2 problems

Whiteley's conjecture. These matroids are equal for every $n\geq 2$:

For $n$ vertices, let $K_n$ be the complete graph, let $\mathcal C^{d-2}_{d-1}(K_n)$ be the cofactor matroid, and let $\operatorname{val}_{K_{d+2}}$ be the valuation associated wit…