16

I would to obtain a result similar to the image below. So far I only have \bigg( \Big( \big( a^q \big)^q \Big)^{\rotatebox{25}{$\cdots$}} \bigg)^q, without the brace.

I tried to follow this question, but there were no parenthesis and I was not able to circumvent this.

test

10
  • 1
    Hi, just a curiosity...for my opinion your question is good and I put +1. But do you have seen this image (I never I have seen this in a textbook)? :-) – Sebastiano Feb 23 at 13:01
  • @Sebastiano : thanks for your encouraging comment. I did the image myself, but admittedly I never saw this in a book – maybe in the future if we get nice answers to my question ;-) – Watson Feb 23 at 13:07
  • 1
    I don't even really know how to do it properly with a horizontal brace. – Watson Feb 23 at 13:09
  • Yes, I'm agree fully with you....In this moment for me it is very complicated done it in math-mode. I think with TiKZ or PSTricks it is very simple. I have understood your thought. :-) – Sebastiano Feb 23 at 13:09
  • 1
    @Sebastiano : a solution with TikZ (or PSTricks that I don't really know) would be fine. This is the approach used in the quesiton I linked. – Watson Feb 23 at 13:10
15

Very easy with horizontal brace; somewhat less easy with rotated brace. I have no time right now to implement a general solution, so I'll go with a brute-force version for now.

\documentclass{article}

\usepackage{mathtools}% loads amsmath and graphicx

\begin{document}

\[
\biggl(\Bigl(\bigl(a
{% extra group for correct spacing
 \overbrace{
     {}^q \bigr)^q \Bigr)^{\rotatebox{20}{$\scriptstyle\dots$}} \biggr)^{\!\!q\mathstrut}
 }^{\text{$n$ times}}
}
\]

\[
\biggl(
\Bigl(
\bigl(a^q\bigr)^{q}
\Bigr)\quad
\biggr)^{
         \!\! q
         \setbox0=\hbox to 0pt{\hss
            \rotatebox{15}{$
              \overbrace{\kern1.8em\scriptstyle\mathstrut\dots\kern1.2em}^{\rotatebox{-15}{\scriptsize$n$ times}}
            $}%
         }%
         \lower1.5ex\box0
        }
\]

\end{document}

enter image description here

4
  • Thanks for your answer :-). In the horizontal case, it is possible to make the overbrace closer to the math formula? I tried to use \overbracket from mathtools but I am not able to get what I want. I tried to implement solutions from here, but negative depth does not seem to work anyway... – Watson Feb 23 at 17:09
  • Probably using your idea with "\lower3ex\box0" can make it work, but I am not sure how. – Watson Feb 23 at 17:13
  • @Watson No, you need no \lower in the first case. I've put an extra \mathstrut to increase the distance; you can simply remove that. – campa Feb 23 at 19:38
  • Excellent works for every user! +1 for all. – Sebastiano Feb 23 at 21:52
11

As given in my answer at Nested Mathematical Functions

The .4pt stacking gap added with each nesting will determine the growth rate of the parens.

\documentclass{article} 
\usepackage{scalerel,stackengine,graphicx,amsmath}
\stackMath
\ignoremathstyle
\newcommand\Comp[1]{\scaleleftright{(}{\addstackgap[.4pt]{#1}}{)}}
\newcommand\rdots{\ThisStyle{.\raisebox{.1ex}{$\scriptstyle.$}%
  \raisebox{.2ex}{$\scriptstyle.$}}}
\begin{document} 
\[ 
\stackinset{r}{1pt}{t}{-14.5pt}{\rotatebox{6}
  {$\overbrace{\rule{30pt}{0pt}}^{\textrm{\tiny$n$ times}}$}}{%
\Comp{\Comp{\Comp{a^q}^q}^{\rdots}}^q}
\] 
\end{document}

enter image description here

Here's a version where the stackgap is increased to .6pt, to bring out the increasing size of parens:

enter image description here

2
  • 1
    Thanks but you are missing the diagonal brace above the parenthesis, so this does not really address my question. – Watson Feb 23 at 13:40
  • 1
    @Watson Please see my revision. – Steven B. Segletes Feb 23 at 14:02
8

A solution with pstricks-add:

\documentclass{article}
\usepackage{pstricks-add}

\begin{document}

\[
\biggl(\Bigl(\bigl(a^{\pnode[0,1ex]{E}{q}}\bigr)^{\! \rnode{F}{\scriptstyle q}}\Bigr)\enspace \biggr)^{\!\!\rnode{G}{\scriptstyle q}\pnode[0,1ex]{H}}%
\psset{singleline, braceWidth=1.2pt, braceWidthInner=2pt, braceWidthOuter=2pt, nodesepB=-2pt}
\psbrace[rot=14,ref=c, linewidth=0.3pt](H)(E){\scriptstyle n\:\mathrm{times}}%
\ncline[linestyle=dotted, dotsep=2.pt, nodesepA=4.5pt, nodesepB=3.2pt]{F}{G}
\]

\end{document} 

enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.