-- Slide 32

-- Reverse list order
myexchanger xs zs = case xs of
	[] -> zs
	y:ys -> myexchanger ys (y:zs)

myreverse xs = myexchanger xs []

-- Delete the first item
mydelete l y = case l of
	[] -> []
	x:xs -> if x == y then xs else x:(mydelete xs y)

-- Find the maximum
mymaximum l = mymaximumof l 0

mymaximumof l x = case l of
	[] -> x
	y:ys -> if y > x then mymaximumof ys y else mymaximumof ys x

-- Sort the list
trimax l = if l == []
	then []
	else let y = mymaximum l in y:(trimax (mydelete l y))