title: sign bit of a NAN in IEEE 754 standard
body: <p>I want to perform a floating point single precision addition operation in which </p>
  
  <p>A = + infinity ( 7F800000)
  B = - infinity ( FF800000)</p>
  
  <p>Will the result(A+B) be +NAN or -NAN ?</p>
  
  <p>another related question :</p>
  
  <p>We get qNAN if NAN propagates through the arithmetic operation.
  Whereas sNAN represents an invalid exception operation.
  So, the above operation will result into a sNAN. 
  Is my understanding correct ?</p>