On Thu, Aug 27 2015, Fabrice Couvreur wrote:

> I did not know it because, before migrating to context, I used latex with
> this :  \newcommand{\repere}{$\bigl(O\,;I,J\bigr)$.

In LaTeX there is no space neither:

--8<---------------cut here---------------start------------->8---
\newcommand{\repere}{$\bigl(O\,;I,J\bigr)$}
\documentclass{article}
\begin{document}
x \repere x
\end{document}
--8<---------------cut here---------------end--------------->8---

--
           Peter

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