# Missing character: There is no ℕ in font cmss10!

How can I select and specify a font which contains the character I have in my file ?

Missing character: There is no ℕ in font cmss10!

I can see them perfectly within emacs, but I am unable to process them with xelatex because of this error

(edit) in emacs ℕ is said to be :

             position: 129 of 190 (67%), column: 14
character: ℕ (displayed as ℕ) (codepoint 8469, #o20425, #x2115)
preferred charset: unicode (Unicode (ISO10646))
code point in charset: 0x2115
script: symbol
syntax: w    which means: word
category: .:Base, L:Left-to-right (strong)
to input: type "\Bbb{N}" or "\bn" with Agda input method
buffer code: #xE2 #x84 #x95
file code: #xE2 #x84 #x95 (encoded by coding system utf-8-unix)
display: by this font (glyph code)
mac-ct:-*-Arial Unicode MS-bold-normal-normal-*-12-*-*-*-p-0-iso10646-1 (#xD24)

• this for the moronic silent down vote – nicolas Apr 25 '16 at 8:37
• Without any hint of how to reproduce the warning, there's not much anybody can say (I wasn't the downvoter). – egreg Apr 25 '16 at 8:40
• \usepackage{amssymb} and $\mathbb{N}$ does it. What's the purpose of comparing the font substitutions Emacs makes with typesetting? – egreg Apr 25 '16 at 8:52
• @nicolas You should be using the unicode-math package, if you want to input your math as unicode characters. – Henri Menke Apr 25 '16 at 9:03
• The question is why your document is trying to use cmss10 to typeset your char. So make a complete example. – Ulrike Fischer Apr 25 '16 at 9:04

cmss10 is not a Unicode font unfortunately - you need to use a font which implements Unicode maths - the TeX Gyre collection is probably a good starting point. Here is an example:

\documentclass{article}
\usepackage{unicode-math}
\setmainfont{TeX Gyre Schola}
\setmathfont{TeX Gyre Schola Math}
\begin{document}
Some Unicode maths: $x ∈ ℕ$
\end{document}


Process with xelatex or lualatex to produce this:

You may need to install the TeX Gyre fonts.

Some other compatible fonts are listed on the Github page for unicode-math but the list there is slightly out of date. The Tex Gyre project also maintains a list of suitable maths fonts.