Preface Volume 41, Issue 3

AbstractThis volume contains the proceedings of the Fourth International Workshop on Higher Order Operational Techniques in Semantics (HOOTS 2000). The workshop was held on 22 September 2000 in Montréal, Canada, as part of the ACM Colloquium on Principles, Logics, and Implementations of high-level programming languages (PLI 2000).These proceedings are available as Issue 3 of Volume 41 of Elsevier's Electronic Notes in Computer Science:http://www.elsevier.nl/locate/entcs/Thanks are due to a number of people, especially the programme committee: Andrew Gordon, Microsoft ResearchRobert Harper, Carnegie Mellon UniversityAlan Jeffrey, DePaul University (Chair)Andrew Pitts, Cambridge UniversityJulian Rathke, Sussex UniversityDavid Sands, Chalmers UniversityDavide Sangiorgi, INRIA Sophia AntipolisCarolyn Talcott, Stanford UniversityWe would also like to thank the anonymous referees who helped to review the papers for this meeting.There were two invited talks for this workshop: A Second Glance at Feferman-Landin Logic by Ian Mason, University of New England, Australia (joint work with Carolyn L. Talcott, Stanford University).Weak Bisimulations by Decreasing Diagrams by Cédric Fournet, Microsoft Research (joint work with Georges Gonthier, INRIA Rocquencourt).The PLI 2000 workshops were organized by Amy Felty, University of Ottawa, and Franck van Breugel, York University.The ENTCS series is edited by Michael Mislove, Tulane University.On behalf of the participants, we would like to thank Microsoft Research for their generous sponsorship of this workshop