spacing between symbols in math mode

Question

The following code will

\begingroup
\everymath{\displaystyle}
\scriptsize
$XXXXXXX(XXXX(A,B,C),XXXX(D,E,F)) \leftarrow XXXXXX(A,B,C) \wedge XXXXXX(D,E,F) \wedge     XXXXX(XX(A,B),XX(D,E)) \wedge XXXXX(XX(B,C),XX(E,F)) \wedge XXXXXX(XXX(A,B,C),XXX(D,E,F)).$
\endgroup

format my rule like this: enter image description here

I really do not like this because it has the tendency to stretch the expressions to cover a whole line, which is absolutely unnecessary. I just want some natural spacing there even if it did not expand to cover the whole line. Any suggestions?

You are probably interested in removing the stretch/shrink associated with the space around operators/operands in math mode. For this, see Keeping the distance between mathematical symbols consistent? — Werner, Aug 27 '14 at 04:58

Mico · Accepted Answer · 2014-08-27T05:07:25.353

This look, maybe?

enter image description here

\documentclass{article}
\begin{document}
$\scriptstyle
\begin{array}{l@{\quad}r}
XXXXXXX(XXXX(A,B,C),XXXX(D,E,F)) &\leftarrow \\
XXXXXX(A,B,C) \quad \wedge \quad XXXXXX(D,E,F) &\wedge\\
XXXXX(XX(A,B),XX(D,E)) & \wedge \\
XXXXX(XX(B,C),XX(E,F)) & \wedge \\
XXXXXX(XXX(A,B,C),XXX(D,E,F)).\\
\end{array}$
\end{document}

If \quad provides too much space for you, try \mkern n mu -- \mkern18mu corresponds to \quad.

Addendum: If you want the end-of-line \rightarrow and \wedge symbols to be separated from the material to the right by the same amount (say, \quad), a single column in the array might be what you're looking for.

enter image description here

\documentclass{article}
\begin{document}
$\scriptstyle\begin{array}{l}
XXXXXXX(XXXX(A,B,C),XXXX(D,E,F)) \quad\leftarrow \\
XXXXXX(A,B,C) \quad \wedge \quad XXXXXX(D,E,F) \quad\wedge\\
XXXXX(XX(A,B),XX(D,E)) \quad \wedge \\
XXXXX(XX(B,C),XX(E,F)) \quad \wedge \\
 XXXXXX(XXX(A,B,C),XXX(D,E,F)).\\
\end{array}$
\end{document}

it's not so satisfactory, how do I shrink the space between my expression and "and" symbol on the third and forth line? — user1935724, Aug 27 '14 at 04:56
@user1935724 - Does the look in the addendum meet your needs? — Mico, Aug 27 '14 at 05:07

score 1 · Answer 2 · answered Aug 27 '14 at 09:43

You can make TeX decide for the line breaks:

\documentclass{article}
\usepackage{amsmath}
\usepackage{lipsum} % just for the example

\newcommand{\lrand}{\mathrel{\land}} % a relation, while \wedge=\land is an operation

\newenvironment{mrule}
 {\relpenalty=0 \flushleft$\displaystyle}
 {$\endflushleft}

\newenvironment{mruleA}
 {\relpenalty=0
  \quote
  \raggedright
  $\displaystyle}
 {$\endquote}

\begin{document}

\lipsum*[2]
\begin{mrule}
XXXXXXX(XXXX(A,B,C),XXXX(D,E,F)) \gets
XXXXXX(A,B,C) \lrand
XXXXXX(D,E,F) \lrand
XXXXX(XX(A,B),XX(D,E)) \lrand
XXXXX(XX(B,C),XX(E,F)) \lrand
XXXXXX(XXX(A,B,C),XXX(D,E,F)).
\end{mrule}
\lipsum*[3]
\begin{mruleA}
XXXXXXX(XXXX(A,B,C),XXXX(D,E,F)) \gets
XXXXXX(A,B,C) \lrand
XXXXXX(D,E,F) \lrand
XXXXX(XX(A,B),XX(D,E)) \lrand
XXXXX(XX(B,C),XX(E,F)) \lrand
XXXXXX(XXX(A,B,C),XXX(D,E,F)).
\end{mruleA}
\lipsum[4]

\end{document}

I'd prefer the second approach, leaving some space on the left (and right). If you want to possibly reach the right margin, change the definition into

\newenvironment{mruleA}
 {\relpenalty=0
  \list{}{\leftmargin=\leftmargini \rightmargin=0pt}
  \raggedright\item\relax$\displaystyle}
 {$\endlist}

By setting \relpenalty=0 we tell TeX that breaking at relation symbols is OK. Using \lrand instead of \wedge ensures the same spacing around ∧ and ← (note that \gets is the same as \leftarrow, but shorter to type).

enter image description here

spacing between symbols in math mode

2 Answers2