  Skew product systems with monotone one-dimensional fibre maps driven by
piecewise expanding Markov interval maps may show the phenomenon of
intermingled basins. To quantify the degree of intermingledness the uncertainty
exponent and the stability index were suggested by various authors and
characterized (partially). Here we present an approach to evaluate/estimate
these two quantities rigorously using thermodynamic formalism for the driving
Markov map.
