SCENE 1: Ellie's Arrival in Setrópolis Narration: "Ellie

SCENE 1: Ellie's Arrival in Setrópolis Narration: "Ellie, an intrepid explorer, arrives at the amazing city of Setropolis, where all citizens are groups. Your mission: understand how this unique city holds together." content: Ellie watches the city from a hill, impressed by the organization and structure of the different districts. Here, The definition of a set is introduced by explaining that each inhabitant of the city is a set composed of elements.