[Math] Fano plane drawings: embedding PG(2,2) into the real plane

combinatorial-designsdiscrete geometryincidence-geometryprojective-geometry

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

Traditional Fano plane (source)

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:

Non-intersecting Fano plane (source)

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)

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