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Purpose: To provide a GAMS formulation for the collection
of Gupta Problems

Reference: Branch and bound experiments in convex nonlinear
integer programming, Management Science, 1533-1546, 31, 1985.

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Variables  i1,i2,objvar;

Integer Variables i1,i2;

Equations  e1;


e1..  - (100*sqr(0.5 + i2 - sqr(0.6 + i1)) + sqr(0.4 - i1)) + objvar =E= 0;

* set non default bounds

i1.up = 200; 
i2.up = 200; 

* set non default levels

i1.l = 100; 
i2.l = 100; 

* set non default marginals


Model m / all /;

m.limrow=0; m.limcol=0;

$if NOT '%gams.u1%' == '' $include '%gams.u1%'

Solve m using MINLP minimizing objvar;