On several papers, I found the following model for a multiple integral equation:
$$g(s)=\int\limits_{\Omega} h(s,t)f(t)\,\mathrm{d}t$$
where $s,t \in \mathbb{R}^3$, and $\Omega \subseteq \mathbb{R}^3$.
I would like to know wether it is possible to express the above equation as:
$$g(x,y,z)=\iiint\limits_{\Omega} h\left(x,y,z,u,v,w\right) f\left(u,v,w\right) \, \mathrm{d}u\, \mathrm{d}v\, \mathrm{d}w$$
or are two different problems.
The question if these are two different problems or not, will depend upon whether and how $s$ and $t$ might be dependent on $\Bbb R^3$. There is no dependency between your expressions yet if you dont clearly express a dependency between $s$ and $t$.