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 16 rows, 14 columns and 44 nonzeros Presolve removed 4 rows and 4 columns Presolve time: 0.00s Presolved: 12 rows, 10 columns, 36 nonzeros Variable types: 0 continuous, 10 integer (10 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 0.00000 0 4 - 0.00000 - - 0s 0 0 infeasible 0 - 0.10000 - - 0s Explored 0 nodes (12 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 22 rows, 18 columns and 66 nonzeros Presolve time: 0.00s Presolved: 22 rows, 18 columns, 66 nonzeros Variable types: 0 continuous, 18 integer (18 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 0.00000 0 6 - 0.00000 - - 0s 0 0 0.00000 0 8 - 0.00000 - - 0s Cutting planes: Clique: 3 Zero half: 4 Explored 0 nodes (29 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