list1 = [1,2,3,4,5]

list2 :: [Int]
list2 = [1,2]

list3 = 0:list2

list4 = [1..10]
list5 = [0,5..100]

listLength []    = 0
listLength (h:t) = 1 + listLength t

element _ [] = False
element e (h:t) | h == e    = True
                | otherwise = element e t

append [] l    = l
append (h:t) l = h:append t l

setUnion [] l = l
setUnion (h:t) l | elem h l  = setUnion t l
                 | otherwise = h:setUnion t l

setIntersect [] l = []
setIntersect (h:t) l | elem h l  = h:setIntersect t l
                     | otherwise = setIntersect t l

flatten []          = []
flatten ([]:t)      = flatten t
flatten ((h:t1):t2) = h:flatten (t1:t2)

doubleElems []    = []
doubleElems (h:t) = (2*h):doubleElems t

listSumm []    = 0
listSumm (h:t) = h + listSumm t

listMaximum [a] = a
listMaximum (h:t) = max h (listMaximum t)

myMap f [] = []
myMap f (h:t) = f h:myMap f t

doubleElems1 = myMap (2*)

myFoldr f s [] = s
myFoldr f s (h:t) = f (myFoldr f s t) h

listSumm1 = myFoldr (+) 0

mapC f l = [ f x | x <- l ]
filterC f l = [ x | x <- l, f l ]
decProductC a b = [ (x,y) | x <- a, y <- b ]