# Strike-through Tilde Accent

I am working with graphs (V, E) which have a fixed number of common neighbours and common non-neighbours for each pair of adjacent vertices, and non-adjacent vertices as well. To denote these four invariants, I'm using the following symbols:

I'm not too keen on it though (I don't like how _\sim and _\nsim look). I'm considering using the \tilde accent, but I would like an analogous \nottilde accent, that is, a stricken-through \tilde accent:

I'd imagine creating such a command would involve quite a bit of hassle, especially to be compatible with \widetilde. I have no idea how to go about creating it (I used paint for the picture above).

I'm also open to other suggestions for this notation! Thanks.

• What do you mean "compatible with \widetilde"? How would you envision the proper way to strike through a \widetilde? With the same small strike or with an enlarged one? – Steven B. Segletes Dec 5 '17 at 18:29
• @StevenB.Segletes I'd imagine the strikethrough to stretch out horizontally as the tilde does, however it's not that important to be honest. I'd be more interested in getting it to position itself correctly on the letter f or capital A for example. – Luke Collins Dec 5 '17 at 18:45

\documentclass{article}
\usepackage{amsmath,amssymb}
\def\nottilde#1{\overset{\ifx#1f\hspace{.5ex}\fi\lower0.8ex\hbox{\tiny$\nsim$}}{#1}}
\def\xtilde#1{\overset{\ifx#1f\hspace{.5ex}\fi\lower0.8ex\hbox{\tiny$\sim$}}{#1}}
\begin{document}
$\tilde{e}\xtilde{e}\nottilde{e}\xtilde{f}\nottilde{f}$
\end{document}


• Very nice! Is there any reason the \sim looks slimmer than the \nsim here? – Luke Collins Dec 5 '17 at 18:33
• Also, would it be possible to get \xtilde{f} and \nottilde{f} to look right also? I might use the letters e and f. – Luke Collins Dec 5 '17 at 18:43

A variation on my answer at Big tilde in math mode, showing \reallywidetile and \reallywidenotilde.

\documentclass{article}
\usepackage{scalerel}
\usepackage{stackengine,wasysym}

\newcommand\reallywidetilde[1]{\reallywideXtilde{#1}{\AC}}

\newcommand\reallywidenotilde[1]{\reallywideXtilde{#1}{\NAC}}

\newcommand\NAC{\stackengine{1.5\LMpt}{$\SavedStyle\AC$}{\smash{$\SavedStyle\vstretch{.35}{/}$}}{O}{c}{F}{F}{L}}

\newcommand\reallywideXtilde[2]{\ThisStyle{%
\setbox0=\hbox{$\SavedStyle#1$}%
\stackengine{-.1\LMpt}{$\SavedStyle#1$}{\kern.3ex%
\stretchto{\scaleto{\SavedStyle\mkern.2mu#2}{.5150\wd0}}{.6\ht0}%
}{O}{c}{F}{T}{S}%
}}

\def\test#1{$% \reallywidetilde{#1}\, \scriptstyle\reallywidetilde{#1}\, \scriptscriptstyle\reallywidetilde{#1}\qquad \textstyle\reallywidenotilde{#1}\, \scriptstyle\reallywidenotilde{#1}\, \scriptscriptstyle\reallywidenotilde{#1}$\par}

\parskip 1ex
\begin{document}

\test{abcdefghijklm}
\test{abcdefghijk}
\test{abcdefghi}
\test{abcdefg}
\test{abcde}
\test{abc}
\test{ab}
\test{a}
\test{f}
\test{A}
\end{document}