38

To typeset that H is a normal subgroup of G, I would use H\unlhd G.

However, the result doesn't satisfy myself, since the G seems too close to the triangle:

enter image description here

Adding a space \ makes "too much space".

Is there a neat way to typeset such a thing ?

lockstep
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Klaus
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    There is also an half-space \,. – Martin Scharrer Dec 05 '11 at 16:55
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    Since this is used as a relation, use \mathrel{\unlhd} instead. It will allow for the appropriate spacing around the operator/relation. How do you currently typeset the relation - please show the entire code that produced the image. It seems like you might not be using math mode correctly. – Werner Dec 05 '11 at 16:56
  • @Werner, I simply typed $H\unlhd G inside a paragraph. Your solution works really fine, thank you! – Klaus Dec 05 '11 at 17:00
  • For very bizarre reasons latexsym classifies \unlhd as a binary operation symbol. Either use the command suggested by Martin, or say in your preamble \DeclareMathSymbol\unlhd{\mathrel}{lasy}{"02}, after \usepackage{latexsym}; in this way $H\unlhd G$ will render correctly. – egreg Dec 05 '11 at 17:13
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    By the way, in all of these answers, it's probably a good idea for you to define a personal macro for this symbol, like \nsub (normal subgroup?). That way, first, you save a lot of writing, and second, if you decide again that you hate the symbol, you can change it easily. Semantic markup and all that. – Ryan Reich Dec 05 '11 at 17:39

2 Answers2

53

The same symbol is also available as \trianglelefteq from the amssymb package. It gives a much wider spacing.

\documentclass{article}
\usepackage{amssymb}
\begin{document}
$H\trianglelefteq G$
\end{document}

Result

Martin Scharrer
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23

Appropriate math spacing for relational operators is obtained using \mathrel:

$H\mathrel{\unlhd}G$
Werner
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