Real a;
  Real b = time;
  Real c;
  Real d;
  Real e;
equation
  if time >= 3 then
    der(a) = der(b);
    der(c) = der(b);
    e = 2 - der(c) - der(a) - der(b);
  else
    der(a) = 3;
    der(c) = 3;
    e = 2 - c - a - der(b);
  end if;
  d = a + b + c;