This paper firstly provides a re-appraisal of the development of techniques for inverting deduction, secondly introduces Mode-Directed Inverse Entailment (MDIE) as a generalisation and enhancement of previous approaches and thirdly describes an implementation of MDIE in the Progol system. Progol is implemented in C and available by anonymous ftp. The re-assessment of previous techniques in terms of inverse entailment leads to new results for learning from positive data and inverting implication between pairs of clauses.

Inductive Logic Programming (ILP) is a research area which investigates the construction of first-order definite clause theories from examples and background knowledge. ILP systems have been applied successfully in a number of real-world domains. These include the learning of structureactivity rules for drug design, finite-element mesh design rules, rules for primary-secondary prediction of protein structure and fault diagnosis rules for satellites. There is a well established tradition of learning-in-the-limit results in ILP. Recently some results within Valiant's PAC-learning framework have also been demonstrated for ILP systems. In this paper it is argued that algorithms can be directly derived from the formal specifications of ILP. This provides a common basis for Inverse Resolution, ExplanationBased Learning, Abduction and Relative Least General Generalisation. A new general-purpose, efficient approach to predicate invention is demonstrated. ILP is underconstrained by its logical ...

Traditionally logic was considered as having two branches: deductive and inductive. However the development of the subject from Frege (1879) up to about 1970 brought about a divergence between deductive and inductive logic. It is argued in this paper that developments in artificial intelligence in the last twenty or so years (particularly logic programming and machine learning) have created a new framework for logic in which deductive and inductive logic can, once again, be treated as similar branches of the same discipline. Keywords: deductive logic, inductive logic, logic programming, machine learning, PROLOG 1 Introduction The aim of this paper is to explore some consequences for the philosophy of logic and the philosophy of science of advances in artificial intelligence (AI) made in the last twenty or so years. Let me begin by listing some of these advances. I will describe the philosophically relevant aspects of these developments in more detail later. As far as the philosophy o...