This article introduces proximal Cech complexes, restricted to the Euclidean plane. A Cechh complex of a set of points is the nerve of a collection of convex sets that are closed geometric balls all with the same radius, that have non-empty intersection. Both spatial and descriptive closed balls are considered. Cech complexes are proximal, provided the complexes are close to each other, either spatially or descriptively. A main result is that a descriptive Cech complex is homotopically equivalent to the description of the union of its closed balls. 查看全文>>