Strong Hanani–Tutte theorem on surfaces
Determine whether the Strong Hanani–Tutte theorem holds on every compact orientable surface without boundary, namely, whether an independently even drawing implies that the graph is embeddable on that surface.
References
Does it hold on other surfaces without boundary?
— Generalizations of the Crossing Lemma
(2509.14074 - Toth, 17 Sep 2025) in Section 5, Open problems, item 3