Apparently, this user prefers to keep an air of mystery about them.
17 If $\,A^k=0$ and $AB=BA$, then $\,\det(A+B)=\det B$ Jan 19 '14
14 Krull dimension of quotient by principal ideal May 17 '14
12 Let $G$ be a group of order $360$ and suppose $M$ is a maximal subgroup of $G$ which is isomorphic to $A_5$. Prove that $G$ is isomorphic to $A_6$. Jan 2 '14
10 Existence of prime ideals in rings without identity Dec 13 '13
8 Direct proof of non-flatness Feb 9 '14