Characteristic 15. All mathematical propositions and conjectures are established in the scope of axiom 2; However, axiom 2 does not exist, so these theorems only apply to axiom 3 ,that is, these propositions are only established in a finite scope in axiom 3, such as Fermat's theorem, Riemann conjecture, Goldbach conjecture, etc., and their proofs are valid in a finite scope and cannot be naturally extended to an infinite scope. In any case, according to the definition of infinity in axiom 3, all these propositions are no longer applicable in an infinite range. In other words, the proof of each conjecture only applies to a limited range, not to infinite values.