How to use the font bbold in TeXmacs?

I would like to write mathematical formulas involving the symbol delta
image
which is conventionally produced by the package bbold (see http://mirrors.ctan.org/fonts/bbold/bbold.pdf and CTAN: Paket bbold). I would be very grateful if you could tell me how to install the font on TeXmacs.

1 Like

Hi @xuyiqi1 and welcome to the TeXmacs community!

This font is already installed in TeXmacs. It is available as TeX Blackboard Bold Variant in the Document->Font dialog.

In this font the symbol you want is encoded as U+00B4, ACUTE ACCENT. So, if you insert the character ´ when the right font is selected, you get the symbol you want.

2 Likes

Another way to do it:

  1. Input a \vartriangle: enter this code directly, or input @ then input Tab several times to switch to the triangle.
  2. Select this character, then click FormatFont effectBlackboard embold.

You could also create a macro:

<assign|Prism|<embbb|\<vartriangle\>>>
2 Likes

Interesting method, @re4zuaFe! It looks slightly different from the symbol in the first post, but it’s pretty close. I believe that the blackboard embold font effect is using TeXmacs’ font emulation features:
http://www.texmacs.org/joris/fontart/fontart-abs.html

1 Like

@jeroen @re4zuaFe Thanks a lot for your nice solutions. Following your methods, I get the symbols as in the picture.
image
The first one is more sufficient for my writing. Thanks again.

However, the outcome is slightly different from what I wanted (the double line is misplaced). I am still wondering if there is a way to get exactly this delta below.
image

That’s very odd. I get the same symbol as in your first post, not the mirrored one.
Just to make absolutely sure we are doing the same thing, could you please copy the following code and paste it into TeXmacs with Edit -> Paste from -> TeXmacs?

<with|font|Bbb**|\A>

2 Likes

Thank you @jeroen. With your code I get the same symbol as in my first post. I know why it happens. If I insert the character ´ and apply TeX Blackboard Bold Variant, I get what I want. But if I insert \Delta then apply the same font, I get the mirrored one.

I still have two questions. I would like to know how to using Unicode to insert symbols (like U+00B4 you mentioned), and how to insert character ´ using keyboard (earlier I just copied and pasted it from your post.) By the way, I am using TeXmacs on Windows 10. Thank you in advance.

You’re welcome. You can enter Unicode characters in TeXmacs by first doing ^q (on my system that’s Esc+q). Then you can enter the #B4 to get the symbol. I don’t know how to enter it via the keyboard. This will be system and keyboard dependent.

As @re4zuaFe pointed out, it may be convenient to define a macro for your symbol. You could also attach a keyboard shortcut to it.

1 Like

In order to get the correct semantic editing, seemingly it is better to specify the semantic in the macro. For example, I would use this one (where I also made the font larger):

<assign|Prism|<math-ordinary|<large|<with|font|Bbb**|\A>>>>

which should be closer to the LaTeX code

\usepackage{relsize}
\usepackage[bbgreekl]{mathbbol}
\usepackage{amsfonts}
\DeclareSymbolFontAlphabet{\mathbb}{AMSb} %to ensure that the meaning of \mathbb does not change
\DeclareSymbolFontAlphabet{\mathbbl}{bbold} 
\newcommand{\Prism}{{\mathlarger{\mathbbl{\Delta}}}} 

Then you could simply input \Prism to get this symbol, and I tested the following codes

<math|<value|Prism><rsub|R/A>>, <math|X<rsub|<value|Prism>>>
2 Likes