current bounds on the number of colors: 0 -- 13 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:54 2012 Optimize a model with 259 rows, 119 columns and 816 nonzeros Presolve time: 0.00s Presolved: 259 rows, 119 columns, 816 nonzeros Variable types: 0 continuous, 119 integer (119 binary) Root relaxation: objective 0.000000e+00, 30 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 (59 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 -- 6 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:54 2012 Optimize a model with 136 rows, 80 columns and 408 nonzeros Presolve time: 0.00s Presolved: 136 rows, 80 columns, 408 nonzeros Variable types: 0 continuous, 80 integer (80 binary) Root relaxation: objective 0.000000e+00, 27 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 24 - 0.00000 - - 0s 0 0 0.00000 0 26 - 0.00000 - - 0s 0 0 infeasible 0 - 0.10000 - - 0s Explored 0 nodes (205 simplex iterations) in 0.01 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 17:55:54 2012 Optimize a model with 177 rows, 93 columns and 544 nonzeros Presolve time: 0.00s Presolved: 177 rows, 93 columns, 544 nonzeros Variable types: 0 continuous, 93 integer (93 binary) Root relaxation: objective 0.000000e+00, 27 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 (72 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