_B_u_i_l_t-_i_n _C_o_n_s_t_a_n_t_s
	
	     LETTERS
	     letters
	     month.abb
	     month.name
	     pi
	
	_D_e_s_c_r_i_p_t_i_o_n:
	
	     R has a limited number of built-in constants.  (there
	     is also a rather larger library of data sets which can
	     be loaded with the function data).
	
	     The following constants are available:
	
	LETTERS : The 26 letters of the Roman alphabet in upper
	          case.
	
	letters : The 26 letters of the Roman alphabet in lower
	          case.
	
	month.abb : The three-letter abbreviations for the English
	          month-names.
	
	month.name : The English names for the months of the year.
	
	     pi : The ratio of the circumference of a circle to its
	          diameter.
	
	_S_e_e _A_l_s_o:
	
	     data.