current bounds on the number of colors: 0 -- 3 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:51 2012 Optimize a model with 4 rows, 4 columns and 6 nonzeros Presolve removed 4 rows and 4 columns Presolve time: 0.00s Explored 0 nodes (0 simplex iterations) in 0.00 seconds Thread count was 1 (of 16 available processors) Model objective exceeds cutoff Best objective -, best bound -, gap - current bounds on the number of colors: 1 -- 3 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:51 2012 Optimize a model with 5 rows, 7 columns and 12 nonzeros Presolve removed 5 rows and 7 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: 2