# How to use mathbbol only for greek and lowercase

I would like to use the mathbbol for all blackboard fonts that aren't already contained in the usual \mathbb command: this includes lower case, greek (both lower and upper case) letters, digits, and more. But I still would like capital letters to work with the usual blackboard font (e.g. \mathbb{E}). I have tried to fiddle with the answers to this question for hours without success. Ideally, I would like to use \mathbb just for upper case letters, and something else (like \mathbbm) for everything else. Here is what I've tried:

1. \usepackage[bbgreekl]{mathbbol}: this way I get the greek letters (\mathbb{\gamma}, \bbgamma), but the old commands \mathbb{E} are overwritten;
2. This answer works fine for lower case letters (and does not overwrite the upper case blackboard ones), but the greek ones (e.g. \bbdelta) are not defined;
3. In mathbbol's readme file it suggests to load the package before amsmath and amsfonts, but this does not prevent the \mathbb command from being overwritten.
4. Define the symbols one by one using this answer; this is my solution for now, but it is far from ideal.

There has got to be a really easy workaround, but I simply do not know enough about LaTeX fonts to find it. I would really appreciate any help. Thank you.

Imho they don't fit. It would be better to take all from mathbbol. But if you want it, you only need to reset mathbb:

\documentclass{article}
\usepackage{amsfonts}
\usepackage[bbgreekl]{mathbbol}

\DeclareSymbolFontAlphabet{\mathbbm}{bbold}
\DeclareSymbolFontAlphabet{\mathbb}{AMSb}%

\begin{document}

$\mathbb{ABCD} \mathbbm{abcdelki} \bbalpha \bbomega$
\end{document}


• That's it! Thank you very much. I take your point about the two fonts not fitting well, but mathbbol upper case letters are just too ugly... Aug 1, 2017 at 11:06