{ diff(x1, t) = ((-1)*k12*k2*x1*x3 + 1*k12*k1*x2 + 1*k12*k6 + (-1)*k12*k8*x1 + (-1)*k12*k7*x1*x5)/k12, diff(x2, t) = (1*k12*k2*x1*x3 + (-1)*k12*k1*x2)/k12, diff(x3, t) = ((-1)*k12*k2*x1*x3 + 1*k12*k1*x2)/k12, diff(x4, t) = (1*k12*k4*x3 + 1*k12*k3*x2 + (-1)*k12*k5*x4)/k12, diff(x5, t) = (1*k12*k10*x4 + (-1)*k12*k9*x5 + (-1)*k12*k7*x1*x5)/k12, diff(x6, t) = (1*k12*k7*x1*x5 + (-1)*k12*k11*x6)/k12 }