How to remove space from mathematical formulas?

This almost looks like what I would like to have

enter image description here

but the space between, for example, $f_1($ and $v_1$ is too large.

How can I fix this?


I got this with

\begin{equation}
  \begin{array}{llllll}
    f_1( & v_1, & v_2  &     &     & ) = 0 \\
    f_2( &      & v_2, & v_3 &     & ) = 0 \\
    f_3( &      & v_2, &     & v_4 & ) = 0 \\
    f_4( & v_1, &      &     & v_4 & ) = 0 
  \end{array}
\end{equation}

I also tried \mathtt and lots of \ but the alignment was always a little bit off (due to the subscript?) and LaTeX tips: Displayed Math says that I shouldn’t insert spaces like that. The \quad proposed there inserted too much space.

Solutions Collecting From Web of "How to remove space from mathematical formulas?"

One way to reduce the spacing between the columns is to use @{}

enter image description here

I’ve put @{} between every column, but of course you can use it just on the columns that you wish.

You can think of the @{<stuff>} operation as adding <stuff> to every element in that column.

\documentclass{article}


\begin{document}

Original
\begin{equation}
  \begin{array}{llllll}
    f_1( & v_1, & v_2  &     &     & ) = 0 \\
    f_2( &      & v_2, & v_3 &     & ) = 0 \\
    f_3( &      & v_2, &     & v_4 & ) = 0 \\
    f_4( & v_1, &      &     & v_4 & ) = 0 
  \end{array}
\end{equation}

New
\begin{equation}
  \begin{array}{@{}l@{}l@{}l@{}l@{}l@{}l@{}}
    f_1( & v_1, & v_2  &     &     & ) = 0 \\
    f_2( &      & v_2, & v_3 &     & ) = 0 \\
    f_3( &      & v_2, &     & v_4 & ) = 0 \\
    f_4( & v_1, &      &     & v_4 & ) = 0 
  \end{array}
\end{equation}

\end{document}

Suggested by @egreg: you can use this idea to put \, after columns 2, 3, and 4, which gives

screenshot

\begin{equation}
  \begin{array}{@{}l@{}l@{\,}l@{\,}l@{\,}l@{}l@{}}
    f_1( & v_1, & v_2  &     &     & ) = 0 \\
    f_2( &      & v_2, & v_3 &     & ) = 0 \\
    f_3( &      & v_2, &     & v_4 & ) = 0 \\
    f_4( & v_1, &      &     & v_4 & ) = 0 
  \end{array}
\end{equation}

As @barbarabeeton pointed out, it doesn’t seem necessary to use 6 columns; 5 columns will work ok

\begin{equation}
  \begin{array}{l@{\,}l@{\,}l@{\,}l@{}l@{}}
    f_1( v_1, & v_2  &     &     & ) = 0 \\
    f_2(      & v_2, & v_3 &     & ) = 0 \\
    f_3(      & v_2, &     & v_4 & ) = 0 \\
    f_4( v_1, &      &     & v_4 & ) = 0 
  \end{array}
\end{equation}

I assume you have the last column empty so that the closing ) will be aligned.