{ x32 = piecewise(0, t < 0, 0),
  x33 = piecewise(0, t < 0, 1),
  x34 = x2,
  x35 = x6,
  x36 = x8,
  x37 = x10 + x12,
  x38 = x11 + x12,
  x39 = x15,
  x40 = x17,
  x41 = x19,
  x42 = x21 + x23,
  x43 = x22 + x23,
  x44 = x25 + x27,
  x45 = x26 + x27,
  1*k61*x1 + 1*k61*x2 + 1*k61*x3 = k61*k62,
  1*k61*x4 + 1*k61*x5 + 1*k61*x6 = k61*k63,
  1*k61*x7 + 1*k61*x8 = k61*k64,
  1*k61*x9 + 1*k61*x10 + 1*k61*x11 + 1*k61*x12 = k61*k65,
  1*k61*x13 + 1*k61*x14 + 1*k61*x15 = k61*k66,
  1*k61*x16 + 1*k61*x17 = k61*k67,
  1*k61*x18 + 1*k61*x19 = k61*k68,
  1*k61*x20 + 1*k61*x21 + 1*k61*x22 + 1*k61*x23 = k61*k69,
  1*k61*x24 + 1*k61*x25 + 1*k61*x26 + 1*k61*x27 = k61*k70,
  1*k61*x28 + 1*k61*x29 = k61*k71,
  1*k61*x30 + 1*k61*x31 = k61*k72 }