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diff --git a/methods.top.tex b/methods.top.tex
index 174a783..c05165a 100644
--- a/methods.top.tex
+++ b/methods.top.tex
@@ -1,10 +1,9 @@
-\section{\acrlong{TOP}}
-\subsection{\gls{iTasks}}
+\section{iTasks}
 \gls{TOP} is a recent programming paradigm implemented as
 \gls{iTasks}\cite{achten_introduction_2015} in the pure lazy functional
 language \gls{Clean}\cite{brus_cleanlanguage_1987}. \gls{iTasks} is a
 \gls{EDSL} to model workflow tasks in the broadest sense. A \CI{Task} is just
-a function that, given some state, returns the observable \CI{TaskValue}. The
+a function that --- given some state --- returns the observable \CI{TaskValue}. The
 \CI{TaskValue} of a \CI{Task} can have different states. Not all state
 transitions are possible as shown in Figure~\ref{fig:taskvalue}. Once a value
 is stable it can never become unstable again. Stability is often reached
@@ -20,7 +19,7 @@ image in the \CI{NoValue} state, the second image does not have all the fields
 filled in and therefore the \CI{TaskValue} remains \CI{Unstable}. In the third
 image all fields are entered and the \CI{TaskValue} transitions to the
 \CI{Unstable} state. When the user presses \emph{Continue} the value becomes
-\CI{Stable} and can not be changed any further.
+\CI{Stable} and cannot be changed any further.
 
 \begin{figure}[H]
 	\centering
@@ -66,19 +65,20 @@ functions that are captured in the class \CI{iTask}. Basic types have
 specialization instances for these functions and show an according interface.
 Generated interfaces can be modified with decoration operators.
 
-\subsection{Combinators}
+\section{Combinators}
 \Glspl{Task} can be combined using so called \gls{Task}-combinators.
 Combinators describe relations between \glspl{Task}. \Glspl{Task} can be
 combined in parallel, sequenced and their result values can be converted to
-\glspl{SDS}. Moreover, a very important combinator is the step combinator that
-starts a new task according to the \CI{TaskValue}. The type signatures of the
-basic combinators are shown in Listing~\ref{lst:combinators}.
+\glspl{SDS}. Moreover, a very important combinator is the step combinator which
+starts a new task according to specified predicates on the \CI{TaskValue}.
+Type signatures of the basic combinators are shown in
+Listing~\ref{lst:combinators}.
 
 \begin{itemize}
 	\item Step:
 
 		The step combinator is used to start \glspl{Task} when a predicate on
-		the \CI{TaskValue} holds or an action has been taken place. The bind
+		the \CI{TaskValue} holds or an action has taken place. The bind
 		operator can be written as a step combinator.
 		\begin{lstlisting}[language=Clean]
 (>>=) infixl 1 :: (Task a) (a -> (Task b)) -> (Task b) | iTask a & iTask b
@@ -87,8 +87,8 @@ basic combinators are shown in Listing~\ref{lst:combinators}.
         onValue (Value a _)     = Just (f a)
         onValue _               = Nothing
 
-		onStable (Value a True) = Just (f a)
-		onStable _              = Nothing
+        onStable (Value a True) = Just (f a)
+        onStable _              = Nothing
 		\end{lstlisting}
 	\item Parallel:
 
@@ -117,5 +117,24 @@ basic combinators are shown in Listing~\ref{lst:combinators}.
 (-&&-) infixr 4 :: (Task a) (Task b)              -> Task (a,b) | iTask a & iTask b
 \end{lstlisting}
 
-\subsection{\acrlongpl{SDS}}
+\section{\acrlongpl{SDS}}
+\Glspl{SDS} are an abstraction over resources that are available in the world
+or in the \gls{iTasks} system. The shared data can be a file on disk, it can be
+the time, a random integer or just some data stored in memory. The actual
+\gls{SDS} is just a record containing functions on how to read and write the
+source. In these functions the \CI{*World} is available and therefore it can
+interact with the outside world. The \CI{*IWorld} is also available and
+therefore the functions can also access other shares, possibly combining them.
+
+The basic operations for \glspl{SDS} are get, set and update. The signatures
+for these functions are shown in Listing~\ref{lst:shares}. All of the
+operations are atomic in the sense that during reading no other tasks are
+executed.
+
+\begin{lstlisting}[%
+	language=Clean,label={lst:shares},caption={\Gls{SDS} functions}]
+get ::          (ReadWriteShared r w)           -> Task r | iTask r
+set :: w        (ReadWriteShared r w)           -> Task w | iTask w
+upd :: (r -> w) (ReadWriteShared r w)           -> Task w | iTask r & iTask w
 
+\end{lstlisting}