not to nitpick, but there's a ton of stuff in mathematics that is just defined out of convenience or convention, it's not natural law. Rather, a better definition would be that mathematics is a description of reality, rather than law itself.
Isn't it the same? Laws of physics describe how the physical world works, similarly to "laws of math" that describe how the mathematical world works. In both cases we tend to define our laws in a way that's easy for humans to use and understand.
