“…At the same time, it should be pointed out that Theorem 1.1 only provides an upper bound for the number of data points that are needed for a positive and F K (Ω)-exact CF. Indeed, for standard domains (e. g. Ω = [0, 1] d ) and weight functions (e. g. ω ≡ 1) as well as classical functions spaces (e. g. algebraic polynomials), it is possible to construct CFs that use even fewer points [75,73,45,11,10,7,115]. Such CFs are referred to as minimal or near-minimal CFs and usually utilize some kind of symmetry in the domain, weight function, and function space.…”