Wave number includes the previous number, not the latter number. As explained on the fourth page of compulsory mathematics in senior high school, the 0-degree wavy line is 360 degrees, which means that it is greater than or equal to 0 degrees and less than 360 degrees, so the wavy line includes the front numbers, but does not include the back numbers. Mathematically, it is a mathematical symbol representing equivalence relation, which means equivalent infinitesimal.