Command \frac works in strange way:

Any suggestions?
\documentclass{report}
\usepackage{polski}
\usepackage[cp1250]{inputenc}
\usepackage{graphicx}
\begin{document}
\setcounter{secnumdepth}{3}
\setlength{\textheight}{24.4cm}
\setlength{\parindent}{0mm}
\frac{1}{2}
\end{document}
\fracis a math mode command so you are seeing 'error recovery':$\frac{1}{2}$is correct for input and gives the right result. – Joseph Wright Jun 29 '14 at 13:09\fracis only valid in math mode (e.g. within$...$). You shouldn't expect the output document to look right if you get compilation errors. – jub0bs Jun 29 '14 at 13:10