A more formal definition for $\max(|S_1 \setminus S_2|, |S_2 \setminus S_1|)$

Question

Given two sets $S_1$ and $S_2$, I am working with a function that returns $\max(|S_1 \setminus S_2|, |S_2 \setminus S_1|)$.

I think this definition of the function is intuitive, but I wonder if there is a correct (better) way to define it mathematically.

Answer 1

Maybe you could try $\max(|S_1|,|S_2|)-|S_1\cap S_2|$?