Line Mixing

In the mathematical discipline of graph theory, the [line graph](https://en.wikipedia.org/wiki/Line_graph) of a simple undirected graph $G$ is another simple undirected graph $L(G)$ that represents the adjacency between every two edges in $G$. Precisely speaking, for an undirected graph $G$ without self-loops or multiple edges, its line graph $L(G)$ is a graph such that - Each vertex of $L(G)$