Functions: Definitions and Notations

This lecture covers the generalities of functions, including the definition of an application between sets, the concept of image by a function, and the uniqueness of elements in the image set. It also explains the notion of an application of one set into another, the starting set, and the corresponding arrival set. The lecture delves into the definition of functions, the matching of elements between sets, and the application of functions. It concludes with examples and remarks on the properties of functions.