/* check if curr is a stable set */
for (i=bitset_next_set(curr, 0); i!=-1; i=bitset_next_set(curr, i+1))
for (o=bitset_next_set(curr, i); o!=-1; o=bitset_next_set(curr, o+1)) /* !!!!! difference to ou_max_ind_set_costs(): NOT (curr, i+1) */
/* check if curr is a stable set */
for (i=bitset_next_set(curr, 0); i!=-1; i=bitset_next_set(curr, i+1))
for (o=bitset_next_set(curr, i); o!=-1; o=bitset_next_set(curr, o+1)) /* !!!!! difference to ou_max_ind_set_costs(): NOT (curr, i+1) */