{ diff(x1, t) = (1*k30*k4*ceiling(sin(pi*t/12)/2) + (-1)*k30*k4*x1)/k30,
  diff(x2, t) = (1*k30*(1 + 0*t)*(0*t + (1 + 0*t)*(k7 + k8*x1)/(1 + k7 + k8*x1 + (k5*(1 + k28*(k23 - 1))*x7)^k6)) + (-1)*k30*k9*x2)/k30,
  diff(x3, t) = (1*k30*(1 + 0*t)*k10*x2 + (-1)*k30*(ceiling(sin(pi*t/12)/2)*k11 + (1 - ceiling(sin(pi*t/12)/2))*k12)*x3)/k30,
  diff(x4, t) = ((-1)*k30*(1 + 0*t)*(ceiling(sin(pi*t/12)/2)*k13 + (1 - ceiling(sin(pi*t/12)/2))*k14)*x4 + 1*k30*(ceiling(sin(pi*t/12)/2)*k11 + (1 - ceiling(sin(pi*t/12)/2))*k12)*x3)/k30,
  diff(x5, t) = (1*k30*(1 + 0*t)*(0*t + (1 + 0*t)*((1 + k26*(k24 - 1))*x4*(ceiling(sin(pi*t/12)/2)*k16 + (1 - ceiling(sin(pi*t/12)/2))*k17))^k15/(((1 + k26*(k24 - 1))*x4*(ceiling(sin(pi*t/12)/2)*k16 + (1 - ceiling(sin(pi*t/12)/2))*k17))^k15 + 1)) + (-1)*k30*k18*x5)/k30,
  diff(x6, t) = (1*k30*(1 + 0*t)*k19*x5 + (-1)*k30*k20*x6 + (-1)*k30*(1 + 0*t)*(ceiling(sin(pi*t/12)/2)*k21 + (1 - ceiling(sin(pi*t/12)/2))*k22)*x6)/k30,
  diff(x7, t) = (1*k30*k20*x6 + (-1)*k30*(1 + 0*t)*(ceiling(sin(pi*t/12)/2)*k21 + (1 - ceiling(sin(pi*t/12)/2))*k22)*x7)/k30,
  diff(x8, t) = (1*k30*k26*(1 + 0*t)*(1 + 0*t)*(k7 + k8*x1)/(1 + k7 + k8*x1 + (k5*x7)^k6) + (-1)*k30*k9*x8)/k30,
  diff(x9, t) = (1*k30*(1 + 0*t)*k10*x8 + (-1)*k30*(ceiling(sin(pi*t/12)/2)*k11 + (1 - ceiling(sin(pi*t/12)/2))*k12)*x9 + (-1)*k30*k2*x9)/k30,
  diff(x10, t) = (1*k30*(ceiling(sin(pi*t/12)/2)*k11 + (1 - ceiling(sin(pi*t/12)/2))*k12)*x9 + (-1)*k30*(1 + 0*t)*(ceiling(sin(pi*t/12)/2)*k13 + (1 - ceiling(sin(pi*t/12)/2))*k14)*x10 + (-1)*k30*k2*x10)/k30,
  diff(x11, t) = (1*k30*k28*(1 + 0*t)*(1 + 0*t)*(x4*(ceiling(sin(pi*t/12)/2)*k16 + (1 - ceiling(sin(pi*t/12)/2))*k17))^k15/((x4*(ceiling(sin(pi*t/12)/2)*k16 + (1 - ceiling(sin(pi*t/12)/2))*k17))^k15 + 1) + (-1)*k30*k18*x11)/k30,
  diff(x12, t) = (1*k30*(1 + 0*t)*k19*x11 + (-1)*k30*(1 + 0*t)*(ceiling(sin(pi*t/12)/2)*k21 + (1 - ceiling(sin(pi*t/12)/2))*k22)*x12 + (-1)*k30*k2*x12)/k30,
  diff(x13, t) = (1*k30*k27*(1 + 0*t)*(k7 + k8*x1)/(1 + k7 + k8*x1 + (k5*x7)^k6) + (-1)*k30*k3*x13 + 1*k30*k29*(1 + 0*t)*(x4*(ceiling(sin(pi*t/12)/2)*k16 + (1 - ceiling(sin(pi*t/12)/2))*k17))^k15/((x4*(ceiling(sin(pi*t/12)/2)*k16 + (1 - ceiling(sin(pi*t/12)/2))*k17))^k15 + 1))/k30,
  diff(x14, t) = (1*k30*(1 + 0*t)*k25*x13 + (-1)*k30*k2*x14)/k30 }