1. The Economic Framework -- 2. Introduction to the Mathematics -- 3. Differentiable Manifolds and Mappings, Tangents, Vectorfields -- 4. Regular Equilibria. A First Approach -- 5. Scarf’s Example -- 6. Excess Demand Functions -- 7. Debreu’s Theorem on the Finiteness of the Number of Equilibria of an Economy -- 8. Continuity of the Walras Correspondence for C° Demand Functions -- 9. Density of Transversal Intersection -- 10. Regular Economies -- 11. Stability Questions and the Number of Equilibria -- 12. Large Economies -- Some Standard Notation -- References.