\magnification=\magstep1 \centerline{\bf Report on `$C$-Ball
Curves in Space $\Gamma_n$'} \medskip \centerline{\bf by G. Wang
and Q. Hu} \bigskip The authors extend the $C$-B\'ezier curves of
[1] to `$C$-Ball curves' in an analogous manner to the extension
from B\'ezier curves to the Wang-Ball curves of [6]. Apart from
many minor errors in presentation, particularly in English, the
work is correct and quite clear. However the work follows exactly
the same approach as the extension mentioned above (which is
summarised in the Appendix) and the proofs are of standard form.
So I suggest that, if this is published, it should be abbreviated
to a fairly short note giving the results and ideas but omitting
discussions and technical details.

For example, I suggest that equation (4.1) should be included at
the end of Section 2 under `degree raising' and expressed in the
form
$$J_{i,n}=\alpha_{i,n}J_{i,n+1}+\alpha_{n-i,n}J_{i+1,n+1},\quad i=0,\ldots,n, $$ where $\alpha_{i,n}$ is given as the appropriate formula in terms of
$\delta$'s. Then equations (3.1)-(3.4) can be simplified as
$$\lambda_{k,2k+1}=\alpha_{k,2k}\lambda_{k,2k}=\lambda_{k+1,2k+1},$$
$$\lambda_{k-1,2k}=\alpha_{k-1,2k-1}\lambda_{k-1,2k-1}=\lambda_{k+1,2k},$$
$$\lambda_{k,2k}=2\alpha_{k,2k-1}\lambda_{k,2k-1}.$$

Also the discussion after (3.5) can be removed. Although I did
find the Appendix useful, I feel that it is also not necessary.
\end
