Zdeněk Sýkora and François Morellet: Parallels and Complementarity

This paper compares and examines in mathematical terms the work of Zdeněk Sýkora and François Morellet devoted to structures and lines. Using concrete examples, the paper demonstrates that, despite many apparent similarities, the artists' approaches are considerably different. A farewell letter by François Morellet to Zdeněk Sýkora, who died on 12 July 2011, is included.