Number of definable degrees among simple exact nonnuclear algebras
Determine whether there are infinitely many or uncountably many definable degrees among simple exact nonnuclear C*-algebras.
References
Are there infinitely many, or uncountably many, definable degrees among simple exact nonnuclear $C*$-algebras?
— Solution to Dixmier's Problem about spectra of C*-algebras
(2609.26319 - Lupini, 22 Sep 2026) in Question 6.1(iv), Section 6, subsection 'Limits of the obstruction'