an element of a tensor product of modules not equal to any generator.
128838
Showing a tensor is not a simple tensor
23735
Divisible module which is not injective
103665
Product of matrices of different order is not invertible
79056
Prove that $\mathbb Z^n$ is not isomorphic to $\mathbb Z^m$ for $m\neq n$
122121
Is there a vector space that cannot be an inner product space?
119545
Nonzero rationals under multiplication are not a cyclic group
90826
Constructing a subset not in $\mathcal{B}(\mathbb{R})$ explicitly
62123
Proving that Tensor Product is Associative
31729
Tensor products of simple modules over algebras
153852
Example of modules that are projective but not free; torsion-free but not free
34798
Example of element of double dual that is not an evaluation map
89990
Direct limit of arbitrary family of tensor products of A-algebras
158232
Tensor product of a module with an ideal is isomorphic to their standard product
86724
Example of a non-zero module that has no associated primes
6646
A (non-artificial) example of a ring without maximal ideals
149973
Showing the following coordinate rings are not isomorphic
75970
$\mathbb Z[1/2]$ is not finitely generated?