SUMMARY
Although testing is an essential part of software development, until re- cently, P system testing has been completely neglected. Mutation testing (mutation analysis) is a structural software testing method which involves modifying the pro- gram in small ways. In this paper, we provide a formal way of generating mutants for systems specified by context-free grammars. Furthermore, the paper shows how the proposed method can be used to construct mutants for a P system specification.