I want to write a math equation that needs power of dots. I tried these code
{2^{2^{2^{\ddots^{2}}}}}
But the dots needs to be rotated
3 Answers
Adapted from The TeXbook, Exercise 18.45:
\def\rddots#1{\cdot^{\cdot^{\cdot^{#1}}}}
$ 2^{2^{\rddots2}} $
\bye
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(+1) Again, I feel like it provides a better alignment than
\iddots!– chlCommented May 7, 2011 at 18:46 -
1When used like this, on math.stackexchange.com each subsequent dot is smaller... Commented Jan 26, 2014 at 0:40
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@Tomáš: That's because MSE uses [mathjax], which is a bit different thing from TeX and I am not very familiar with it. There is a glyph with [unicode-math],
\adotsfor U+022F0, but I don't think it's available with mathjax (nor if it's the appropriate glyph for this). If mathjax understands different mathstyles, you could try the more explicit definition:\def\rddots#1{{\scriptstyle\cdot}^{{\scriptstyle\cdot}^{{\scriptstyle\cdot}^{#1}}}}– morbusgCommented Jan 26, 2014 at 9:06 -
@TomášZato: Or, with Unicode, something like:
\def\sadots{{\scriptstyle\char"22F0\relax}}(note that there is no family or class definitions, so for use just in this context).– morbusgCommented Jan 26, 2014 at 9:12
An easy way would be to replace \ddots by \udots from the MnSymbol package, or \iddots from mathdots (better rendering in math mode).
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I could not define the MnSymbol package, when I define it the program does not compile the file– user5376Commented May 7, 2011 at 8:09
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@user5376 Add
\usepackage{MnSymbol}in your preamble. Still, I'd recommend using\iddotsinstead.– chlCommented May 7, 2011 at 8:11 -
In TexLive you find the package
mathdotsin the packagetexlive-generic-extraCommented May 18, 2020 at 12:31
you could try (with 5 dots for the fun of it!):
\[
{2^{2^{2^{\mathstrut^{.^{.^{.^{.^{.^{\raisebox{-.5\height}{$\scriptscriptstyle
2$}}}}}}}}}}}
\]
\[
{2^{2^{2^{\mathstrut^{.^{.^{.^{.^{.^{\raisebox{-.25\height}{$\scriptscriptstyle
2$}}}}}}}}}}}
\]
or the simpler
\[
{2^{2^{2^{\mathstrut^{.^{.^{.^{\raisebox{-.25\height}{$\scriptscriptstyle
2$}}}}}}}}}
\]
\[
{2^{2^{2^{\mathstrut^{.^{.^{.^{2}}}}}}}}
\]
they give (respectively):
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@jbfu (+1) Your 2nd solution seems to provide a better alignment.– chlCommented May 7, 2011 at 12:30
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@chl yes, I agree. The
\mathstrutis to put the first dot higher than where it would fall otherwise. One could fine-tune that positioning if needed.– user4686Commented May 7, 2011 at 12:55
\iddotsfrom mathdots. Could prove easier indeed to rotate slightly\iddotsthan a lot\ddots, and perhaps actually\iddotsalready quasi solves your problem.