Alexandra Silva Institution: Centre for Mathematics and Computer Science (CWI) E-mail: a.m.silva@cwi.nl
Marcello Bonsangue Institution: Leiden Institute of Advanced Computer Science (LIACS) Centre for Mathematics and Computer Science (CWI) E-mail: marcello@liacs.nl
Y.F. Li Institution: University of Singapore (now at Monash University) E-mail: yuanfang.li@monash.edu
Gheorghe Stefanescu Institution: University of Bucharest, Faculty of Mathematics and Computer Science E-mail: gheorghe@funinf.cs.unibuc.ro
Chucky Ellison Institution: Formal Systems Laboratory, University at Illinois at Urbana Champaign, US E-mail: celliso2@illinois.edu
