[texhax] differentiation variables

[Steven Lau]

Dear texhax,

I am setting out equations in

$$ $$ or in \begin{equation} \end{equation} and sometimes
inline with $ $
I want to show

Max U(c)

in the normal sized maths font and have the variables I am 
differentiating/maximizing with such as
m(h), n(h)
centered directly underneath Max U(c) in a smaller font.
I am trying to achieve the look given by the sum operator
with the summation items below.
I have tried using the array environment, stacking, atop
but these do not quite get the right effect.
I am using the amsmath package.

Any suggestions would be a great help. Thanks in advance.

Steven Lau