Hi Vyatcheslav,

In fact you should say \NR[+] at the end of each line in \startalign in order to get numbers.
This works for me:
\starttext

\placeformula 
\startformula 
\startalign
\NC \dot{x}(t) \NC=f(x(t), u(t)) \NR[+]
\NC y(t) \NC=h(x(t), u(t)), \NR[+]
\stopalign
\stopformula

\stoptext
Best regards: OK

On 31 janv. 2011, at 11:38, Vyatcheslav Yatskovsky wrote:

\starttext

% has number
\placeformula \startformula
f(x_0, u_0)=0.
\stopformula

% has no number
\placeformula \startformula \startalign
\NC \dot{x}(t) \NC=f(x(t), u(t)) \NR
\NC y(t) \NC=h(x(t), u(t)), \NR
\stopalign \stopformula


% no numbers even here
\startsubformulas
\placeformula \startformula
\dot{x}(t)=f(x(t), u(t))
\stopformula
\placeformula \startformula
y(t) =h(x(t), u(t)),
\stopformula
\stopsubformulas

\stoptext

Regards,
Vyatcheslav

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Otared Kavian
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