--returns the rightmost component of a list
last= \ xs -> --
    if xs == [] then [] --
    else if tail xs == [] then head xs --
    else last (tail xs) --
--
--checks if a list is sorted
issorted = \ xs -> --
    xs /= [] && --
    ( --
        tail xs == [] || --
        ( --
            head xs <= head(tail xs) && --
            issorted(tail xs) --
        ) --
    ) --
--
--a list of the values lo to hi
range = \ lo -> \ hi -> --
    if hi < lo then [] --
    else lo:(range (lo+1) hi) --
--
--a list of n copies of x
copies = \ n -> \ x -> --
    if n <= 0 then [] --
    else x : (copies (n-1) x)--