  We prove that for almost square tensor product grids and certain sets of
bivariate polynomials the Vandermonde determinant can be factored into a
product of univariate Vandermonde determinants. This result generalizes the
conjecture [Lemma 1, L. Bos et al. (2009), Dolomites Research Notes on
Approximation, 2:1-15]. As a special case, we apply the result to Padua and
Padua-like points.

Numerical Analysis