Apparently, this user prefers to keep an air of mystery about them.
2 How do we determine if the set of rational numbers and the set of all english sentences are countable or not? Aug 28 '12
1 How to apply pigeonhole principle to this problem? Oct 10 '12
0 Proof that if a set $S$ has a proper subset which is infinite, then $S$ must be infinite. Aug 30 '12