%%
%% The LaTeX Companion, 3ed
%%
%% Example 11-2-26 on page II-145 in "Vertical space in and around displays".
%%
%% 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{183.0pt}
% Overwrite the value in \normalsize to better visualize the problem.
% As that is executed at begin of document we need to make the setting there
% of course that will only last until the next font size change
\AtBeginDocument{\setlength\abovedisplayshortskip{0pt}
\setlength\belowdisplayshortskip{0pt}}
%StartShownPreambleCommands
% The behavior without amsmath
%StopShownPreambleCommands
\begin{document}
Empty line before display:
\[ a \neq b \]
Enough space now, but do not rely on it!
\begin{equation} a \neq b \end{equation}
Less space after in this case!
\end{document}
