This paper provides an overview on Set operation,Formal Language and Automata theory. We defined Formal Language and Automata Theory,the terms involved and the application of set operations in defining Languages. In the light of this we design a simple model of a Virtual Machine, that converst Decimal Numbers to Binary Number and vice versa. We implemented this simple model in Java, the program is executed and verified correct. This paper aim at introducing Formal Language and Automata theory applicationin Modeling complex systems andVirtual Machines that performs complex operations.
: Formal Language, Automata Theory,Virtual Machine.