var x {1..3};

minimize obj: 
  x[1]^2 + x[2]^2 + x[3]^2
  ;

subject to constr1: x[1]^2 + x[2]^2 <= 1;
subject to constr2: 1 <= x[1] <= 10;
subject to constr3: -10 <= x[2] <= 10;
subject to constr4: -10 <= x[3] <= 10;

let x[1] :=  1;
let x[2] :=  1;
let x[3] :=  1;

#printf "optimal solution as starting point \n";
#let x[1] :=  1;
#let x[2] :=  0;
#let x[3] :=  0;

display obj;

solve;

display x;

display obj;

display obj - 1;