current bounds on the number of colors: 0 -- 7 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:52 2012 Optimize a model with 31 rows, 29 columns and 93 nonzeros Presolve time: 0.00s Presolved: 31 rows, 29 columns, 93 nonzeros Variable types: 0 continuous, 29 integer (29 binary) Root relaxation: objective 0.000000e+00, 14 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 (20 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 17:55:52 2012 Optimize a model with 15 rows, 15 columns and 31 nonzeros Presolve removed 15 rows and 15 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 17:55:52 2012 Optimize a model with 23 rows, 22 columns and 62 nonzeros Presolve removed 7 rows and 7 columns Presolve time: 0.00s Presolved: 16 rows, 15 columns, 48 nonzeros Variable types: 0 continuous, 15 integer (15 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 0.00000 0 7 - 0.00000 - - 0s Explored 0 nodes (28 simplex iterations) in 0.00 seconds Thread count was 1 (of 16 available processors) Model objective exceeds cutoff Best objective -, best bound 1.000000000000e+00, gap - optimal solution found: number of colors: 3