题目内容：

LINGO 报错
model:
集;
sets:
i/1 2 3 4/;
eg/ E1 E2 E3 E4 E34 E43/:value;
price/p1 p2 p3 p4/:cost1;
last_year_price/p01 p02 p03 p04/:cost0;
output/s1 s2 s3 s4 /:volume1;
last_year_output/s01 s02 s03 s04 /:volume0;
endsets
数据;
data:
value=0.4 2.7 1.1 0.4 0.1 0.4;
cost0=297 720 1050 815;
volume0=4820 320 210 70;
enddata
目标函数;
max=s1*p1+s2*p2+s3*p3+s4*p4;
产量约束;
s1=s01-(p1-p01)*E1*s01/p01;
s2=s02-(p2-p02)*E1*s02/p02;
s3=s03+(p4-p04)*E34*s03/p04-(p3-p03)*E3*s03/p03;
s4=s04+(p3-p03)*E43*s04/p03-(p4-p04)*E4*s04/p04;
4*s1+80*s2+35*s3+25*s4=0;s3>=0;s4>=0;
p1>=0;p2>=0;p3>=0;p4>=0;
end