10

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.

egreg
  • 1,121,712
C-Otto
  • 933

2 Answers2

8

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}

enter image description here

egreg
  • 1,121,712
6

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}

enter image description here