Triple Integral - Simple one

Hey there, I'll be delighted to get some help in the following question:

Let A be the region in space bouded by the next planes:

, , ,

, , ...

Write the integral as shown in the next theorem:

Let E be a closed region with a surface in R^2 and let [tex] g^1, g^2[tex] be two real functions, continous in E. Let's look at A:

. Then if f is a continous function with 3 variables, continous in A, then:

...

The problem is I can't figure out how the region A looks like...

Hope you'll be able to help me dealing with this question...

Thanks in advance