param n := 5;

param lb {j in 1..n};
param ub {j in 1..n};

var x {j in 1..n} := Uniform(lb[j],ub[j]);

minimize obj: 42.*x[1]-50.*x[1]**2+44.*x[2]-50.*x[2]**2+45.*x[3]- 50.*x[3]**2+47.*x[4]-50.*x[4]**2+47.5*x[5]-50.*x[5]**2;

subject to IEC1: -40.+20.*x[1]+11.99999999999999*x[2]+11.*x[3]+7.*x[4]+4.*x[5] <=0;

subject to bounds {j in 1..n}: lb[j] <= x[j] <=ub[j];