title: What is the internal representation of inf and NaN?
body: <p>A friend &amp; I were debating how Inf's and NaN's are stored during lunch today.</p>
  
  <p>Take Fortran 90 for example.  4-byte reals can obtain the value of Inf or NaN.  How is this stored internally?  Presumably, a 4-byte real is a number represented internally by a 32 digit binary number.  Are Inf's and NaN's stored as 33 bit binary numbers?</p>