Computing or bounding Hankel and circuit rank
Determine how to compute, or derive general upper bounds for, the Hankel rank or circuit rank associated with an arbitrary graph property P, and characterize the information about P sufficient to perform such estimates or computations.
References
However, we do not know how to compute (or even give an upper bound for) the Hankel rank or the circuit rank for P in general. It remains a challenging project to investigate what one has to know about P in order to estimate or compute the Hankel or circuit rank.
— Extensions of Courcelle's Theorem without Logic
(2608.21081 - Filmus et al., 21 Aug 2026) in Section 5, “Conclusions,” p. 15