I am really struggling with the Error 150 which pops up when I run my simple script. I am a beginner with GAMS. I am using the elements of a set (within quotes) to define the individual equations, but it is giving me the error. I think it has got something to do with domain violation, but I can't figure out a way to write it. Every single one of the equations are different, so I don't know of a way to define them other than defining them individually. Here I am showing only 6 equations, but I have over 35 in my actual script. I will really appreciate if you can help me out here.

Thank you,

Anby

**Script**

Sets

ii actual masses /m26, m27, m28, m29, m30, m31/

j contributions / d1, d2, d3, d4/;

Variables

d(j), mz_sim(ii);

Equations

mz_sim_eqn(ii);

mz_sim_eqn('m26') .. mz_sim('m26') =e= d('d1')*x1;

mz_sim_eqn('m27') .. mz_sim('m27') =e= d('d1')*x2 + d('d2')*x1;

mz_sim_eqn('m28') .. mz_sim('m28') =e= d('d1')*x3 + d('d2')*x2 + d('d3')*x1;

mz_sim_eqn('m29') .. mz_sim('m29') =e= d('d2')*x3 + d('d3')*x2 + d('d4')*x1;

mz_sim_eqn('m30') .. mz_sim('m30') =e= d('d3')*x3 + d('d4')*x2 ;

mz_sim_eqn('m31') .. mz_sim('m31') =e= d('d4')*x3 ;

Here is the

**output**from the .lst file.

394 mz_sim_eqn('m26') .. mz_sim('m26') =e= d('d1')*x1;

395 mz_sim_eqn('m27') .. mz_sim('m27') =e= d('d1')*x2 + d('d2')*x1;

**** $150

**** LINE 137 INPUT GAMS_dir\globalopt_v5.gms

396 mz_sim_eqn('m28') .. mz_sim('m28') =e= d('d1')*x3 + d('d2')*x2 + d('d3')*x1;

**** $150

**** LINE 138 INPUT GAMS_dir\globalopt_v5.gms

397 mz_sim_eqn('m29') .. mz_sim('m29') =e= d('d2')*x3 + d('d3')*x2 + d('d4')*x1;

**** $150

**** LINE 139 INPUT GAMS_dir\globalopt_v5.gms

398 mz_sim_eqn('m30') .. mz_sim('m30') =e= d('d3')*x3 + d('d4')*x2 ;

**** $150

**** LINE 140 INPUT GAMS_dir\globalopt_v5.gms

399 mz_sim_eqn('m31') .. mz_sim('m31') =e= d('d4')*x3 ;

**** $150

**** LINE 141 INPUT GAMS_dir\globalopt_v5.gms