Apparently, this user prefers to keep an air of mystery about them.
11 A subset of a compact set is compact? oct 13 '12
7 A question about showing $f(x)=0$ sep 10 '12
6 If $B\subset A$ and the exist a injection $A\rightarrow B$, then $A$ and $B$ has same cardinality? mar 17 '12
6 Is $\partial (A \cup B)=\partial A\cup\partial B$? oct 22 '12