X_IN = \textrm{(sum of all edges with X on one end and a node inside the circle on the other end)} X_OUT = \textrm{(sum of all edges with X on one end and a node outside the circle on the other end)} C(v_4,v_5,v_9) = C(v_1,v_2,v_3,v_6,v_7,v_8) = C(v_1,v_2,v_3) + C(v_6,v_7,v_8) - 2*c(v_1 v_2 v_3, v_6 v_7 v_8) \leq C(v_1,v_2,v_3) + C(v_6,v_7,v_8) \leq C(v_1,v_2,v_6) + C(v_6,v_7,v_8)