中央研究院 数學研咒所 Weight of a lattice path Let w be a function from Zo XZto r, wherer is the set of real numbers For any lattice path P=(x,yu(2, 22).(xkdk define the weight of P, denoted by w(P),as k w(P)=wx,yi) 第9页第9页 Weight of a lattice path • Let w be a function from Z≥0×Z to R, where R is the set of real numbers. • For any lattice path P=(x1 ,y1 )(x2 ,y2 )…(xk ,yk ) define the weight of P, denoted by w(P), as = = k i i i w P w x y 1 ( ) ( , )