新人求问错误在哪？

min=t;
t=(a+b)/5+c*(1+@exp(10-0.1*r^2))/5;
a=@sqrt((x^2+y^2)-r^2);
b=@sqrt(((300-x)^2+(300-y)^2)-r^2);
c=r*((pi/2)-(m+n));
a=@sqrt((x-r*@cos(m))^2+(y+r*@sin(m))^2);
b=@sqrt((300-y-r*@cos(n))^2+(300-x+r*@sin(n))^2);
pi=3.1415926;
x1=(x-r*@cos(m));
y1=(y+r*@sin(m));
x2=(x-r*@sin(n));
y2=(y+r*@cos(n));
r>@sqrt((x-80)^2+(y-210)^2)+10;
@sqrt((x1-80)^2+(y1-210)^2)>10;
@sqrt((x2-80)^2+(y2-210)^2)>10;
x1<80;
y2>210;
x<230;
y<210;
x>80;y>60;
z=a+b+c;