New minimal axiom group of rough set

Rough set axiomatization is one aspect of rough set study, and the purpose is to characterize rough set theory using dependable and minimal axiom groups. Thus, rough set theory can be studied by logic and axiom system methods. To characterize the rough set theory, an axiom group named G, consisting of three axioms, is proposed. The reliability of the axiom group, which shows that characterizing of rough set theory is rational, is proved. Simultaneously, the minimization of the axiom group, which requests that each axiom is an inequality and each is independent, is proved. The axiom group is helpful to research on the rough set theory by logic and axiom system methods.