Section: New Results
Dual feasible functions
Dual-feasible functions have proved to be very effective for
generating fast lower bounds and valid inequalities for integer linear
programs with knapsack constraints. However, a significant limitation
is that they are defined only for positive arguments. Extending the
concept of dual-feasible function to the general domain and range R is
not straightforward. In [10] , we propose the
first construction principles to obtain general functions with
domain and range