1. Computer Science; University College London; Gower Street London WC1E 6BT United Kingdom
2. Computing and Information Systems; University of Melbourne; CIS Melbourne Victoria 3204 Australia
3. Department of Philosophy; King's College; Strand, London London WC2R 2LS United Kingdom
4. Computer Science; University of Sheffield; Regent Court, 211 Portobello Sheffield S Yorks S1 4DP United Kingdom