Here's a new implementation of `\widebar`

, based on `\overline`

. It works by hacking into `amsmath`

's accent placement, so it needs that package. Here's a comparison of `\widebar`

(first line) and `\overline`

(second line):

I think the placement of the bars in the first line is better, except for the `\sin z`

, where there's no difference. Note that `\widebar`

works well together with superscripts, but not necessarily with subscripts. (`\overline`

has the same issue.) It also works well over combined symbols like `AB`

in most cases.

```
\documentclass{article}
\usepackage{amsmath}
\makeatletter
\let\save@mathaccent\mathaccent
\newcommand*\if@single[3]{%
\setbox0\hbox{${\mathaccent"0362{#1}}^H$}%
\setbox2\hbox{${\mathaccent"0362{\kern0pt#1}}^H$}%
\ifdim\ht0=\ht2 #3\else #2\fi
}
%The bar will be moved to the right by a half of \macc@kerna, which is computed by amsmath:
\newcommand*\rel@kern[1]{\kern#1\dimexpr\macc@kerna}
%If there's a superscript following the bar, then no negative kern may follow the bar;
%an additional {} makes sure that the superscript is high enough in this case:
\newcommand*\widebar[1]{\@ifnextchar^{{\wide@bar{#1}{0}}}{\wide@bar{#1}{1}}}
%Use a separate algorithm for single symbols:
\newcommand*\wide@bar[2]{\if@single{#1}{\wide@bar@{#1}{#2}{1}}{\wide@bar@{#1}{#2}{2}}}
\newcommand*\wide@bar@[3]{%
\begingroup
\def\mathaccent##1##2{%
%Enable nesting of accents:
\let\mathaccent\save@mathaccent
%If there's more than a single symbol, use the first character instead (see below):
\if#32 \let\macc@nucleus\first@char \fi
%Determine the italic correction:
\setbox\z@\hbox{$\macc@style{\macc@nucleus}_{}$}%
\setbox\tw@\hbox{$\macc@style{\macc@nucleus}{}_{}$}%
\dimen@\wd\tw@
\advance\dimen@-\wd\z@
%Now \dimen@ is the italic correction of the symbol.
\divide\dimen@ 3
\@tempdima\wd\tw@
\advance\@tempdima-\scriptspace
%Now \@tempdima is the width of the symbol.
\divide\@tempdima 10
\advance\dimen@-\@tempdima
%Now \dimen@ = (italic correction / 3) - (Breite / 10)
\ifdim\dimen@>\z@ \dimen@0pt\fi
%The bar will be shortened in the case \dimen@<0 !
\rel@kern{0.6}\kern-\dimen@
\if#31
\overline{\rel@kern{-0.6}\kern\dimen@\macc@nucleus\rel@kern{0.4}\kern\dimen@}%
\advance\dimen@0.4\dimexpr\macc@kerna
%Place the combined final kern (-\dimen@) if it is >0 or if a superscript follows:
\let\final@kern#2%
\ifdim\dimen@<\z@ \let\final@kern1\fi
\if\final@kern1 \kern-\dimen@\fi
\else
\overline{\rel@kern{-0.6}\kern\dimen@#1}%
\fi
}%
\macc@depth\@ne
\let\math@bgroup\@empty \let\math@egroup\macc@set@skewchar
\mathsurround\z@ \frozen@everymath{\mathgroup\macc@group\relax}%
\macc@set@skewchar\relax
\let\mathaccentV\macc@nested@a
%The following initialises \macc@kerna and calls \mathaccent:
\if#31
\macc@nested@a\relax111{#1}%
\else
%If the argument consists of more than one symbol, and if the first token is
%a letter, use that letter for the computations:
\def\gobble@till@marker##1\endmarker{}%
\futurelet\first@char\gobble@till@marker#1\endmarker
\ifcat\noexpand\first@char A\else
\def\first@char{}%
\fi
\macc@nested@a\relax111{\first@char}%
\fi
\endgroup
}
\makeatother
\newcommand\test[1]{%
$#1{M}$ $#1{A}$ $#1{g}$ $#1{\beta}$ $#1{\mathcal A}^q$
$#1{AB}^\sigma$ $#1{H}^C$ $#1{\sin z}$ $#1{W}_n$}
\begin{document}
\test\widebar
\test\overline
\end{document}
```

Here is my previous simpler implementation; the intended use is for single symbols. It also works when applied to several symbols, but then the placement of the bar may not be appropriate (see `AW`

at the end). Moreover, subsequent superscripts may be placed too close to the bar.

```
\documentclass{article}
\usepackage{amsmath}
\makeatletter
\newcommand*\rel@kern[1]{\kern#1\dimexpr\macc@kerna}
\newcommand*\widebar[1]{%
\begingroup
\def\mathaccent##1##2{%
\rel@kern{0.8}%
\overline{\rel@kern{-0.8}\macc@nucleus\rel@kern{0.2}}%
\rel@kern{-0.2}%
}%
\macc@depth\@ne
\let\math@bgroup\@empty \let\math@egroup\macc@set@skewchar
\mathsurround\z@ \frozen@everymath{\mathgroup\macc@group\relax}%
\macc@set@skewchar\relax
\let\mathaccentV\macc@nested@a
\macc@nested@a\relax111{#1}%
\endgroup
}
\makeatother
\begin{document}
$\widebar{M}$ $\widebar{A}$ $\widebar{\mathcal A}$ $\widebar{g}$ $\widebar{\beta}$
$\widebar{AB}$ $\widebar{AW}$
$\overline{M}$ $\overline{A}$ $\overline{\mathcal A}$ $\overline{g}$ $\overline{\beta}$
$\overline{AB}$ $\overline{AW}$
\end{document}
```

In comments you indicated that it is the height of the `~`

that is your concern, perhaps one of these does what you want:

```
\documentclass{article}
\begin{document}
a\textasciitilde b\raisebox{-1ex}{\textasciitilde}c\raisebox{-1.2ex}{\textasciitilde}d\raisebox{-2ex}{\textasciitilde}e
\end{document}
```

## Best Answer

## TL;DR

`\textbackslash`

produces a backslash in text-mode. The math-mode`$\sim$`

and`\texttildelow`

(from`textcomp`

package) are options for a lower tilde(while`\~{}`

and`\textasciitilde`

produce a raised tilde in text-mode)## Long Answer:

The

Comprehensive LaTeX Symbol Listis your friend. The correct link seems to keep changing, but if you have a complete TeX Live installation, the command`texdoc symbols-a4`

will display your local copy.`\textbackslash`

and`\textasciitilde`

are found in several places in the document, but theLaTeX 2e ASCII Table(Table 529 as of this writing) and the following discussion are a convenient resource for all ASCII characters. In particular, the discussion notes that`\~{}`

and`\textasciitilde`

produce a raised tilde, whilst the math-mode`$\sim$`

and`\texttildelow`

are options for a lower tilde; the latter is in the`textcomp`

package, and looks best in fonts other thanComputer Modern. If you are typesetting file names or urls, the document recommends the`url`

package.Remember to delimit TeX macros from surrounding text, e.g.

`bar\textasciitilde{}foo`

.