New command to change vertical space in overset doesn't work

Question

I want to reduce the vertical space between a symbol and a letter that are above each other. I have the following code, using a new command $\oset$ that gives exactly the output I need. But unfortunately I get a compiling error, namely: missing $ inserted. When I use $\overset$ the output is wrong, but the compiler works..

\documentclass{article}
\usepackage{amsmath}
\makeatletter
\newcommand{\oset}[2]{%
   {\mathop{#2}\limits^{\vbox to -.5\ex@{\kern-\tw@\ex@
    \hbox{\scriptsize #1}\vss}}}}
\makeatother

\begin{document}
$\oset{\sim}{t}$ gives a compiling error.
$\overset{\sim}{t}$ works, but the $\sim$ too high. 
\end{document}

to establish link: https://tex.stackexchange.com/questions/194798/change-vertical-space-in-overset/194805?noredirect=1#comment1632361_194805 (I assume you got your code from @Mico's answer) — D.R, Aug 24 '22 at 07:25

egreg · Accepted Answer · 2022-08-24T14:07:58.003

It should be \hbox{$\scriptstyle#1$}. However, there's a better way:

\documentclass{article}
\usepackage{amsmath}
\makeatletter
\newcommand{\oset}[2]{{\mathpalette\o@set{{#1}{#2}}}}
\newcommand{\o@set}[2]{\o@@set{#1}#2}
\newcommand{\o@@set}[3]{%
  \vbox{\offinterlineskip
    \ialign{\hfil##\hfil\cr
      $\m@th\o@set@demote{#1}#2$\cr
      \noalign{\vskip0.2pt}
      $\m@th#1#3$\cr
    }%
  }%
}
\newcommand{\o@set@demote}[1]{%
  \ifx#1\displaystyle\scriptstyle\else
  \ifx#1\textstyle\scriptstyle\else
  \scriptscriptstyle\fi\fi
}
\makeatother
\begin{document}
$\oset{\sim}{t}$ versus $\tilde{t}$
\end{document}

On the other hand, \tilde{t} seems much better.

For completeness here's how to define \uset and \ouset.

\documentclass{article}
\usepackage{amsmath}
\usepackage{accents} % for comparison
\makeatletter
\newcommand{\oset}[2]{{\mathpalette\o@set{{#1}{#2}}}}
\newcommand{\uset}[2]{{\mathpalette\u@set{{#1}{#2}}}}
\newcommand{\ouset}[3]{\oset{#1}{\uset{#2}{#3}}}
\newcommand{\o@set}[2]{\o@@set{#1}#2}
\newcommand{\o@@set}[3]{%
  \vbox{\offinterlineskip
    \ialign{\hfil##\hfil\cr
      $\m@th\ou@set@demote{#1}#2$\cr
      \noalign{\vskip0.2pt}
      $\m@th#1#3$\cr
    }%
  }%
}
\newcommand{\u@set}[2]{\u@@set{#1}#2}
\newcommand{\u@@set}[3]{%
  \vtop{\offinterlineskip
    \ialign{\hfil##\hfil\cr
      $\m@th#1#3$\cr
      \noalign{\vskip0.6pt}
      $\m@th\ou@set@demote{#1}#2$\cr
    }%
  }%
}
\newcommand{\ou@set@demote}[1]{%
  \ifx#1\displaystyle\scriptstyle\else
  \ifx#1\textstyle\scriptstyle\else
  \scriptscriptstyle\fi\fi
}
\makeatother
\begin{document}
$\oset{\sim}{t}$ versus $\tilde{t}$
$\uset{x}{t}$ versus $\underaccent{x}{t}$
$\ouset{\sim}{x}{t}$ versus $\underaccent{x}{\tilde{t}}$
\end{document}

I was trying to generalize your \oset into \uset (underset) and \ouset (overunderset), but couldn't quite figure it out. Do you mind also writing these commands? — D.R, Aug 24 '22 at 07:41
thank you. I was playing around, and \ouset{}{}{} works great with letters, and the plus and minus signs, but there is some asymmetry when I use it on \to or the equal sign. This is not so important for my use cases, but it'd be nice to know why. — D.R, Aug 24 '22 at 17:05

score 2 · Answer 2 · answered Oct 29 '19 at 16:20

Remember: it is possible to use also mtpro2 (I like very much this package), lite version. Here there are several examples in relation to your tastes for the lenghts of the tilde symbol. The vertical spacing is automatic.

\documentclass{article}
\usepackage[lite]{mtpro2}
\begin{document}
\[
\tilde t+\wtilde t +\wwtilde t+\widetilde t
\]
\end{document}

score 1 · Answer 3 · answered Oct 29 '19 at 16:31

1

Why not use the \accentset command?

\documentclass{article}
\usepackage{amsmath, amssymb}
\usepackage{accents}

\begin{document}

$\accentset{\sim}{t}$ compared to $ \tilde{t} $ and to $\widetilde{t}$

\end{document}

answered Oct 29 '19 at 16:31

Bernard

271,350

New command to change vertical space in overset doesn't work

3 Answers3