current bounds on the number of colors: 0 -- 9 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:52 2012 Optimize a model with 69 rows, 51 columns and 216 nonzeros Presolve time: 0.00s Presolved: 69 rows, 51 columns, 216 nonzeros Variable types: 0 continuous, 51 integer (51 binary) Root relaxation: objective 0.000000e+00, 18 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 (31 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 -- 4 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:52 2012 Optimize a model with 39 rows, 33 columns and 108 nonzeros Presolve removed 9 rows and 9 columns Presolve time: 0.00s Presolved: 30 rows, 24 columns, 90 nonzeros Variable types: 0 continuous, 24 integer (24 binary) Root relaxation: objective 0.000000e+00, 12 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 9 - 0.00000 - - 0s 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: 2 -- 4 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:52 2012 Optimize a model with 54 rows, 42 columns and 162 nonzeros Presolve time: 0.00s Presolved: 54 rows, 42 columns, 162 nonzeros Variable types: 0 continuous, 42 integer (42 binary) Root relaxation: objective 0.000000e+00, 20 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 14 - 0.00000 - - 0s Cutting planes: Clique: 3 Zero half: 4 Explored 0 nodes (60 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: 4