Which at the moment is both the start and the end of

, which at the moment is both the start
and the end of the tour. During the search, we always consider cities C
i
such that there
is an arc between C
i
and C
end
. The cost of this arc, plus the cost of the current partial
tour, gives us the cost so far. The cost to go is estimated by the path connecting C
i
and
C
start
on the MST containing C
i
, C
start
and all the nodes that have not been added yet,
6