The problem of locating and computing with certainty all the simple roots o
f a twice continuously differentiable function f: [a, b] subset of R --> R
is studied when some additional information on the distribution of the root
s in the interval is available. The framework is the one proposed by [SIAM
J. Sci. Comput., 17 (1996), pp. 1232-1248], where only the uniform case was
examined. This paper settles some of the problems posed there and generali
zes some of its results by considering an arbitrary distribution of the roo
ts in [a, b]. The theoretical results are accompanied by simulations in a n
umber of problems of various size.