param N := 5;

var x{1..N};

minimize f:
(x[1]-x[2])^2 + (x[2]+x[3]-2)^2 + (x[4]-1)^2 + (x[5]-1)^2;

subject to cons1:
x[1] + 3*x[2] = 0;

subject to cons2:
x[3] + x[4] - 2*x[5] = 0;

subject to cons3:
x[2] - x[5] = 0;

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

solve;

display x;