Consistently use "a diagnostics"

chapters/annotations.tex

@@ -1697,7 +1697,7 @@ \subsubsection{Conversion rules}\label{conversion-rules}
 \end{itemize}
 
 The converted modifiers and existing modifiers are merged such that the existing modifiers take precedence over the result of \lstinline!convertModifiers!.
-A diagnostics is recommended if this merging removes some modifiers unless those modifiers are identical or it is the special case of an empty \lstinline!OldModifier! list.
+A diagnostic is recommended if this merging removes some modifiers unless those modifiers are identical or it is the special case of an empty \lstinline!OldModifier! list.
 \begin{nonnormative}
 This can be used to handle the case where the default value was changed.
 \end{nonnormative}

chapters/equations.tex

@@ -803,7 +803,7 @@ \section{Initialization, initial equation, and initial algorithm}\label{initiali
 the \lstinline!start!-value can be used as a guess-value during initialization.
 
 \begin{nonnormative}
-In the case a parameter has both a binding equation and \lstinline!fixed = false! a diagnostics is recommended, but the parameter should be solved from the binding equation.
+In the case a parameter has both a binding equation and \lstinline!fixed = false! a diagnostic is recommended, but the parameter should be solved from the binding equation.
 
 Non-discrete-time \lstinline!Real! variables \lstinline!vc! have exactly one initialization value since the rules above assure that during initialization
 \lstinline!vc = pre(vc) = vc.startExpression! (if \lstinline!fixed = true!).

chapters/functions.tex

@@ -246,7 +246,7 @@ \section{Pure Modelica Functions}\label{pure-modelica-functions}
   If a function is declared as \lstinline!impure! any function extending from it shall be declared as \lstinline!impure!.
 \item
   A deprecated semantics is that external functions (and functions defined in Modelica directly or indirectly calling them) without \lstinline!pure! or \lstinline!impure! keyword are assumed to be
-  impure, but without any restriction on calling them.  Except for the function \lstinline!Modelica.Utilities.Streams.print!, diagnostics must be given if called in a simulation model.
+  impure, but without any restriction on calling them.  Except for the function \lstinline!Modelica.Utilities.Streams.print!, a diagnostic must be given if called in a simulation model.
 \end{itemize}
 
 Calls of pure functions used inside expression may be skipped if the
@@ -2385,7 +2385,7 @@ \subsection{Annotations for External Libraries and Include Files}\label{annotati
 platform specific directory is used.
 
 \begin{nonnormative}
-A tool may give diagnostics if the directory corresponding to the selected compiler version is missing.  The directories may use symbolic links or use
+A tool may give a diagnostic if the directory corresponding to the selected compiler version is missing.  The directories may use symbolic links or use
 a text-file as described below: e.g.\ a text-file \filename{vs2008} containing the text \emph{../win32/vs2005} (or \emph{vs2005}) suggesting that it is
 compatible with vs2005.
 \end{nonnormative}

chapters/scoping.tex

@@ -189,7 +189,7 @@ \section{Instance Hierarchy Name Lookup of Inner Declarations}\label{instance-hi
   In other cases, i.e.\ if a unique non-partial class is used for all
   \lstinline!outer! declarations of the same name lacking a matching inner
   declaration, then an \lstinline!inner! declaration of that class is automatically
-  added at the top of the model and diagnostics is given.
+  added at the top of the model and a diagnostic is given.
 \item
   The annotations defined in \cref{annotations-for-the-graphical-user-interface} does not affect this process,
   other than that:

chapters/synchronous.tex

@@ -6,7 +6,7 @@ \chapter{Synchronous Language Elements}\label{synchronous-language-elements}
 variables and equations, as well as an additional kind of \lstinline!when!-clause.
 The benefits of synchronous behavior is that it allows a model to define large
 sampled data systems in a safe way, so that the
-translator can provide good diagnostics in case of a modeling error.
+translator can provide good a diagnostic in case of a modeling error.
 
 The following small example shows the most important elements:
 \begin{figure}[H]