Until now I was using XePersian package to typeset Persian articles, now I want insert some Persian word in an English document, what is minimum code to do that without using XePersian package?
\documentclass{article}
\usepackage{fontspec}
\setmainfont{Tahoma}
\begin{document}
book
کتاب
% rendered as ک ت ا ب but should be rendered کتاب
\end{document}