computational problems. One of the Millennium Prize Problems, the famous "P=NP?" problem, is an open problem in the theory of computations. Formal methods are a particular kind of mathematically-based technique for specification which develops and verifies software and hardware systems. The use of formal methods for software and hardware design is motivated by the expectation, as in other engineering disciplines, performing appropriate mathematical analysis can contribute to the reliability of a design. In that case, the high cost of using formal methods means that they are usually only used in the development of high-integrity and life-critical systems, where safety or security is of