  For both extremal and non-extremal spherically symmetric black holes in
theories with massless scalars and vectors coupled to gravity, we derive a
general form of first-order gradient flow equations, equivalent to the
equations of motion. For theories that have a symmetric moduli space after a
dimensional reduction over the timelike direction, we discuss the condition for
such a gradient flow to exist.
  This note reviews the results of arXiv:0810.1528 [hep-th].
