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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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We discuss some classes of computationally hard integer programming instances. A common feature is that they remain hard even for very few variables. For one of the classes we analyze why a particular reformulation is easy to solve. The reformulation makes use of a lattice interpretation and the analysis uses knowledge of the corresponding lattice determinant.