Two approaches to generate non-equivalent ground terms as test cases for object-oriented software

Software testing is an important technique for improving the reliability and quality of software systems. Object-oriented programming is considered to be the most promising programming methodology. We propose two approaches to generate non-equivalent ground terms as test cases. These approaches are based on the technique of fundamental equivalent pair. The basic idea of these approaches is as follows. Suppose u₁~u₂ is a fundamental equivalent pair, u ₂* is the normal form of u₂. Suppose further that by changing the values of parameters of constructor contained in u₂ *, or by inserting a basic constructor into u₂*, we obtain another ground term u₂´, then u₁ and u₂´ are nonequivalent, and can be used as a test case