TY - GEN A1 - Borndörfer, Ralf A1 - Heismann, Olga T1 - The Hypergraph Assignment Problem N2 - The hypergraph assignment problem (HAP) is the generalization of assignments from directed graphs to directed hypergraphs. It serves, in particular, as a universal tool to model several train composition rules in vehicle rotation planning for long distance passenger railways. We prove that even for problems with a small hyperarc size and hypergraphs with a special partitioned structure the HAP is NP-hard and APX-hard. Further, we present an extended integer linear programming formulation which implies, e. g., all clique inequalities. T3 - ZIB-Report - 12-14 KW - directed hypergraphs KW - hyperassignment KW - assignment Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-14822 SN - 1438-0064 ER -