  We derive exact series solutions for the Wheeler-DeWitt equation
corresponding to a spatially closed Friedmann-Robertson-Walker universe with
cosmological constant for arbitrary operator ordering of the scale factor of
the universe. The resulting wave functions are those relevant to the
approximation which has been widely used in two-dimensional minisuperspace
models with an inflationary scalar field for the purpose of predicting the
period of inflation which results from competing boundary condition proposals
for the wave function of the universe. The problem that Vilenkin's tunneling
wave function is not normalizable for general operator orderings, is shown to
persist for other values of the spatial curvature, and when additional matter
degrees of freedom such as radiation are included.
