To incorporate integer or binary variables in a linear programming problem, you need to specify them in the formulation. This means that you need to define the objective function, the constraints ...

A “dummy” or “indicator” variable takes on a value of either 0 or 1. The appeal of these particular values is that they are numerical and can be used with routines that only accept numerical data ...

However, the problem is formulated as a binary constraint linear programming, in the sense that all the arcs/paths are the variables, which can be taken or not taken (hence a binary problem). We have ...