param N := 6;

var x{1..N};

param t{i in 1..13} := i/10;
param y{i in 1..13} := exp(-1*t[i]) - 5*exp(-10*t[i]) + 3*exp(-4*t[i]);
minimize f:
sum {i in 1..13} (x[4]*exp(-1*x[1]*t[i]) - x[5]*exp(-1*x[2]*t[i]) + x[6]*exp(-1*x[3]*t[i]) - y[i])^2;


data;
var x:=
1	1
2	2
3	1
4	1
5	1
6	1;


solve;

display x;