A spreading metric on the graph G for a given MLA problem instance is an assignment, δ : E → Q, of lengths to the edges of the graph that has the following properties: • The volume of a spreading metric, ∑ (i,j)∈E δi,jwi,j, of graph G in the MLA problem instance provides a lower bound on the value of the optimal solution of the MLA problem. • It “spreads apart” (w.r.t. metric lengths) the nontr...