WebDec 8, 2014 · Let $R$ be a PID and $M$ a module. Show the following: (i) If $M$ is finitely generated and $S$ is a free submodule with $M/S$ torsion-free, then $M$ is free. (ii) If ... Web11. Finitely-generated modules 11.1 Free modules 11.2 Finitely-generated modules over domains 11.3 PIDs are UFDs 11.4 Structure theorem, again 11.5 Recovering the …
11. Finitely-generated modules - University of Minnesota
WebMar 14, 2007 · Q as a module over Z. I'm self-teaching maths to preper myself for the next term of uni, so I'm reading this book on abstract algebra, and somewhere it says that R (the set of real numbers) is not finitely generated as a module over Q (set of rational numbers). Now, I can see that it's not, but i can't think of a rigorous proof for it. Web10.5 Finite modules and finitely presented modules. 10.5. Finite modules and finitely presented modules. Just some basic notation and lemmas. Definition 10.5.1. Let R be a ring. Let M be an R -module. We say M is a finite R-module, or a finitely generated R-module if there exist n \in \mathbf {N} and x_1, \ldots , x_ n \in M such that every ... low profile peg
modules - Flatness and local freeness - MathOverflow
Web10.78 Finite projective modules. 10.78. Finite projective modules. Definition 10.78.1. Let R be a ring and M an R -module. We say that M is locally free if we can cover \mathop {\mathrm {Spec}} (R) by standard opens D (f_ i), i \in I such that M_ {f_ i} is a free R_ {f_ i} -module for all i \in I. We say that M is finite locally free if we can ... WebJan 1, 2015 · The module Q\oplus P' is finitely generated projective, therefore is a direct summand in a module L\simeq \mathbf {A}^ {\!n}. Then, by the second case, P\oplus P' is a direct summand in L. We deduce that P is the image of a projection Finally, the restriction of \pi to Q is a projection whose image is P. 6. WebUPDATE: Exercise 24.4.F in Ravi Vakil's notes gives a finitely generated, not finitely presented module which is flat but not projective. By BCnrd's comment on Akhil's answer it is, however, stalk-wise free. low profile pem nuts