{ diff(x1, t) = (1*k15*k1 + (-1)*k15*k2*x1 + 1*k16*4*k3*k4^k5*x1^k5/((x1^k5 + k4^k5)*(x1^k5 + k6^k5))*x3^k7/(x3^k7 + k8^k7)*(x2 - x1) + (-1)*k15*k9*x1^2/(x1^2 + k10^2) + 1*k16*k11*(x2 - x1))/k15, diff(x2, t) = ((-1)*k16*4*k3*k4^k5*x1^k5/((x1^k5 + k4^k5)*(x1^k5 + k6^k5))*x3^k7/(x3^k7 + k8^k7)*(x2 - x1) + 1*k15*k9*x1^2/(x1^2 + k10^2) + (-1)*k16*k11*(x2 - x1))/k16, diff(x3, t) = (1*k15*k12*x1^2/(x1^2 + k13^2) + (-1)*k15*k14*x3)/k15 }