anchor.diff:  (* Issue a report with a newline.                                            *)
   (* ------------------------------------------------------------------------- *)
   
  +/// Prints a string and a following line break.
   let report s = 
       Format.print_string s
       Format.print_newline()
  
positive.code: (* Apply a destructor as many times as elements in list.                     *)
  (* ------------------------------------------------------------------------- *)
  
  /// Applies a destructor in right-associative mode a specied number of times.
  let rec nsplit dest clist x = 
      if clist = [] then [], x
      else 
  
negative.code: (* Greatest common divisor.                                                  *)
  (* ------------------------------------------------------------------------- *)
  
  /// Computes greatest common divisor of two integers.
  let gcd = 
      let rec gxd x y = 
          if y = 0 then x
  