 |
Suppose arc BC with flow
is added to the feasible spanning tree. The above network shows next to
each arc the resulting incremental flow (in parentheses) and the cost per
unit flow (to the left of the parentheses). |
When ,
the resulting overall increment in total cost ( )
is |
= 2(1) + 3(1) + 4(-1) + 3(-1) = -2. |
Hence, the rate of change of
as
is increased is -2. |