We show an Omega(log log n) lower bound on the deterministic communication complexity of the following problem. Three parties A, B, C are given inputs x, y, z epsilon (Z/2)(n), respectively, subject to the constraint x + y + z = 1(n). The function to be computed is f(x, y, z) = boolean ORi(x(i) boolean AND y(i) boolean AND z(j)). (C) 1998 Academic Press.