We may convert the production cost into a negative value in two ways; either by defining the value in the 窶徑ocal factor窶 field in the 窶廸ode dialog box窶 as a negative value, or by allocating a function to the link or the 窶彳dge窶 between the nodes. As an example, we choose the edge-function option.
Select the 窶弃roduction cost窶 node. Hold down the Shift key and click on the 窶彝evenue窶 node. This way both nodes should be selected:
Then, choose 窶廾pen Edge(s)...窶 from the 窶廴odel窶-menu, and a dialog box should appear.