Math of QM: Appendix on Lebesgue-Stieltjes Integrals, part 2

Lebesgue-Stieltjes integral for measurable functions; integrable functions and Lp-spaces.
This is part 2 of the Appendix in the lecture series "Mathematical Aspects of Quantum Mechanics" of Roland Speicher in the winter term 2020/21 at Saarland University, Germany. The Appendix, which is split into 6 parts, provides some basic background information about Lebesgue-Stieltjes integration and absolutely continuous functions.