MIPLIB 0-1 instances in OPB format

0-1 integer linear programming instances from the MIPLIB benchmark sets, converted to OPB, the pseudo-Boolean optimization format.

The MIPLIB benchmark sets used are MIPLIB 2, 3, 2003, 2010 and 2017. Links to these benchmark sets are available on http://miplib.zib.de/links.html. The original paper for which these instances were created (Learn to Relax: Integrating 0-1 Integer Linear Programming with Pseudo-Boolean Conflict-Driven Search - 2020) incorrectly describes this benchmark set as consisting only of MIPLIB 2017 instances.

Since few MIPLIB instances are pure decision problems, we created additional decision versions of the optimization problems. For this, we constructed a first instance by replacing the objective function with a constraint stating that the objective should be at least the best known value, and a second where the objective should be strictly better. To reduce integer values to a value of at most 10^9, some of the instances were rescaled.