Gurobi 5.6.3 (linux64) logging started Tue Oct  7 20:53:51 2014

Optimize a model with 6807 rows, 6806 columns and 20254 nonzeros
Presolve time: 0.14s
Presolved: 6807 rows, 6806 columns, 20254 nonzeros
Variable types: 0 continuous, 6806 integer (6806 binary)
Found heuristic solution: objective 16.4702483

Root relaxation: objective 8.671379e+00, 992 iterations, 0.04 seconds

    Nodes    |    Current Node    |     Objective Bounds      |     Work
 Expl Unexpl |  Obj  Depth IntInf | Incumbent    BestBd   Gap | It/Node Time

     0     0    8.67138    0   54   16.47025    8.67138  47.4%     -    0s
H    0     0                       8.6798359    8.67138  0.10%     -    0s
     0     0     cutoff    0         8.67984    8.67984  0.00%     -    0s

Cutting planes:
  Gomory: 1
  Zero half: 1

Explored 0 nodes (994 simplex iterations) in 0.24 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 8.679835880078e+00, best bound 8.679835880078e+00, gap 0.0%