# \tau symbol like a real number \Re

How can I get \tau to be like the real number symbol \Re similar to the ones in the attached photo.

• Why is this tagged as latex3? – user31729 Jun 2 '17 at 14:51
• Sorry, a mistake. – OOzy Pal Jun 2 '17 at 14:53
• @ChristianHupfer I have removed that tag (and formatted a bit). OOzyPal Do you mean this blackboard math font? – TeXnician Jun 2 '17 at 14:54
• @TeXnician: I could have removed the tag also, but I wanted to 'annoy' the O.P. ;-) – user31729 Jun 2 '17 at 14:55
• Your Title is very confusing as you show blackboard bold (double struck) R but you ask for a style like \Re which makes a script R not at all like the image that you show. – David Carlisle Jun 2 '17 at 15:05

Very ugly version with \bbtau from package mathbbol and its bbgreekl option. Don't use it ;-)

\documentclass{article}

\usepackage[bbgreekl]{mathbbol}

\begin{document}

$\bbtau$
\end{document}


• interestingly enough Unicode only has the math double struck in latin and arabic, not greek..... So if this was used in publication once could apply to extend Unicode... – David Carlisle Jun 2 '17 at 14:56
• As you said it is ugly :). Also it does not scale well with the other equations. I will just go with \mathbb{T}. – OOzy Pal Jun 3 '17 at 8:55
• @OOzyPal: Well, you asked for \tau in black board letters. \mathbb{T} is black board T ;-) – user31729 Jun 3 '17 at 9:06