param N := 4;

var x{1..N};

minimize f:
x[1]^2+x[2]^2+2*x[3]^2+x[4]^2 - 5*x[1] - 5*x[2] - 21*x[3] + 7*x[4];

subject to cons1:
-1*x[1]^2 - x[2]^2 - x[3]^2 - x[4]^2 - x[1]+x[2]+x[3]+x[4]+8 >= 0;

subject to cons2:
-1*x[1]^2 - 2*x[2]^2 - x[3]^2 - 2*x[4]^2 + x[1] +x[4] + 9 >= 0;

subject to cons3:
-2*x[1]^2 - x[2]^2 - x[3]^2 - 2*x[1] + x[2] + x[4] + 5 >= 0;

data;
var x:=
1	0
2	0
3	0
4	0;
solve;

display x;