2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27127For a large class of tilings, including those which are obtained by the generalized dual method from regular grids, it is shown that their algebra is stably isomorphic to a crossed product with $\Z^d$. Penrose tilings belong to this class. This enlarges the class of tilings of which can be shown that a set of possible gap labels is completely determined by an invariant measure on the hull.13 pages, 1 figure, Latex, KCL-TH-94-10Condensed MatterHigh Energy Physics - Theorytext