.he 'ATOM''Page %'
.fo 'Steven Hardy''January 78'
ATOM	This function returns TRUE if applied to an object to which
HD and TL should not be applied.  So, for example, ATOM([]) is TRUE,
as is ATOM("X") but ATOM([A\ B\ C\ D]) is FALSE.  ATOM is 
defined as:
 	: FUNCTION ATOM(X);
 	:	NOT(DATAWORD(X) = "PAIR")
 	: END;
.br
Attempting to apply HD or TL to an ATOM results in ERROR 60.  Note
that [], the empty list, is an ATOM.  It is the only object which is both a list and an ATOM.
