Gurobi 5.0.1 (linux64) logging started Tue Nov 20 12:32:54 2012 Optimize a model with 426 rows, 135 columns and 852 nonzeros Presolve removed 88 rows and 7 columns Presolve time: 0.00s Presolved: 338 rows, 128 columns, 712 nonzeros Variable types: 0 continuous, 128 integer (128 binary) Found heuristic solution: objective 47.0000000 Root relaxation: objective 5.750000e+01, 209 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 57.50000 0 105 47.00000 57.50000 22.3% - 0s 0 0 57.00000 0 125 47.00000 57.00000 21.3% - 0s H 0 0 51.0000000 57.00000 11.8% - 0s 0 0 56.49206 0 127 51.00000 56.49206 10.8% - 0s 0 0 56.08333 0 126 51.00000 56.08333 10.0% - 0s 0 0 55.50000 0 124 51.00000 55.50000 8.82% - 0s 0 0 55.14737 0 121 51.00000 55.14737 8.13% - 0s H 0 0 52.0000000 55.14737 6.05% - 0s 0 0 55.06494 0 125 52.00000 55.06494 5.89% - 0s 0 0 54.73874 0 125 52.00000 54.73874 5.27% - 0s 0 0 54.71924 0 126 52.00000 54.71924 5.23% - 0s 0 0 54.71924 0 124 52.00000 54.71924 5.23% - 0s H 0 0 53.0000000 54.71924 3.24% - 0s 0 2 54.71924 0 124 53.00000 54.71924 3.24% - 0s Cutting planes: Zero half: 37 Explored 11 nodes (1018 simplex iterations) in 0.07 seconds Thread count was 1 (of 16 available processors) Optimal solution found (tolerance 1.00e-04) Best objective 5.300000000000e+01, best bound 5.300000000000e+01, gap 0.0%