\section{Computational aspects}
-\subsection{Charging basics and cost policies}
+%\subsection{Charging basics and cost policies}
In order to charge based on the incoming resource events, time (\DTime) and the unit of measure (\DUnitR) for a resource ($R$) play a central role. \DUnitR can be taken into account either as whole value or as a difference \DeltaDUnitR. On first approximation, these lead to linear formulas that capture the essence of charging algorithms. Below, we will briefly study charging scenarios for three well-known resources, namely \textsf{bandwidth}, \textsf{diskspace} and \textsf{vmtime}. For the analysis of each case, we assume:
\begin{itemize}
The charging algorithms for the sample resources given previously motivate related cost policies, namely \textsf{discrete}, \textsf{continuous} and \textsf{onoff}. Resources employing the \textsf{discrete} cost policy are charged just like \textsf{bandwidth}, those employing the \textsf{continuous} cost policy are charged like \textsf{diskspace} and finally resources with a \textsf{onoff} cost policy are charged like \textsf{vmtime}. Due to space limits we omit a more detailed analysis and the description of more involved scenarios.
-\subsection{State management}
+%\subsection{State management}
%The only data mutation that takes place is the
%actor's state. Since each actor handles only its user's events and