current bounds on the number of colors: 0 -- 6 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 19:35:30 2012 Optimize a model with 21 rows, 23 columns and 63 nonzeros Presolve time: 0.00s Presolved: 21 rows, 23 columns, 63 nonzeros Variable types: 0 continuous, 23 integer (23 binary) Root relaxation: objective 0.000000e+00, 9 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 0.0000000 0.00000 0.0% - 0s Explored 0 nodes (9 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 -- 3 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 19:35:30 2012 Optimize a model with 11 rows, 11 columns and 21 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) 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 19:35:30 2012 Optimize a model with 16 rows, 17 columns and 42 nonzeros Presolve removed 6 rows and 6 columns Presolve time: 0.00s Presolved: 10 rows, 11 columns, 30 nonzeros Variable types: 0 continuous, 11 integer (11 binary) Root relaxation: objective 0.000000e+00, 4 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 0.0000000 0.00000 0.0% - 0s Explored 0 nodes (4 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