Strictly layered feedforward networks with binary neurons are viewed as map
s from the vertex set of an n-cube to the vertex set of an l-cube. With onl
y one output neuron, they can in principle realize any Boolean function on
n inputs. We address the problem of determining the necessary and sufficien
t numbers of hidden units for this task by using separability properties of
affine oriented hyperplane arrangements. (C) 2000 Academic Press.