# Using \left( and right) puts a space after an operator [duplicate]

When I use \left( and \right) to get appropriately sized parentheses for an operator, a space is created between the operator and the parentheses. I think it looks bad. Is it intentional? If so, why? If not, is it easy to 'repair'?

\documentclass{article}

\usepackage{amsmath}
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{align*}
\begin{document}
\begin{align*}
\log(a) &= 0\\
\log\left(a\right) &= 0\\
\log\left(\frac{a}{b}\right) &= 0
\end{align*}
\end{document}


Gives the following output:

## marked as duplicate by user156344, campa, Community♦Apr 2 at 9:15

• A left-right pair forms an "inner" construction, and the operator sees that as a symbol and inserts a space. Often it is better to just scale manually, using the \bigl and \bigrvariants (there are four left and four right), which also classifies as open/close and thus no space is inserted. For the autoscaled, see the mleftright package. – daleif Apr 2 at 8:54

Using the \mleft ...mright pair also yields a correct spacing. Compare:

\documentclass{article}

\usepackage{amsmath}
\usepackage{mleftright}
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{align*}
\begin{document}

\begin{align*}
\log(a) &= 0\\
\log\left(a\right) &= 0\\
\log\mleft(a\mright) &= 0\\
\log\left(\frac{a}{b}\right) &= 0\\
\log\mleft(\frac{a}{b}\mright) &= 0
\end{align*}

\end{document}


The space looks good. But if you still want to decrease the space between the operator and the parentheses, a quick method is to use a negative space, \!. It works in this way:

\documentclass{article}

\usepackage{amsmath}
\usepackage[active,tightpage]{preview}

\PreviewEnvironment{align*}

\begin{document}
\begin{align*}
\log(a) &= 0\\
\ \\
\log \left(a\right) &= 0\\
\log\!\left(a\right) &= 0\\
\ \\
\log\left(\frac{a}{b}\right) &= 0\\
\log\!\left(\frac{a}{b}\right) &= 0
\end{align*}
\end{document}
`

The result is below.

This question might also be useful for you: link