Improve symmetry of footnotes for Mathematica and MATLAB

This also fixes some strange leading whitespace in the source code.

chapters/operatorsandexpressions.tex

@@ -95,11 +95,8 @@ \section{Operator Precedence and Associativity}\doublelabel{operator-precedence-
 is non-associative. The array range operator is non-associative.
 
 \begin{nonnormative}
-The unary minus and plus in Modelica is slightly different than
-in Mathematica and in MATLAB\footnote{MATLAB is a registered trademark
-  of MathWorks Inc.}, since the following expressions are illegal
-(whereas in Mathematica\footnote{Mathematica is a registered trademark
-  of Wolfram Research Inc.} and in MATLAB these are valid expressions):
+The unary minus and plus in Modelica is slightly different than in Mathematica\footnote{\emph{Mathematica} is a registered trademark of Wolfram Research Inc.} and in MATLAB\footnote{\emph{MATLAB} is
+a registered trademark of MathWorks Inc.}, since the following expressions are illegal (whereas in Mathematica and in MATLAB these are valid expressions):
 \begin{lstlisting}[language=modelica]
 2*-2  // = -4 in Mathematica/MATLAB; is illegal in Modelica
 --2   // = 2 in Mathematica/MATLAB; is illegal in Modelica