On 18 Jul 2006 11:42:33 -0700, "MoeBlee" <firstname.lastname@example.org> wrote:
>MoeBlee wrote: >> As I defined a 'circle', it is a set of points in RXR all >> equidistant (for a distance greater than 0) from a given point. That's >> a circle, not a sphere. > >I'm correcting myself. What I defined in RXR is both a circle and a >sphere. For dimension greater than 2, such a set is not a circle but is >a sphere. But it is not a disc nor a ball.
No idea what this is in aid of. If you assume a plane you define a circle? I agree. The difficulty is in set definitions you assume what you should be demonstrating.