[求助]Llingo程序出问题，请求帮助！

legence

<>谢谢！</P>
<>MODEL:
   TITLE LOCATION PROBLEMS;</P>
<>   SETS:
   DEMAND/1..6/:A,B,D;
   SUPPLY/1..2/:X,Y,E;
   LINK/DEMAND,SUPPLY/:C;
   ENDSETS</P>
<P>   DATA:
   A=1.25,8.75,0.5,5.75,3,7.25;
   B=1.25,0.75,4.75,5,6.5,7.75;
   D=3,5,4,7,6,11; E=20,20;   
   ENDDATA</P>
<P>   INIT:
   X,Y=5,1,2,7;
   ENDINIT</P>
<P>   !objective function;
   [OBJ] MIN = @SUM(LINK(I,J):C(I,J) * ((X(J)-A(I))^2 + (Y(J)-B(I))^2)^(1/2) );
   !demand constraints;
   @FOR(DEMAND(I):[DEMAND_CON] @SUM(SUPPLY(J):C(I,J)) = D(I););
   !supply contraints;
   @FOR(SUPPLY(I):[SUPPLY_CON] @SUM(DEMAND{J):C(J,I) &lt;= E(I););
   @FOR(SUPPLY: @FREE(X); @FREE(Y););
END</P>
<P>出如下问题，编译提示：</P>

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