7

This answer addresses the possible way to typeset a bigger integral sign, but one has to choose the right size of the symbol that better fits the situation.

My question is: why can't we resize the \int symbol as we usually do for common delimiters (), [] and \{\}?

By writing

\left\{ \left[ \left( stuff \right) \right] \right\}

delimiters are automatically sized with respect to stuff and the preceding/subsequent delimiter.

Why can't we write 

\left \int \left\{ \left[ \left( stuff \right) \right] \right\} \right.

so that the \int symbol is automatically sized, too?

Alessandro Cuttin
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    most fonts only have the integral and summation in two sizes, they are not really delimiters that should stretch, but stylized S and Sigma characters – David Carlisle Mar 11 '20 at 17:26
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    Indeed, they are not delimiters. But from a practical point of view, they are treated almost likewise, at least from an aesthetical point of view (maybe). – Alessandro Cuttin Mar 11 '20 at 17:34
  • well not really \sum can't scale at all and \int you could only scale if it has a vertical style , actually I think there is at least one tex font package that does scale int but I'm out of time now, may look later if no one has answered – David Carlisle Mar 11 '20 at 17:41
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    @AlessandroCuttin Please, don't. Four story or bigger fractions are evil and should be avoided like the plague. – egreg Mar 11 '20 at 18:02
  • @AlessandroCuttin This said, look at this picture taken from the manual of an available package. I have no doubt whatsoever which realization to prefer, namely the one on the left. – egreg Mar 11 '20 at 18:14
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    Have you seen the posting Big integral sign? – Mico Mar 11 '20 at 20:30
  • @Mico the old answer doesn't cover the newer OpenType Math fonts though. – David Carlisle Mar 11 '20 at 22:08
  • @egreg don't worry: I don't mean to. And I am glad that the meaning of things is put on top of aesthetics, though! :) – Alessandro Cuttin Mar 12 '20 at 15:08

1 Answers1

8

Opentype Math fonts can make use of the Integral extension character U+23AE

enter image description here

I'm not sure I like the result but this is Cambria Math with LuaLaTeX.

\documentclass{article}
\usepackage{unicode-math}
\setmathfont{Cambria math}

\begin{document}


\[
\Uleft\Udelimiter 0 0 "222B
\begin{pmatrix}
  1
\end{pmatrix}
\Uright.
\rightarrow
\Uleft\Udelimiter 0 0 "222B
\begin{pmatrix}
  1\\2
\end{pmatrix}
\Uright.
\rightarrow
\Uleft\Udelimiter 0 0 "222B
\begin{pmatrix}
  1\\2\\3\\4
\end{pmatrix}
\Uright.
\rightarrow
\Uleft\Udelimiter 0 0 "222B
\begin{pmatrix}
  1\\2\\3\\4\\5\\6
\end{pmatrix}
\Uright.
\]
\end{document}
David Carlisle
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