On the solvability of the Birkhoff interpolation problem (Q1414075)

The authors study a univariate Birkhoff interpolation problem. They determine the smallest \(N\) for which the Birkhoff interpolation problem is always solvable. This is the main result of the paper and it is contained in Theorem 2.1, where is obtained the best possible upper bound for the solvability number of an incidence matrix \(E\) in terms only of its number of ones, its number of odd supported sequences and its almost-Pólya defect. Finally, an example is presented.