Hi, Nowadays I am using Hugs 98 interpreter (2001 version) to finish my final work to get my Computer Master Degree at Instituto Tecnológico de Costa Rica. Next, I have transcribed part of the code from Hugs's Help in Multiple Parameter Classes and Dependencies Section --- module KK where class E a b | a -> b, b -> a where go :: a -> b -- line 5, personal addition back :: b -> Maybe a -- personal addition --- With the previous declaration Hugs gives me the following message: ERROR KK.hs:5 - Haskell 98 does not support dependent parameters. And I tried too: --- module KK where class C a b where -- line 3 ok :: a -> b ko :: b -> Maybe a --- and Hugs gives me the message: ERROR KK.hs:3 - Haskell 98 does not support multiple parameter classes Comment: Hugs 98 User Manual of September 1999, says that the facility of Multiple parameter type classes already is available in Hugs 98. Then, how can I use this? I installed the following files again again (from Web site) * Win32.zip * Win32exes.zip * Hugs98-Feb2001.zip -- Hugs for Windows 32 * Hugs.hlp Thank you for paying attention to this, Javier. ********************************************************************* Po.Box TELEFONOS (PANAMA) Javier Torres Salgado Panama: (507)770-5042 Estafeta Universitaria Costa Rica: (506)551-4336* Universidad Autonoma de Chiriqui (506)551-6503 Chiriqui, Panama (COSTA RICA) E-MAIL Javier Torres Salgado Apdo 13307050 jatosa@mail.chiriqui.com Cartago, Costa Rica jtorres@ganimedes.cic.itcr.ac.cr *********************************************************************