The aggregation closure is polyhedral for packing and covering integer programs

Recently, Bodur, Del Pia, Dey, Molinaro and Pokutta studied the concept of aggregation cuts for packing and covering integer programs. The aggregation closure is the intersection of all aggregation cuts. Bodur et al. studied the strength of this closure, but left open the question of whether the aggregation closure is polyhedral. In this paper, we answer this question in the positive, i.e., we show that the aggregation closure is polyhedral. Finally, we demonstrate that a generalization, the k-aggregation closure, is also polyhedral for all k.