Model hs69 Parameters a = 0.1 b = 1000 d = 1 n = 24 l[1] = 0.0001 l[2] = 0 l[3] = 0 l[4] = 0 u[1] = 100 u[2] = 100 u[3] = 2 u[4] = 2 End Parameters Variables x[1:4] = 1, >=l[1:4], <=u[1:4] obj End Variables Equations x[3] - 2*erf(-x[2]) = 0 x[4] = erf(-x[2] + d*sqrt(n)) + erf(-x[2] - d*sqrt(n)) ! best known objective = -956.71288 ! best known solution ! x[1] = 0.02937141 ! x[2] = 1.1902534 ! x[3] = 0.23394676 ! x[4] = 0.7916678 obj = ( a*n - (b*(exp(x[1])-1) - x[3])*x[4]/(exp(x[1]) - 1 + x[4]) )/x[1] End Equations End Model