[rectang]

Math entries in Wikipedia generally favor completeness and correctness over clarity, which makes them of limited use for many users.

In order to explain something simply, you usually have to lie a little bit — but I speculate that those little lies bother the contributors to mathematical Wikipedia articles a great deal. So they correct those little lies, making the articles more accurate but less useful for many of us.

[pmiller2]

In this instance, though, you don't really have to lie, but a lot of the hard work is fobbed off to Fubini's theorem.