# [texhax] \subsubsection*{}

Philip G. Ratcliffe philip.ratcliffe at fastwebnet.it
Mon Jan 7 23:03:53 CET 2008

> I redefined \subsubsection so as not to put the header on a
> separate line.
> Inevitably some author decided to use \subsubsection*{} (for no
> discernable reason;  why not use \par\kern5pt\noindent?)

Better still might be something like \\[\parskip]

> This results in
> an unwanted space, which you will see if you compose this:
> [snip]

Hmm, this does look like an oversight in the basic LaTeX file and I would
expect that someone else already has a solution (the same problem arises for
any sectioning command that does not provide a number (as in the use of
\paragraph below without my hack).  The problem seems to be the space
inserted between the chapter/section number and the title even when the
latter is absent.

So here's my hack (the insertions are clearly marked):

\documentclass{article}
\makeatletter
%
\renewcommand\subsubsection{\@startsection{subsubsection}{3}{\z@}%
{-3.25ex\@plus -1ex \@minus -.2ex}%
{-1.5ex \@plus -.2ex}%
{\normalfont\normalsize\bfseries}}
%
\def\@sect#1#2#3#4#5#6[#7]#8{%
\ifnum #2>\c at secnumdepth
\let\@svsec\@empty
\else
\refstepcounter{#1}%
\protected at edef\@svsec{\@seccntformat{#1}\relax}%
\fi
\@tempskipa #5\relax
\ifdim \@tempskipa>\z@
\begingroup
#6{%
\@hangfrom{\hskip #3\relax\@svsec}%
\interlinepenalty \@M #8\@@par}%
\endgroup
\csname #1mark\endcsname{#7}%
\ifnum #2>\c at secnumdepth \else
\protect\numberline{\csname the#1\endcsname}%
\fi
#7}%
\else
\def\@svsechd{%
#6{\hskip #3\relax
\@svsec #8}%
\csname #1mark\endcsname{#7}%
\ifnum #2>\c at secnumdepth \else
\protect\numberline{\csname the#1\endcsname}%
\fi
#7}}%
\fi
\@xsect{#5}}
%
\def\@ssect#1#2#3#4#5{%
\@tempskipa #3\relax
\ifdim \@tempskipa>\z@
\begingroup
#4{%
\@hangfrom{\hskip #1}%
\interlinepenalty \@M #5\@@par}%
\endgroup
\else
\def\@svsechd{#4{\hskip #1\relax #5}}%
\fi
\@xsect{#3}}
\newif\if at sectspace \@sectspacetrue
%
\def\@setsectspace#1{%
\def\reserved at a{#1}%
\ifx\reserved at a\@empty\@sectspacefalse\else\@sectspacetrue\fi
}
\def\@xsect#1{%
\@tempskipa #1\relax
\ifdim \@tempskipa>\z@
\par \nobreak
\vskip \@tempskipa
\else
\@nobreakfalse
\global\@noskipsectrue
\everypar{%
\if at noskipsec
\global\@noskipsecfalse
{\setbox\z@\lastbox}%
\clubpenalty\@M
\begingroup \@svsechd \endgroup
\unskip
\@tempskipa #1\relax
\hskip -\@tempskipa
\else
\clubpenalty \@clubpenalty
\everypar{}%
\fi}%
\fi
\ignorespaces}
%
\makeatother
\begin{document}

\paragraph{}This is a test.  This is a test.  This is a test. This is a
test.  This is a test.  This is a test.  This is a test.  This is a test.
This is a test.  This is a test.

\paragraph{Test}This is a test.  This is a test.  This is a test. This is a
test.  This is a test.  This is a test.  This is a test.  This is a test.
This is a test.  This is a test.

\subsubsection{}This is a test.  This is a test.  This is a test. This is a
test.  This is a test.  This is a test.  This is a test.  This is a test.
This is a test.  This is a test.

\subsubsection{Test}This is a test.  This is a test.  This is a test. This
is a test.  This is a test.  This is a test.  This is a test.  This is a
test.  This is a test.  This is a test.

\subsubsection*{}This is a test.  This is a test.  This is a test. This is a
test.  This is a test.  This is a test.  This is a test.  This is a test.
This is a test.  This is a test.

\subsubsection*{Test}This is a test.  This is a test.  This is a test. This
is a test.  This is a test.  This is a test.  This is a test.  This is a
test.  This is a test.  This is a test.

\end{document}

Cheers,  Phil