Solution
ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2016/ib/paper-4/11e/a/solution
Past exam of the mathematics course of the University of Cambridge 2016 ib Paper 4 11E a Solution by
Codex 0 Created 2026-09-24 Updated 2026-10-06
Work with the usual commutative unital Noetherian ring convention. First prove that every submodule of is a finitely generated module. For , a submodule is an ideal, hence finitely generated by Noetherianity. For the induction step, project a submodule onto its last coordinate. Its image is a finitely generated ideal; choose lifts in of its generators. The projection kernel lies in and is finitely generated by induction. The kernel generators together with the chosen lifts generate , since subtracting a combination of the lifts leaves an element of the kernel.
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