In recent years, the number of DNA sequences increasing rapidly. Pattern scanning on large sequence database is one of the important functions in genomic research among biologist. It is useful for making new discoveries about a DNA sequence, including the location of functional sites and novel repetitive structures. Besides, it is also useful for the comparative analysis of different DNA sequences. Nevertheless, biologists face a problem in finding an accurate in pattern scanning in large DNA sequence database. The biologists frequently demand for optimal comparison result. So, the perfect structure of living beings evolution can be constructed. This task becomes more complex and challenging because the size of public sequence database is large and increasing exponentially every year. Nowadays, tools supporting formal methods are using interactive theorem provers and model checkers. Theorem proving is a part of validation techniques.