[NTG-context] large right brace grouping lines of equations

Dear all, First, thanks Wolfgang and Hans for suggestions about the chapter head. Using \cases, I can use large left brace for lines of equations. But, how to put a large right brace after lines of equations which groups them. Is it possible in the \startformula\startalign ... \stopalign\stopformula? Thanks Best regards, Dalyoung