exercise update

programming/lecture/programming.tex

@@ -18,7 +18,7 @@ simple.
 
 The ultimate goal of scientific computing is to analyze gathered data,
 correlate it with e.g. the stimulus conditions and infer rules and
-dependencies. These may be used to constrain model that allow us to
+dependencies. These may be used to constrain models which allow us to
 understand and predict a system's behavior. In order to work with data
 we need to store it somehow. For this purpose we use containers called
 \emph{variables}.  Variables store the data and are named for easier
@@ -83,8 +83,8 @@ the \code{double} (a numeric data type, see below) data type. In
 line 9, however, we create a variable \varcode{z} and assign the
 character ``A'' to it. Accordingly, \varcode{z} does not have the
 numeric \code{double} data type but is a
-\enterm{character} type. \textbf{Note:} \matlab{} uses single quotes for
-both characters or strings of characters.
+\enterm{character} type. \textbf{Note:} \matlab{} uses single quotes
+for characters and double quotes for strings of characters.
 
 There are two ways to find out the actual data type of a variable: the
 \code{class()} and the \code{whos} functions. While \code{class()}