2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/78208A two-dimensional array of independent random signs produces coalescing random walks. The position of the walk, starting at the origin, after N steps is a highly nonlinear, noise sensitive function of the signs. A typical term of its Fourier-Walsh expansion involves the product of about square roof of N signs.9 pages, 3 figures, LaTeX2eProbability60K35 (Primary) 42C10, 43A75, 60C05 (Secondary)text