Abstract
Symbolic objects (Diday (1987, 1992), Brito, Diday (1990), Brito (1991)) allow to model data on the form of descriptions by intension, thus generalizing the usual tabular model of data analysis. This modelisation allows to take into account variability within a set. The formalism of symbolic objects has some notions in common with VL1, proposed by Michalski (1980); however VL1 is mainly based on prepositional and predicate calculus, while the formalism of symbolic objects allows for an explicit interpretation within its framework, by considering the duality intension-extension. That is, given a set of observations, we consider the couple (symbolic object — extension in the given set). This results from the wish to keep a statistics point of view. The need to represent non-deterministic knowledge, that is, data for which the values for the different variables are assigned a weight, led to considering an extension of assertion objects to probabilist objects (Diday 1992). In this case, data are represented by probability distributions on the variables observation sets. The notions previously defined for assertion objects are the generalized to this new kind of symbolic objects. Other extensions can be found in Diday (1992). © Springer-Verlag Berlin Heidelberg 1993.

Abstract

Abstract
Inductive Logic Programming (ILP) is concerned with construction of logic programs from examples. It shares many concerns of Machine Learning (ML), but is committed to logic. As logic can help to provide a basis for elaborating such a methodology for learning, the area of ILP has attracted a wide attention of many researchers1. This paper reviews some of the methods and techniques in ML that exploit logic.

Abstract

Abstract

Abstract
We prove that the speed of convergence of two Markov families determines the smoothness of the conjugacy between them. One of the applications of this result that we give is that the attractors of any two quadratic foldings at the Feigenbaum accumulation point of period doubling are C2+0.11 conjugate. Our main result provides the basis for a complete unification of renormalization and smooth conjugacy results which includes both the classical theorems and more recent results about critical systems.