# 0: file ended while scanning use of \@genfrac [closed]

The code is here

\documentclass{article}
\usepackage{amsmath}

\begin{document}
$$\begin{array}{ll} \hat{\mu_1}&=\dfrac{\sum_{i=1}^nX_{i,1}}{n}\\ \hat{\mu_2}&=\dfrac{\sum_{i=m+1}^nX_{i,2}}{n-m}\\ \hat{\sigma_1^2}&=\dfrac{\sum_{i=1}^n(X_{i,1}-\hat{\mu_1})^2}{n}\\ \hat{\sigma_2^2}&=\dfrac{\sum_{i=m+1}^n(X_{i,2}-\hat{\mu_2})^2}{n-m}\\ \hat{p}&=\dfrac{\sum_{i=m+1}^n(X_{i,1}-\hat{\mu_1})(X_{i,2}-\hat{\mu_2})}{n-m} \end{array}$$

\end{document}


I try to reproduce the problem,and check whether missing bracket.But the error is still there.

• Please complete your code to a minimal document (in the sense of a minimal working example) allowing us to reproduce the problem. – Gonzalo Medina Oct 12 '12 at 3:59
• Your code works OK in my system. Does this exact code triggers the error mentioned? – Gonzalo Medina Oct 12 '12 at 4:48
• @GonzaloMedina I second that. – azetina Oct 12 '12 at 4:51
• Please add the .log file obtained after processing the code you just posted. If the file is too long, you can upload it elsewhere (pastebin, for example) and provide a link here. – Gonzalo Medina Oct 12 '12 at 4:54
• @baker perhaps there was a corrupted .aux file from a previous run causing the problem. – Gonzalo Medina Oct 12 '12 at 5:38

The error message you mention is triggered by a missing closing brace in \dfrac (or one of its variants), as the following simple example illustrates:

\documentclass{article}
\usepackage{amsmath}

\begin{document}

$\dfrac{a}{b$
\end{document}


Processing the above document yields

Runaway argument?
{b$\end {document} ! File ended while scanning use of \@genfrac. <inserted text> \par <*> a.tex  The solution is to add the missing brace: \documentclass{article} \usepackage{amsmath} \begin{document}$\dfrac{a}{b}\$
\end{document}

• the error detector says it is in the line 0. And I put all content to comment, the error is still there – baker Oct 12 '12 at 4:24
• @baker Then, please (as I suggested in my comment to your question) add a complete document allowing us to reproduce the problem; if you say that commenting out all the contents still triggers the error, such a complete document can be easily built. – Gonzalo Medina Oct 12 '12 at 4:26
• I tried to reproduce the problem ,and check the bracket already, but it seems that error does not be solved. Code is showed above. Thanks for your help. – baker Oct 12 '12 at 4:51