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module TermPoly where

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-- COMP2600 -- Assignment 1, 2003
-- Skeleton script

-- Represent a polynomial as a list of terms, where a term is
-- represented as a coefficient, exponent pair.  Terms with zero
-- coefficients do not appear.  The terms appear in decreasing
-- order of exponent.

type Coeff = Float
type Expon = Int
type Term  = (Coeff, Expon)
type Poly  = [Term]

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add :: Poly -> Poly -> Poly
add [] [] = []
add x [] = x
add [] y = y
add x y = 
	(fst (unzip x)) + (fst (unzip y))

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sub :: Poly -> Poly -> Poly
sub x y = []
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eval :: Float -> Poly -> Float
eval x [] = 0
eval x p = 
     ((head (fst (unzip p))) * (x ^ head (snd (unzip p)))) + (eval x (tail p))
     
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