Place the union of two double precision windows into a third 
   window. 

   WINDOWS 

   VARIABLE  I/O  DESCRIPTION 
   --------  ---  -------------------------------------------------- 
   a, 
   b          I   Input windows. 
   c          I   Union of a and b. 

   a, 
   b           are CSPICE windows, each of which contains zero or more 
               intervals. 

               a and b must be declared as double precision 
               SpiceCells.

   c           is the output CSPICE  window, containing the union of 
               a and b---every point contained in a, or in b, 
               or in both. 

               c must be declared as a double precision SpiceCell.

               c must be distinct from both a and b. 

   None. 

   The union of two windows contains every point contained in the 
   first window, or the second window, or both. 

   Let a contain the intervals 

         [ 1, 3 ]  [ 7, 11 ]  [ 23, 27 ] 

   and b contain the intervals 

         [ 2, 6 ]  [ 8, 10 ]  [ 16, 18 ] 

   Then the union of a and b contains the intervals 

         [ 1, 6 ]  [ 7, 11 ]  [ 16, 18 ]  [ 23, 27 ] 

   None. 

   1) If any of the function arguments are SpiceCells of type
      other than double precision, the error SPICE(TYPEMISMATCH)
      is signaled.

   2) If the union of the two windows results in an excess of 
      elements, the error SPICE(WINDOWEXCESS) is signaled. 

   None. 

   N.J. Bachman    (JPL)
   H.A. Neilan     (JPL) 
   W.L. Taber      (JPL) 
   I.M. Underwood  (JPL) 

   None. 

   -CSPICE Version 1.0.0, 29-JUL-2002 (NJB) (HAN) (WLT) (IMU)

   union two d.p. windows