# symbol for proper ideal (\unlhd + \lneq)

How can I write the symbol

for a proper ideal?

The standard relations \leq,\subseteq both have a "proper" version \lneq,\subsetneq, but I was unable to find a "proper" version of either \unlhd or \trianglelefteq.

Any suggestions?

-

You can do by superimposing the symbols:

\documentclass[a4paper]{article}
\usepackage{amssymb}

\newcommand{\properideal}{%
\mathrel{\ooalign{$\lneq$\cr\raise.22ex\hbox{$\lhd$}\cr}}}

\begin{document}
$I\properideal A$
\end{document}


A version that changes size in subscripts/superscripts; some artifacts may appear at low screen resolution.

\documentclass[a4paper]{article}
\usepackage{amsmath}
\usepackage{amssymb}

\makeatletter
\DeclareRobustCommand{\properideal}{\mathrel{\text{$\m@th\proper@ideal$}}}
\newcommand{\proper@ideal}{%
\ooalign{$\lneq$\cr\raise.22ex\hbox{$\lhd$}\cr}%
}
\makeatother
\begin{document}
$I\properideal A_{\properideal_{\properideal}}$
\end{document}


-
great, thank you – Leon Nov 6 '11 at 0:57
Is there any other way of doing this? The $<$ bit of this symbol is bold when I put it into a document, which is less than ideal... – user1729 May 9 '12 at 15:36
@user1729 Maybe a follow-up question with a minimal example is better. – egreg May 9 '12 at 15:38
I was contemplating asking a new question, but I thought I would ask briefly here first. What do you mean by "a minimal example"? – user1729 May 9 '12 at 15:43
An example of a .tex document that exhibits the problem, including all necessary packages. Don't forget a link to this question. – egreg May 9 '12 at 15:50