Widecheck over two \hat [duplicate]

I need to write a formula with a \widecheck over two \hat. The equation is the following:

\documentclass[a4paper,11pt]{article}
\usepackage{amsmath}
\usepackage{amsfonts,amssymb,mathabx}

\begin{document}
$$\tilde{A}^\mu_\Lambda = \widehat{\widehat{G}\cdot\widehat{j^\mu_\Lambda}}.$$
\end{document}


If I write this code I obtain a lot of errors (undefined control sequence, missing number treated as zero, illegal unit of measure (pt inserted), etc...).

If I use \widehat instead of \widecheck, the result is the same. I have problems also writing

\widecheck{\hat{G} \cdot j}


because the result is not correct (G is translated to the right and overwrites j).

How can I write the \widecheck?

marked as duplicate by egreg, Guido, Werner, Benedikt Bauer, Martin SchröderMay 16 '14 at 21:21

• Welcome to TeX.SX! This is another example of the bug described in Why do arguments to nested tilde or breve commands reappear when amsmath is used?; the solutions shown there seem to apply to your case as well. – egreg May 16 '14 at 19:32