Lecture
This lecture delves into the definition of a surface and focuses on the study of the torus through various examples and constructions. It covers the concept of surfaces being space-separated and the notion of bridges admitting different surfaces. The lecture also explores the construction of the torus as the quotient of a core, along with the morphic images and compositions involved. Additionally, it discusses the relation of sw to ix and the formation of two pieces. The lecture concludes with an examination of the perfect horizontal image as a lace and the significance of needles in the context of surfaces.