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Relationship between SharpP-dimension and SpanP-dimension

Determine whether there is any general implication or separation between SharpP-dimension and SpanP-dimension; specifically, establish whether dim_{#P}(X) ≤ dim_{SpanP}(X) (or the reverse) holds for all classes X, or produce counterexamples.

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Background

The paper defines counting dimensions via #P- and SpanP-martingales, generalizing time-bounded dimension. While bounds relative to P- and PSPACE-dimensions are proved, the mutual comparison between the #P- and SpanP-dimensions is unresolved.

Clarifying this relationship would position counting dimensions within the larger landscape of fractal dimensions in complexity.

References

We do not know of any relationship between $$ and $$.

Counting Martingales for Measure and Dimension in Complexity Classes (2508.07619 - Hitchcock et al., 11 Aug 2025) in Section 3.2, Counting Measures and Counting Dimensions (Counting Dimensions)