[Tex/LaTex] Notation for proper normal subgroup

Question

Is there any easy way to put not-equal sign to any binary operation symbol like \triangleright etc.

For example, I want to use it for a proper normal subgroup.

If found one solution for \lhd but it is not so simple (symbol for proper ideal (\unlhd + \lneq))

Answer 1

You may choose between the amssymbversion and a variant borrowed from mathabx:

\documentclass{article}
\usepackage{amssymb}

\DeclareFontFamily{U}{matha}{\hyphenchar\font45}
\DeclareFontShape{U}{matha}{m}{n}{ <-6> matha5 <6-7> matha6 <7-8>
matha7 <8-9> matha8 <9-10> matha9 <10-12> matha10 <12-> matha12 }{}
\DeclareSymbolFont{matha}{U}{matha}{m}{n}
%
\DeclareMathSymbol{\nvartrianglelefteq}{\mathrel}{matha}{"9E}
\DeclareMathSymbol{\vartrianglelefteq}{\mathrel}{matha}{"9C}

\begin{document}

    \[ H \nvartrianglelefteq G \qquad H \vartrianglelefteq G\]

    \[ H \ntrianglelefteq G \qquad H \trianglelefteq G \]

\end{document}