type equatorial = {ra : float;dec : float;
}type horizontal = {az : float;alt : float;
}val hours : float -> float -> float -> floatval degrees : float -> floatval dms : int -> float -> float -> float -> floatval to_degrees : float -> floatval to_hours : float -> floatval normalize : float -> floatval julian_date : float -> floatval centuries : float -> floatval gmst : float -> floatval lst : float -> lon:float -> floatval obliquity : float -> floatval of_ecliptic : obliquity:float -> float -> float -> equatorialval of_vector : (float * float * float) -> equatorialval to_vector : equatorial -> float * float * float