The Haskell 98 Library Report says: Function toUpper converts a letter to the corresponding upper-case letter, leaving any other character unchanged. However, there are two lower case letters that doesn't have the corresponding upper case letter in hugs (since it's only iso-8859-1 yet). In hugs: toUpper 'ÿ' = 'ß' toUpper 'ß' = '¿' but they should be unchanged (they have no corresponding upper-case letter). Regards, Martin -- Martin Norbäck Safelogic AB martin.norback@safelogic.se Stena Center 1C +46 (0)31 772 81 70 S-412 92 GÖTEBORG http://www.safelogic.se SWEDEN