[Tex/LaTex] What symbol is this

symbols

Symbol

I need the command to display this symbol in LaTeX or, at least, its name.

I guess it’s from some kind of a mathematical or informatics discipline. I saw it in article called “A comparison of collapsed Bayesian methods for probabilistic finite automata”. Actually, I have no idea what it is all about: I just started learning LaTeX and I have to copy this article. This symbol is used just as if it is a casual letter like x or y. The line which includes it is,

Input : a(this symbol), N, BurnInTime, SamplingNum, Period

Best Answer

To me this looks like a blackboard bold lowercase a. Specifically, it looks like the lowercase a from the bbold font.

bbold font

For blackboard bold capitals you can use the \mathbb macro provided by the amsfonts or amssymb packages. But $\mathbb{a}$ gives a backwards G.

Instead, you need to load the whole bbold font. Here's a quick snippet to do that. 

\documentclass{article}
\DeclareSymbolFont{bbold}{U}{bbold}{m}{n}
\DeclareSymbolFontAlphabet{\mathbbold}{bbold}

\begin{document}
$\mathbbold{a}$
\end{document}

bbold a

See also Blackboard bold characters

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