Did Fubini's Theorem Fail?

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SUMMARY

Fubini's Theorem did not fail in the discussed case because the necessary conditions for its application were not met. Specifically, the function f:[0,1]^2→[-∞,+∞] must either be non-negative for all x, y in [0,1] or the integral of the absolute value of f over the square [0,1]^2 must be finite. In this instance, neither of these conditions was satisfied, confirming that Fubini's Theorem is applicable only under strict criteria.

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Did Fubini's Theorem fail here?
 
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Fubini's theorem didn't fail here, because the conditions are not satisfied.

Roughly, Fubini's theorem (in our case) states that if [tex]f:[0,1]^2\rightarrow [-\infty,+\infty][/tex] is a continuous function, such that one of following conditions holds:
1) [tex]f(x,y)\geq 0[/tex] forall x,y in [0,1]
2) [tex]\iint_{[0,1]^2}{|f(x,y)|dxdy}<+\infty[/tex]
then
[tex]\iint_{[0,1]^2}{f(x,y)dxdy}=\int_0^1{\int_0^1{f(x,y)dy}dx}=\int_0^1{\int_0^1{f(x,y)dx}dy}[/tex]

The problem is that neither (1) nor (2) are satisfied in this case.
 
Thank you!
 

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