Top Network Posts

• 60 $A$ is isomorphic to $A \oplus \mathbb{Z}^2$, but not to $A \oplus \mathbb{Z}$
• 41 Is it consistent with ZF that $V \to V^{\ast \ast}$ is always an isomorphism?
• 40 Example of an unnatural isomorphism
• 38 Are there any nontrivial abelian categories with only finitely many objects?
• 35 Does the symmetric group on an infinite set have a minimal generating set?
• 33 Word evaluating to a group element and its inverse with different frequency
• 27 Are there only finitely many associative algebras of fixed dimension?
• View more network posts →