Henry's personal picture gallery
- Five minutes before my PhD ceremony, with Ralph du Long and Joost Schrickx (1993).
- Automatic for the people in Athens, Georgia (1995).
- Thinking about
VIrtual Multicomputers in Granada (1997).
or computation? With Trevor Bench-Capon in Pitlochry, Scotland, 2000.
- Explaining what is odd about even cycles in
- With Gerd Brewka and Abraham Kuijper before Martin Caminada's thesis defence.