[NTG-context] \everymath and ' accent

Hi everyone, This topic has already been discussed on the list, but I didn't clearly understand the conclusion, so I'm asking again... It is not clear to me why the following \everymath{\displaystyle} \starttext \startformula \frac{1}{A'} \stopformula $\frac{1}{A'}$ \stoptext fails with ConTeXt (on the ' inside $.$), while \documentclass{minimal} \everymath{\displaystyle} \begin{document} \[ \frac{1}{A'} \] $\frac{1}{A'}$ \end{document} is ok with LaTeX. The use of \everymath is to blame here, but why? Thanks in advance! Morgan