  Let R=k[x_1,...,x_d] be the polynomial ring in d independent variables, where
k is a field of characteristic p>0. Let D be the ring of k-linear differential
operators of R and let f be a polynomial in R. In this work we prove that the
localization R[1/f] obtained from R by inverting f is generated as a D-module
by 1/f. This is an amazing fact considering that the corresponding
characteristic zero statement is very false.
