  A topological space TO(S) of total orderings on any given set S is introduced
and it is shown that TO(S) is compact if S is countable. The set NO(N) of all
normal orderings of the nth Weyl algebra W is a closed subspace of TO(N), where
N is the set of all normal monomials of W. Hence NO(N) is compact and, as a
consequence of this fact and by a division theorem valid in W, we give a proof
that each left ideal of W admits a universal Groebner basis.
