Ross: Do you have any objection to my spreading your spendid message of a few minutes ago on this topic far and wide? Cheers Brian Dept. of Computing Science, University of Newcastle, Newcastle upon Tyne, NE1 7RU, UK EMAIL = Brian.Randell@newcastle.ac.uk PHONE = +44 191 222 7923 FAX = +44 191 222 8232 URL = http://www.cs.ncl.ac.uk/~brian.randell/