“…This label is added to the empty queue PQ and is immediately removed from it by takeNext~PQ!. Label Step 1: Nodes v 2 and v 3 are children of s; suppose that, for example, v 2 is considered first: Step 2: @~20,20,10,10!,~s,1!# v 2 1 is selected and becomes permanent. Step 3: @~58,60,13,15!,~v 2 ,1!# v 3 1 is selected and becomes permanent.…”