The main purpose
of this paper is to prove that Mn⊂ EN, where N = n(n + 1)∕2, the
characteristic (n − 1)-dimensional submanifolds of Mn are the asymptotic
hypersurfaces.
Departamento de Matematica
Universidade de Brasilia
Campus Universitário Darcy Ribeiro
ICC Centro - Bloco A - Asa Norte
70910-900 DF Brasília-DF
Brazil