"projective sphere" (fwd)

[boud]

hi, 
  i received this from a friend.

The projective sphere is the 2-sphere S^2 where each point is
identified with its opposite point. So the fundamental polygon 
is a hemisphere.  Geodesics only intersect once in the projective
sphere.

> Hi Boud, 
> what an irony, but I am looking for your help with Polish !!!
> Could you or your collaborators on topology in Torun 
> enlighten me with Polish term for "projective sphere" ?
> Thanks in advance,

Can anyone help?

boud