[Tex/LaTex] Element of or Equal To Symbol

Question

I would like to typeset a symbol that means "element of or equal to," which is just the element symbol with a short horizontal line underneath.

I tried $\underline{\in}$, but that makes the underline too thick:

Is there a way to typeset this symbol directly, or to make the underline thinner?

Answer 1

This is a first approximation:

\documentclass{article}
\newcommand{\ineq}{%
  \mathrel{\mkern1mu\underline{\mkern-1mu\in\mkern-1mu}\mkern1mu}}

\begin{document}
$\alpha\ineq\beta$
\end{document}

This automatically changes size in subscripts.

You may prefer a solution with a roundcap bar below the main symbol:

\documentclass{article}
\usepackage{amsmath}

\makeatletter
\newcommand{\ineq}{\mathrel{\text{\in@eq}}}
\newcommand{\in@eq}{%
  \oalign{%
    \hidewidth$\m@th\in$\hidewidth\cr
    \noalign{\nointerlineskip\kern1ex}%
    $\m@th\smash{-}$\cr
    \noalign{\nointerlineskip\kern-.5ex}%
  }%
}
\makeatother
\begin{document}
$\alpha\ineq\beta_{\ineq}$
\end{document}