Full rank of the max-min set-composition matrix

Prove that, for each fixed d, the matrix whose rows are indexed by loopless nested matroids on [d] and whose columns are indexed by max-min set compositions of [d], with entries recording whether a set composition is generic for the corresponding matroid, has full rank d!.

Background

Max-min set compositions are set compositions (π1,…,πk)(\pi_1,\ldots,\pi_k) satisfying max⁡πi>min⁡πi+1\max \pi_i>\min \pi_{i+1} for every adjacent pair. The paper proves that these set compositions are in bijection with permutations, so there are d!d! of them.

The proposed matrix tests genericity of each max-min set composition for each loopless nested matroid. Full rank would provide an explicit certificate for the conjectured linear independence of the chromatic word-quasisymmetric functions of loopless nested matroids.

References

We conjecture this matrix to have full rank $d!$.

— Chromatic word-quasisymmetric functions of matroids  (2609.29927 - Penaguiao et al., 24 Sep 2026) in Conjecture 3.15 (labelled conj:kernelspanspecific), Section 3.4, Conjectures based on computations