Math.Exp of large negative number
<p>On my machine, and current .net version Math.exp(-1000) returns 0.0, as is reasonable because
it is a number that is too small to represent as a double.  </p>

<p>Can I rely on this to remain so on other machines, and in future .net builts? Msdn tells me 
Math.exp(Double.NegativeInfinity) return 0.0 (which I therefore expect to remain so in future), but what about -1000? </p>
