Published online by Cambridge University Press: 04 August 2014
For a continuous semicascade on a metrizable compact set  ${\rm\Omega}$, we consider the weak
${\rm\Omega}$, we consider the weak $^{\ast }$ convergence of generalized operator ergodic means in
$^{\ast }$ convergence of generalized operator ergodic means in  $\text{End}\,C^{\ast }({\rm\Omega})$. We discuss conditions under which: every ergodic net contains a convergent sequence; all ergodic nets converge; all ergodic sequences converge. We study the relationships between the convergence of ergodic means and the properties of transitivity of the proximality relation on
$\text{End}\,C^{\ast }({\rm\Omega})$. We discuss conditions under which: every ergodic net contains a convergent sequence; all ergodic nets converge; all ergodic sequences converge. We study the relationships between the convergence of ergodic means and the properties of transitivity of the proximality relation on  ${\rm\Omega}$, minimality of supports of ergodic measures, and uniqueness of minimal sets in the closure of trajectories of a semicascade. These problems are solved in terms of three associated algebraic-topological objects: the Ellis semigroup
${\rm\Omega}$, minimality of supports of ergodic measures, and uniqueness of minimal sets in the closure of trajectories of a semicascade. These problems are solved in terms of three associated algebraic-topological objects: the Ellis semigroup  $E$, the Köhler operator semigroup
$E$, the Köhler operator semigroup  ${\rm\Gamma}\subset \text{End}\,C^{\ast }({\rm\Omega})$, and the semigroup
${\rm\Gamma}\subset \text{End}\,C^{\ast }({\rm\Omega})$, and the semigroup  $G=\overline{\text{co}}\,{\rm\Gamma}$. The main results are stated for semicascades with metrizable
$G=\overline{\text{co}}\,{\rm\Gamma}$. The main results are stated for semicascades with metrizable  $E$ and for tame semicascades.
$E$ and for tame semicascades.