I want to know if there exists any mathematical operator which can represent the idea of accessing explicitly a member of some object.
In this case it would be for describing that a node $n_l$ is left child of a node $n$. At the moment I know there exists the operator $::$ which states that its right side operand is member of its left side one. But I want to know if there is some alternative way because in C++ the operator $::$ is used for indicate global scope or static variable accessing.
Here one example: $\text{BalanceFactor}(n)=h(n::n_r)-h(n::n_l)$
Note: I thought in the $\rightarrow$ operator but it is also used in function definitions, I do not want to confuse my students.