Let $X$ and $Y$ be metric spaces and $f: X \rightarrow Y$ a Borel measurable function. Does $f$ have to be of bounded class, i.e. are the sets $f^{-1}\lbrack H ...

This is a preview. Log in through your library . Abstract It is shown that there exist $2n + 1$ real valued, continuous functions $\phi_0,\ldots, \phi_{2n}$ defined on $\mathbf{R}^n$ such that every ...