  We present an alternative Double Description representation for the domain of
NNC (not necessarily topologically closed) polyhedra, together with the
corresponding Chernikova-like conversion procedure. The representation differs
from the ones adopted in the currently available implementations of the Double
Description method in that it uses no slack variable at all: this new approach
provides a solution to a few technical issues caused by the encoding of an NNC
polyhedron as a closed polyhedron in a higher dimension space. A preliminary
experimental evaluation shows that the new conversion algorithm is able to
achieve significant efficiency improvements with respect to state-of-the-art
implementations.
