§ Shortest walk versus shortest path

• path is a sequence of vertices connected by edges.
• walk is a simple path or a path with no loops.
• djikstra's solves shortest walk, not shortest path, since it can't hangle paths with negative cycles!
• Bellman ford solves shortest path, since it reports when the question of "shortest path" does not have a sensible answer (ie, the set of paths ordered by length is not well founded).