摘要: A method for learning Horn theories based on a systematic use of abduction is presented. Abduction applied the basis examples provided initially and hypothesis space to generate queries missing positive negative examples. The added are treated in same way again until no more can be added. process seen as exploring order build backward all existing proof trees initial abductive completion procedure used solve problems extensional top-down methods. By means abduction, solution consistent with respect given always found, if it exists space.