# \overline and \widehat with subscript

I would like to create commands to produce overlines (respectively wide hats or arrows) with a subscript at the end. The commands

\overline{X}^{1}   \widehat{X}^{2}  \overrightarrow{X}^{3}


do not suit my needs since the subscripts should be controlled by the overline (respectively wide hat, right arrow). Ideally I would like to have a command like

\myoverline_{1}{X}   \mywidehat_{2}{X}  \myoverrightarrow_{3}{X}


What would be the cleanest way to do so?

P.S. The closest thing I was able to find is this question.

Update Here is a picture of what I wish to obtain:

• i'm unable to picture what you want from this description. in the cited answer, the "superscripts" are actually set above the "decoration". do you want your "subscripts" stacked below the over-accents, and then that whole construction stacked on top of what it's embellishing? if you could draw a picture, and post it as a scan, that would be very helpful. Dec 23, 2013 at 16:43
• \overline{X_1}? Dec 23, 2013 at 16:44
• I think you meant superscript instead of subscript. Dec 23, 2013 at 18:13
• @kevin-c No, I mean subscript, the subscript is relative to the bar, not to the X. Dec 23, 2013 at 18:21
• I'm not sure the reader would understand that the little number is a subscript to the decoration rather than an exponent for the expression. Dec 23, 2013 at 18:35

This approach gives the subscript to the "overline" as you seemed to indicate. With this implementation, the overline thickness is .4pt which can be changed. The bottom of the subscript is 1.5pt below the top of the argument. The 2pt setting determines the vertical location of the overbar relative to the subscript.

\documentclass{article}
\usepackage{stackengine}
\stackMath
\newcommand\subline[2]{\stackon[-1.5pt]{#1}{\rule[2pt]{\widthof{$#1$}}{.4pt}_{#2}}}
\begin{document}
\renewcommand\stackalignment{l}
$A = \subline{X}{1} \subline{g}{2} \subline{Xyzq}{12}$
\end{document}


For the widehat, I adopt a bit of a different approach, making added use of the scalerel package. The parameter \hatgap gives the vertical gap between item and hat, and \subdown gives the relative placement of the subscript relative to the hat.

\documentclass{article}
\usepackage{scalerel}
\usepackage{stackengine}
\stackMath
\def\hatgap{2pt}
\def\subdown{-2pt}
\newcommand\reallywidehat[2][]{%
\renewcommand\stackalignment{l}%
\stackon[\hatgap]{#2}{%
\stretchto{%
\scalerel*[\widthof{$#2$}]{\kern-.6pt\bigwedge\kern-.6pt}%
{\rule[-\textheight/2]{1ex}{\textheight}}%WIDTH-LIMITED BIG WEDGE
}{0.5ex}% THIS SQUEEZES THE WEDGE TO 0.5ex HEIGHT
_{\smash{\belowbaseline[\subdown]{\scriptstyle#1}}}%
}}
\begin{document}
$\reallywidehat[1]{zbcdklm} \times \reallywidehat[ijk]{zbcdefghijk} = \reallywidehat{zb}$
\end{document}


The widehat EDIT is very loosely based on my solution at Really wide hat symbol, though this implementation is superior to that one.

• I like this solution. Is it possible to adapt it also for \widehat (and other decorations) ? Dec 24, 2013 at 10:01
• I tried using this but latex is complaing that "stackengine.sty" not found. Do you have any suggestions? Apr 12, 2018 at 9:58
• @MikhailKatz If your LaTeX installation doesn't load it automatically, it can be found at ctan.org/pkg/stackengine Apr 12, 2018 at 9:59

your example looks enough like a symbol with a (raised) \overline and a superscript to the base symbol that i'm going to construct that.

the second image might suffice:

\documentclass{article}
\begin{document}
$\overline{\mathrm{X}\vphantom{()}}^1 \quad \smash{\overline{\mathrm{X}\vphantom{()}}}\vphantom{X}^1$
\end{document}