b) Create a Prolog predicate listForPath(X,Y,L) that succeeds if L is the list of edges constructing a path between node X and node Y. E.g., ?- listForPath(a,d,L). L = [edge(a,b,2),edge(b,c,2),edge(c,d,2)].

c) Create a Prolog predicate pathLength(X,Y,R) that succeeds if R is the length of the path (sum of lengths of all edges on the path) between node X and node Y. E.g., ?- pathLength(a,d,R). R = 6.