The prelude contains instance Bounded Char where minBound = '\0' maxBound = '\xffff' I didn't follow all the discussion about unicode, but the maxBound seems to be wrong. It probably should be '\x10ffff'. The exact specification could also be avoided by defining maxBound = primUnicodeMaxBound where primUnicodeMaxBound is imported from UnicodePrims. -- OLAF CHITIL, Dept. of Computer Science, University of York, York YO10 5DD, UK. URL: http://www.cs.york.ac.uk/~olaf/ Tel: +44 1904 434756; Fax: +44 1904 432767