3

Overleaf is saying that both \unlhd and \trianglelefteq are undefined control commands, although \traingleleft works fine.

How else can I make normal subgroup symbol i.e. enter image description here

with an equality sign below.

Mico
  • 506,678
Bhaskar Vashishth
  • 469

1 Answers1

3

You need the amssymb package:

\documentclass{article}
\usepackage{amssymb}

\begin{document}
$H \unlhd G$
\end{document}

output

Or even without the package you could say:

\documentclass{article}

\DeclareSymbolFont{AMSa}{U}{msa}{m}{n}
\DeclareMathSymbol{\Bhaskarunlhd}{\mathrel}{AMSa}{"45}

\begin{document}
$H \Bhaskarunlhd G$
\end{document}
Ruben
  • 13,448
  • @BhaskarVashishth, you're welcome, but note that the usual way of say thanks in this site is upvote any good answer (of any question) and accept the best answer (only one) to your own question. – Ruben Jul 12 '15 at 01:09
  • Yeah, I am aware of stack rules sir, but I was first trying it, I guess I am too dud with tex to actually use your help, or overleaf doesnot accept ams package. It didnt work. thanks anyways – Bhaskar Vashishth Jul 12 '15 at 01:12
  • Oh, ok. Overleaf seems to be a nasty little thing... – Ruben Jul 12 '15 at 01:13
  • @BhaskarVashishth, I added a package indipendent solution. – Ruben Jul 12 '15 at 01:40
  • Jjust copying it inside \(\) is giving many errors. I am not sure I am doing it right, acn you try it in a blank page in overleaf.com and see how can I make it work. If you are not busy, thanks. Otherwise I will just use the one without equal sign, not a problem – Bhaskar Vashishth Jul 12 '15 at 01:47
  • @BhaskarVashishth, works fine for me. Did you go to source mode and pasted seperately what belongs to my examples preamble into overleafs preamble (preamble := "everything that comes before \begin{document}") and the instruction itself, i.e. $H \Bhaskarunlhd G$ or \(H \Bhaskarunlhd G\) where you want it to be in the text body, which means somewhere in between \begin{document} and \end{document}? – Ruben Jul 12 '15 at 08:28
  • yeah thanks very much ruben. Can you do me a favour and edit your answer to explain how to add other such symbols which overleaf isnt accepting, like \nmid and \blacksquare also it says \mathbb is unvalid control sequence. How to declare symbolfont and declaremathsymbol, for various fonts is there a list ? – Bhaskar Vashishth Jul 12 '15 at 15:21