{ x16 = piecewise(0, t < k28, exp((-1)*k27*(t - k28))),
  1*k32*x1 + 1*k32*x2 = k32*k34,
  1*k32*x3 + 1*k32*x4 + 1*k32*x5 + 1*k32*x8 + 1*k32*x9 = k32*k35,
  1*k32*x3 + 1*k32*x4 + 1*k32*x6 + 1*k32*x7 + 1*k32*x8 + 1*k32*x9 + 1*k32*x15 = k32*k36,
  1*k33*x13 + 1*k33*x14 = k33*k37 }