2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/77697This is the second in a series of papers giving a proof of the Kepler conjecture, which asserts that the density of a packing of congruent spheres in three dimensions is never greater than $π/\sqrt{18}\approx 0.74048...$. This is the oldest problem in discrete geometry and is an important part of Hilbert's 18th problem. An example of a packing achieving this density is the face-centered cubic packing. This paper defines a local formulation of the conjecture which is used in the proof.23 pages. Second in a series beginning with math.MG/9811071Metric Geometrytext