current bounds on the number of colors: 0 -- 6 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:52 2012 Optimize a model with 30 rows, 26 columns and 90 nonzeros Presolve removed 1 rows and 3 columns Presolve time: 0.00s Presolved: 29 rows, 23 columns, 87 nonzeros Variable types: 0 continuous, 23 integer (23 binary) Root relaxation: objective 0.000000e+00, 11 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 8 - 0.00000 - - 0s 0 0 0.00000 0 10 - 0.00000 - - 0s Cutting planes: Clique: 6 Zero half: 2 Explored 0 nodes (34 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 - current bounds on the number of colors: 3 -- 6 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:52 2012 Optimize a model with 38 rows, 32 columns and 120 nonzeros Presolve removed 1 rows and 4 columns Presolve time: 0.00s Presolved: 37 rows, 28 columns, 116 nonzeros Variable types: 0 continuous, 28 integer (28 binary) Root relaxation: objective 0.000000e+00, 10 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 (18 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: 4