Electronic Journal of Differential Equations, Vol. 2004(2004), No. 97, pp. 1-19. Title: Superlinear equations and a uniform anti-maximum principle for the multi-Laplacian operator Author: Eugenio Massa (Univ. degli Studi, Milano, Italy) Abstract: In the first part of this paper, we study a nonlinear equation with the multi-Laplacian operator, where the nonlinearity intersects all but the first eigenvalue. It is proved that under certain conditions, involving in particular a relation between the spatial dimension and the order of the problem, this equation is solvable for arbitrary forcing terms. The proof uses a generalized Mountain Pass theorem. In the second part, we analyze the relationship between the validity of the above result, the first nontrivial curve of the Fucik spectrum, and a uniform anti-maximum principle for the considered operator. Submitted May 25, 2004. Published August 7, 2004. Math Subject Classifications: 35G30, 49J35. Key Words: Higher order elliptic boundary value problem; superlinear equation; mountain pass theorem; anti-maximum principle.