I have defined a set L and another set R, and a set S = L x R for the Cartesian product of the two sets.
My question is quite naive. Given an element $s \in S$, is there a formal way to express its left part $l$ and right part $r$, where $s = (l,r)$?
Another question is... given a set $S' \subseteq S$, is there a formal way to express its left part $L'$ and right part $R'$, where $S'=L' \times R'$?
Thank you very much!