Uniform-contraction conjecture for bounded complexes of affine oriented matroids

Let $(E,\mathcal{L},g)$ be an affine oriented matroid, where $g$ is the distinguished element and $\mathcal{L}/g$ denotes contraction by $g$. The bounded complex is denoted by $\mathcal{L}^{++}$. Uniform-contraction conjecture. If the contraction $\mathcal{L}/g$ is uniform, then the bounded complex $\mathcal{L}^{++}$ is a ball. This generalizes Zaslavsky's conjecture for hyperplane arrangements without parallelism among the hyperplanes and intersections. The result established in the paper covers the uniform-contraction case, so the claim is solved.