  Sturm-Liouville oscillation theory is studied for Jacobi operators with block
entries given by covariant operators on an infinite dimensional Hilbert space.
It is shown that the integrated density of states of the Jacobi operator is
approximated by the winding of the Pruefer phase w.r.t. the trace per unit
volume. This rotation number can be interpreted as a spectral flow in a von
Neumann algebra with finite trace.
