%%
%% The LaTeX Companion, 3ed
%%
%% Example 12-4-4 on page II-258 in "Adjusting the formula style".
%%
%% 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{351.0pt}
% typeset with lualatex
%StartShownPreambleCommands
\usepackage[math-style=ISO,bold-style=ISO]{unicode-math}
\usepackage{array,booktabs}
%StopShownPreambleCommands

\begin{document}
\small
\begin{tabular}{l@{\enspace$\to$\quad}>$l<$@{\enspace}>$l<$}
  \toprule
    \multicolumn{1}{l}{\ttfamily math-style}
  & \multicolumn{1}{c}{\itshape Latin}
  & \multicolumn{1}{c}{\itshape Greek}
  \\
  \midrule
  \texttt{TeX}     &       a,       b,       X,       Y
  &        \alpha,       \beta,\symup \Gamma,\symup \Omega
  \\
  \texttt{ISO}     &       a,       b,       X,       Y
  &        \alpha,       \beta,       \Gamma,       \Omega
  \\
  \texttt{french}  &       a,       b,\symup X,\symup Y
  & \symup \alpha,\symup \beta,\symup \Gamma,\symup \Omega
  \\
  \texttt{upright} &\symup a,\symup b,\symup X,\symup Y
  & \symup \alpha,\symup \beta,\symup \Gamma,\symup \Omega
  \\
  \bottomrule
\end{tabular}
\hfill
\begin{tabular}{>{\ttfamily}l@{\enspace$\to$\quad}>$l<$@{\enspace}>$l<$}
  \toprule
    \multicolumn{1}{l}{\ttfamily bold-style}
  & \multicolumn{1}{c}{\itshape Latin}
  & \multicolumn{1}{c}{\itshape Greek}
  \\
  \midrule
  TeX     &\symbfup a,\symbfup b,\symbfup X,\symbfup Y
  &\symbf  \alpha,\symbf \beta,\symbfup \Gamma,\symbfup \Omega
  \\
  ISO     &\symbf a,\symbf b,\symbf X,\symbf Y
  &\symbf  \alpha,\symbf \beta,\symbf \Gamma,\symbf \Omega \hspace{-1em}  % hide width
  \\
  \multicolumn{3}{c}{}
  \\
  upright &\symbfup a,\symbfup b,\symbfup X,\symbfup Y
  & \symbfup \alpha,\symbfup \beta,\symbfup \Gamma,\symbfup \Omega
  \\
  \bottomrule
\end{tabular}
\end{document}