求大佬指点； lingo 一直报错： Index variables may not share names with other variables

已经困扰了几个晚上了，一直找不出来哪里错了 我的代码： model: sets: S/1..56/:p ; T/1,2,3/; U(S,T):x; endsets data: p=41,45,44,44,26, 44,42,20,20,38, 37,25,45,45,45, 44,20,30,39,35, 38,38,38,25,30, 36,20,24,32,33, 41,33,51,39,20, 20,44,37,38,39, 42,40,37,50,50, 42,43,41,42,45, 42,19,39,75,17,17; enddata min = 680 - @sum(S(i):p(i)*x(i,j)); @for(S(i):@sum(T(j):x(i,j))=1); @for(T(j):@sum(S(i):x(i,j)*p(i))<=680); @for(U(i,j):@bin(x(i,j)));