Suppose that vertex b is labeled, If fcb>0 then c is abeled(b,△c), where△c min(Ab, fcb If t is labeled, then an increasing flow is constructed ◆ We change fi to后+ At when(1j)∈E,if Gi,jEEthen we change fi to fi-At b(c-,2) 8,8 7,0 6 s(-,+0 9, c(s+,3) 身t(b+,2) 4,2 5,5 5,5◆Suppose that vertex b is labeled, If fcb>0， then c is labeled (b- ,Δc), where Δc = min{Δb,fcb} ◆If t is labeled, then an increasing flow is constructed. ◆We change fij to fij +Δt when (i,j)E, if (i,j)E then we change fji to fji -Δt