a <- <3,5,4,6,2,9,12,4,6>;
b <- <2,3,4,4,5,6,6,9,12>;
c <- {2,3,4,4,5,6,6,9,12};
d <- <2,3,4,5,6,9,12>;

inverso(a,b)=if(a > b  -> -1, 
                else   -> 1);

_ok("sort", sort(reverse(a)),b);
_ok("sort2 lambda...", sort2(lambda(x,y). y .- x , a),reverse(b));
_ok("sort2 inv", sort2(inverso,a),reverse(b));
_ok("sort set", sort(c),d);

quit.