Hello,

I made a simple datatype called Pair and I'd like to make it an instance of 
Show class. But when I try to do that I run into troubles:


data Pair a b = Pair a b
instance Show a b => Show (Pair a b) where show (Pair a b) = show a ++ "_" ++ 
show b


In Hugs I get this error: "Haskell does not support multiple parameter classes" 
When I run it in ghci I get a kind error "Show is applied to too many type 
arguments in the instance declaration for Show (Pair a b)"

Am I jsut using wrong syntax or is it not possible to do?

Thanks in advance

Zdenes
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