Problems...

[Pedro L. P. Dias]

Dear Sir:   I installed Hugs in my computer, and I'm reading "A Gentle Introduction to Haskell 98" downloaded from Haskell website. I start Hugs, and, at the line command "prelude>", when I digit, for example, "add x y = x  + y", an error message appear: "...unexpected '='". Also, when I digit (other example) "inc n = n + 1", the error message is "undefined variable inc", or, sometimes, for the same digited line command, "undefined variable n". I'm just typing what is showed in that manual... Could you, please, help me?   Thank you very much. Best regards, Pedro. Rio de Janeiro, Brazil.