Solving the Minimum Label Spanning Tree Problem by Mathematical Programming Techniques

Figure 3

Example of node-label-constraints for sets of two nodes (3.23) dominating Inequalities (3.22), that is, the node-label constraints for single nodes. For both nodes 𝑣_𝑖, 𝑖=1,2 it holds that ∑_{𝑙∈𝐿(𝑣𝑖)}𝑙≥1. Corresponding Inequality (3.23) is however violated, as ∑_{𝑙∈𝐿(𝑣1)∪𝐿(𝑣2)}𝑙=3/2.