[Tex/LaTex] Subscript spacing in equation

math-modespacingsubscripts

I have a document, where I want to use $\tau_{ff}$ . If this is rendered it looks like a space is inserted between the two f's. $\tau_{rl}$ looks fine …

Where does this additional space come from and how can I avoid it being inserted?

(Miktex 2.9 on windows, if this is relevant).

Best Answer

Math fonts do not make ff into a ligature the way text fonts do as it may sometimes obscure the meaning of two separate identifiers juxtaposed,

enter image description here

$\tau_{ff}$ $\tau_{f\!f}$ $\tau_{\mathit{ff}}$

If the meaning of your subscript is some kind of invisible product of two f then use one of the first two, or some other negative space other than \! to taste. If on the other hand it is a multi-letter identifier with name ff then it is more appropriate to use a text font, as in the third example where the text italic font is used in math mode via \mathit and there ff produces a single ff ligature glyph.

Related Solutions

[Tex/LaTex] Uneven vertical spacing displaymath

Never use consecutive math environments. The correct output can be obtained by

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{gather*}
(a,b,c,d,e,f,g,h)\\
(a,b,c,d,e,f,g,h)\\
(a,b,c,d,e,f,g,h)
\end{gather*}
\end{document}

The amsmath package has a bunch of environments for proper math typesetting, consult its documentation; you should have on your system the file amsldoc.pdf that contains it.

[Tex/LaTex] Vertical spacing between equations and text

You can put the \nomenclature command inside the equation environment.

Recall also that consecutive display environments are not recommended and that amsmath provides many environments for displays. Here's with align:

\documentclass{report}
\usepackage{amsmath}
\usepackage{nomencl}
\makenomenclature

\begin{document}

\printnomenclature

\cleardoublepage

Some text
\begin{equation}
a=A
\nomenclature{$a$}{Anything}
\end{equation}
Some other text
\begin{align}
a&=
\begin{pmatrix}
1 & 0 \\
0 & 1 \\
\end{pmatrix}
\\
b&=
\begin{pmatrix}
1 & 1 \\
1 & 1 \\
\end{pmatrix}
\nomenclature{$b$}{Anything}
\\
c&=
\begin{pmatrix}
0 & 0 \\
0 & 0 \\
\end{pmatrix}
\end{align}

\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Uneven vertical spacing displaymath

[Tex/LaTex] Vertical spacing between equations and text

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