Watch me and Henry explore the Multiverse Library here. This video explains the maths used to create the Multiverse Library, namely branch cuts and multifunctions. Featuring Oxford Mathematician Dr Tom Crawford and Dr Henry Segerman of Oklahoma State University. The main maths content of the video focuses on defining a holomorphic branch of the complex logarithm, which is exemplified by looking at the complex square root function. Multifunctions are usually covered in a Complex Analysis course at university.