%%
%% The LaTeX Companion, 3ed
%%
%% Example 11-4-39 on page II-179 in "mattens --- Commands to typeset tensors".
%%
%% 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{tlc3examargin}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{135.0pt}

  % Shorten the vertical size of the example ...
  \AtBeginDocument{%
    \setlength\abovedisplayskip{.8\abovedisplayskip}%
    \setlength\belowdisplayskip{.8\belowdisplayskip}%
  }

%StartShownPreambleCommands
\usepackage[mathstrut]{mattens}  \SetSymbFont{\mathsfsl}
\DeclareMathAlphabet\mathsfsl{OT1}{lmss}{bx}{sl}
%StopShownPreambleCommands

\begin{document}
\begin{gather}
 \aSb{x} \neq \aSb*{x} \neq \aSb[\hat]{x} \neq \bSa{X} \\
 \bS{\delta} \neq \bS*{\delta} \neq \bS[\hat]{\delta}  \\
 \bCSb{a} \cdot \bS{c} = \bS{a} \times \bS{c}
\end{gather}
\end{document}