On July 19, 2001 I gave an invited talk at CMAF at the University of Lisbon, Portugal.

The title of my talk was ** Muchnik and Medvedev Degrees of Pi01
Subsets of 2^omega**. My abstract is available in several
formats: DVI, PDF, PS, HTML.
My slides are available in several
formats: PDF, PS.

A list of my recent and upcoming talks is available.

My publication list is available.

I run FOM, an automated e-mail list for discussing foundations of mathematics.

t20@psu.edu / 29 January 2002