LyX ⇒ Macro with LyX : pb of size symbol ...

[loursbrun]

Hello,
I'm doing macro with LyX, but I still have a problem.
I want to include Big ( or bigger, Huge ... ) size of matgh symbol in my macro, mixed with normal size parameters. How to proceed ?
When I do manually the formula, it works perfectly, but doing with a macro, it seems to be impossible.
Any ideas ?
In advance thank you.

For example, just combine with stackrel \forall ( big ) and a letter centered on top (but with a normal size.

[loursbrun]

Ok pb solved !

I missed a command, sorry.