So can the definition be proved? Obviously not. Proof is to explain the process of advanced application with basic theory, and to explain the complex process with simplicity. Since definition is the basis of everything, it means that it can never be proved, and it can only be used to prove something else. (Note: Mathematician Godel's Incompleteness Theorem: In any axiomatic formal system, such as modern mathematics, on the basis of defining the axioms of the system, there are always problems that can neither be proved nor falsified. )