# Unity element 1 [duplicate]

Possible Duplicate:
How to look up a symbol?

I'd like to write the unity element 1 in LaTeX. I have tried these methods:

``````\$\mathbbm{1}\$ \\
\$\mathbb{1}\$\\
\$\mathbbss{1}\$\\
\$\mathbbtt{1}\$\\
\$\mathds{1}\$\\
``````

but I receive the integer 1. I think that I'm missing a suitable package. How to solve this problem?

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Does this help?: douglas.stebila.ca/blog/archives/2004/06/27/… –  Jellby Jul 5 '12 at 10:59
If you load the package `bbold`, you can type `\mathbb{1}` (in math-mode, of course) to get what you want. The "standard" blackboard bold glyphs are available only for uppercase letters -- hence the need to load an extra package. –  Mico Jul 5 '12 at 10:59
@Mico I believe you have answered the question. I recommend you post your comment as an answer. –  azetina Jul 5 '12 at 14:34
@azetina: done! –  Mico Jul 5 '12 at 15:25
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## marked as duplicate by egreg, Mico, percusse, Martin Schröder, Marco DanielAug 17 '12 at 8:01

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

## 1 Answer

The "standard" blackboard bold math font contains only uppercase latin-alphabet letters. To get a blackboard bold "1" symbol, you need to load an additional LaTeX package.

For instance, the commands `\mathbb{1}` (load the `bbold` package) and `\mathds{1}` (load the `mathds` package) will generate:

respectively.

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