My undergraduate thesis [report] done with the absolutely fantastic Manindra Agrawal as my undergrad advisor. A couple of things about this : First of all, the stuff written in this report is like one half-known and one-half meaningless (coming to think of it, it is one-quarter known, one-quarter stupid and one-half meaningless). Secondly, Manindra should not be blamed for this. It was my and my stupid ideas alone which went into this report. Had I actually ever paid a teensy bit attention to what he was saying, then this thesis would have had a few meaningful lines. But probably most importantly, the problems Manindra suggested taught me two things : a) that extractor constructions are really hard ; I have been reminded of that time and time again b) There is nothing quite as satisfying as constucting an extractor :-)