DEFINITION MODULE Intro;

   (* EXPORT QUALIFIED FlMoon; *)

   FROM NRSystem IMPORT LongInt;

   PROCEDURE FlMoon(    n, nph:  INTEGER; 
                    VAR jd:   LongInt; 
                    VAR frac: REAL); 
   (*
     Our programs begin with an introductory comment summarizing their purpose 
     and explaining their calling sequence. This routine calculates the phases 
     of the moon. Given an integer n and a code nph for the phase desired
     (nph=0 for new moon, 1 for first quarter, 2 for full, 3 for last quarter),
     the routine returns the Julian Day Number jd, and the fractional part of a
     day frac to be added to it, of the n^th such phase since January, 1900.  
     Greenwich Mean Time is assumed. Note that this routine will not run on 
     systems with 2-byte integers. The type LongInt (4-byte integer) is discussed 
     further in section1.2.
   *)
END Intro.