  The electrovac axisymmetric extreme isolated horizon/CFT correspondence is
considered. By expansion techniques under the Bondi-like coordinates, it is
proved that the near horizon geometry of electrovac axisymmetric extreme
isolated horizon is unique. Furthermore, explicit coordinate transformation
between the Bondi-like coordinates and the Poincare-type coordinates for the
near horizon metric of the extreme Kerr-Newmann spacetime is found. Based on
these analyses and the thermodynamics of the isolated horizon, then, the
Kerr/CFT correspondence is generalized to nonstationary extreme black holes
with electromagnetic fields.
