Proving a specific module is projective.
93176
Projectivity of a module
114640
Showing that an ideal is not a free $R-$module.
81112
Proving that the dual of the $\mathcal{l}_p$ norm is the $\mathcal{l}_q$ norm.
144122
A problem about an $R$-module that is both injective and projective.
141477
Decomposition of finitely generated graded modules over PID
148111
Every $R$-module is projective if and only if every $R$-module is injective
28518
Hom of finitely generated modules over a noetherian ring
14259
If M+N and M$\cap$N are finitely generated modules, so are M and N.
157236
Tensor product of modules.
101860
Relating the normal bundle and trivial bundles of $S^n$ to the tautological and trivial line bundles of $\mathbb{R}P^n$
51465
New, elegant proofs for $\varphi(p^{k})=p^{k}-p^{k-1}$
42552
Localisation is isomorphic to a quotient of polynomial ring
102879
$\operatorname{Ext}$ and injectives, respectively projectives
41294
Permutation module of $S_n$
65333
Weighted projective space and projective space are isomorphic
65873
A proof for Atiyah-Macdonald Exercise I.21.iii
29231
Proof of : $x^{n}\equiv x^{\varphi(m)+[n \bmod \varphi(m)]} \mod m$