  text of abstract (Integer quantum Hall effect (IQHE) has been analysed
considering the degeneracies of localized and extended states separately.
Occupied localized and extended states are counted and their variation is
studied as a function of magnetic field. The number of current carrying
electrons is found to have a saw-tooth variation with magnetic field. The
analysis attempts to answer certain basic questions besides providing a simple
but complete understanding of IQHE.)
