Notation for Lp spaces

Question

I do not have a lot of experience in analysis, but I do know the definition of the space $L^p(X)$ to be the complex valued measurable functions with \begin{equation} \int|f|^pd\mu < \infty \end{equation} I was reading a couple of articles, and was wondering about what $L^p(\Omega; \mathbb{R})$ means with the semicolon in the article https://en.wikipedia.org/wiki/Nemytskii_operator (under "Boundedness Theorem").

Answer 1

It's the subset of $L^p(\Omega)$ containing maps whose range is strictly real (i.e., imaginary part 0).