This book contains the proceedings of the 5th European Working Session on Learning (EWSL-91), which describes the most recent advances in the field, especially those originating from European research groups. The topics have been divided into groups covering new trends in machine learning (ML), such as in multi-strategy learning, inversion of resolution and multi-agents, as well as established topics such as discovery, numeric and statistical approaches, theorem proving and explanation-based learning, and case-based reasoning.
