$R_{1} \oplus R_{2}$
I know that $R_{1} \oplus R_{2} = R_{1} \cup R_{2} - R_{1} \cap R_{2}$, and $R_{1} \cup R_{2}$ is not necessarily an equivalence relation but $R_{1} \cap R_{2}$ is always an equivalence relation, when we subtract what we will get? For example consider this, what will be the graph of $R_{1} \oplus R_{2}$?
