\begin{definition}[Definition:Inverse Fourier Transform/Real Function/Formulation 3]
Let $F: \R \to \R$ be a real function which is Lebesgue integrable.
The '''inverse Fourier transform''' of $F$ is defined and denoted as:
:$\ds \map \FF {\map F s} := \map f t = \dfrac 1 {\sqrt {2 \pi} } \int_{-\infty}^\infty e^{i t s} \map F s \rd s$
\end{definition}