By a drawing of the Fano plane I mean a system of seven simple curves and
seven points in the real plane such that
- every point lies on exactly three curves, and every curve contains
exactly three points; - there is a unique curve through every pair of points, and every two
curves intersect in exactly one point; - the curves do not intersect except in the seven points under
consideration.
The familiar picture
does not count as a drawing, since the last requirement is not satisfied:
there are two "illegal" intersections. In fact, this is easy to fix:
However, this drawing is degenerate in the sense that two of the curves
just "touch" each other, without crossing, at some point. And here,
eventually, my question goes:
Is every drawing of the Fano plane degenerate?
(Although I can give a topological definition of degeneracy, it is a little technical and, may be, not the smartest possible one, so I prefer to suppress it here.)
Best Answer
Does this one work?
(source)