007: All-Interval Series

language ESSENCE 1.2.0
$ prob007.essence: All-interval Series
$ Problem details available at http://www.csplib.org/Problems/prob007/
$ 05 September 2007
$

given n : int(1..)

letting Num be domain int(0..n-1),
        Interval be domain int(1..n-1)

find s : function (total, bijective) int(1..n) --> Num,
     v : function (total, bijective) int(1..n-1) --> Interval

such that forAll i : int(1..n-1) . v(i) = |s(i+1) - s(i)|