> Like with \left?
> 
>   $\left(\left( ... \right)\right)$
> 
> Best wishes,
> Taco

maybe im doing something wrong here. i have this expression

\startformula
\sum\limits_{i = 1}^n {\left( {\left( {\left( {\alpha { \odot 
_{C}}{{\tilde k}_i}\left( y \right)} \right){ \oplus _{C}}\left( {\beta 
{ \odot _{C}}{{\tilde k}_i}\left( z \right)} \right)} \right){ \odot 
_Y}{u_i}} \right)}
\stopformula

and the first 3 parentheses have the same size. i would like the outer 
to be bigger than the inner, like in the attached image (i hope 
attachments work).


tobias