LaTeX forum ⇒ LaTeX Beginner's Guide ⇒ Vertically aligning limits of consecutive math operators

[Reader]

Near the end of Chapter 9, Writing Math Formulas, it's mentioned that with the mathtools package we can align limits of consecutive math operators vertically.

Do you have an example how to do that?

[Stefan Kottwitz]

Here is an example taken from the LaTeX Cookbook, Chapter 10, Advanced Mathematics:

\documentclass[border=10pt,preview]{standalone}
\usepackage{dsfont}
\begin{document}
\[
  \lim_{n\to\infty} \sup_{x\in\mathds{R}} f_n(x^2)
  < n \Big(\sum_{x\in\mathds{R}, n\in\mathds{N}}
  \big| f_n(x^2) \big| \Big)
\]
\end{document}

We get:

inequality.png (14.04 KiB) Viewed 4664 times

Now we load the mathtools package, use the \adjustlimits command right before the \lim operator, insert \smashoperator to remove that big white space before \sum, and change x^2 to \cramped{x^2} to slightly lower the exponent, at both places:

\documentclass[border=10pt,preview]{standalone}
\usepackage{dsfont}
\usepackage{mathtools}
\begin{document}
\[
  \adjustlimits\lim_{n\to\infty} \sup_{x\in\mathds{R}}
    f_n(\cramped{x^2})
    < n \Big( \smashoperator{\sum_{x\in\mathds{R},
    n\in\mathds{N}}}
    \big\lvert f_n(\cramped{x^2}) \big\rvert \Big)
\]
\end{document}

We get:

finetuned.png (12.5 KiB) Viewed 4664 times

You can see that the limits onm the left side have been adjusted vertically, and some more mentioned finetuning. The mathtools manual gives further information.

Stefan