Simple, reducible Venn diagrams on five curves and Hamiltonian cycles (Q1379516)

Continuing joint papers of the authors and \textit{K. B. Chilakamarri} [J. Comb. Theory, Ser. B 67, No. 2, 296-303, Art. No. 0047 (1996; Zbl 0856.05028) and Geom. Dedicata 62, No. 1, 73-91 (1996; Zbl 0863.05030)], the paper investigates and classifies simple, reducible Venn diagrams on five sets. In particular a simple, reducible Venn diagram consisting of five congruent ellipses is given correcting erroneous statements traced back to Venn himself. By the way some questions recently raised by B. Grünbaum are answered.