creating set with alias

GAMS
1

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how can i create this set. second j is alias of first j. Also, If i create a multidimensional set for main indices , do i have to create one more set for alias of main indices.
.

2

Hi,

Maybe the following example is helpful.

set m machines / m1*m5 /
    j jobs     / j1*j10 /
    mj(m,j)    mapping of jobs to machines
    mjj(m,j,j) mapping of intersection of two jobs to machine
;
*create alias for jobs
alias (j,j1,j2);
*craete dummy data for job-machine-mapping
mj(m,j) = uniform(0,1) < 0.3;
*display mj in list format
option mj:0:0:1; display mj;

*compute mjj map (exclude j1=j2).
mjj(m,j1,j2)$(not sameas(j1,j2)) = mj(m,j1) and  mj(m,j2);
*display mjj in list format
option mjj:0:0:1; display mjj;

Best,
Fred