In graph theory [Graph theory], a cycle in a graph [Graph] is a non-empty trail [Trail (Graph theory)] in which only the first and last vertices [Vertices] are equal.

(“Cycle (Graph Theory)” 2022)

Also see Circuit (Graph theory).

Negative cycle

[…] a cycle whose edges sum to a negative value […]

(“BellmanFord Algorithm” 2022)

Bibliography

“BellmanFord Algorithm.” 2022. Wikipedia, May. https://en.wikipedia.org/w/index.php?title=Bellman%E2%80%93Ford_algorithm&oldid=1088801570.
“Cycle (Graph Theory).” 2022. Wikipedia, September. https://en.wikipedia.org/w/index.php?title=Cycle_(graph_theory)&oldid=1110268538.