Point taken, let me be more clear:
I am using Greek as the text's main language and English as a second one, so I have to type something like this for the hyphenation to work:
Code: Select all
\setmainlanguage{greek}
\setotherlanguage{english}
Since it's a bit difficult the standard font to be Greek, I have also to define the fontspec package:
Code: Select all
\usepackage{fontspec}
\setmainfont[Mapping=tex-text]{DejaVu Sans}
(I've changed my font to DejaVu Sans, a quite common font, I hope. Feel free to change it to any other font that supports Greek)
So, the minimal tex file to reproduce my problem is the following:
Code: Select all
\documentclass{book}
\usepackage{fontspec}
\setmainfont[Mapping=tex-text]{DejaVu Sans}
\usepackage{polyglossia}
\setmainlanguage{greek}
\setotherlanguage{english}
\begin{document}
\tableofcontents
\appendix
\chapter{a}
\end{document}
The error comes again the second time I am running xelatex:
! Undefined control sequence.
<argument> ...@chapter <\@ne \space \gr@ill@value
{\c@chapter }\else \ifnum ...
l.2 ...umberline {\Greeknumber {\c@chapter }}a}{3}
gmedina, your code produces no errors, indeed. This is how I'm using the polyglossia package, though.