# Looking for \bigCap or \bigdoublecap

I know \Cap (or \doublecap) and I know \bigcap. However, now I also need \bigCap (or \bigdoublecap) which is a \bigcap with another \cap in between.

I already tried using \stackinset from the stackengine package, but was not able to produce decent results.

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Do you just want these symbols overlaid? –  Werner Oct 17 '13 at 22:48
I could live with that solution, although a smaller \cap would make it better to read. –  C-Otto Oct 17 '13 at 22:54
i believe this was added to unicode. check the stix fonts. –  barbara beeton Oct 18 '13 at 2:45

Not pretty, but if nothing else comes along, maybe you can do with this.

\documentclass{article}
\usepackage{amsmath,graphicx}
\newcommand{\bigdoublecap}{%
\mathop{\vphantom{\bigcap}\vcenter{\hbox{\text{%
\ooalign{$\displaystyle\bigcap$\cr
\hidewidth
\raisebox{-.1ex}{\resizebox{.7\width}{.875\height}{$\displaystyle\bigcap$}}%
\hidewidth\cr
}%
}}}}%
}

\begin{document}
$\bigdoublecap_{i=1}^n A_i$
\end{document}


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Looks very pretty to me :) –  C-Otto Oct 17 '13 at 22:57
@C-Otto Note that a % was missing and I added it. –  egreg Oct 17 '13 at 22:58
+1. How can you say not pretty? –  Sigur Oct 17 '13 at 23:01
Noted, thanks. And say hi to Fausto Spoto from me :) –  C-Otto Oct 17 '13 at 23:24

I used \stackinset AND routines from the scalerel package. What it insets is a \bigcap that has been scaled down to 1.6ex in height (which narrows it to the proper width), and then vertically stretched to 2ex in height. The manipulated inset is placed, horizontally centered, .15pt above the base of the unaltered \bigcap.

\documentclass{article}
\usepackage{amsmath}
\usepackage{scalerel}
\usepackage{stackengine}[2013-10-15]
\newcommand\bigdoublecap{%
\mathop{\ensurestackMath{\stackinset{c}{}{b}{.15pt}%
{\stretchto{\scaleto{\bigcap}{1.6ex}}{2ex}}{\bigcap}}}
}
\begin{document}
$\bigdoublecap_{i=1}^n A_i$\end{document}


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