Solving the Minimum Label Spanning Tree Problem by Mathematical Programming Techniques
Figure 2
Example of node that is feasible connected w.r.t. its incoming arcs, but not w.r.t. Inequalities (3.22). Edges in the current LP-solutions, but as both edges have assigned the same label the sum over the set of all labels assigned to incident edges of the considered node is also 1/2. Such situations are forbidden by Inequalities (3.22).
