Avogadro's number water pressure per unit height of water mercury pressure per unit height of mercury au astronomical unit 'Pound' is a unit of mass. When searching for a unit, if the specified string does not appear exactly as a unit name, then the units program will try to remove a trailing 's' or a trailing 'es' and check again for a match. All of these definitions can be read in the standard units file, or you can supply your own file. The units program will not detect infinite loops that could be caused by careless unit definitions. Prefixes are defined in the same was as standard units, but with a trailing dash at the end of the prefix name.
Exponents entered by the user can be only one digit.
You can work around this by multiplying several terms. The program should use a hash table to store units so that it doesn't take so long to load the units list and check for duplication.