type Poly = [Float]

 

addPoly::Poly->Poly->Poly
addPoly x y = zipWith (+) x y

 

instance (Float a) => Num (Poly a) where
                   x + y = addPoly x y

 

 

I got the "Cannot use type synonym in instance head" error message when I was trying to compile the above code. Can you tell me why and how to solve it?

 

Cheers

 

Benny