semiPareRecEq :: [Int] -> [Int]
semiPareRecEq [] = []
semiPareRecEq (h:t)
 |even h = h `div` 2 : t'
 |otherwise = t'
 where t' = semiPareRecEq t
 
inInterval :: Integer -> Integer -> [Integer] ->[Integer]
inInterval a b [] = []
inInterval a b (h:t)
 |a<=h, h<=b = h:t'
 |otherwise = t'
 where t' = inInterval a  b t
 
semiPareComp :: [Integer] -> [Integer]
semiPareComp l = [ x `div` 2| x <- l, even x]



inIntervalComp :: Integer -> Integer -> [Integer] -> [Integer]
inIntervalComp a b l = [x | x<-l, a<=x , x<=b]

propInt :: Integer -> Integer -> [Integer] -> Bool
propInt a b l= inInterval a b l == inIntervalComp a b l

pozitiveRec :: [Integer] -> Integer
pozitiveRec l
    |null l =0
	|h>0 = s+1
	where 
	h= head l
	t= tail l
	s=pozitiveRec t