I haven't been able to get hold of a copy of NHC (ftp does not seem to work). Can you possibly put a copy (scources, x86) on the web page?

Ok, try http://www.cs.york.ac.uk/fp/nhc98/nhc98src-1.08.tar.gz for the source, and http://www.cs.york.ac.uk/fp/nhc98/nhc98-1.08-ix86-Linux.tar.gz for a ready-built linux executable. Regards, Malcolm