Determine whether an item is an element of a character set. 

   SETS 

   VARIABLE  I/O  DESCRIPTION 
   --------  ---  -------------------------------------------------- 
   item       I   Item to be tested. 
   set        I   Set to be tested. 

   The function returns SPICETRUE if item is an element of set. 

   item        is an item which may or may not be an element of 
               the input set. Trailing blanks in item are not
               significant.

   set         is a CSPICE set.  set must be declared as a character
               SpiceCell.  Trailing blanks in the members of set are
               not significant.

   The function returns SPICETRUE if item is a member of the specified
   set, and returns SPICEFALSE otherwise.

   The comparison between item and members of set is case-sensitive.
   Trailing blanks are ignored.

   None. 

   The functions 

      elemc_c
      elemd_c
      elemi_c

   provide a convenient shorthand notation for a binary search
   on a set's data array for the item of interest.

   Let the character sets planets and asteroids contain the 
   following elements. 

      planets            asteroids 
      --------           ---------- 
      "Earth"            "Apollo" 
      "Mars"             "Ceres" 
      "Pluto" 
      "Venus" 

   Then all of the following expressions are SPICETRUE. 

      elemc_c ( "Earth",  &planets   ) 
      elemc_c ( "Pluto",  &planets   ) 
      elemc_c ( "Ceres",  &asteroids ) 

   And all of the following expressions are SPICEFALSE. 

      elemc_c ( "saturn", &planets   ) 
      elemc_c ( "pluto",  &asteroids ) 
      elemc_c ( "ceres",  &asteroids ) 

   1) String comparisons performed by this routine are Fortran-style:
      trailing blanks in the input array or key value are ignored.
      This gives consistent behavior with CSPICE code generated by
      the f2c translator, as well as with the Fortran SPICE Toolkit.

      Note that this behavior is not identical to that of the ANSI
      C library functions strcmp and strncmp.

   1) If the input set argument does not qualify as a CSPICE set, 
      the error SPICE(NOTASET) will be signaled.  CSPICE sets have
      their data elements sorted in increasing order and contain
      no duplicate data elements.

   2) If the input set does not have character data type, the error
      SPICE(TYPEMISMATCH will be signaled.

   3) If the input string pointer is null, the error SPICE(NULLPOINTER)
      is signaled.

   None. 

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

   None. 

   -CSPICE Version 1.0.0, 21-AUG-2002 (NJB) (CAC) (HAN) (WLT) (IMU)

   element of a character set