v1.9.0

• The definion of modules, algebras, strict domains, polynomials, and various structures on them
• A synthetic definition of a derivative and its basic properties
• The definition of real numbers and the construction of the structure of an ordered field on them (except for multiplication).
• A tactic for solving systems of linear equations
• The definition of schemes, affine schemes, and a prove that affine schemes are schemes.
• A partial prove of the univalence for the precategory of ringed locales.