problem with integer infeasible

Problems with modeling
ozge
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Posts: 6
Joined: 7 months ago

problem with integer infeasible

Hi everyone, why do I get no solution? Can you help me again?

set i /0*7/;
alias (i,ip);
display i,ip;

set subset(i) /1*6/;
alias (subset,subsetp);
display subset, subsetp;

table d(i,ip) 'distances between cities'
\$onDelim
,1,2,3,4,5,6
1,0.00,1.66,5.08,6.52,8.83,5.53
2,1.66,0.00,4.09,6.02,9.20,5.76
3,5.08,4.09,0.00,2.45,6.96,4.00
4,6.52,6.02,2.45,0.00,4.80,2.71
5,8.83,9.20,6.96,4.80,0.00,3.44
6,5.53,5.76,4.00,2.71,3.44,0.00

\$offDelim
;

display d;
Scalar m 'total number of cities' / 6 /;

variables x(i,ip) 'if ip is visited after i 0-15 arasÄ±'
z 'total distance travelled' ;

binary variables x;

equations of
eq1
eq2
eq3(ip) 'city balance constraint'
eq4(subset)
eq5(subset);

of.. z=e= sum((subset,subsetp), x(subset,subsetp)*d(subset,subsetp));
eq1.. sum(subsetp, x('0',subsetp))=e= 1;
eq2.. sum(subset, x(subset,'7'))=e=1;
eq3(subsetp).. (sum( subset \$(not sameas(subset,subsetp)), x(subset,subsetp)) - sum(subset \$(not sameas(subset,subsetp)), x(subsetp,subset)) ) =e= 0;
eq4(subset).. sum(subsetp \$(not sameas(subset,subsetp)), x(subset,subsetp) ) =g= m*x('0', subset);
eq5(subset).. sum(subsetp \$(not sameas(subset,subsetp)), x(subsetp,subset) )=g= m*x(subset,'7');

model tsp2test / all /;
solve tsp2test minimizing z using mip;

display x.l, x.m, z.l;
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