On Mon, 28 Jan 2013, Roland Thiers wrote:

>
> Le 28 janv. 13 à 10:11, Janne Junnila a écrit :
>
>> Indeed it seems like the alignment is good with \dfrac, but this does
>> not solve my problem, since I wish to also use fractions with
>> script-size or scriptscript-size (\xfrac, \xxfrac). The specific
>> formula I have is
>> 
>> \startformula
>> f_{B_t | B_s = S, B_u = U}(x) = \frac{e^{-\frac{(u-s)x^2 - 2x(S(u-t) +
>> U(t-s)) + \frac{(S(u-t) +
>> U(t-s))^2}{(u-s)}}{2(t-s)(u-t)}}}{\sqrt{2\pi\frac{(t-s)(u-t)}{u-s}}}
>> \stopformula
>> 
>> Thanks,
>> Janne
> OK !
> So you need an expert, I'm just a newbie :)
> I would be  interested to know how to do that.
> Best, Roland

I'll look into fractions later this week. All the fraction macros of 
ConTeXt were based on \genfrac macro from AMSTeX so, in principle, they 
should behave in the same manner.

Aditya