{ diff(x7, t) = (1*k27*k18*x5 + (-1)*k27*k18*x7)/k27,
  diff(x8, t) = (1*k27*k18*x7 + (-1)*k27*k18*x8)/k27,
  diff(x9, t) = (1*k27*k18*x8 + (-1)*k27*k18*x9)/k27,
  diff(x10, t) = (1*k27*k18*x9 + (-1)*k27*k18*x10)/k27,
  diff(x11, t) = (1*k27*k19*x6 + (-1)*k27*k19*x11)/k27,
  diff(x12, t) = (1*k27*k19*x11 + (-1)*k27*k19*x12)/k27,
  diff(x13, t) = (1*k27*k19*x12 + (-1)*k27*k19*x13)/k27,
  diff(x14, t) = (1*k27*k19*x13 + (-1)*k27*k19*x14)/k27,
  diff(x1, t) = (1 - x3)*(1 - x4)*k26*x1*(1 - x1/k24) - (1 + x10)*(1 + x14)*k25*x1,
  diff(x2, t) = (1 + x10)*(1 + x14)*k25*x1 - k25*x2 }