The lecturer lined up all the students in a row, gave each one two numbers and told everyone to calculate the difference to the neighbor's numbers. Given the results, one needs to calculate a triple integral...

This was the problem in my dream. The thing was, I didn't know whether there was a solution or not - maybe there was enough data after all.

So I decided to ask @dannipenguin and already explained half of the conditions, but at that moment the alarm finally rang.