Fix two cases of 'parenthesis' -> 'parentheses'

Fixes #3026.

chapters/annotations.tex

@@ -1669,7 +1669,7 @@ \subsubsection{Conversion rules}\label{conversion-rules}
 \end{lstlisting}
 
 Normal case; if any modifier among \lstinline!OldModifier! exist then replace all of them with the list of\linebreak[4] \lstinline!NewModifiers!.
-The \lstinline!$\ldots$%OldModifier2%$\ldots$! indicate an expression that may involve the values of the old modifiers (tools are responsible for adding parenthesis if needed).
+The \lstinline!$\ldots$%OldModifier2%$\ldots$! indicate an expression that may involve the values of the old modifiers (tools are responsible for adding parentheses if needed).
 The lists of old and new modifiers can have different lengths.
 The defaults (if present) are used if there are multiple \lstinline!OldModifier! and not all are set in the component instance.
 The defaults are optional if there is at most one \lstinline!OldModifier! element, and should otherwise be provided.

chapters/operatorsandexpressions.tex

@@ -103,7 +103,7 @@ \section{Operator Precedence and Associativity}\label{operator-precedence-and-as
 
 Non-associative exponentiation and array range operator:
 \begin{lstlisting}[language=modelica]
-x^y^z         // Not legal, use parenthesis to make it clear
+x ^ y ^ z     // Not legal, use parentheses to make it clear.
 a:b:c:d:e:f:g // Not legal, and scalar arguments gives no legal interpretation.
 \end{lstlisting}
 \end{nonnormative}