Improve language

chapters/annotations.tex

@@ -728,7 +728,7 @@ \subsection{Component Instance}\label{component-instance}
 
 A component instance can be placed within a diagram or icon layer.
 It has an annotation with a \lstinline!Placement! modifier to describe the placement.
-Placements are defined in term of coordinate systems transformations:
+Placements are defined in terms of coordinate system transformations:
 \begin{lstlisting}[language=modelica]
 record Transformation
   Point origin = {0, 0};