Given a relational operator, compare two sets of any data type. 

   CELLS, SETS 

   VARIABLE  I/O  DESCRIPTION 
   --------  ---  -------------------------------------------------- 
   a          I   First set. 
   op         I   Comparison operator. 
   b          I   Second set. 

   The function returns the result of the comparison: a (op) b. 

   a           is a CSPICE set.  a must be declared as a character,
               double precision, or integer SpiceCell. 


   op          is a comparison operator, indicating the way in 
               which the input sets are to be compared. op may 
               be any of the following: 

                  Operator             Meaning 
                  --------  ------------------------------------- 
                    "="     a = b is true if a and b are equal 
                            (contain the same elements). 

                    "<>"    a <> b is true if a and b are not 
                            equal. 

                    "<="    a <= b is true if a is a subset of b. 

                    "<"     a < b is true if a is a proper subset 
                            of b. 

                    ">="    a >= b is true if b is a subset of a. 

                    ">"     a > b is true if b is a proper subset 
                            of a. 

                    "&"     a & b is true if a and b have one or more 
                            elements in common (the intersection of
                            the two sets in non-empty.)

                    "~"     a ~ b is true if a and b are disjoint 
                            sets. 

               When comparing elements of character sets, this routine
               ignores trailing blanks.

   b           is a CSPICE set of the same data type as a. 

   The function returns the result of the comparison: a (op) b. 

   None. 

   None. 

   1) In the following code fragment, set_c is used to repeat an operation 
      for as long as the integer set finished remains a proper 
      subset of the integer set planned. 

         #include "SpiceUsr.h"
               .
               .
               .
         while (  set_c( &finished, "<", &planned )  )
         {
               .
               .
               .
         }


   2) In the following example, let the integer sets a, b, and c 
      contain the elements listed below. Let e be an empty integer 
      set. 

         a        b        c 
        ---      ---      --- 
         1        1        1 
         2        3        3 
         3 
         4 

   Then all of the following expressions are SPICETRUE. 

      set_c ( b, "=",  c )      "b is equal to c" 
      set_c ( a, "<>", c )      "a is not equal to c" 
      set_c ( a, ">",  b )      "a is a proper superset of b" 
      set_c ( b, "<=", c )      "b is a subset of c" 
      set_c ( c, "<=", b )      "c is a subset of b" 
      set_c ( a, "<=", a )      "a is a subset of a" 
      set_c ( e, "<=", b )      "e is a subset of b" 
      set_c ( e, "<",  b )      "e is a proper subset of b" 
      set_c ( e, "<=", e )      "e is a subset of e" 
      set_c ( a, "&",  b )      "a has elements in common with b." 
      set_c ( b, "&",  c )      "b has elements in common with c." 

   And all of the following are SPICEFALSE. 

      set_c ( b, "<>", c )      "b is not equal to c" 
      set_c ( a, "=",  c )      "a is equal to c" 
      set_c ( a, "<",  b )      "a is a proper subset of b" 
      set_c ( b, "<",  c )      "b is a proper subset of c" 
      set_c ( b, ">=", a )      "b is a superset of a" 
      set_c ( a, ">",  a )      "a is a proper superset of a" 
      set_c ( e, ">=", a )      "e is a superset of a" 
      set_c ( e, "<",  e )      "e is a proper subset of e" 
      set_c ( a, "~",  b )      "a and b are disjoint sets." 

   1) String comparisons performed by this routine are Fortran-style:
      trailing blanks in the input sets 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 set relational operator is not recognized, the error 
       SPICE(INVALIDOPERATION) is signaled. 

   2) The error SPICE(EMPTYSTRING) is signaled if the input operator
      string does not contain at least one character, since this
      input string cannot be converted to a Fortran-style string
      in this case.

   3) The error SPICE(NULLPOINTER) is signalled if the input operator
      string pointer is null.

   4) If the input set arguments don't have identical data types,
      the error SPICE(TYPEMISMATCH) is signaled.

   5) If either of the input set arguments may be unordered or contain 
      duplicates, the error SPICE(NOTASET) is signaled.

   None. 

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

   None. 

   -CSPICE Version 1.1.0, 15-FEB-2005 (NJB)

       Bug fix:  loop bound changed from 1 to 2 in loop used
       to free dynamically allocated arrays.

   -CSPICE Version 1.0.0, 08-AUG-2002 (NJB) (CAC) (WLT) (IMU)

   compare sets