I have an operation that I call \conv, that I defined as follows:
\newcommand\conv{{}^{\scriptstyle\smile}}
Sometimes I use it in this situation:
$a\conv$
and sometimes I use it in this situation:
$$\big(\prod a\big)\conv$$
In both cases, the superscript \conv is at the same level. However, in the second case, the \sum is so big, that the \conv seems to hit it at mid-level. I want it to somehow adjust to the larger size of the \sum so that it is up at the top of the \big), not so far down.
Please let me know how I can clarify my question.

