Kuntze is a retard. All of quantum physics and differential equations disagrees with this. It is equivalent to saying "its wrong because I don't have the mental capacity to expand a definition when it is necessary".

Examples:

mclaurin series
fourier series
hermite polynomials
... the list is very long.

What you do need to account for is the closure of the vector space describing the span of these infinite linear combinations described as a metric space.

So in terms of vector spaces, he is right, but to suggest somebody is doing something wrong is evidence of his own lack of understanding of a metric space.

>pic related