[Tex/LaTex] How to remove vertical space between two tikz matrix rows

spacingtikz-pgf

I have the following matrix in TikZ:

example showing unnecessary vertical space

Here's the code:

\documentclass{article}
\usepackage{tikz,amssymb}
\usetikzlibrary{matrix,calc,fit}
\begin{document}

\tikzset{
    circled/.style={draw,circle,inner sep=0pt},
    highrow/.style={minimum height=.9cm},
}
\begin{tikzpicture}
  \node[matrix of nodes] (tcm) {
    {}  &
    $a_{00}$  &  $\leqslant$  &
    $a_{10}$  &  $\leqslant$  &
    $a_{20}$  &  $\leqslant$  &
    $\cdots$  &  $\leqslant$  &
    $\lim\limits_{n\to\infty} a_{n0}$  \\
    {}  &
    $a_{01}$  &  $\leqslant$  &
    $a_{11}$  &  $\leqslant$  &
    $a_{21}$  &  $\leqslant$  &
    $\cdots$  &  $\leqslant$  &
    $\lim\limits_{n\to\infty} a_{n1}$ \\
    {}  &
    $a_{02}$  &  $\leqslant$  &
    $a_{12}$  &  $\leqslant$  &
    $a_{22}$  &  $\leqslant$  &
    $\cdots$  &  $\leqslant$  &
    $\lim\limits_{n\to\infty} a_{n2}$  \vspace{-5cm}\\
    |[circled]| $+$  &
    |[highrow]| $\vdots$  &  {}  &
    $\vdots$  &  {}  &
    $\vdots$  &  {}  &
    $\ddots$  &  {}  &
    $\vdots$  \\
    {}  &
    $\sum\limits_{m=0}^\infty a_{0m}$  &  {}  &
    $\sum\limits_{m=0}^\infty a_{1m}$  &  {}  &
    $\sum\limits_{m=0}^\infty a_{2m}$  &  {}  &
    $\cdots$                           &  {}  &
    $\sum\limits_{m=0}^\infty \lim\limits_{n\to\infty} a_{nm}$  \\
  };
  \node[fit=(tcm-5-1) (tcm-5-2) (tcm-5-3) (tcm-5-4) (tcm-5-5) (tcm-5-6) (tcm-5-7) (tcm-5-8) (tcm-5-9) (tcm-5-10),inner sep=0pt] (R5) {};
  \draw (R5.north -| tcm.west) -- (R5.north -| tcm.east);
\end{tikzpicture}

\end{document}

The amount of vertical space between the third and fourth rows is bothering me. The fourth row (the row that follows the circled plus sign) has a lot of vertical space above, and I can't remove it. As far as I know, row sep only works for all the rows at once — I can't use it in only the fourth row.

OBS: The source of the problem is not the minimum height of the circled plus sign. When this minimum height is set to zero, the fourth row has an abnormal amount of vertical space above it.

Best Answer

The "standard" tabular adjustments work so that you can use \\[-4mm], for example, to decrease the space between two consecutive rows. Similarly, \\[3em] will add 3em of space. If you do this then your diagram becomes:

enter image description here

Here is the full code (which is the OP's with this single adjustment):

\documentclass{article}
\usepackage{tikz,amssymb}
\usetikzlibrary{matrix,calc,fit}
\begin{document}

\tikzset{
    circled/.style={draw,circle,inner sep=0pt},
    highrow/.style={minimum height=.9cm},
}
\begin{tikzpicture}
  \node[matrix of nodes] (tcm) {
    {}  &
    $a_{00}$  &  $\leqslant$  &
    $a_{10}$  &  $\leqslant$  &
    $a_{20}$  &  $\leqslant$  &
    $\cdots$  &  $\leqslant$  &
    $\lim\limits_{n\to\infty} a_{n0}$  \\
    {}  &
    $a_{01}$  &  $\leqslant$  &
    $a_{11}$  &  $\leqslant$  &
    $a_{21}$  &  $\leqslant$  &
    $\cdots$  &  $\leqslant$  &
    $\lim\limits_{n\to\infty} a_{n1}$ \\
    {}  &
    $a_{02}$  &  $\leqslant$  &
    $a_{12}$  &  $\leqslant$  &
    $a_{22}$  &  $\leqslant$  &
    $\cdots$  &  $\leqslant$  &
    $\lim\limits_{n\to\infty} a_{n2}$  \\[-4mm]
    |[circled]| $+$  &
    |[highrow]| $\vdots$  &  {}  &
    $\vdots$  &  {}  &
    $\vdots$  &  {}  &
    $\ddots$  &  {}  &
    $\vdots$  \\
    {}  &
    $\sum\limits_{m=0}^\infty a_{0m}$  &  {}  &
    $\sum\limits_{m=0}^\infty a_{1m}$  &  {}  &
    $\sum\limits_{m=0}^\infty a_{2m}$  &  {}  &
    $\cdots$                           &  {}  &
    $\sum\limits_{m=0}^\infty \lim\limits_{n\to\infty} a_{nm}$  \\
  };
  \node[fit=(tcm-5-1) (tcm-5-2) (tcm-5-3) (tcm-5-4) (tcm-5-5) (tcm-5-6) (tcm-5-7) (tcm-5-8) (tcm-5-9) (tcm-5-10),inner sep=0pt] (R5) {};
  \draw (R5.north -| tcm.west) -- (R5.north -| tcm.east);
\end{tikzpicture}

\end{document}