%%
%% The LaTeX Companion, 3ed
%%
%% Example 12-3-19 on page II-246 in "Support for Times math".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{207.0pt}
%StartShownPreambleCommands
  \usepackage{newtxtext}
  \usepackage[frenchmath]{newtxmath}
%StopShownPreambleCommands

\begin{document}
  \[ A = \alpha + \beta
              < \mathnormal{A}_k \]
\end{document}