Mathematical induction is a mathematical proof method, which is usually used to determine whether an expression is valid in all natural numbers or another form is valid in an infinite sequence. There is a generalized formal view used in mathematical logic and computer science, pointing out that the expressions that can be found are equivalent expressions; This is the famous structural induction.

The principle of this method is to first prove that the initial value in the expression is valid, and then prove that the proof process from one value to the next is effective. If these two steps are proved, then the proof of any value can be included in the repeated process.