Let us look at a special type of context sensitive grammars, the so-called Definite Clause Grammars, or DCG, as described by Pereira and Warren (l980). The following question seems natural here: every context sensitive language be described by meeins of a definite clause grammar ? The question must be answered in the eiffirmative, as can be seen by simu­ lating Turing machines or better Markov ...

Growing interest in visual languages has triggered new extended research into the specification and parsing of multi-dimensional structures. The paper discusses the need for a visual specification formalism and introduces such a technique by augmenting logic programming with picture terms which can be considered as partially specified pictures. We define how to match picture terms and how to in...

The problem we are interested in is the best approximation of a given matrix by a positive semi–definite symmetric Toeplitz matrix. Toeplitz matrices appear naturally in a variety of problems in engineering. Since positive semi–definite Toeplitz matrices can be viewed as shift invariant autocorrelation matrices, considerable attention has been paid to them, especially in the areas of stochastic...

Hassan Ait-Kaci introduced the #/-term, an informational structure resembling feature-based functional structures but which also includes taxonomic inheritance (Ait-Kaci, 1984). We describe e-terms and how they have been incorporated into the Logic Grammar formalism. The result, which we call Inheritance Grammar, is a proper superset of DCG and includes many features of PATR-II. Its taxo-nomic ...

  We present a new full Nesterov and Todd step infeasible interior-point algorithm for semi-definite optimization. The algorithm decreases the duality gap and the feasibility residuals at the same rate. In the algorithm, we construct strictly feasible iterates for a sequence of perturbations of the given problem and its dual problem. Every main iteration of the algorithm consists of a feasibili...

This paper describes a system in PROLOG for the automatic transforination of a grammar, written in LFG formalism, into a DCG-based parser. It demonstrates the main principles of the transformation, the representation of f-structures and constraints, the treatment of long-distance dependencies, and left rccursion. Finally some problem areas of the system and possibilities for overcoming them are...

This paper presents the design and implementation of an intelligent document understanding and reproduction system. The system analyses a printed document to create an electronic document. The electronic document is written in a standard type-setting language (L w), and is thus human usable. The output from processing the electronic document closely resembles the original printed document. A ne...