Non-existence of forbidden subgraph characterization of H-line graphs

-line graph, denoted by , is a generalization of line graph. Let and be two graphs such that has at least 3 vertices and is connected. The -line graph of , denoted by , is that graph whose vertices are the edges of and two vertices of are adjacent if they are adjacent in and lie in a common copy of . In this paper, we show that -line graphs do not admit a forbidden subgraph characterization.