Janusz S. Bień

Beliefs, Points of View, and Multiple Environments*

The paper describes a system for dealing with nestings of belief in terms of the mechanism of computational environment . A method is offered for computing the beliefs of A about B (and so on) in terms of the systems existing knowledge structures about A and B separately. A proposal for belief percolation is put forward: percolation being a side effect of the process of the computation of nested beliefs, but one which could explain the acquisition of unsupported beliefs. It is argued that the mechanism proposed is compatible with a general least effort hypothesis concerning human mental functioning. The authors are indebted to comments and criticisms from Dan Dennett, Bill Mann, Bob Balzer, Bob Abelson, Roger Schank, Mike Rosner, and Richard Young. The errors, of course, are all our own.

Efficient search in hidden text of large DjVu documents

The paper describes an open-source tool which allows to present end-users with results of advanced language technologies. It relies on the DjVu format, which for some applications is still superior to other modern formats including PDF/A. The DjVu GPLed tools are not limited just to the DjVuLibre library, but are being supplemented by various new programs, such as pdf2djvu developed by Jakub Wilk. It allows in particular to convert to DjVu the PDF output of popular OCR programs like FineReader preserving the hidden text layer and some other features. The tool in question has been conceived by the present author and consist of a modification of the Poliqarp corpus query tool, used for National Corpus of Polish; his ideas have been very succesfully implemented by Jakub Wilk. The new system, called here simply Poliqarp for DjVu, inherits from its origin not only the powerfull search facilities based twolevel regular expressions, but also the ability to represent low-level ambiguities and other linguistic phenomena. Although at present the tool is used mainly to facilitate access to the results of dirty OCR, it is ready to handle also more sophisticated output of linguistic technologies.

Toward a parsing method for free word order languages

Formal d e s c r i p t i o n s o f =yntax have been u s u a l l y based e i t h e r on t h e immedia te c o n s t i t u e n t s o r on t h e dependency p~ilosophy. Neither of them seems directly applicable to free word order languages. The intertwining phrases cannot be described naturally by IC rules. Some coordinate constructions are difficult to describe by me~us of dependency relations. I n our o p i n i o n , p a r s e r s f o r f r e e word o r d e r l a n g u a g e s shou ld no t be based on t h e methods deve loped w i t h i n t he IC framework. S c a r c e e x p e r i m e n t s w i t h p a r s e r s based on the dependency fo rma l i s m , eg . / 5 / , do no t seem p r o m i s i n g . T h e r e f o r e , we d e c i d e d t o t a k e a f r e s h s t a r t and t o a t t a c k the problem by r e a n a l y s i n g t h e b a s i c n o t i o n s o f syn t ax and p a r s i n g . We focus our a t t e n t i o n on t h o s e f o r m a l a s p e c t s o f a l anguage sys tem which might be most u s e f u l f o r a u t o m a t i c t e x t p r o c e s s i n g . We assmae t h a t t h e m o r p h o l o g i c a l l e v e l i s d e s c r i b e d a l o n g the l i n e s o f /2/4

Towards computer systems for conversing in Polish

The progress in computer hardware in recent years has been enorm.ous. Computers are now extremely fast and relatively cheap, the capacity of their storage has also been multiplied. These factors influence both the range of computer applications and the complexity of software. Computers are now used directly not only by mathematicians, physicists and data processing departments, but also by scientific workers of almost all domains of knowledge (including philology, philosophy, archaeology, etc.), managers and even sometimes laymen such as patients in hospitals. On the other hand, the great computational power of existing hardware allows us to develop very sophisticated systems for solving complicated problems, in a fully automatic manner or by means of interaction with man. There is no reason to doubt this is a steady trend in the computer world. We have to realize now that it means that man-machine communication will become more and more crucial in computer usage. First, if we cannot make communication with computers easier, then the greater number of computer users requires the total cost o f training to rise considerably. Secondly, even an excellent problem solver can be of no use if we do not develop the means for stating a problem correctly. The aim of research in proving the correctness of programs and automatic program synthesis is to solve the software crisis by making the work of programmers easier,

Syntactic Spreadsheets: In Search for a Human-Readable Representation of Parse Tree Forests

The paper presents an example of a representation of parse tree forests advocated by the author. Although motivated by the need to analyse the forests generated by Świdzinskis grammar, the representation can be used for any grammar handled by Wolinskis Birnam parser, and the basic ideas can be applied to any Immediate Constituent grammar. Syntactic spreadsheets can serve several purposes. They can be simply included in printed publications or dynamically displayed by an appropriate viewer. Unfortunately the implementation of the idea is not easy and therefore it is still in progress.

An Approach to Computational Morphology

Traditional linguistic terminology is not sufficiently precise to be used directly for text processing. In particular the term word is higly ambiguous. We postulate the linguistic objects, also called words, which can be classified according to 3 dimensions: the level of linguistic description and text representation (alphabetic, graphemic, morphological and morphosyntactic), set versus elements (paradigmatic vs syntagmatic words) and type versus token. We use also the notions of flexeme and vocable, which are specific kinds of paradigmatic words; all words belonging to a flexeme have the same syntactic properties, while vocable is a set of flexemes roughly equivalent to a traditional dictionary entry. The development of this theoretical framework has been driven by practical tasks of processing (in particular parsing) Polish texts.

Book Reviews : Prolog for Programmers Publisher: Academic Press, Inc., 111 Fifth Ave., New York, NY 10003 Year of Publication: 1985 Length: 400 pages Price:

This book reveals many things about Prolog that a programmer would like to know. It would not be a good choice for beginners. It contains a variety of applications which might be useful to social scientists, including a natural-language parser, and a small program for implementing plans in a fixed physical environment. It is very clearly written. (Reviewed by Jeffrey Hart, Indiana University.)