what is the apostrophe symbol?

Question

The following code

\documentclass[varwidth, margin = 1cm]{standalone}
\begin{document}
apostrophe '\\
apostrophe  as a Unicode character 2032 `^^^^2032\\ %requires xelatex                                                                                                                                         
apostrophe in math mode $'$
\end{document}

gives the result

As one can see the apostrophe in free form, as a Unicode character 2032 and in math mode appears in different ways.

How can I produce an apostrophe similar to the one in math mode in a free text without using the awkward step of going into math mode?

Do you mean something like \newcommand{\apostrophe}{{\quotefont'}}? Display real apostrophe in parts of a document — Bobyandbob, Oct 27 '17 at 21:34
It's a prime (Unicode U+2032) but most text fonts for pdftex do not have both a curly and straight right quote — David Carlisle, Oct 27 '17 at 21:35
Routine in LuaLaTeX or XeTeX, where you can directly use Unicode with Open Type fonts, thanks to fontspec. Many Open Type fonts, including some available via TeX, have the prime symbol. Then, as David noted, ^^^^2032 places the character without need for math mode. Or you can simply paste it in from a character map. — , Oct 27 '17 at 21:40
@Viesturs Unicode entry only works if your document uses utf-8 encoding. I specifically think of LuaLaTeX and XeTeX (I do not know how it works if it works, in pdflatex). To enter a character at Unicode hex PQRS (where PQRS is 0 to lowercase f) type `^^^^PQRS. Alternatively, find the character in a Unicode character map, copy and paste into your document. — , Oct 28 '17 at 01:52
I inserted the Unicode option. Latex gives a prime symbol different than given in https://unicode-table.com/en/#2032 — Viesturs, Oct 28 '17 at 14:25

score 5 · Accepted Answer · answered Oct 27 '17 at 21:59

If you want to use pdflatex:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{newunicodechar}

\newcommand{\textprime}{\ensuremath{'}}
\newunicodechar{′}{\textprime}

\begin{document}

Arnol′d

$f'(x)$

\end{document}

Don't use ′ in math mode, unless it's for a single prime.

For XeLaTeX or LuaLaTeX:

\documentclass{article}
\usepackage{fontspec}
\usepackage{newunicodechar}

\setmainfont{Libertinus Serif}

\newcommand{\safeprime}{\ensuremath{'}}
\newunicodechar{′}{%
  \iffontchar\font`′′\else\safeprime\fi
}

\begin{document}

Arnol′d

\end{document}

The usage of \newunicodechar is a safety measure in case the font doesn't have the glyph corresponding to U+2032 PRIME.

what is the apostrophe symbol?

1 Answers1