> Fabrice Couvreur <mailto:fabrice1.couvreur@gmail.com>
> 13. Juli 2016 um 01:02
> Hello,
> I would like the text of the property is in italic without using the 
> environment {\it}.
Use the enumeration environment.
> Is this the best way when I use\setuptextrules[width=-1ex] ?
You can set the width and distance values to 0pt and put a space after 
the counter.

%%%% begin example
\setupbodyfont[pagella,11pt]

\define[1]\ProprieteHeadcommand
   {\textrule[top]{#1}}

\defineenumeration
   [propriete]
   [text=Propriété ,
    style=italic,
    headcommand=\ProprieteHeadcommand,
    numbercommand=\groupedcommand{}{\nbsp},
    after=\textrule]

\setuptextrules[width=0pt,distance=0pt]

\starttext

\startpropriete
     Soit \math{q} un réel \math{\neq 1}, alors pour tout entier naturel 
\math{n\geqslant 1} on a :
     \startformula
     S=1+q+q^2+\dots+q^n=\frac{1-q^{n+1}}{1-q}.
     \stopformula
\stoppropriete

\stoptext
%%%% end example

Wolfgang