Set builder notation for addition?
Solution 1:
A function $f:X \to Y$ can be represented as a subset of $X \times Y$. The addition (lets say in the real numbers) is a function $+:\Bbb R \times \Bbb R \to \Bbb R$, which means its a subset of $(\Bbb R \times \Bbb R) \times \Bbb R$.
So $2+2=4$ can be written as $((2,2),4) \in +$.