Does unbounded width imply linear width for PCSPs?
Ascertain whether every promise constraint satisfaction problem PCSP(A, B) with unbounded width necessarily has linear width; equivalently, determine if the converse of the known implication for CSPs (that unbounded width implies linear width) extends to the promise setting.
References
For non-promise CSPs, the converse also holds: Every CSP of unbounded width has linear width. For PCSPs, the analogous statement is not known to hold.
— The periodic structure of local consistency
(2406.19685 - Ciardo et al., 28 Jun 2024) in Overview of results and techniques, Footnote (footnote_bounded_equals_nonlinear_for_CSPs)