular field in the Arab World due to the importance of a morphological component in any language model of Arabic. In the West, Arabic attracts attention because of its intriguing morphological system, viz., the root-and-pattern system. However, little interaction exists between Arab and western researchers. This is apparent in works published by the two communities which lack cross-community references, understandably since most work on Arabic morphology in the Arab World is published in the native language...

This paper establishes a framework under which various aspects of prosodic morphology, such as templatic morphology and infixation, can be handled under two-level theory using an implemented multi-tape two-level model. The paper provides a new computational analysis of root-and-pattern morphology based on prosody.

This paper demonstrates how the challenging problem of the Arabic broken plural and diminutive can be handled under a multi-tape two-level model, an extension to two-level morphology. 1 Introduction The phenomenon of the broken plural and diminutive in Arabic poses a challenge to main-stream two-level morphology, not only because of its nonconcatenative nature, but also because its analysis relies heavily on prosodic structure. The purpose of this paper is to present an implemented morphological model which is capable of analysing the broken plural. The following convention has been adopted. Morphemes are represented in braces, f g, and surface forms in solidi, / /. In examples of grammars, variables begin with a capital letter. Cs denote consonants and Vs denote vowels. In two-level rules, square brackets mark optional segments. The structure of the paper is as follows: section 2 presents the problem of the broken plural; section 3 introduces a computational framework for solving the...

This document contains draft information from a section of a preliminary version of a VERBMOBIL deliverable (TP 5.3-P1). It is distributed in this form to assist partners in advance planning. This document contains a simple version of the core DATR inference engine in Prolog in order to illustrate the principles of DATR inference to Prolog programmers. Note that in minor details it departs slightly from DATR conventions: - nonstandard nodenames are permitted; - the knowledge base must be pre-sorted to permit 'longest path first' inference; - queries include the theory name. Note also that this is not a directly usable implementation: there is no user interface, no DATR-Prolog interpreter, no DATR-specific trace or debugging, no attention paide to efficiency, etc. The aim is to provide a minimal 'core DATR standard inference' interpreter in logical style. 1 Illustration of a DATR theory: a 'microlexicon' MINILEX.DTR Tablecloth: !? == Compound !ilex? == lemma !relation? == (for covering) !modifier? == "Table:!?" !head? == "Cloth:!?". Table: !? == Simplex !ilex? == lemma !meaning? == (horizontal surface to put things on) !orthography? == (t a b l e). Cloth: !? == Simplex !ilex? == lemma 32 Dafydd Gibbon !meaning? == (variety of textile) !orthography? == (c l o t h). Compound: !? == Word !ilex? == generalisation !type? == compound !meaning? == ("!head meaning?" "!relation?" "!modifier meaning?") !orthography? == ("!modifier orthography?" "!head orthography?"). Simplex: !? == Word !ilex? == generalisation !type? == simplex. Word: !ilex? == generalisation !type? == word. Theorems: Tablecloth:!relation?=(for covering). Tablecloth:!meaning?=(variety of textile for covering horizontal surface to put things on). Tablecloth:!orthography?=(t a b l e c l o t h). Table:!orthography...

This paper demonstrates how a (multi-tape) two-level formalism can be used to write two-level grammars for Arabic non-linear morphology using a high level, but computationally tractable, notation. Three illustrative grammars are provided based on CV-, moraicand affixational analyses. These are complemented by a proposal for handling the hitherto computationally untreated problem of the broken plural. It will be shown that the best grammars for describing Arabic non-linear morphology are moraic in the case of templatic stems, and affixational in the case of a-templatic stems. The paper will demonstrate how the broken plural can be derived under two-level theory via the `implicit' derivation of the singular. 1 INTRODUCTION Arabic is known amongst computational linguists, in particular computational morphologists, for its highly inflexional morphology. Its root-and-pattern phenomenon has become the prototype for the evaluation of the few non-linear morphological models which have emerged...

For the computer, word forms in an online text are simply letter sequences between blanks. A rule-based automatic language analyses presupposes, however, that the computer can recognize the individual word forms. This includes assigning the base form (lemmatization) and determining the morphosyntactic properties (categorization). It is shown that there are three principled methods of automatic word form recognition, based on word forms, morphemes, and allomorphs, respectively. After describing these different methods using the notions of traditional morphology, they are compared with regards to their handling of neologisms, time efficiency, and space requirements. 1 Morphemes and allomorphs In traditional morphology, word forms are analyzed by disassembling them into their elementary parts. These are called morphemes and defined as the smallest meaningful units of language. In contrast to the number of potential words, the number of morphemes is finite. The notion of a morp...