current bounds on the number of colors: 0 -- 11 Gurobi 5.0.1 (linux64) logging started Sat Dec 15 16:12:41 2012 Optimize a model with 11 rows, 55 columns and 55 nonzeros Presolve removed 11 rows and 55 columns Presolve time: 0.00s Explored 0 nodes (0 simplex iterations) in 0.00 seconds Thread count was 1 (of 16 available processors) Optimal solution found (tolerance 1.00e-04) Best objective 0.000000000000e+00, best bound 0.000000000000e+00, gap 0.0% current bounds on the number of colors: 0 -- 5 Gurobi 5.0.1 (linux64) logging started Sat Dec 15 16:12:41 2012 Optimize a model with 11 rows, 22 columns and 22 nonzeros Presolve removed 11 rows and 22 columns Presolve time: 0.00s Explored 0 nodes (0 simplex iterations) in 0.00 seconds Thread count was 1 (of 16 available processors) Optimal solution found (tolerance 1.00e-04) Best objective 0.000000000000e+00, best bound 0.000000000000e+00, gap 0.0% current bounds on the number of colors: 0 -- 2 Gurobi 5.0.1 (linux64) logging started Sat Dec 15 16:12:41 2012 Optimize a model with 11 rows, 11 columns and 11 nonzeros Presolve removed 11 rows and 11 columns Presolve time: 0.00s Explored 0 nodes (0 simplex iterations) in 0.00 seconds Thread count was 1 (of 16 available processors) Optimal solution found (tolerance 1.00e-04) Best objective 0.000000000000e+00, best bound 0.000000000000e+00, gap 0.0% optimal solution found: number of colors: 1