Hi all, I have two questions about math formula. 1) I'd like to use \startalign to typeset mathematical formulas since it is more convenient than \eqalign. But the formula number cannot be located between two lines just as \eqalign can. I hope following example can make me clear. \starttext \placeformula \startformula \eqalign{ a + b & = c + d\cr & = e + f\cr} \stopformula \placeformula \startformula \startalign \NC a + b \NC = c + d \NR[+] \NC \NC = e + f \NR \stopalign \stopformula \stoptext The number of equations in second formula can only be put on the first line or second line but not between them. My question is how to make the location of formula number in \startalign the same as it is in \eqalign ? 2) It seems that \left and \right cannot be used on separate groups. Here is a simple example: \starttext \placeformula \startformula \eqalign{ a & = \left(\frac{b+c}{d+e}\cr &\phantom{=~} + \frac{g}{h}\cr} \stopformula \stoptext If I change \left and \right to \big, it compiles successfully. But I think \left and \right are more convenient. Are there some solutions to use \left and \right in this situation ? Regards, Xiao Jianfeng