An innovative list of 75 logic problems for testing ATP systems was introduced in 1986. The problems are presented in a natural first-order form (FOF), and most of them are also given in an equivalent negated conclusion clause normal form (CNF). However, shortly the introduction of the logic problems, some errata are presented. In particular, Problem 62 was corrected. But recently, it has been discovered that both the CNF and FOF version of the Problem 62 of the errata presented are incorrect. This paper presents the correct version of Problem 62. Problem 62 is on of four variations on the same problem, the others being Problems 17, 33 and 38. The relationships among these problems are discussed. Their CNF versions and an explanation of the relevant of Problem 62 are also given.
ASJC Scopus subject areas
- Computational Theory and Mathematics
- Artificial Intelligence