neighbors/4¶

neighbors(+ Vertex, + Graph, - Vertices)*

Unify Vertices with the list of neighbors of vertex Vertex in Graph. If the vertice is not in the graph fail. In the next example:

 ?- neighbors(4,[1-[3,5],2-[4],3-[],
 4-[1,2,7,5],5-[],6-[],7-[],8-[]],
 NL).

 NL = [1,2,7,5]