The 'Hdr' directory is organized into 8 sub-directories:
  
   (1)   'Function'            Functions you can use directly in a NAPA netlist '.nap', '.net' or '.dat' (algebra, terminate, print ...)
   (2)   'Max'                 Linear schematics for the SARC Schematic Editor and their outputs
   (3)   'PostProcess'         Postprocess functions used with NAPA instruction 'post'
   (4)   'Random_Generator'    (reserved for advanced users willing to write a pseudo random generator)
   (5)   'Resource'            Functions used essentially as ancillary functions in 'user', 'tool' or 'postprocess' functions
   (6)   'Rom_Gen'             (reserved for advanced users)
   (7)   'Tool'                Functions of 'dtool', 'itool' nodes or short form 'tool'
   (8)   'User'                Functions of 'iuser', 'duser' nodes
   
      (1), (3), (7) and (8) are automatically called if they are used in a NAPA netlist '.nap', '.net' or '.dat'.
      (5) are not automatically called, and you will have to include the corresponding file in a 'header' instruction.
      
  You are encouraged to write your own ANSI-C functions. Please consult the documentation if you want a deep understanding.
  It is easier to copy an existing function with similar I/O and edit it.
  
  You will have to include the corresponding file in a 'header' instruction.