@techreport{KleinertLabbeSchmidtetal.2020, author = {Thomas Kleinert and Martine Labb{\´e} and Martin Schmidt and Fr{\"a}nk Plein}, title = {Closing the Gap in Linear Bilevel Optimization: A New Valid Primal-Dual Inequality}, journal = {Optimization Letters}, number = {15}, pages = {1027 -- 1040}, year = {2020}, url = {https://opus4.kobv.de/opus4-trr154/315}, type = {Preprint}, institution = {TRR 154} }