[NTG-context] Enumerations in an environment

Hello, How to have : Démonstration --- 1.one 2.two 3.three Thanks Fabrice \defineenumeration [proof] [text=Démonstration, alternative=serried, number=no, headcommand=\groupedcommand{}{~---~}, headstyle=bolditalic, %headcommand=\groupedcommand{}{:\,}, width=broad, closesymbol={\symbol[square]}] \starttext \startproof \startitemize[n] \item one \item two \item three \stopitemize \stopproof \stoptext