(G. Megyesi, F. Sottile and Th. Theobald)
(image by F. Sottile; green lines transversal to red line and line at infinity, tangent to orange and light brown quadrics)
| Problem: | Fixing 2 lines and one quadric in projective 3-dimensional space, describe the set of all quadrics for which there are infinitely many lines simultaneously transversal to both lines and tangent to both quadrics. |