param Vsize := 3;
set V "Vertices" := (0..Vsize-1);
set E "Edges" within V cross V := {(0, 1), (1, 2), (2, 0)};

var v{i in V} >= 0;
minimize rank_total: sum{i in V} v[i];
edge{(i, j) in E}: v[j] - v[i] >= 1;

solve;

printf "#OUTPUT:n";
printf (if ((exists{i in V} v[i] >= 1) or card(E) = 0) then "" else "Infeasible, has cycles or loops.n");
printf{i in V} (if ((exists{j in V} v[j] >= 1) or card(E) = 0) then "v_%d: %dn" else ""), i, v[i];
printf "#OUTPUT ENDn";

end;