mathlib

808ea4eb - feat(algebraic_geometry/elliptic_curve/weierstrass): define a basis for the coordinate ring (#18101)

feat(algebraic_geometry/elliptic_curve/weierstrass): define a basis for the coordinate ring (#18101) Also refactor `coordinate_ring` definitions and lemmas into the `coordinate_ring` namespace, and compute the degree of the norm of an element of the `coordinate_ring` as an `R[X]`-algebra in terms of this basis.