I would like to use the unicode character ∞ in a LaTeX document. I use the default font. If this character is not defined in this font, I can replace it by $\infty$.
How can I do that?
I tried to play with \DeclareUnicodeCharacter{}{$\infty$} but did not find what to put in the first argument.
xetexnotluatex. – Colas Jan 15 '16 at 15:57