Currently studying the complexity of natural numbers in various simple computational models, and occasionally unusual operations on ordinals. See website for more.
19 Surreal exponentiation — are the varying definitions equivalent? If not, is there agreement on which ones are better? Feb 19 '12
15 Axiomatic definition of integers May 1 '10
14 Examples of common false beliefs in mathematics Feb 6 '11
12 Start with a topological group, take the meet of the two uniformities, and take the topology. Is the result again a topological group? [xpost from math.SE] Oct 19 '12
10 Theorems with unexpected conclusions Dec 9 '10