**MSC:**- 41A25 Rate of convergence, degree of approximation
- 41A30 Approximation by other special function classes

finite set of functions $\phi_\nu(\nu=0,\ldots ,r-1)$

which are not necessarily compactly supported, but have

a suitable decay rate. Assuming that the function vector

$\mbox{\boldmath$\phi$}\mbox{\unboldmath$

=(\phi_\nu)^{r-1}_{\nu =0}$}$ is refinementable, we sketch

a new way, how to derive necessary and sufficient conditions

for the refinement mask in Fourier domain.