Some Properties of Shortest Paths

Here's an example s to t shortest path in the example graph...

• What can we say about the length of any shortest path to a node u on the path from s to t ($\delta(s,u)$)?

• What can we say about the length of any shortest path to nodes v not on the path from s to t ($\delta(s,v)$)?

• What can we say about the sequence $\delta(s,v_i)$ along a shortest path $v_1,\ldots,v_l$?