# greater equal sign \leq in blackboard bold style

Is there any package that makes the math symbols with blackboard bold style? For example, I want to have $mathbb{\leq}$

• i've never seen "blackboard bold" inequalities. can you cite a published source? it they are in use, then they should be added to unicode, and i can make such a submission. – barbara beeton Mar 4 '16 at 16:38
• No, I have not seen either. Just I have an order on a model and based on that order there is the order in the language. So to distinguish them but still be similar I would like to have mathbbleq: A \leq B iff [[A]] \mathbbleq [[B]]. – Fibo Kowalsky Mar 4 '16 at 16:54
• . Bad idea, in my opinion, as it might easily be confused with \leqslant. – Bernard Mar 4 '16 at 17:05
• @Bernard that's why I put thick part up that it will be less confused. – Fibo Kowalsky Mar 4 '16 at 18:01

If you are using pdftex, then you can use \pdfliteral like this:

\def\spleq{\mathrel{\hbox to5pt{%
\pdfliteral{q .9963 0 0 .9963 0 0 cm .5 0 0 .5 0 1.5 cm 1 j 1 J .7 w
10 8 m 0 3 l 10 -3 l S 0 1 m 10 -5 l S 2 2 m 10 6 l S Q}\hss}}}

$A \spleq B < C$

\bye


If you need different sizes in \scriptstyle and scriptscriptstyle then you use this modification:

\def\spleq{\mathrel{\mathpalette\spleqA\relax}}
\def\spleqA#1#2{\mkern1mu\hbox to\spleqB#1em{%
\pdfliteral{q .9963 0 0 .9963 0 0 cm \spleqB#1 0 0 \spleqB#1 0 1\spleqB#1 cm
1 j 1 J .7 w 10 8 m 0 3 l 10 -3 l S 0 1 m 10 -5 l S 2 2 m 10 6 l S Q}\hss}%
\mkern1mu}
\def\spleqB#1{\ifx#1\displaystyle.5\fi \ifx#1\textstyle.5\fi
\ifx#1\scriptstyle.35\fi \ifx#1\scriptscriptstyle.25\fi}

• What is pdfliteral? Does it also work in xetex or luatex? Where can I learn about it? – User Mar 4 '16 at 19:20
• When using xetex, you must define \def\pdfliteral#1{\special{pdf:literal #1}}. When using luatex then you have no problem, because pdfliteral is ready, pdfTeX is a part of luatex. pdfliteral produces low levet PDF code, you can learn about it in PDF specification. – wipet Mar 4 '16 at 20:41

It could be perfected in scriptscript style, but I don't think you really need it in second level subscripts or superscripts.

\documentclass{article}
\usepackage{amssymb,pict2e}

\makeatletter
\DeclareRobustCommand{\bleqslant}{%
\mathrel{\mathpalette\@bleqslant\relax}%
}

\newcommand{\@bleqslant}[2]{%
\sbox\z@{$#1\m@th\leqslant$}%
\ifx#1\displaystyle
\def\@blqwd{0.75}%
\else
\ifx#1\textstyle
\def\@blqwd{0.75}%
\else
\ifx#1\scriptstyle
\def\@blqwd{0.7}%
\else
\def\@blqwd{0.65}%
\linethickness{0.75\@wholewidth}%
\fi
\fi
\fi
\setlength{\unitlength}{\dimexpr\wd\z@+\dp\z@}%
\vcenter{\hbox{%
\begin{picture}(1,1)
\roundcap\roundjoin
\polyline(\@blqwd,0.3)(0.1,0.6)(\@blqwd,0.9)
\polyline(0.1,0.4)(\@blqwd,0.1)
\polyline(\@blqwd,0.8)(0.22,0.555)
\end{picture}%
}}%
}
\makeatother

\begin{document}

$\leqslant\bleqslant$

$\scriptstyle\leqslant\bleqslant$

$\scriptscriptstyle\leqslant\bleqslant$

\end{document}