Particularly, for multi-type bounded elementary regions, we can change the order of integration in any order, (informally) by making sense using a "box" in which we can partition.
How does this apply to the indefinite multiple integration, for example proving some theorem's on Laplace Transforms apply (not specifically)
$$\int_{}\int_{}{}{\frac{g(x,y)}{f(y)}}dydx = \int_{}{}{\frac{1}{f(y)}}\int_{}{}{{g(x,y)}}dxdy$$
How to make sense of this like the case for the said definite integration ?