“…In 2002, Lin further generalised to study the L(d 1 , d 2 ; l 1 , l 2 )-assignment problem (Lin, 2002) of paths and Cartesian of two paths. During several decades, the problem has attracted many researchers (Some of them are: Bertossi et al, 2003;Chang and Kuo, 1996;Chang and Lu, 2003;Chang et al, 2000Chang et al, , 2006Chou, 2003;Georges and Mauro, 2002;Georges et al, 1994;Heuvel et al, 1998;McDiarmid, 2003;van den Havet, 2001;West, 2001;Whittlesey et al, 1995;Yeh, 2006).…”